The Peter Attia Drive - #343 – The evolving role of radiation: advancements in cancer treatment, emerging low-dose treatments for arthritis, tendonitis, and injuries, and addressing misconceptions | Sanjay Mehta, M.D.
Episode Date: April 7, 2025View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter’s Weekly Newsletter Sanjay Mehta is a radiation oncologist with over 20 years of ex...perience at St. Joseph's Medical Center in Houston, Texas. In this episode, Sanjay explores the rapidly evolving field of radiation oncology, addressing common misconceptions about radiation exposure. He delves into radiation's critical role in modern oncology, examining recent advancements that precisely target tumors while minimizing damage to surrounding healthy tissues and reducing side effects, with specific insights into breast, prostate, and brain cancers. Sanjay discusses fascinating international practices involving low-dose radiation therapy for inflammatory conditions such as arthritis, tendonitis, and sports injuries, highlighting its effectiveness and potential for wider adoption in the United States. Wrapping up on a lighter note, Peter and Sanjay discuss their mutual passion for cars and reveal how this shared interest first brought them together. We discuss: How radiation oncology became a distinct, rapidly evolving medical specialty [2:45]; Defining radiation, ionizing vs. non-ionizing, and common misconceptions about radiation exposure [5:30]; How radiation doses are measured, real-world examples of radiation exposure, and safety practices [9:00]; Radiation doses from common medical imaging tests, and why benefits of routine imaging outweigh risks [14:15]; Therapeutic radiation oncology: the evolution of breast cancer treatment toward less invasive surgery combined with targeted radiation [23:30]; Modern radiation oncology treatments for breast cancer—minimizing risks and maximizing patient comfort and outcomes [27:15]; How advances in radiation dosing, technology, and treatment precision have significantly reduced side effects [39:45]; How breast implants affect radiation treatment [44:45]; Radiation therapy for prostate cancer: advancements in precision, effectiveness, and patient selection criteria [48:00]; Radiation therapy options for inoperable prostate cancer or those seeking alternatives to surgery, and a remarkable patient case study [55:15]; How patients can effectively evaluate and select a high-quality radiation oncologist [1:05:45]; Radiation therapy for brain cancer: the shift toward precise, targeted techniques that minimize cognitive side effects, and remaining challenges [1:08:30]; The origins of radiophobia and how it influenced perceptions of radiation use in medicine [1:18:00]; Treating chronic inflammatory conditions such as tendinitis, arthritis, and more with very low-dose radiation [1:23:45]; Using low-dose radiation to treat spine injuries, scar tissue, fibrosis, keloids, and more [1:30:00]; The current barriers preventing widespread adoption of low-dose radiation therapy for inflammatory conditions [1:35:45]; The durability and versatility of low-dose radiation therapy in treating chronic inflammatory and arthritic conditions [1:40:45]; Sanjay’s talent as a drummer [1:44:45]; Peter and Sanjay’s shared passion for cars and racing [1:47:15]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube
Transcript
Discussion (0)
Hey everyone, welcome to the Drive Podcast. I'm your host, Peter Attia. This podcast,
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My guest this week is Dr. Sanjay Mehta. Sanjay is a radiation oncologist at St. Joseph's Medical
Center in Houston, Texas, where he's been in practice for more than 20 years. I wanted to
have Sanjay on the podcast to talk about all things pertaining to radiation oncology,
but also the history and some of the misconceptions around radiation exposure and radiophobia. We
talk about some of the very interesting applications that I only learned about recently that are very common outside of the United States
that involve low dose radiation to treat inflammatory conditions and athletic injuries.
Now, of course, those of you who are interested may recall that because this podcast is called
The Drive, I do occasionally talk about cars. And given that Sanjay and I have a shared passion for them,
and in fact, that's how Sanjay and I met,
we do end this discussion with a little bit
of a deep dive into cars.
But of course, back to the main point of this discussion,
we talk about the evolution of breast cancer,
including the shift from radical mastectomies
to more conservative approaches like lumpectomies
and sentinel node biopsies.
We talk more broadly about the role that radiation plays in modern oncology,
how doses have changed and how advancements in targeting tumors while
minimizing damage to surrounding tissues have rendered side effects much more
rare, certainly more rare than they were even 20 to 25 years ago.
Sanjay talks about the role of low dose radiation for inflammatory conditions
such as arthritis and tendonitis, and how this approach is more widely used outside of the US and why it's his hope
in mind that becomes more adopted here in the US.
We speak about the history and misconceptions of radiation exposure, including radiophobia,
nuclear accidents, and early uses of radiation.
So without further delay, please enjoy my conversation with Dr. Sanjay Mehta.
Sanjay, welcome back to Austin.
Thank you, Peter.
Pleasure to be here.
I think this is the first time we're together not driving, right?
I think so, yeah.
That is true.
I don't know.
Somehow, we're going to resist the urge for most of this discussion to not talk about
cars. Don't want wanna bore your audience.
I know, it is called the drive.
This is true.
So I feel like we will reserve the right
to have some automotive discussions at the end.
For listeners, Sanjay might be one
of the most knowledgeable human beings on cars.
He's also a very dangerous friend to have.
Because he's always the bad one on the shoulder when you're
contemplating a new set of wheels or a new something for your cars.
But in his other life, in addition to being the founder of MD Motorheads, right?
That's right.
Yeah.
Which is a Facebook group of doctors who are gearheads.
We're about to crack 3,000 members.
It's exploded.
That's awesome.
So shout out to MD Motorheads.
You're also a radiation oncologist,
which we also spend some time talking about.
I guess we thought it would be a really fun idea to do a podcast
for a couple of reasons.
One is just the bread and butter of what
you do as a radiation oncologist is a bit of a black box
to many people, myself included, if I'm
going to be completely truthful. even training in surgical oncology, I feel like I had much
more familiarity with the medical side of oncology than I did with the radiation side
of oncology. So for myself, for the audience, I think it would be wonderful to understand
more as it's a field that has evolved a lot. I'm guessing the last 25 years has seen a lot of change.
It's one of the youngest fields too, in that respect.
It's not steeped in some of the traditions
that surgery and medicine are.
So yeah, it's a new field, highly evolving very rapidly
and the technology has changed so much.
Just in really in the last decade or two,
it's pretty incredible.
Just out of curiosity, when did it become its own discipline,
its own set of boards and everything like that?
As a kid growing up in Houston, some of my family friends
were radiologists.
And I remember just like probably an elementary school
kid that some of them were talking about radiotherapy.
And these were diagnostic radiologists
who at the time, CT scanning was pretty new in the 80s.
Prior to that in the 70s and then prior to that,
it was kind of just a fellowship.
Radiologists would have a Cobalt 60 machine
that they would train on for a few weeks and you do a few
easy calculations and do some crude treatments. But it really started, it came
into its own starting in the 70s and then really more into the 80s and that's
when it became its own discipline. The ACR had a separate carve out and so our
residency training is completely independent of diagnostics now. So we
just do, it's an intern year followed by four years of radiation oncology with a
little bit of overlap, but not a lot of diagnostic training at all, just because there's so much
to do and just on the therapeutic side.
Got it.
I had no idea that it was that new.
And in terms of medicine, that's obviously like very new.
The second thing that I wanted to talk about on the radiation front is this idea of using
very low dose radiation to heal injuries. I think that while
people will be incredibly interested to understand the ins and outs of radiation oncology, again,
given the ubiquity of it in treating people, I think a lot of people are going to be very
interested in this idea that why aren't we using low dose radiation more to heal some of
these nagging orthopedic injuries that people have.
Of course, we'll go far down the rabbit hole on that.
I don't think we can have this discussion without giving people some understanding of
what radiation is.
I would like us to do it in a way that's both rigorous enough that we can really get into
some of the science of this, but also get into it gently enough that people that maybe don't
remember high school physics well enough can come along for the ride and not get lost.
But once we get into grays and millisieverts and all that stuff, I want everyone to be
fluent when we start talking about doses.
Right, right, right.
Radiation itself, the term itself has got a bit of a negative connotation, but basically
it's part of the electromagnetic spectrum. So we have everything on the one in the range of increasing energy of photons, which are
just particles of light. On the one end you have radio waves and microwaves, and the other
end you've got infrared and, excuse me, you've got ultraviolet, and then you get into X-rays
and radio waves. And in the middle of all that is the visible spectrum. So when you
see, I'm sure everyone's seen the graphs where you've got the rainbow red, green, blue, that
we can see, the human eye can only perceive a tiny little visible spectrum. So when you see, I'm sure everyone's seen the graphs where you've got the rainbow, red, green, blue that we can see, the human eye can only perceive
a tiny little narrow spectrum.
These are wavelengths.
These are actually wavelengths and energies
which are the very low end energies
you have things like radio waves.
In that situation, both radio waves and microwaves
are what they call non-ionizing.
And I know you've talked about this
on some of your previous podcasts.
I know you had a really good one with Atari Walla from
Prunuvo. It was a really nice in-depth discussion.
But essentially the bottom line is that the low energy stuff that is non-ionizing
cannot damage tissue and that goes all the way up to visible light. Then when you start going to the higher energy x-rays
that's when you get both x-rays as well as ultraviolet light and then the higher particle stuff.
But basically the higher you go in the energy and the energetics of the
particles the more likely exposure to these packets of energy are going to
cause damage to your DNA. Why is it that the shorter the wavelength because
that's what's changing as you go from radio waves to microwaves to visible
waves to ultraviolet. Why is it that as the wavelength gets shorter the energy
gets bigger? Yeah I'm not sure what the reason is. They are inversely proportional to each other. I don't know
that, I guess I'm probably not enough of a physicist to answer that question precisely.
But having said that, that is the characteristic of this. And in doing so, that's one of the big
reasons why all the fallacies about your cell phone giving you brain cancer and all are just that.
They're fallacies because even having a cell phone
on your ear for hours a day, it's non-ionizing radiation.
And standing too close to a microwave oven,
again, non-ionizing radiation,
so that cannot damage your cells.
The radio wave is too long.
That's right.
The microwave is too long.
It doesn't have the energy.
You can stand on it all you want.
It can heat, but it can't damage. Correct, it all you want it can heat but it can't damage correct
It can excite the molecules, but it won't actually eject an electron
Which is what would cause an ion to form which is why it's called ionizing and that's where we deal with on the I'm on
the therapeutic end so
Diagnostic radiologists deal with lower energy x-rays than we do the very high energy X is what we use in our linear accelerators to treat cancer
So that's the big difference there is kilo voltageoltage versus megavoltage, but all of these are ionizing.
Okay.
So let's talk about how these are measured.
How do we quantify them?
Because people on the podcast have heard me talk about this, I suspect.
We talk a lot about calcium scores and CT angiograms and PET-CT.
I think the frequent listener will have been somewhat familiar with how we talk about how
to dose those things.
06 So radiation dosage, there's a couple of different terms that we've talked about.
The main one we talk about when we're talking about patient treatment is the unit called
the gray.
And that's an SI unit that essentially is joules of energy per kilogram of tissue.
So that's what they call absorbed dose.
So that's in tissue.
Whereas when you're talking about exposure in the general in the air and in general exposure,
it's in the air, we usually use the term sievert for that. And actually both those terms for the
most part are equivalent. It's just that the sievert itself will take into account if you
have different types of X-rays, different qualities of X-rays that have different degrees of
potential to be ionizing that they have a quality factor you'll multiply by.
But for the most part, we use the term gray when we're talking about, for example, when
I treat a prostate patient, they're going to get somewhere between 70 and 80 gray, but
it's fractionated into small daily doses as to be tolerable for the body.
And then when we talk about millisieverts like we're going to, that's really just a
measure of exposure, not absorbed dose in tissue per se.
Trevor Burrus What's the relationship between a gray and
a millisievert?
Is it a one-to-one relationship?
Michael Svigel Yeah, so a gray and a sievert technically.
If anyone's kind of old school, you listen to older stuff, you heard the term rads.
A lot of people have heard of rads.
So one rad is equal to one centigrade.
One hundred rads is a gray.
It's just an SI unit versus the old terminology. And a
sievert is the equivalent, only it's in air, not in tissue.
But a sievert is a gray?
Correct. Correct.
So, when you give 70 gray, you're giving 70 sieverts or 70,000 millisieverts over the
course of the treatment?
That's correct.
Okay. Just so people can kind of anchor this to things that are familiar, living at sea level exposes
us to one to two millisieverts of ionizing radiation a year.
That's exactly right. At altitude, it could be double that actually.
That's right. If you live in Denver, it's easily double that or triple that, correct?
Just another thing for comparison, a pilot who spends a lot of time traversing the North
Pole, which is typically how they're going to fly.
They're not going to go all the way around the center of the earth, might get another
three or four millisieverts of radiation.
It's quite a bit, quite a bit.
That's right, per trip actually.
So that can add up.
And I was actually talking to a pilot friend about this.
They don't really have any limitation in terms of total exposure
that requires them to be taken out of the air. A lot of them they're forced to
retire at 65, I think is the commercial requirement, but they don't really
monitor the actual exposure to that level. I think the reason they don't
really use that as a limiting factor for the amount of work is really just that
even though they can get a higher dose, there's been no proven increase in
cancer in those types of populations, even in flight attendants or anything like that.
The same way that people in Denver and the people here in Texas don't have any higher
incidence of cancer.
Adam Felsenfeld Now, the NRC recommends that a person not be exposed to more than 50, I
believe, 50 millisieverts of radiation in a year.
Correct.
Now, someone like me, that's easy, unless I'm out there getting a lot of diagnostic
radiology or of course undergoing therapeutic radiation treatment.
But for someone like you, who has to set patients up or one of your techs, are you guys approaching
that level of exposure?
Not at all. And so it depends on what type of radiation we do.
Now typically for our external beam machines, we're doing it all remotely from behind a shielded wall.
So the vault in which the machine is placed is custom built just to shield based on the angles
that the machine can move through. If there's like a direct angle where the machine is hitting a wall,
that wall has to be built 10 times thicker than the walls where the beam can't reach. So essentially our dose when
treating remotely is close to zero. So we keep film badges and it's almost become
kind of a joke that when we're not doing brachytherapy which is dealing with
actual live radioactive sources, our exposure is super low, almost negligible
really. But back when I was in residency doing a lot of GYN implants and things
like that where you're putting cesium or iridium actually into the body cavities and you're actually
up there putting it in up close.
We had a ring badge on.
As a residence, we'd rotate every month, but if we didn't rotate, some of the faculty actually
got pretty high doses.
Any idea what the sequelae of that was?
I know of a couple of folks, the ones who did a lot of GYN therapy, especially in the
older days, we're talking about in the 80s and the 70s, where you could actually see
dermatitis on their hands from doing that,
just from the hand exposure. One of my faculty members actually had a giant cell tumor of
the bone in her finger. And again, this is after decades and decades of doing it. It
was a benign growth, but that was a real thing. There's a lot of data out there on especially
people who were dealing in x-rays for dentistry and stuff like that back in the day when they
didn't have shielding or anything like that, that they would get dermatitis.
The most common thing you'd see is skin irritation in that sort of situation, dermatitis and
even some chronic flaking and things like that.
Adam Felsenfeld So let's talk about some types of x-rays that
people are familiar with and give a sense of radiation dose.
And I'm also curious as to how much this depends on the size of the individual.
In other words, does a person that is larger receive more radiation for this same test
like a chest x-ray?
They certainly do because you have to use more energy to get into a larger person.
Having said that, there's two different things here because what we normally deal with when
I'm talking about dose to a tumor is the dose actually at that spot versus a whole
body dose which is a very different metric. And so for someone who I'm treating with say eight
weeks of radiation for prostate cancer, their prostate may get 80 gray in 1.8 to 2 gray fractions
per day but that's literally only to a small volume roughly the size of the prostate gland
itself.
And when you even get just a few millimeters away from that, that dose gets cut in half
and then it's exponentially lower because the intensity of the radiation varies with
the square of the distance.
So as you get even a couple of feet away, that goes down significantly.
But typically a patient who is getting 80-grays, if 80-gray was a whole body dose, that would
obviously be lethal.
But the whole body dose is more like a few milligray in that sort of situation.
So we typically don't see full body sequelae or anything from doing even the heavy duty
diagnostic treatment.
Now for the CT scan, we almost consider that negligible in our area because again, I'm
dealing with mega voltage, high dose cancer killing radiation And so when they get a CT scan,
which is going to be just a few millisieverts or milli-gray, that's almost considered rounding
error versus what they're getting to the tumor area.
But let's take something like a chest X-ray. So chest X-ray, people should anchor to this idea
for what it's worth and we can come back to this. NRC says, hey, limit your annual radiation to 50 millisieverts. You've got 2% of that just being
alive because you happen to go outside and be exposed to the sun. The other 98% might come
through flying diagnostic. Let's say you fly a lot, that might get you up another 10%. Let's talk
about a chest X-ray. You got a cough, you go to your doctor, they do a chest x-ray. That's how many millisieverts for a normal size person?
Normal size person, it's a fraction. It's probably less than one millisievert actually.
So, it's significantly, it's something that where people who are concerned about things
like diagnostic mammograms and all every year, you're still talking about maybe one millisievert,
even a little bit less than that with some of the newer machines. You're in a zone where
there's a principle we talk about, it's called ALARA, A-L-A-R-A,
which is as low as reasonably achievable.
And that's been the mantra for our radiation safety people, the Nuclear Regulatory Commission
and whatnot, that you want to keep things as low as possible.
But having said that, when you're talking about numbers of less than 50 millisieverts,
that's kind of an arbitrary number.
I should have maybe gotten a chest x-ray when I had my cough last time, but I just don't want to do it.
I don't want the exposure. But it's so minimal in terms of biologic effect that we really don't even
really worry about those, even if it's getting one of them a month or so. And a big reason for that is
a lot of these numbers, especially the 50 millisievert number, is extrapolated from higher
exposure rates. There's something called the Linear No Threshold Model or LNT and that's been written about
extensively and that's what we're all taught in radiobiology and residency.
One fourth of my radiation training in residency was actually radiation biology in addition
to clinical oncology and radiation physics.
So the Linear No Threshold Model is what states that we know based on all the data from nuclear fallout from Chernobyl, from Three Mile Island, of
course from Hiroshima, Nagasaki, from the bombs, that at a certain dose exposure
there's a certain risk of developing a cancer or any other endpoint whether it
be dermatitis or bone marrow suppression. There's all these numbers are well
sorted. But when you try to extrapolate lower, so you take maybe say a dose of
one full sievert, the thousand mill extrapolate lower, so you take maybe say a dose of one
full sievert, the thousand millisievert, and you start extrapolating that lower and lower
to where you're looking at a hundred or fifty millisieverts, the linear model assumes that
there's some level of damage even at those lower levels, but in reality there's actually
a threshold, the LNT, which is linear no threshold, has actually been proven to be actually erroneous.
And so at very low doses
It's actually been shown that there's almost no incidence of any sort of biological damage and there's also it's controversial
But there's animal studies showing there may be a hormesis effect at low low doses like that
Tell people what that means because that's obviously gonna come back later in our regular listeners of your podcast know all about
later in our discussion. Regular listeners of your podcast know all about hormesis and you talk about in the exercise realm and cold plunges and
saunas and whatnot but the whole idea is doing some degree a small amount of
cellular damage when the body repairs that it actually comes back stronger
than it was without the exposure in the first place and in animal studies they've
actually shown at very low doses we're talking about single-digit millisieverts
here that they've seen in mouse bones, for example, decreased osteoclasts and increased osteoblastic
activity so the bones actually heal quicker.
Some of the soft tissue as well has been shown to actually recuperate much in the way you
see in the hormesis from other causes.
And that's not something that we're claiming is widely accepted, but there is a lot of
data showing that that is certainly a possibility which goes against this classic LNT model.
And the LNT model itself, the guy that won the Nobel Prize for it in the 1940s did this
all on fruit flies, and his work was disproven over the years after that.
And so a lot of this low dose radiation safety stuff we have is certainly a noble goal to
keep the dose as low as possible.
But when we get down to these millisievert range, I think that they're probably a little bit
overblown in terms of the actual negative effects on the human body.
Adam Backer When I think about where, for example, something
like a CT angiogram used to be, that would easily have exposed a person to 25 millisieverts
to do a CT scan of the heart. You're doing it, slowing the heart down, getting
the contrast in there, et cetera. Today, the really fast scanners, the best of the best
scanners are somewhere between one and three millisieverts for that same procedure. I certainly
favor having patients getting a scan with that. Acknowledging though that I don't have
amazing data to point to, to say that the
25 millisievert one versus, just to make the math easy, the 2.5 millisievert one, tenfold
difference poses any difference in risk.
Exactly.
How do you think about that?
What would be your confidence in saying that 2.5 is not actually better than 25 from a
cancer risk standpoint?
So again, going back to that Allara principle, there's not a whole lot of data at these levels.
I certainly would strive to keep it as low as possible, which is what that mantra says,
but I would go with the machine that has the best resolution.
And if 25 is, if the radiologist tells me that that image is significantly better than
a 2.5 millisievert exposure, Some of the older machines are just less efficient.
You may get a better image with the lower dose.
I think the dose is pretty negligible.
Got it.
So in other words, you're saying, I don't really care if it's 25 or 2.5 as well.
And the good news is these brand new scanners are faster, which is why they're giving you
less radiation.
Exactly.
They seem to have better resolution.
And the same thing applies.
That's on the diagnostic side.
On the therapeutic side where I am, our machines are called linear accelerators and there's
a similar progression as we've been able to focus the beams more and more precisely.
It's a modulation of the beam and you have a lot of photons being showered in the general
vicinity of a patient, but you're blocking out everything except for a small area to
treat and the same way the newer machines do definitely have a lower exposure to the yeast in the room in general.
So what should people be thinking about in terms of extraneous radiation?
When should people be saying to their doctors, hey, do I really need this?
For example, when you go to the dentist every year, they typically want to do a set of x-rays.
Is that anything people should be worried about?
Not at all.
Not in the least. I would certainly not skimp on dental x-rays, mammograms, if
it's someone that needs cardiac workups and things like that. The risk-benefit ratio is
so heavily in favor of doing these studies that I don't even think twice about them.
I think part of this comes from, I've been doing this 25 years now, I have so many patients,
by the time they come to me as a cancer patient, they've been through so many CT scans and nowadays we do PET scans. We follow up with
annual PET scans after the fact which are not only the CT but you've got a radioactive
isotope that's being injected into them and we just really don't see. Now there are certain
situations where you are giving, for example, an intravenous therapeutic dose of radiation
say for thyroid cancer or things like that. There's certain new theranostics that are out there.
In those situations, you have to be concerned because they can get into the multiple, again,
into a sievert range.
But when you're in these millisievert ranges, it's so important to do these studies.
The benefits of mammograms are so proven.
Dental x-rays, I don't really think twice about them.
Okay.
By the way, just on the PET scan, so if you do a PET CT, for example, which again,
these are not routinely done. These are typically done in oncology patients only. But just for
my own understanding, are we talking 50 to 100 millisieverts if you're doing a whole
body PET CT?
I think it can be in that range, yes. I think that's exactly right. So PET CTs are relatively
new, but up until maybe a decade ago, the PET scan was independent of the CT. They would
do them separately.
But the data is so much better when you have the anatomical CT data overlay with
the PET that whatever that extra dosage is,
I think it's well worth it in terms of the resolution of what we're able to see
and what we're able to gain from that information.
Okay. So now let's pivot from the diagnostic to the
therapeutic.
Is it safe to say that the majority or the most prevalent or common type of radiation
oncology treatment would be for breast cancer?
Breast and prostate are the number one and number two, depending on what patient population
you're talking about.
Prostate may even be a little bit higher.
And this goes back to the 80s when the trend from doing a
Halsteadian type of radical mastectomy was falling out of favor
and the randomized data was obtained in the 80s showing that a
lumpectomy, breast conservation, which is lumpectomy followed by radiation,
has the same outcomes in terms of overall survival as a full mastectomy.
That's when breast really took off in the 80s.
And around the same time is when
prostate radiation started becoming a thing. But at the time, radical prostatectomy was obviously
still king. But now in the 2020s, I think prostate is taken off and it's probably close to matching
breast cancer now. Those are number one and number two, but we also do, depending on where you are
in the country and what your affiliation with the hospital is tons of CNS, lung, lymphoma,
GI, not colon, but more rectal and anal distal GI cancers.
Even in the pediatric world, we try to avoid radiating children, but it's a very big part
of that as well.
So we use it for almost all types of cancer now, actually, all solid tumors anyway.
Well, let's talk a little bit about breast cancer given how common it is.
I'll tell you something funny. Despite training at Hopkins, I never once did a radical mastectomy.
Isn't that right?
It was already long gone from clinical practice 25 years ago.
Again, just for listeners to make sure they understand the difference between a radical
mastectomy and a mastectomy, or what's called now a modified radical mastectomy. The current version of a mastectomy removes all the breast tissue along with the lymphatic
tissue in the axilla.
Certainly I did more than my fair share of those, but the radical mastectomy, the Halsteadian
procedure removed also the entire musculature of the pec, pec major, pec minor, the whole
thing.
It basically was a disfiguring operation.
Debilitating, disfiguring.
It left the woman with nothing but ribs. Imagine what it's like to not even have peck muscles.
You sort of take for granted what you need to do to move your humerus. And yeah, to think
that it's only been 40 or 50 years that someone had the courage, I think it was probably Fisher.
Right.
Fisher's big study in the 80s, which now we have 40-year data from that.
And it's interesting how now even the modified radicals are relatively rare.
We still have some advanced cases that they have to go that route.
But we see tons and tons of patients now who are so much happier, their quality of life
is much better.
By just having a simple lumpectomy, a central node biopsy, and if it's all negative, especially if they've had their mammograms, you get a small T1 or T2 tumor, we give radiation
to the whole breast following that. And the radiation is again fractionated into small
daily bits. They'll get somewhere in the neighborhood of these days, it's actually only about three
weeks of treatment, maybe about, I say 40 gray in roughly 15 fractions. We used to give, even when I was in a couple of decades ago,
we were giving 50 to 60 gray,
it was quite a bit higher dose.
But the 40 gray in 15 fractions to the full breast,
and with the modern technology,
we can cover the breast tissue
without a significant heart or lung dose.
We can even use tangential beams,
even if it's a left-sided tumor,
to stay away from the heart,
which is things that we couldn't do very well in the past.
The overall and disease-free survivals
are pretty much comparable to someone
who had a modified radical.
Yeah, for folks who wanna know more about that,
Sid Mukherjee in, I think it was in The Emperor of All Maladies
has a chapter on this.
Fantastic book and one of your best podcasts.
Love that guy.
Yeah, he's a legend.
So let's talk about that.
So a woman has a stage one or a stage two breast cancer.
Typically these days, I think they're moving mostly
to neoadjuvant chemo before resection.
Yes, in a more advanced case, but if it's a typical T1
or even a small T2 that we see,
they may not need any neoadjuvant therapy.
They just will have their lung.
If it's like I say, a one and a half centimeter mass
that's easily resectable, they'll remove that just without any neoadjuvant treatment.
And we'll do adjuvant radiation and then potentially depending on the receptor status, adjuvant
hormone therapy, which is the domain of the medical oncologist, but we still work with
them. So just surgery followed by three to four weeks of radiation.
How long after surgery can you begin radiation?
Wound healing, we give them a little bit of time. We generally do our CT-based simulation and three-dimensional planning maybe two to three
weeks after their surgery.
And then by the time it takes about a week to do all of our computer programming, and
then we'll start the treatment within three to four weeks post-op.
So tell me a little bit about that.
I was completely unaware of that.
So I'm a woman, I've had a lumpectomy, sentinel node was negative.
So I've got an incision about this long for the listener,
five centimeter, six centimeter incision.
They've probably closed it with beautiful internal sutures.
I've got some sterile strips, they're off in a week
and I've got a nice little scar a week later.
I come and see you how many weeks after that?
I usually will see patients for consultation.
A lot of times the breast surgeon will send them
prior to anything being done.
So I'll see them for their initial consultation ahead
of time.
But then we plan on doing what's called a planning procedure or a simulation where we're
going to put the patient on the table and essentially do a dry run for their treatment,
usually a couple of weeks after treatment.
And that involves essentially positioning the patient.
Typically for a breast patient, they'll be prone with their arm behind their head, we
call it the movie star pose, to get the arm out of the way of the axilla essentially.
So by putting them in this position and then putting them on a wing board that will slightly
elevate their torso, and there's a lot of different geometry here that we can use.
Back in the old days, they had all kinds of ways of doing plaster casts and things like
that, but what we essentially do now, we'll use what we call a vac lock, essentially a
bean bag with a vacuum port.
The patient sinks into the bag, we suck all the air out of and lock it becomes a rigid cast of their body and that way they fit into
the groove that we've made for them will actually form it molded around their
elbow so they're comfortable. Many times with patients who've had an axillary
dissection they may have a little bit of scarring, a little decreased range of
motion to be able to get their elbow back there so we'll work with them the
best we can. Whatever position we get them in we do a CT in that position and
that's the position we have to reproduce for the daily treatment. And the key there
is that when they have their arm out of the way, we have to have room so that the
machine can move around from different angles. The actual radiation machine has
a gantry that can move really 360 degrees, can treat from any angle you want.
But we have to be able to model tangential beams. We don't want direct
anterior field that's going to radiate the breast, but the photons
are going to go right into the chest.
By using an angle, we can cut across the surface and actually shape the beam to match the curvature
of the chest wall.
So we cover the entire thickness of the breast tissue, or even in the case of an advanced
maybe a T4 patient, something like that.
We may even do this post mastectomy, so you're treating the full chest wall.
And we go a little deeper below, into the ribs, into maybe the first inch of lung tissue like that. We may even do this post mastectomy, so you're treating the full chest wall. We go a little deeper into the ribs, into maybe the first inch of
lung tissue below that. By using these tangential beams, that really minimizes the treatment,
the photons damaging the lung tissue. All of that is planned ahead of time. We do a CT
scan.
Just to be sure, planned pre-resection because you're seeing the tumor itself.
What I meant was pre-treatment.
Got it. So post-resection. So post-resection, you'll see a tumor bed. What I meant was pre-treatment. Got it, so post-resection.
You'll see a tumor bed.
The lumpectomy cavity is obviously clearly visible.
It's a fluid pocket on CT.
So I'll scan the whole chest.
Takes about a week.
I have a whole team.
I have a wonderful staff, a radiation dosimetrist
that helps do the computer planning,
and then a radiation physicist
that actually calibrates the machine
prior to actually starting the patient.
So we do the scan.
Of course, the CT scan is two dimensional slices, but we have three dimensional modeling
software.
So I have a full 3D model of the patient.
I can look at the slices are how thin it varies.
This is not a diagnostic scanner thing.
So usually something like two millimeters, three millimeters, we don't have to go super
high resolution.
And so that way, once it's reconstructed, then I can have a nice idea of what angles
to bring the beams in at, because every person
has a slightly different curvature to the chest wall.
You're gonna have to customize the anatomy.
Different breast sizes.
We have all kinds of different techniques,
so I won't go too much into the details,
but if someone is very large-breasted,
we could even treat them prone,
have a special pillow to allow the breast to hang down.
And it's also, I'm guessing,
where the tumor was in the breast.
So if you have large breast and a superficial tumor, definitely prone would be amazing.
The tumor bed is so far from the patient, right?
That's true, but our technically, what we call the clinical target volume, the area
that we're trying to radiate would actually include the entirety of the breast tissue,
even-
Oh, really?
All the way down to the chest wall.
So there's two different ways.
There's full breast radiation, which is what most people get, but what you're describing
actually is partial breast.
We would just target the lumpectomy cavity and that can also be done.
We save that for, usually for older women who have a very small tumor.
And when I say older women, it's more because of the fact that the remainder of the breast
remains untreated.
So a local recurrence is a little bit more likely in someone that has not had full breast
radiation.
But in a selected subpopulation of small breast cancers, in some with a very large breast,
you can do partial breast where you're only targeting the lumpectomy cavity.
But for most of our patients, we actually do treat the whole breast as standard of care,
plus or minus the axilla.
That's where the pathology comes in because if they did have a positive lymph node, then
we have to go after the axilla and sometimes the supraclavicular and even internal memory nodes in some cases.
Okay.
Yeah.
So this is infinitely more involved than I thought, which means I'm not the only one
that probably was ignorant of what is involved.
How long does each session take?
When they're actually on treatment, it's about 15 minutes, sometimes even a little bit less
than that.
Some of the newer machines can deliver the beam even faster.
But when I say 15 minutes, I'm talking about I have four patients an hour typically, so
in and out of the room in 15.
That includes getting them on the table.
The key thing for accuracy and reproducibility is positioning.
So the reason we made that mold and we've not only did we get them in position but I've
also got a couple of dots on their skin to use as reference marks to make sure that the patient is in the correct position.
That whole process probably takes five minutes every day when the patient gets in the room
and then maybe another five to ten minutes for the actual beam to be on.
And my favorite thing is to come in the room after the patient's first treatment and then
the most common question I get is, hey doc, when do we start?
And I'm like, no ma ma'am, that was...
They're like, really?
That was it?
Because the patient feels nothing.
So the machine will go through its various angles.
It's pre-programmed.
The entire process is about 15 minutes a day.
And they can leave feeling the same as when they got there, just like getting any x-ray.
They jump in their car and go right back to work or to the gym or the golf course.
When did this become so automated with the robotic arm and stuff?
Did you do this in your residency,
or were you the ones manually doing that in residency?
So I was in residency in the late 90s, early 2000s.
So it was a very interesting time,
because we were at the cusp.
My first year of residency, and I was at UTMB in Galveston.
It was a combined rotation with MD Anderson.
So we were at a time, this is 1998 we're talking about,
where at the end of the old era, we didn't even use CT planning.
We just had a couple of orthogonal films and we were literally drawing our tumor volumes
out with a grease pencil on a physical x-ray and using that cutout to go trace a styrofoam
negative and make a metal or a lead alloy block, which you would slide this basically
this aperture in the path of the beam.
That's the way it was done for decades.
And so we were still doing that when I started residency. But by the end of residency, we had
full-on CT planning. Where now we're doing a full CT scan, doing everything virtually. And of course,
it's far more precise and you can model multiple different iterations. Okay, do I want a beam
coming in from this angle? Do I want to bring in an orthogonal beam from here? Do I want to block
out a little bit more of the chest wall to get the
heart dose down? I can see all that stuff now. So by the time I finished residency, we were basically
doing what we do now, albeit with much slower computers and just being in the infancy of that,
it was probably more like 20 to 30 minutes per patient. But the last 15 years, roughly,
to answer your question, things have been much more automated. And instead of having lead blocks
that you're sliding into the path of the beam,
now everything is shaped in the head of the beam by our computer.
So you hit a button and when I've already programmed the treatment planning values,
the machine knows how to shape the beam to match the aperture of whatever you're trying to do.
So that's all fully automatic now.
So the therapist job, we have a radiation therapist who actually positions the patient in the room.
They get them in position,
they take a picture x-ray first, either a cone beam CT, which is a low-dose CT, or just a PA in a lateral film,
and we actually overlay that with our planning imaging to make sure that the original reference from the planning day matches today's image.
The machines will actually superimpose the daily image with the reference image. So everything is automatic. I can see,
okay, we're directly on. If everything lines up correctly, then we literally have two images
that look identical. I just see one image, which if it's slightly off, if there's even
a few millimeters this way or that way, we account for that by moving the table. The
table is motorized. So the patient will be laying there and they'll feel it move just
a few millimeters this way or that way until we have perfect concordance between the daily setup and the original.
That's really, really improved our accuracy and the regional miss, the geographic miss,
which was a problem in the old days when we didn't have digital imaging and all this stuff
is essentially gone now.
The actual radiation beam is generated by what?
The ion is generated by?
So that's another thing that has changed.
Now essentially, when I say now, the last basically 30 years, most machines in the US
are linear accelerators.
So these are artificially generated x-rays.
It's essentially accelerating electrons through a long vacuum tube, an essential electron
gun.
And at the very end of the tube, you've got a tungsten target.
And so the electrons hammer that target and then they shower photons out.
So you're generating the x-rays that way.
And this has been done, actually, I think your alma mater, Stanford, had the very first
one in the US, the medical linear accelerator.
But prior to that, they were using these for atom smashers and they have the gigantic machines
they were used for physics.
But it started in London, I think, in 53, and then I think in the late 50s, Henry Kaplan
at Stanford had the first one.
So we're essentially still doing that, even today, what, 70 years later.
But the key difference is how we're able to shape those photons once they come out of
the machine now.
And so when the actual photons are coming out, they're completely unfiltered.
It comes out in a cone shape and it diverges just as any light source would.
You know how when you hold a flashlight to a wall, you get a nice precise circle as you
pull the flashlight away, it diverges.
So we have filters and we have what's called the multi-leaf collimator that can actually
shape the beam, as I mentioned earlier, that can actually match the anatomy of the patient.
But now that's all done automatically.
We program it ahead of time as opposed to the old days when we had to use lead blocks
that were actually physically blocking the beam.
But basically the LINAC has been the standard.
Prior to that, we were using a Cobalt-60 machine, which is essentially, it's not even a machine.
It's basically just exposing a patient to a radioactive isotope and then shutting the
jaws again.
Then actually those are still in use in most of the world.
There's a few left in the US, but they've mostly been decommissioned now because the
LINACs have taken over.
Soterios Johnson When you say that a typical treatment might
be 15 gray over the course of the three weeks,
fractionated over 15 treatments.
So it's actually about 40 gray.
40 gram, sorry, 40.
Yeah, so roughly 2.5, 2.6 gray per day.
And you're right, times 15 treatments, so you're getting roughly 40 gray to the breast.
And then we usually actually do a boost.
So we'll give what we call a tumor bed boost.
We give a little extra dose to just the lump itself, the lumpectomy cavity itself.
And there was a couple of French trials that showed that adding an extra 10 gray over an
extra five days, so two gray times five, just to the lumpectomy cavity itself improves local
control over just whole breast.
Okay.
That's actually what I was going to ask.
I was going to ask if the 40 gray is distributed completely uniformly across the breast, the answer is no.
It is, but then you have that boost.
It is an extra boost. It's a customization based on the patient's pathology. I'll occasionally
have a patient that the breast surgeon will call me and say, hey, Sanjay, we did our best,
but we had a persistent positive margin. I went back and did a rear resection and there's still
a positive margin. Maybe the positive margin is at the chest wall. They can only go so far.
In that case, instead of giving a 10 gray boostay boost, I might give a 16-gray boost or something to account for
instead of just treating microscopic disease, potentially macroscopic residual in that sort of situation.
So every patient is a little different.
And then the axillary nodes themselves are normally not treated in an early stage patient,
but depending on the risk factors, if it's a very large tumor or if there was a positive sentinel node, maybe an incomplete axillary dissection, in many cases we end up treating the
full axilla. And in some cases when it's advanced disease, we end treating level two and level three,
so you end up getting the superclav as well. If we go back in time to 25 years ago, 30 years ago
versus today, what are the typical side effects that a woman experiences from this treatment?
And by the way, was she typically
getting 40 gray 25 years ago, or was that a little more,
I think you said, and now they've come down a bit,
it was sort of 50, 60 gray?
This brings up a point I need to kind of emphasize.
It's not so much the total dose, it's the dose per fraction.
So how quickly are you getting it?
So the standard of care was actually 50 gray rather
than today's 40-ish gray. But it would usually be given in two gray per fraction daily doses
rather than the 2.6 2.7 that we're using now. So the effective dose when you take
into account there's a whole radiobiology lecture that we're not going
to bore people with but taking into account the dose per fraction and the
total dose the biologically equivalent dose with the BED is roughly the same now at 39.9 gray
given in 15 treatments versus the old 50.4 gray that was given in, say, 25 to 28 treatments.
So it was a longer process, if you're right.
And we still do that in some cases.
And this comes back to another question you asked about, about the homogeneity of the
dose.
And so our goal, of course, is to have 100% coverage of the whole breast,
but the reality is the way that photons are going to be interacting from different beam
angles and whatnot, you're always left with hot spots and cold spots. And so the biggest
difference between what we're doing now versus the old days wasn't so much the total dose,
it was the actual homogeneity that you touched on. So the heterogeneous old way of doing
things with a cobalt machine or with a
low energy x-ray unfortunately meant that there were hot spots and cold spots in the breast.
And that of course could either be manifested as scar tissue if it's a hot spot or heaven forbid
a geographic recurrence if there was an area that was under dosed. So with the modern computer
planning we were much more homogeneous. So even though you may say, I got 50 gray back in 1995,
and now I'm getting 40 gray, you're now getting 40 gray
in 2 and 1 half gray fractions, which
is equivalent to the old 50.
Plus, we don't have 150% hot spot and a 60% cold spot.
We have a nice 100% match all the way across.
It's like a CAD-CAM type of thing.
I'm about as close to an engineer as an MD can be.
And so we do actually simulate the dose distribution of the radiation in the tissue.
In modern days, we get a nice homogeneous dose and therefore that goes to your next
question which was what is the patient experience?
Maybe not so much 20 years ago but more like 30, 40 years ago with the older cobalt machines,
they would get a terrible dermatitis.
Many times it was moist desquamation, confluently over the whole chest wall.
Axillary desquamation is always bad because of the friction of the arm.
But with the modern treatment now with, first of all, not using cobalt, using linear accelerators,
the energy of the photons is higher, which means the skin dose is slightly lower.
So you're getting maybe 100% on the the skin rather than a hundred and fifty percent like you once did. So we don't see anywhere near
the skin reaction that we used to. It's more of a maybe a grade one or a grade
two erythema. So mild redness or maybe sometimes a little bit of sunburn but
nothing as severe as we used to. So these days patients do still get a sunburn. We
give them a little free samples of aqua four. They can use an aloe vera plant if they have it, just your normal type of skincare stuff
as opposed to the old days when we were actually treating essentially burn
victims with silver sulfidazine and heavy-duty narcotics and things like
that. The modern era it's so much better than a lot of the patients, especially if
it's someone that doesn't have a very large breast. There's less energy being
put into a smaller size person. They don't get anywhere near the skin reaction and that's why if you did have a very large breast, there's less energy being put into a smaller size person, they don't get anywhere near the skin reaction.
And that's why if you did have a very large patient, we actually still use the old 50
gray in 25 because you're giving less dose per day and you do have a very large breast
where you're going to have areas that are going to have hot and cold spots.
Sometimes that's still needed.
So we have to tailor it to the individual is I guess my bottom line there. Did anybody ever look at when you had the very disparate hot and cold spots and follow
women for recurrence?
Yes.
Was there any association between the cold spots and recurrences?
There certainly is. And so the problem was, is that in the old days, you didn't have computer
modeling and actually the old school physicists got to give your hats off to those guys that
had slide rules and probably abacuses or whatever the heck they had back then. You couldn't really tell exactly where the hot and cold spots were
by actually having a computer show you. You had to go based on the fact you choose a photon energy
and you know what the dose distribution at various depths is. And so you would try to minimize that
by again having beams coming in from different angles and then by using multiple angles and
multiple fields you could paint in the dose as best as you could.
But yes, certainly there were issues where as you get deeper into the tissue, the dose
would be lower.
And then this is again before my time, but there certainly were studies showing that
there were geographic misses.
That was obviously not good, which sometimes would lead to like a salvage mastectomy or
something like that.
But in the modern era, not so much.
What is the impact of breast implants in this type of treatment, either saline implants
or the older, actually they're not older now, they're back in vogue, right?
They're back in vogue, right?
Yeah, of course.
The silicone, either way, the x-rays we use, they are not at all affected by that.
That's essentially tissue equivalent.
Pardon my ignorance, I completely forget.
Are those implants typically under the pec or between the pec and the breast? So we see both.
What's the current standard? I think most of them we see are actually under the
muscle. Silicone under the pec? But I've seen them both even now the plastic
surgeons have different criteria for that but regardless of what it is if
it's under the pec then of course it's really a little farther away. It's not a
huge issue but the radiation will still affect that area But typically these implants are pretty tolerant of that.
The only issue down the road is they may have a capsular contracture or something from fibrosis.
The bigger challenge we run into is for our post mastectomy patients who are going to
be reconstructed and they have expanders put in.
And that's where the relationship between the radiation oncologist, the surgeon and
the plastic surgeon is key.
Trevor Burrus explain to folks what expanders are, how that works surgically.
Dr. David C. McKeon So essentially what's happening is when you
have a full mastectomy, if a patient wants to have their breast reconstructed later on,
the breast surgeon will remove the breast, but then the plastic surgeon will come in
and place some sort of a placeholder to allow the soft tissue, the connective tissue, and
the skin to stretch to allow for future implant
placement. And so those tissue expanders, they can actually inject saline into them with a port and
gradually stretch them with time. That's normally what they would do if there was no radiation
involved. Again, most mastectomy patients really don't need radiation because this gets away from
what we mentioned earlier where breast conservation is lumpectomy only. But there are some patients with a full mastectomy who are going to get reconstructed.
So they come to me and when I do their CT scan, they have this expander in place from
the breast surgeon.
So we have to, again, modulate the beams and we treat the entire chest while we make sure
we're covering everything.
But simultaneously, we have to make sure that we don't have those hot spots in the area
of the expander where potentially you could cause scarring and fibrosis and cause the
expander to have to be removed, have the plastic surgeon have to revise it, that
becomes a whole nother hell of a beans there that we don't like to mess with.
But we have techniques now to be able to keep the dose off of them and again as
you mentioned earlier whether it's silicone or saline it's roughly the same
density but some of these tissue expanders have bits of metal in them, they may have other artifacts, and so when I'm treating
with photons with x-rays, depending on what you're hitting, the effect is based
on the density, the atomic number of that tissue. So metal behaves very differently,
bone behaves differently from air, but when you're in the spectrum of saline
tissue, water, it's all basically the same. We can model all that very much like, I'm
getting ahead of myself, but very much like when we have a prostate patient with a prosthetic
hip, a piece of metal right next door, we're able to compensate for that with the modern
computer treatment planning systems.
Do women experience any systemic symptoms from radiation like nausea or vomiting or
is that pretty much?
Not at all. The only time we see radiation patients who have nausea or vomiting,
a lot of times for other sites,
they may get concurrent chemo radiation
where the chemo could be responsible.
But for breasts, we don't do concurrent.
It's usually sequential.
The only time I really see radiation induced nausea
is if I'm treating an esophagus or a pancreas
or something that's treating in the abdomen
or somewhere along the GI tract
where nausea is more of an issue.
Typically not for breast.
Okay, let's talk about prostate, which is obviously also the bread and butter of the field.
So first off, which patients are typically being radiated?
The answer to that has been evolving. There was a time as recently as probably 20 years ago where
we only treated patients who were probably medically inoperable that the urologist would say,
hey, this is a high risk anesthesia patient. let's send them to Dr. Maeda for radiation.
And that's a big reason why a lot of the older data was not as good for radiation because
of the patient selection criteria.
But in the modern era, as we've gotten more and more precise and our side effects have
gone down and our cure rates have gone up, now it's pretty much wide open where pretty
much anybody who's eligible for surgery would also be eligible for radiation.
So there's not that big of a divergence as there once was.
You've gotten to know Ted Schaefer, who's not only been on the podcast, but is equally,
let's just say, interested in cars.
He sure is.
So you, me and Ted have a lovely little text thread about cars.
He and I may have another text thread in case our teams meet in the playoffs as well. He's a big Ravens fan so I'm from Houston so I'm
hoping we get there. Let's talk about a patient that comes in to see Ted for a
biopsy. They've got a Gleason 3 plus 4 and then another patient who's a Gleason
4 plus 4 or 4 plus 5 or something like that. How does that patient navigate
their way through the system
as to whether or not they need radiation
or should they undergo surgery?
And does androgen deprivation therapy
necessarily come with radiation?
Or is there a scenario where you undergo radiation
but you don't require androgen deprivation?
So to answer your last question first,
androgen deprivation for high risk disease
is certainly standard of care. Gleason 8 or higher for sure.
The Gleason 7s are always a gray zone and so a 4 plus 3 with high-volume disease typically
also do get concurrent and adjuvant androgen suppression along with radiation.
But one of the things that's really changing now is I know Ted talked a lot about the decipher
score where they can look at the chromosomes of the actual cancer cells and have a much more granular view of exactly are they truly
high risk or can you say that this one 3 plus 4 is more like a 3 plus 3.
So for a lot of the 3 plus 4s now with the decipher test and there's also an AI test,
I knew you had a really interesting discussion with your AI expert and that wasn't too long
ago called ARTERA and we're using that.
That's actually in the NCCN guidelines now so that Arterra tests can help us
differentiate between a unfavorable and a favorable intermediate risk patient.
I treated my own father not too long ago. He was the first person I did this on.
The Arterra test is essentially they just use the actual images of the H&E
slides that were already done from the pathologist and it's interpreted by a
machine learning computer that has been trained on hundreds
of thousands of prostate images from the old RTOG studies, the 94s, all the stuff that
was done back in the 90s.
And it cannot come back and say, okay, very much like decipher, it can say that this is
a 3 plus 4, but it's a favorable or an unfavorable person in that subgroup.
And so because of that, we can stratify better and actually tailor it to where maybe at 3 plus 4 doesn't need androgen ablation at
all. And maybe even some 4 plus 3 so they come back low enough on the scale.
You also have to talk about the side effects and whatnot but the standard of
care was always to give concurrent androgen ablation for intermediate risk.
But now we're able to really take some of those people out of the equation with
these new studies. And is the main selling point, because most patients just want things taken out, I have
cancer take it out, is the reason that a person might select radiation therapy, especially
if it comes with androgen deprivation therapy, because of the sexual function and urinary
function, like what's the main advantage?
Those are number one and number two. Lack of incontinence and lack of impotence,
but of course when you have androgen ablation
that clouds things a little bit.
But typically the number one thing we see
is patients who don't wanna deal with diapers.
And for the most part, although incontinence
is still described to some degree in the literature
in my personal experience, I don't think I've seen
a single patient who came in continent who left with anything
less than that.
There's no pads.
There's no nothing.
And then of course, as I talked about with breast cancer, we can also focus very precisely
on the prostate itself.
So the dose to the penile bulb, the dose to the rectum, the dose to the bladder are so
low now that the side effect profile is essentially zero from a radiation standpoint.
Now they may be having hot flashes from the androgen deprivation and decreased libido and fatigue, as you know.
But on the radiation side, because we have all these tricks now, very much like with breast, the way we can avoid the heart and the lungs,
in the case of the prostate, we can almost completely avoid the bladder and the rectum and even the penile bulb now.
So the quality of life, those are the reasons why people tend to choose radiation.
And I know we've talked about this before,
you're just not seeing the proctatitis.
Yes, almost none.
In fact, I think a Ted had mentioned in his last talk,
there's a gel spacer that is often inserted.
It's an injection that's done transparently
and it separates the rectum from the bladder.
But in my years of doing this,
when you're very diligent about how you do this, very much like a surgeon pays attention to the details, so
do we. I can actually trim the dose off of the posterior prostate and just make
sure the dose fall off between the posterior prostate and the anterior
rectal wall is so rapid that the anterior rectal wall is always going to
get some dose, but usually it's not clinically significant. And what we do to
manifest to make sure that that is a daily thing, because we're talking
about treating patients for multiple weeks, we actually coach the patient to come in with
a full bladder and an empty bowel.
And by being diligent about that and imaging daily to double check that in fact the bowel
is empty and the bladder is full, that allows those two organs to separate from the prostate.
And even a few millimeters of separation is all we need to take advantage of our
modern focused radiation beams. And does the patient need to be coached to time their breath
or anything as the beam is at that most delicate edge of the rectum? Not so much for pelvic
patients but we do that for breast cancer especially left-sided breast so just to go back to that
you actually have a deep breath hold, which will get
the chest wall away from the heart.
So we do that in the case of thoracic tumors, but in the pelvis, the diaphragmatic
position doesn't really make any difference.
It's more about bladder and rectal filling and emptying respectively.
That's much more important.
Everybody I've talked to who's had LASIK eye surgery always says they're so
worried that they're going to do something, they're going to flinch.
And do patients feel the same way when they're undergoing radiation?
Like, what if I just flinch my pelvis or do something like that?
It's going to get too close and get that question all the time.
And from a LASIK standpoint, I think I would be worried about.
That's probably why I'm still wearing these Coke bottles, unfortunately.
But in the case of prostate cancer, first of all, the dose is given
over the course of several minutes.
And then each of those fractions is again talking about one fraction out of multiple weeks. So even if someone
absolutely had a coughing fit or something like that, first of all we're
watching them, we can stop the beam. We can stop it at any given moment but
slight variations day to day, the biggest variations are going to be based on
bladder and rectal filling. We take that into account when we're doing the
treatment planning. So there should really be no adverse outcome because
what I actually do is I'll map out
where the volume of the prostate is
and we will actually purposely expand that volume
and treat the full dose of radiation,
even a few millimeters outside of the prostate
to make sure that there is any internal organ motion
or anything like that, that we take that into account.
But typically if someone's coughing or something like that,
we'll just hit the pause button and get them reset
and ultimately it's not an issue.
What about patients that are inoperable?
First of all, what leads to a patient being inoperable and how do they show up?
Typically the urologists have already screened the patient.
Everyone's first exposure is going to be to what the urologist tells them.
And luckily in this day and age, I'm lucky we have people much like Ted who are very
open and who are very open to not just doing surgery but who actually look at the other options and present
everything to the patient. But typically a patient who maybe was medically
inoperable will certainly come to me but even somebody who maybe is on the
borderline who wants to see both sides of the token, a general urologist will
send them to a surgical specialist and to me and we'll go through all the pros
and cons of everything and really what it comes down to to not belabor the
point. It comes down to two things.
You want to be cured, cure rate is key, but quality of life is equally important, if not
more important for most people.
And so now that cure rates with our modern focused radiation allow us to get such a high
dose into the prostate, we can say that they're essentially equivalent to surgery.
So we don't have that deficit like we did 20 years ago when our fields weren't as precise.
It was sort of the shotgun approach versus our sniper approach.
Now because the cure rates are better, then it really comes down to the quality of life
changes.
And that's where there's a spectrum of things.
Now is this an apples to apples comparison because the patient who undergoes the robotic
prostatectomy today does not go on androgen deprivation therapy.
They get to walk around.
In fact, you've probably heard Ted on the podcast, he says, we'll give those patients
TRT if they're hypogonadal.
Why does the patient after radiation therapy still need to be androgen deprived if in theory
the radiation is as effective as the surgery?
That comes to a key point where it's trading one thing for another.
You don't have the incontinence.
You don't have the, at least the short-term risk of impotence like there is from surgery.
You don't have the penile shortening or whatever other sort of things that they have to deal
with, but you have to deal with hot flashes and decreased libido and whatnot.
But again, most of the patients who are intermediate or high intermediate risk are going to, if
they end up not having a negative margin or seminal vesicle invasion after prostatectomy,
they're still gonna come to me for radiation anyway and they're still gonna need to be
on androgen ablation.
So there's a significant number.
Now these days, we'd certainly treat a lot less Gleason 6 than we used to.
We observe most of them.
But there's a lot of Gleason 6 folks that even in this day and age will choose to have radiation just because it's maybe a little bit more aggressive form
of watchful waiting. And in that case, there is no endogen ablation and they just glide
through the whole process.
Have there been a trial of Gleason three plus three watchful waiting versus XRT no ablation?
No, unfortunately, there's no actual trial. There's just observational studies. That's
kind of what we're dealing with there.
Oh, gosh.
And obviously, you can't figure out what the biases are, but what do those observational
studies show?
People don't die from Gleason's Six Disease, as we all know, because quality of life, they
do so well with the radiation.
There is just less of a chance of it progressing to a seven.
And when they come to me, it's interesting the different patient populations.
I also get people, this is not mainstream, but I get a lot of transplant candidates who
need a renal transplant and they cannot get their transplant unless they're cancer free.
Even if it's one core of a Gleason 6, they're ineligible for their transplant.
So those guys I will certainly treat, but I've been following them now for 20 plus years
that we've been doing it.
Quality of life, they do so well and this way they don't have to worry about androgen
ablation when they do become a Gleason 7.
It's really interesting.
There would be a very interesting and elegant study taking, let's call it medium to high
risk 3 plus 3s.
People based on family history or some other phenomenon, genetic or otherwise, you randomize
them to watchful waiting versus radiate them without androgen deprivation.
I mean, you'd have to do this as a very long-term study. So the question is outcome number one could
be conversion to 3 plus 7 requiring surgery and or androgen deprivation therapy. And then of course,
outcome two, the very long-term outcome would be overall survival.
That's the key. That's why these haven't been done. You would need decades to do a trial like that.
Yeah, it's a 20-year study.
But it certainly would be interesting to see what it would show.
But the real-world observational studies show that all the Gleason 6 guys,
I would say until maybe a decade ago, we did a lot of Gleason 6 patients.
They mostly were sent for radiation.
Why were they sent?
I guess the combination of different things.
People have different levels of tolerance for watchful waiting.
In the pre-MRI days, everyone had to have an annual biopsy and that alone is more anxiety
invoking than really the radiation is.
Not to mention we'd see a fair number of folks with urocepsis and complications from that.
So now in the MRI era, we don't really see that anymore, but that was done very routinely.
And because the patients had so little proctitis and cystitis especially in a Gleason 6 where
not only am I not worried about pelvic lymph nodes I'm not even really worried
about the seminal vesicles. So my field is very small which really minimizes the
side effects because the bladder, a full bladder when it's actually full it'll
move superiorly and anteriorly where the dose is close to zero. So most of these
patients they just kind of laugh and say, I'm coming in for my daily
treatment and I'm right back to my normal life again.
In the absence of androgen deprivation, radiation has become very simple for prostate patients
now.
And again, what fraction of Gleason 7s can do radiation without requiring androgen deprivation
therapy?
That answer would have been zero probably five years ago even as recently, but now with
Arterra and Decipher, it's probably I'd say a quarter of them don't need it.
If it's a 3-4 with a low Decipher, low Arterra score.
And again, this is still an evolving area where I don't think anyone has the exact answer,
but that's what most people are doing nowadays.
And even some 4 plus 3s that have low deciphers are potentially candidates to avoid that.
And the biggest change in this has now been our ability to do PSMA PET scans to follow
up because otherwise, I think that the extra androgen deprivation was more of a band-aid
for not being able to see what's going on afterwards.
Now if someone has a recurrence and you do a PSMA PET, I've got a guy that had treatment
20 years ago with radiation.
Now he's rising PSA.
Otherwise he'd just be stuck with ADT for years.
Now I see a positive parietic lymph node on a PSMA PET.
I can just treat that area and very successfully.
There's no long-term data yet, but it seems to be working really well.
Similarly to how we would use a FDG PET to target a lung tumor in the past.
What about these patients that show up with two spine meds?
How effective is radiation there,
given that that's a favorite spot for prostate two?
You're talking about initial presentation
with oligometastatic disease?
No, let's say, okay, we could talk about that,
or we could talk about post-treatment three years later.
So post-treatment three years later,
palliative radiation does work very, very well.
It would be probably five treatments.
You can even do what they call SBRT, which is stereotactic body radiation,
maybe in a single fraction. And it definitely is very good. We kind of joke about it and
just kind of spot weld that spot. Of course, it's not going to prevent something else from
popping up elsewhere, but that's extremely well tolerated and usually it'll stop the
progression at that site. So there are people who had high risk disease. And to get back
to what I mentioned earlier, if they had a couple of spots like that at the time of initial
diagnosis now, it's been shown that you can treat the oligometastatic disease if it's
in the bone only at the same time as the primary lesion. And the outcomes are actually not
significantly worse if it's just limited disease.
And what is a more favorable presentation, oligometastatic to bone or oligometastatic to para aortic?
Bone, for sure.
Actually I had a guy walk into my office with a PSA of 1900.
He looked just as good as you or me.
I actually took him on a TV show I did many years ago.
It was kind of an interesting story.
1938, 65 year old guy, Mr. Macho had never been to a doctor in his life, widower who
decided that he was
dating a younger woman now and she's like, if you want to be with me, you got to go get
checked out.
Colonoscopy clear, blood work all clear.
Oh, by the way, your PSA is 1900.
Which means the lab made a mistake.
I mean, that's what you would think, right?
Yes, that's what you would think except for his bone scan looked like a Christmas tree.
This was in the pre-pet era.
I mean, he had disease in every bone in his body with zero symptoms.
So this is an outlier situation, but in that situation you need lifelong androgen deprivation
and chemotherapy.
Back then it was mostly taxol-based therapy.
We didn't have all the second generation androgen ablation drugs that we do now like Enzalutamide.
But at that time when we saw that, you know, he went and got chemo and got androgen ablation,
when he came back to see me, fully functional guy, perfect shape, His PSA was down to 1.5 with just the systemic therapy. And at that time, the tumor board,
we presented him, the decision was made to go ahead and treat his prostate as though
he was a de novo presentation because all the bone disease had resolved. He did great.
So, you treated his prostate and how long did he live?
He's still alive. This has been, I got an email from just about a year ago.
So I think he at least has a year ago.
He was 12 years out, still doing great with zero side effects.
He's on endotrinoblastion for life.
So he's certainly going to have issues from that, but overall still very functional.
How is this possible?
What's the biology of that tumor that allows him to still be alive?
I don't think it's even necessarily just prostate.
I've even seen it in breast cancer patients
in the small subset where it's bone only disease
with no visceral metastasis.
Some folks can live for a very long time
with bone only disease.
And I'm not sure what the answer to that is.
And has he suffered any debilitating fractures?
You would expect that at this point,
but no, not even one.
This guy's in his late 70s now.
Now he's in his, yeah, late 70s and has not fractured a thing and is still active.
The guy plays golf.
I hope he still has that young girlfriend.
I'm not sure about that.
But other than that, other than the hormonal aspects of it, yeah, it's amazing.
I've seen many, many people with four-digit PSAs that we get them down, at least NED for
some window of time, even if it's not that long. Four-digit PSAs that we get them down, at least NED for some window of time, even if
it's not that long.
Four digit PSAs.
Yeah.
I think the highest I've seen is 7,500.
That was a person that ended up passing away.
But the guy who was 1,900, I think a lot of it is a function of just like any other type
of tumor, he had all the other risk factors that were lined up.
He was young, healthy, no other comorbidities, active.
Ted has told me about some of the most
Terrifying cases are the exact opposite these guys that show up with a low PSA
It's a very low PSA a PSA of 1.9. Those are worse rampant metastatic disease
Right, right, right
And that's the thing you get some of these really poorly differentiated cancers that no longer resemble their prostate progenitor cells
They're very hard to monitor and a lot of them even don't even show up on a PSMA PET scan.
Yeah. Anything else you want to talk about on the oncology side of this? As far as what should people
know as they're engaging with a radiation oncologist? What questions should they be asking?
It sounds like it's no different than surgery where
there's clearly a difference between good surgeons and not so great surgeons.
There presumably are people that take the kind of care you take and agonize
over the details. How can somebody find out if their radiation oncologist is
practicing in your philosophy? It's difficult in terms of actual metrics, even for the surgeons.
Like, you know, TED is excellent outcomes,
but it's not like it's a published series.
And not only that, the best surgeons often
are treating the hardest cases.
True.
So it's a handicap right there.
It's a handicap right there, yeah.
100%.
It really comes down to finding someone
who's got the experience.
And in my case, because we do so much prostate,
I think I've done something close to it. In the modern era, 7,000 cases, probably 10,000 when you include the pre-image
guided radiation days. Someone who specializes in the area that the cancer is located in.
So someone like me, I may be extremely experienced in breast and prostate, but maybe for a pediatric
malignancy, you're not going to come to me. You're going to go somewhere else or a CNS
or something that's unusual. You have to find the right tool for the job. But you have to
just interview your doctor. I don't think there's anything specific to radiation.
Adam O'Brien And asking about complications.
Dr. Chris McKeon I think being very open with them saying,
yeah, exactly. And so ideally, maybe you come to someone who knows something. Like I get
a lot of patients who aren't familiar with the field, but they'll have a patient, they'll
have a family member that's a nurse or a dentist or a veterinarian or whatever it is, someone that has some medical
background, they can say, okay, let me ask them more specific questions.
And these days with the internet, you can do all kinds of research in terms of when
I'm talking about matching my volume of the dose distribution to exactly conform to the
tumor volume.
That's something that's very easy to talk about.
But I mean, for an educated patient, they can ask to see the actual computer simulations. A lot of my engineering patients
I was just about to say engineers probably have an easier time than
They do. And my engineering patients are really the only ones who do this. I usually pull
out all the graphs. I show them dose volume histograms with area under the curve for each
organ. And you can see, okay, the prostate dose area under the curve is huge. The dose
to the bladder and the rectum is super low. You can actually quantify that.
But for a lay patient, it's hard.
It's not that easy to do that.
I think a lot of it you have to go with your gut too
in terms of this guy's had a lot of experience
and the initial consultation is where it all comes down.
I'll spend an hour with the patient
and go through every little nuance
of what could and couldn't happen.
And my main MO is to sort of over-prepare them
and have them be pleasantly surprised
maybe when the side effects aren't as bad rather than the other way around.
It's hard to find the right person but there's a lot of good doctors out there.
So.
Let's spend a minute just on the brain because I guess that's sort of a unique case.
I know it's not where you are.
Still do a lot of it.
Oh, you do?
Okay.
Not as much as prostate and breast but yeah, both primary and metastatic.
Yeah.
So again, because the brain is such a sink for METs,
A, it's a source of a lot of primaries,
but it's also where a lot of cancer spreads.
It's often a place where you can't operate,
either because the tumor, the MET, or the primary
is too close to, say, the brain stem or something too vital.
So radiation is a pretty common tool there.
So talk about the history of radiation in the brain and the spectrum of everything from
whole brain radiation to gamma knife and stereotactic and all sorts of things in between.
Sure thing.
The main differentiating factor for brain patients is whether it's primary or metastatic
disease.
And although primary brain tumors are relatively common, they are dwarfed by metastatic disease.
So the vast majority of what most radiation oncologists see when you're treating CNS is
going to be usually lung, especially small cell based brain metastatic disease.
And so in those situations, the trend used to be where everyone would get whole brain
radiation but now with the advent of stereotactic radiosurgery, which is more focused, precise
radiation, the newer data shows that you can actually just treat the area of metastatic disease
as delineated on an MRI scan and not necessarily radiate the whole brain like we used to.
But for decades, everyone got whole brain radiation.
And for the most part, they did all right, but the problem was you're looking at a patient
population that maybe doesn't have that much of a life expectancy.
Now that systemic therapy, immunotherapy, everything has gotten better, especially in
the case of lung patients, they're living longer.
We have evolved where we've been finding people that were previously radiated the brain were having cognitive issues
years down the road, not for the short term, they would tolerate it well,
but maybe they'd start to have more forgetfulness, an inability to remember numbers and names and whatnot.
And this was from whole brain radiation.
Whole brain radiation.
And give me some doses.
So we're talking about 30 gray to the whole brain given in 10 fractions of three gray
each.
Three gray times 10 was a sort of a standard thing.
This is a staggering amount of radiation.
And that's to the brain, so it's a different story.
And just to be clear, do you need to use way more radiation because that's what you're
delivering to the brain?
Is this an example of where the sieverts and the gray are very different because you have to get through
the skull?
No. So the only difference between sieverts and gray in any patient is going to be whether
we're talking about dose in tissue or coming out of the machine. Basically the dose in
air versus dose in the patient. The biggest thing with brain tumors, yes, the bone certainly
is going to attenuate more dose, but what I'm talking about is actually 30 gray into the brain itself, the actual brain tissue.
Doesn't that mean you need much more than 30 gray coming out of the machine?
A little bit more.
The bone doesn't do that much?
It's not like they're wearing a football helmet or something.
Yeah, photons can still pretty much go through everything.
It's not metal, so it'll still go through.
The dose is a little higher and it gets to be like, for example, in a lung patient, it's
more of an issue when you have multiple different areas.
You got bone, soft tissue and air.
In that situation, you have to modulate the dose more.
But in the case of a whole brain, it's been found of course that the hippocampal dose
is very much related to their cognitive deficits down the road.
So now that we have IMRT which is a term I hadn't mentioned before but that's basically
intensity modulated radiation therapy which is also the magic hadn't mentioned before, but that's basically intensity modulated radiation therapy,
which is also the magic behind allowing us to treat a prostate without burning the bladder and the rectum.
And the newest form of IMRT is called image guided radiation therapy.
So you hear IGRT. Basically those two terms go together.
But by using IMRT, it's kind of like an HDTV versus this 1960s black and white blurry set where we can treat
with multiple small pixels and high definition so to speak.
So now when we do a whole brain, if I have to do a whole brain for multiple metastases
by using IMRT, I can literally carve the dose out.
I can map out the hippocampus and carve the dose out of there.
So you see these two cold spots on the hippocampi and really have a very low dose there while
still treating the remainder of the brain parenchyma.
Are there other parts of the brain that you carve out and protect?
That's the main one.
Of course, we are going to not necessarily completely carve out because when you have
multiple metastases, really the whole intracranial space is at risk.
You have to cover everything.
So believe it or not, 30-Gray sounds high to you, which it is, but for a glioblastoma,
we use 60-Gray.
Granted, that's not to the whole brain.
That'll be to the, either if it's an unresectable patient, it'll be the primary mass and then we will give maybe 46 gray to
the peritumoral edema. But then the rest of the brain is getting much less, hopefully
zero in many cases.
Do we know what the survival difference is for an unresectable glioblastoma with and
without radiation?
It's certainly worse. There's again multiple confounding factors there
because someone who's unresectable
probably has other negative issues as well.
They have poor overall performance status.
They have neurologic deficits.
Whatever the reason the surgeon can't operate,
that makes it worse.
But yes, even then in that situation,
you get probably, again, you're measuring survival
in weeks to months,
but it's probably double with radiation and without.
A lot of our GBMs though are resected, hopefully fully resected in terms of at least radiographic
the post-op MRI not showing any enhancement.
If you have someone that's got a fully resected primary who's a younger patient with not
a lot of neurological deficit, they can live a couple of years actually.
Why is this cancer unsurvivable?
That's the key question.
I know you and I are both Rush fans.
Neil Peart was lost to GBM as well, and yeah, it's so many people that's taken away.
But I think it just has to do with the invasiveness of the fingers of the tissue,
in terms of even when you think you've gotten the whole thing,
there's microscopic fingers that are always on the periphery,
and you can't just radiate it indiscriminately like you can other parts of the body,
because you've got the brain there.
There's always a fine line you're walking between causing, say for example, necrosis
of the brain versus letting the tumor recur.
And so that's really the number one issue.
We do have a new tool now as far as radiation oncologists in terms of treating CNS tumors,
which is called proton therapy that you've probably heard about.
There's several centers in the country now, MD Anderson where I am and Houston has a huge one.
But with protons, you potentially can have the dose
go into the brain to a certain depth
and not exit out the other way, like an x-ray would.
X-rays are like light, it goes right through you.
You may have a decreasing dose,
but it's kind of like a bullet,
you got an exit wound going out.
With proton therapy, this is one of the areas
where protons shine because you can actually modulate
what's called the Bragg peak of the physics of the protons to where it'll go a certain
depth and not go out the other way.
So down the road, hopefully, we'll start to see improved survival.
So far, it really hasn't shown to be a huge improvement, but there's less integral dose
to the rest of the brain.
And it's especially important in pediatric patients where you've got children with growing
skull bones.
If you can avoid radiating the growing bone to cause a deformity later on, that's huge.
So proton therapy is one tool we have.
But I wish I had an answer for GBMs.
That's gonna be a game changer whenever that does happen.
I find GBMs to be just such a frightening type of cancer,
and I do wonder if it's gonna require
some sort of injectable immunotherapy or something.
I think so.
Like, I just... Yeah.
You have to basically figure out a way to treat the brain systemically.
You have to mechanically overcome the blood-brain barrier
and come up with some sort of systemic treatment for it.
Okay, so today, how many patients are undergoing whole brain radiation?
Whole brain radiation is probably, to give you a number,
I don't know what the absolute number is, but it's probably 10% of what it was 20-30
years ago. The original studies out of Kentucky that Patchel had done in
neurosurgery, everyone used to get whole brain radiation following resection of
the metastasis or even if it was unresectable and there was some good
data back then supporting that. But nowadays rather than whole brain you're
usually going to do a focused treatment just to a smaller area. And this is kind of a universal trend
to less radiation dose to a smaller volume. Same thing in lymphoma. You want to treat
just the enlarged lymph node and not the entire lymphatic axis. So it's the same idea where
you're trying to minimize side effects. So whole brain, we still use it in specific cases
like for example, small cell lung cancer. part of their regimen is going to be once the primary has been treated, if they have a complete
response in the thorax, prophylactic cranial radiation, only for small cell PCI, 20 gray,
five fractions been done forever, shows an advantage to have lower disease.
How much of a reduction in CNS meds?
It's a lot. I think it's probably 70, 80% reduction in CNS failures because they all fail there otherwise.
Small cell, they just all do that.
And at 20 grade, they really don't have too many side effects.
But again, of course, the caveat is always extensive stage small cell lung patient isn't
going to have a long-term survival, but at least they won't fail in the brain.
It's a quality of life issue.
I'm sorry.
This is done with every small cell patient,
no matter how early it's caught.
If they have a complete response to primary treatment. Yes. Basically,
I read it. Maybe there's some nuances, but for the most part.
Okay. So what's a gamma knife?
So gamma knife is instead of using a linear accelerator,
it's actually using cobalt 60, like I described earlier,
but you have multiple small sources that can actually be used very high
resolution cobalt essentially.
So you're doing the same thing, but instead of using a linear accelerator based treatment,
it's using cobalt.
So is that used anymore?
There still are centers that use it.
It still works very well for what it is, but the focus is very narrow.
There's a lot of children's hospitals and all that I think are still using it, but the
linear accelerator, which is abbreviated LINAC, the LINAC based stereotactic radio surgery
for the most part has taken over from that because it can do all the same things and also have more flexibility to do more than just CNS. St. Jude's hospital has a fantastic PDCNS program and they still have, well, it's been a while now, but they did have a gamma knife last time I checked.
So we've talked a lot about radiation. We've touched a little bit on the idea of radiophobia, but maybe let's use that as a
bridge to talking about using radiation to enhance tissue as opposed to eradicate a subset
of tissue.
Does it stem from nuclear accidents?
Is that largely where radiophobia comes from?
I've done a deep dive into this this year, which goes along with all these benign cases
that I'm treating now.
They're essentially arthritis tendonitis, which we'll talk about.
And what's really interesting is that this radiophobia is largely a US-based phenomenon
because the first cases, first of all, x-rays were discovered in 1895 by Rentkin.
In 1898, there was the first case described of actually radiating both arthritis
type things or ankylosing spondylitis or other arthritis and also tumors. Even back then
we had no idea how it worked, but there were cases pre-1900 that were already being used
for that. And then in the subsequent now 120 plus years, we have this divergence where
Germany and the UK, all of Europe really, are using radiation routinely for arthritis and tendonitis. But in the US, it seems to be a basic nuclear
phobia, the Cold War like you mentioned. But another thing that's been talked about, there's
a guy named Jason Bechta that has a really good podcast on the subject. He's out of Vermont.
Standard Oil, the Rockefellers and all actually had a massive lobby group that were actually
actively promoting
oil over nuclear power plants.
The amount of spread went from just the energy industry into just the general zeitgeist of
the entire country.
And so at that time, the radiophobia just caught on and it was of course bolstered by
World War II and seeing what happened in Hiroshima and Nagasaki.
And then on top of that, you've probably heard about the radium dial workers.
There was a movie, it's actually called The Radium Girls.
These are essentially women in the 1920s that were using radioluminescent phosphorous paint
to paint the watch dials.
Being a watch guy, you'll probably appreciate that.
But that was the only source of illumination they had.
So in order to keep the brushes very fine, they were literally dipping it in the radium
paint and then after each brush, they were licking the brush to keep the tip real fine. And so they were ingesting bits of radium.
So there were a number of cases where they ended up – the radium is metabolized like
calcium. So it was actually incorporating into the mandible and they were getting osteoradionecrosis
of the jaw and things like that. So all of these different phenomena added together became
a big deal because prior to that, people were using radiation for all kinds of crazy things.
It was in suntan lotions and waters and there was something called vigoridine that they
were using for ED that you could topical salves that had radiation in them.
It was literally no end to it.
And then when all this sequela started to come out that, hey, maybe this isn't such
a good idea, that's when things took off.
But now that we look back, the reality of it is,
is that a lot of that was really overblown,
even so much so that those radium dial painters,
which we hear about this from day one
in our residency training,
there was only a small percentage,
like I think 50 out of 1,500 roughly,
that actually had toxic sequela.
So most of them didn't.
Is there a way to quantify how much exposure
they had to radiation?
And that's the thing, you know,
they've looked at different ways, but there have been
some basic ideas.
It was, again, we're talking about at that era was probably a couple of millisieverts
to that particular area, but it was daily for decades.
And so part of the reason why, if you actually look at the numbers, it was probably a super
high exposure.
When you spread that out over such a long period of time, that's sort of the general
trend like I mentioned earlier.
It's not just the dose, it's the dose over time. The denominator matters a lot and so that's
why most of them actually did very well. They even used to use radium internal nasal applications
in the 19, I guess, 1920s to 1940s, essentially a radiation equivalent of a tonsillectomy
or adenoidectomy. And it was done in something like a half million to two million children
in the US and even in the armed forces. It was done routinely something like a half million to two million children in the US and even
in the armed forces.
It was done routinely back then.
And there's been very few adverse sequelae that were reported.
I don't even know what the dose was, but it was high.
So there's a lot of cases where the exposure based on our 50 mil to sever it rule we talked
about would just make people fall out of their chair.
The actual reality of it is, is that many times the actual end results aren't as bad
as we had expected.
Again, hearing you say this, Sanjay, the listeners are going to be thinking, what?
Yes.
Because we're all so brainwashed into believing that radiation is horrible.
Right.
Right.
I can tell you so many stories.
You know, I got patients who I've had to treat.
I had actually had a guy who was involved in nuclear testing at Los Alamos in the 1940s.
He's passed away now, but I saw him in his 80s.
So this was in the early 2000s.
This was 60 years after that.
They had very little monitoring back then, but he was close enough to feel the heat from
a thermonuclear bomb.
And by the time I saw him, he had had thyroid cancer as you would expect.
He'd had one or two lymphomas.
I think I ended up treating his prostate.
So he'd had at least four or five different malignancies but the guy was as functional
as most 80-year-olds are.
The guy was still walking and talking and doing just fine.
And it actually seems that when you look at the population studies that were done outside
the blast at Hiroshima and Nagasaki, when of course the initial concentration, everyone
dies from the thermonuclear energy.
But as you get several miles out, not only are the cancer rates actually roughly the same as the background, you actually see,
again, evidence of hormesis where you have some patients in whom, or maybe not hormesis,
but some sort of radio protection where you actually have lower rates of leukemia and
thyroid cancer when you get a few miles farther out than you did in the general population.
So it's all very much dose dependent, time dependent, but I think the
human body, we're evolved really to handle this to a larger degree than we
realize because again mammalian DNA, we came from the background of the animal
kingdom where there was tons of exposure from natural cosmic rays and whatnot and
then our predecessors had to be able to survive, our DNA had to be somewhat
resilient in order to get to this point. I think it's more resilient than a lot of people give it credit for.
So this first came up maybe a year or two ago when I was lamenting, it must have been
two years ago I guess, because I was kind of lamenting my Achilles tendon, which I wouldn't
say it was injured, I just had a little bit of tendonitis.
It was just bugging me a little bit.
You and me both, brother.
And so it was through that discussion
that we got into what we're talking about now,
which seemed crazy.
I just decided I didn't feel like driving to Houston
all the time to undergo therapy,
and my Achilles is fine now.
I just did sort of standard therapy.
But I've sent a few patients to you
who have had similar injuries,
both high hamstring, tendonopathies,
Achilles tendonopathies.
So talk a little bit about this idea.
How prevalent is this type of treatment in Europe?
How prevalent is it here?
So prior to probably 1970 or maybe 1980,
it was very prevalent even in the US.
It was very widely done.
Everyone, I talk to them about it now.
It sounds like I'm doing something experimental and radical.
But if you go over to Germany,
again, going back to ankylosing spondylitis papers in 1898, they do something like, I hear
between 20 and 50,000 patients a year in Germany. It's mostly observational
studies, there's very few randomized trials, but low dose radiation for
tendonitis, osteoarthritis, plantar fasciitis, all the itidies you can think
of, bursitis.
A low dose of radiation has a similar anti-inflammatory effect to what you would get from a cortisone injection.
Unless to find the dose.
So now we're talking about very low dose, meaning 50 centigrade or 50 rads
given six times over two weeks.
So three gray, 0.5 times six is three gray to the affected joint
using a very low energy machine.
So this is especially in the case of someone who's got a hand, you're talking about electron
beam radiation.
Wait, sorry, let me just make sure I got that straight.
You were giving 40 gray total to a breast.
And now for the Achilles, you're giving how much?
Three gray, six fractions of half a gray each.
So all six fractions combined is about the dose of one fraction for a typical cancer.
That'll give you the idea.
And giving it in a superficial fashion where especially if it's a hand, you only have a
couple centimeters of thickness, so we use what's called electron beam therapy.
The same linear accelerator when the electrons go and hit the tungsten target and make photons,
if you remove the tungsten target, you just get direct electrons.
And electron energy can be modulated to where you can treat a superficial skin cancer, you
can treat a knuckle, I can treat a temple squamous cell and not go into the brain.
In the old days, before they had linear accelerators, I told you this goes back to the turn of the
previous century, they had ortho-voltage machines.
And these basically created kilovoltage X-rays, not the mega-voltage X-rays we use now.
All they could do was superficial stuff back then.
That's where it works very well.
The dosage has changed tremendously, but these days the biggest data comes out of Germany,
half a gray, three times a week, Monday, Wednesday, Friday for two weeks, just to the affected
joint.
It has an anti-inflammatory effect very similar to either a cortisone shot or an NSAID.
How many weeks is the course?
Two weeks.
Monday, Wednesday, Friday, six treatments.
The protocol is what we typically follow, the German protocol is to wait 12 weeks.
You usually see, depending on the joint, somewhere between a 60 and 80 percent success rate where
the pain is, if not zero, at least markedly decreased.
And then after 12 weeks, the German protocol allows for a retreatment.
And at that point, you get up to 90 plus percent success in terms of reducing pain.
And this is for joint arthritis?
Arthritis, tendonitis, bursitis, plantar fasciitis is a really big one now that we're doing a
bunch of.
I've done probably close to 70 cases across the board just this last year.
Which is kind of remarkable because anybody who's had it, you know, I had it once back
in med school exactly 25 years ago.
Did you get it treated or was it just-
I mean, I just went to PT and rolled on golf balls and did the usual thing, but it took
months to get better.
It's such a big deal.
So you're saying of the patients that are coming to see you with plantar fasciitis,
how many of these patients, how long have they been hurting first of all?
Many times for years.
In fact, my biggest cohort recently, which is still relatively new, I haven't done thousands
of patients like I can speak from decades of experience with cancer.
We're talking about dozens to hundreds.
A couple of surgeons that were having trouble standing and operating.
They literally couldn't perform their normal duties.
Six treatments to the fascia and they're walking like nothing ever happened.
How long after the last treatment did it take?
In the case of plantar fasciitis, it was almost immediate. Within a week. I have other cases,
especially when we do like knee arthritis, if there's a lot more pathology going on in a knee.
I treated my own Achilles, which I can tell you about. Took two months or so. I was almost
wondering if it was going to work or not. I was my own first patient. Before
I offered to anybody, I treated my own Achilles.
Like a true doctor.
Physician heal thyself, right? And so I literally jumped on the table because a colleague of
mine had posted about it that he did his, he's a radiation oncologist in Florida. He
tried it out. And so I was like, you know, I have the machine. I know this should work
in theory. We just never taught about it in residency. And I look at all the German data,
there's tons of it. It's like, why do
we not do more of this? And sure enough, I'm actually my own personal case
control study because I did steroids and PRP in my left Achilles and then later
on this past year did the right side with only radiation and no steroids and
now I'm walking without a limp. You obviously did the other side. No, I know
actually I didn't. The PRP actually finally did. So I had two cortisone shots
and PRP in the left and then a year later radiated the right.
Both of them are holding up pretty well so far.
Got it.
The other area that is of huge interest for me at least is the very, very high hamstring
tendinopathies.
So that ischial tuberosity pain, very, very common for runners, seems to be anecdotally much more common in women than
men based on pelvic anatomy.
I've only treated women for some reason with that and they've all had tremendous results.
It's still the same protocol.
It's the three gray over six treatments over two weeks.
Exactly.
For any type of an arthritis, you're essentially lysing all the macrophages and you're eliminating
that cytokine storm that would have normally resulted.
It's very similar to what cortisone does but the
difference is it seems to be based on the study we've seen this much longer
lasting than a cortisone shot. Not to mention the fact that you're not
necessarily violating the capsule and in the case of an Achilles tendon you run
the risk of rupturing it with multiple injections so totally non-invasive. You
just get up on the table most of my patients go right back to whatever they
were doing and many of them are actually quite athletic and they don't take any breaks during treatment.
They just do what they do. They're still working out.
Is there any literature looking at this for spine injuries? By injuries, let me be clear what I mean.
So when you think of all the times that people are getting spinal epidurals for irritation of
spinal nerves, herniated discs, things of that nature. Is
there any reason to believe this could have any efficacy there if indeed there's some
efficacy which there clearly is due to spinal injections or epidural injections?
There is some data for spinal osteoarthritis specifically. It's less robust than all the
extremities. I've actually done a few cases and it's actually worked quite well. Medicare
actually does reimburse for these things.
The issue with the spine is it's such a multifactorial area where if you've got a nerve root compression
or a disc issue, I can't fix that part of it.
But there is limited data that I've seen out of Europe that did show some degree of relief,
but it's not the 80 to 90% that we quote for the extremities.
It's probably half that.
Adam Felsenfeld Interesting.
And do you think it's because of patient selection?
If you knew you were dealing with a facet arthropathy, that should in theory respond
well.
It should, and it does.
I've done a few of those.
SI joints seem to respond quite well, and that's in the literature.
That's included.
So hips, SI joint, lumbar spine, those sorts of things, they are described, they're just
not as routinely treated.
There's not as the level of experience
that we do have with everything else.
But your ability to center the beam is remarkable.
You're using the same high fidelity equipment
you're using for Radonk.
Same equipment, 100%.
You can hit a P inside if you want to.
Well, you could, but that's exactly what you don't wanna do
because you're basically trying to eliminate
all the macrophages in the region,
so you're actually better off treating larger fields.
I see.
So it's the exact opposite of what we do with cancer therapy. And because the dose is so
low, you're not really gaining anything by being too cute with the small fields. You
actually want to treat the region. It's like almost like an abscopal effect for the whole
area.
So if you're treating somebody that comes to you and they've got an Achilles tendinopathy,
usually there's a point of maximum tenderness, but it usually hurts up and down the whole Achilles. How
do you position the beam and are you literally hitting from mid-calf down to heel?
From the insertion in the gap. In my case, part of the inferior gastroc was painful too.
So I treated that entire region, the field was probably about that long, all the way
down to the calcaneal insertion and even onto a little bit of the plantar surface of the heel.
Because again, when you're talking about these super low doses of radiation, if it was a
sarcoma of that area, I'd be treating a tiny little area.
But over here, we want to treat the whole region.
Most radiation oncologists, we talk to their experience treating an extremity, it's usually
for a sarcoma.
So that's a whole different ballgame where you're giving 60 grade to someone who's had a sarcoma in their leg or something and you
have to worry about things like edema. You can have lymphedema of the distal extremity
if you've radiated the whole circumference of a leg or something like that. But with
these low doses, it doesn't affect any of that. So you do treat large fields. It'll
be from the insertion of the Achilles all the way down. If it's a plantar fascia, the
entire plantar surface of the foot. Another thing that we see a lot
which is not arthritis is Daputrin's contracture and also the foot equivalent which is Lederhose
disease. I had to look that one up. That was a trivia question. But it's essentially
Palmar or plantar fibrosis. And so radiation works well there as well, very well documented
and that requires a higher dose though.
You're talking about three gray per fraction, five fractions, and then you do it again after
a few weeks.
So 15-15.
15-15.
It's almost cancer.
Yeah, almost palliative cancer, not a high dose, but again, that's for fibrosis.
Keloids, it works very well.
You get teenagers with big old golf balls hanging off their ear after getting their
ear pierced and things like that.
And so again, you're treating the fibroblast.
In that case, you use four gray times three treatments of 12 gray, relatively large dose
per fraction.
And you can totally protect the brain.
Totally, 100%.
I've seen obviously patients with debilitating keloids.
What does it look like after the treatment?
So the treatment has to be adjuvant after a surgical resection.
If you just radiate an intact keloid,
it's not going anywhere.
Because you don't have the DNA mechanisms
of a weak cancer cell that can be wiped out.
So it's kind of like doing a lumpectomy.
But obviously, if the surgeon just did the resection,
the keloid's coming right back.
The fibroblasts go crazy and they roar right back.
So in order to do it right, a lot of people do it
and they have multiple recurrent keloids
even after treatment. You have to do the first
treatment the same day as surgery. So you're just not letting those fibroblasts
get a chance to have any sort of a foothold. So I would literally arrange it
with the dermatologist to do the resection, send them straight to me so we
get the first dose in that day. And ultimately the cosmetic outcome is as
good as if they didn't have radiation. You'll see the scar wherever it is. We
get sometimes kids that have had acne scars all over their chest that have these bumps everywhere and they were
all resected flat and you radiate them, they just stay flat. You don't see any sort of
dermatitis from radiation.
I think what's amazing to me is I just think there's too many people that don't know this.
I think there's too many people that are walking around suffering either from something that's
cosmetically upsetting like a huge keloid, especially on a visible part of their body.
Obviously everybody listening can relate to some nagging injury, tennis elbow, golfer's
elbow, Achilles tendonopathy, hamstring tendonopathy.
These things nag for years at times.
06.00 The data was showing some like one in seven people in the country are afflicted
and the socioeconomic costs are massive.
And there's also going to your whole quality of life and longevity bias.
I mean, we're talking about something that can really affect someone's ability to exercise at all,
and it can lead to exacerbation of other medical problems.
You know, I was very encouraged to hear you say a second ago that Medicare is covering some of these things.
And private insurance too, yes, for the most part.
Now, a lot of times, because it's relatively new, I'll have to get on there and do a peer-to-peer with the company,
but I've had no rejections at all.
Even for the spinal ones, which are a little bit,
there's less robust data, but I've gotten everybody covered.
So I think the question is, do we need more radiation oncologists?
Because how are you making room in your practice
to treat these patients when your cancer patients are probably
ringing you off the hook as well? That's a big reason why it hasn't caught on. I
think there's a component of just you've got eight hours or 12 hours a day that
the linear accelerator can run. We were busy with that. But one of the things is
that because unless it's a deep hip or something for most of the superficial
for all the other joints you can use one of those old style ortho voltage
machines that I mentioned earlier like what they use in Europe
They still sell those here
There's a company called extra that still makes them and they're perfectly acceptable for all the joint stuff except for the very deep ones
Like maybe a SI or hip joint
But you could have a small center set up and those types of machines don't even require the shielding because the energy of the photons
Is very very low
It's highly underutilized at this point,
and the Europeans have shown us the way.
It clearly works, and America just has to catch up.
Yeah, this is definitely an area
where we are way far behind.
But it's truly exciting.
I mean, I love treating cancer patients.
It's really personally very rewarding
to tell someone that they're NED,
there's no evidence of cancer in their body anymore,
their PSA is low, their mammograms look good.
That's what's kept me going this long.
But the amount of immediate relief we're seeing
from all these inflammatory conditions,
right away, it's a night and day patients come in one day,
they can't grip a doorknob or lift a gallon of milk
out of their fridge.
And after six treatments, they can,
and they're just, they think you hung the moon.
It's an amazing thing.
I'm hopeful that people listening to this,
so if there's a million people listening to us
have this discussion, and one in seven of them,
let's just say one in 10 of them,
at some point in the next couple of years
are gonna experience the type of injury
that would benefit from this.
How can they go about finding,
you know, they can't all come to Houston to see you.
I'm trying to get you to move to Austin,
but regardless of where you end up,
they can't all come and see you.
You already said the answer.
I'm just gonna move to Austin.
We're just gonna do this full time
and drive cars on the weekends.
No, but seriously, there's an uphill battle
because as I've been going out
and trying to get the medical community in Houston aware
of it, you have a lot of pushback
because number one, you've got orthopedic surgeons,
podiatrists, hand surgeons who are looking at this
like number one, what are you doing?
What are you talking about? They look at me like
I'm crazy and number two is like even if this actually works the concern is
someone's got maybe a knee arthritis that's been nagging them and maybe
they're gonna need a total knee at some point. Their concern is wait a minute is
this taking surgery off the table? Which it's not by the way because it's such a
low dose. There's been plenty of cases of surgery after the radiation. It's not an
issue or you're taking away from like when you had your plantar fasciitis
I'm sure the podiatrist build something for when they do those extra corporeal shock treatments and steroids and whatever is it's a different
Paradigm that would potentially be taking away a lot of doctors are very negative about it
Most of them at this point are very negative, but I think that tide is gonna turn just like anything else
It's just gonna take a lot of's just going to take a lot of education, a lot of time, a lot of talks like this.
Well, I think at the end of the day, look, I don't think patients will have any patients
for turf wars.
Yes, that's true.
Right? And so if I'm a patient, every doctor needs to be a fiduciary. They need to put
my interest ahead of their interest.
And what's interesting is that I think you can have your cake and eat it too. The reason
I say that is many times this is an adjuvant for other things.
So if you've got a podiatrist that's doing all these PRPs and other things, I'm actually
looking at starting a protocol.
I just treated a nurse in Houston who's a NP who does stem cells off label, but she
does them routinely, has quite a big practice.
We're going to look at maybe you can do radiation with adjuvant stem cell treatment because
it's such a low dose.
This may be the sort of combined modality thing down the road that we
haven't really approached where there may be options to do other things still.
But again I mean for Medicare to improve something is a huge bar. How are you
getting Medicare to approve this? Are they basically acknowledging that well
hey if Europe's been doing this for a hundred years and it's working like
what's their bar? That's what it looks like you know I've got the C61 which is the
ICD code for prostate cancer which is in most of my patients. We got the
osteoarthritis codes now. They just go right through typically without any sort of problem.
Some of the private insurances, you have to get on a peer-to-peer call, but when I, all I literally
will do is quote them a couple of the German studies. Unfortunately, we got a little bit of
a setback because there's only two randomized clinical trials. They're both heavily underpowered, poorly run studies, just not well done. So that's been a little bit of a setback because there's only two randomized clinical trials. They're both heavily underpowered, poorly run studies, just not well done. So
that's been a little bit of a setback. And the randomized data may never come
just because of the nature of this sort of thing. But having said that, that's not
the obstacle anymore. It's really just public awareness. And like you said, just
like a guy that doesn't want a radical prostatectomy and wants radiation
therapy for his prostate, he's got to be his own advocate. And the data is out
there, the information is out there.
There's a couple of big Facebook groups
and one is only Dupuytren's patients.
And they literally will post up,
I've got this big nodule, what do I do?
My surgeon wants to cut on me.
And so there's actually a whole network now.
So there's a lot more of that education going on.
They've got big PDF files of doctors all over the US
that will do Dupuytren's radiation.
So Dupuytren's is a little bit more commonly accepted,
but as I'm slowly talking to these folks, they're gonna migrate into their arthritis space as well. over the US that will do duputrens radiation. So duputrens is a little bit more commonly accepted,
but as I'm slowly talking to these folks,
they're gonna migrate into their arthritis space as well.
So I think it'll come and the general public
has nothing but great positive outcomes from this.
Do we have a sense of the durability of this?
So for example, I have a little bit of osteoarthritis
at my AC joint on the right.
It barely bothers me, but every once in a while,
if I'm doing something really violent,
overhead, reaching for something,
or I play a ton of football with my son,
it'll bug me for like three weeks.
I'll take a little bit of Advil, it's fine.
If I did a treatment there, would it be done,
or am I doing this treatment annually?
How would it work?
There's a lot of variability there,
depending on what the actual anatomy that's causing it.
If it's literally just a straight up
osteoarthritis case with no physical structural issue,
I've seen cases, now again,
I've only been doing this about a year,
so I don't have the 25 years of experience I did with cancer,
but I've talked to,
there's a couple of doctors who do this routinely.
They've been doing it for 20 years in LA.
One of them treated his own neck, shoulder, and spine.
I think he's at 15 years out,
anecdotal obviously, but never had to retreat himself.
Typically, the German studies allow
for two treatment, two retreatments.
Because the dose is so low radiobiologically,
I don't see any reason why you couldn't do it.
I don't know about annually, but maybe every few years
or something like that, but there seems to be
a fair bit of data that a lot of patients
who don't have others struck, like a knee that's bone on bone,
it might only last a month or may not even work. But for the other ones, like the hands and all,
it seems like it's certainly longer lasting than any sort of cortisone shot. But I think months are
very reasonable and probably years for most people. Now, what about non osteoarthritis,
like rheumatoid arthritis and things like that? Is there any reason to believe that this could help
with the debilitating injuries that those patients experience?
So I've done three cases of rheumatoid arthritis
and one guy that had a gouty arthritis as well.
Because again, it's a systemic disease.
I'm not going to pretend to be able to cure that
with a local treatment.
But to a single knuckle that's driving them nuts,
it's still an inflammatory process.
And yes, it works great for that.
So if a patient has rheumatoid arthritis,
where they're really experiencing
a lot of deformation in the hands,
you think you can help that patient
with the local part of it?
Yes, it won't reduce the deformation necessarily,
a lot of that is long standing.
But if they were treated early enough
in the course of the disease?
Yes, I think there was no strong data to support that,
but I don't see why it wouldn't work personally.
And it definitely, from a purely palliative standpoint, just to reduce pain, it does work. You have to manage their expectations.
What are some other examples of where this could be used, at least in your experience so far,
in terms of reducing reliance on NSAIDs or opioids or other things like that?
Tennis elbows become a big one, doing several of those.
How far down the arm do you irradiate?
I base it on where the patient patient, if they palpate,
if they're getting pain down into the brachioradialis
and if it's radiating further down,
I'll treat a larger field.
Because again, there's no reason not to.
Bigger fields are better, no need to be.
And again, it's just six, three gray.
Three gray, so, and again, that's three gray locally.
It's to an area where there's no vital organs nearby.
The total body dose is negligible.
It's like getting a CAT scan initially
for the rest of the body.
So I would treat definitely the joint capsule and
a little bit of the distal humerus and the proximal radius and whatever else.
But if it's hurting larger, I'll just treat a larger field.
In that case, we use opposed lateral beam.
So the patient will just lay there.
The beam will come in from one side and rotate around from the other side and
we treat them both.
Because that way we get the same type of homogenous dose we do with our cancer patients. I've actually done
several piano players that have Dekuervane's tenosynovitis in their
wrist because when you're stretching to play those notes, I'm a musician as well,
all my musician friends are coming to me, the wrist pain is going away very
quickly. My biggest patient cohort so far are former patients because they don't
have radiophobia. They're like, I've been through 80 grade of my prostate, this is
a joke, I'm bringing my wife with of my prostate. This is a joke.
I'm bringing my wife with me.
And half the times the wives sit there for their daily treatment anyway and they start
chatting in the lobby.
So we do the wife's hand the same time we're doing the husband's prostate.
And for the most part, the hands, the wrists, the elbows, it's very rapid.
In the case of the tendonitis like my Achilles, it was a couple of months, but that's not
outside of the window of what we've been conditioned to expect from all the German studies.
So it can be not as immediate of a relief as a steroid shot, but it does seem to be
more durable.
Yeah.
We failed to mention at the outset that you're also a remarkable musician.
How much do you still play the drums?
I got a couple of, actually a couple of doctor buddies.
We get together in jam every week or two, and one of them is actually a guy now who's
actually got his own YouTube channel and Spotify.
And he was actually a professional musician before becoming a cardiologist.
So we may actually start touring again, but back in the day, we had a full doctor
band, a full 70s rock cover band called ultrasound.
Those are the good old days.
It used to play, you know, journey and rush and led zeppelin all day long.
Yeah.
I was commenting recently on a podcast, how much I regret not seeing Rush during their
last tour.
Again, because of the GBM.
Tie it back into what we're doing here.
Neil was a genius.
So greatest drummer of all time, are you going with Neil or are you going with Bonham?
Neither, because I went to college here at UT and that opened my entire eyes up to the
world of jazz.
So the jazz drummers can all drum circles around those guys in terms of pure technical ability. But yeah, feel, rhythm, not necessarily being
able to wow people the way the jazz guys can, but yeah, Neil and Bonham are both right up
there on the rock side of things.
Would you put them at the top of the rock list?
Yeah. I would put Neil first. I'm just partial to Rush. And a lot of that has to do with
their music, not necessarily. Now, Neil was obviously an innovator, but as a 16-year-old, I'm sitting there trying
to imitate every single note on his drum solos, everything like that.
Neil number one, Babanum and the New Generation Rock guys are incredible.
The guys that grew up with Neil as an inspiration, you've got 12-year-olds who can do this stuff
in their sleep and then all these math metal bands.
You got Dream Theater and things like Animals as leaders.
Some of these guys are doing things.
I pride myself as a drummer on being able to analyze the music really well.
It's getting to the point where it's almost more math than music.
It's so intricate, the modulation of the time signatures and things like that.
It's actually getting beyond where even I'm having trouble understanding it now.
But these guys-
And can you appreciate it from an auditory perspective?
Does it get too technical where it's hard to appreciate and distinguish?
That's a fine line because when you think about it, music is just math with emotion
added in.
And it gets to a point where some of it is not appreciable anyway, at least not to me.
Some of these guys love it.
But that's where the jazz side comes in where it's all about feel.
But even the jazz guys will be extremely talented in terms of their ability to feel the beat
and have it be pleasurable to the ear,
but they're doing such intricate things.
And when you can balance those two things out,
that's heaven as far as I'm concerned.
When you can have the emotional side
and also have you technically challenging
and not just playing a straightforward.
The straightforward stuff is great too,
but it gets a little bit tedious sometimes.
So we met actually driving.
AMG Drift Academy Academy I think it was.
Yeah, which by the way not to crap all over it, I ended up doing it because at
the last second I got a phone call from my driving coach and he was like hey I'm
doing this AMG driving school and they got an extra spot in the advanced drift
school do you want to come? But I'd already been to the Drift Academy with
my friend Josh Robinson I was like yeah sure I'll go was like, boy, this is the last time I ever
do one of these schools.
Josh's school is 100 times better.
It doesn't compare.
It's not even close.
If you want to learn how to drift,
yeah, if you want to learn how to drift,
you go to the Texas Drift Academy.
I want to go to Minnesota with him and do that ice class.
Are you going on this run?
I don't know if I'll be able to make it or not.
I'm trying to.
OK.
Yeah.
Anyway, we met.
But it was totally random.
Well, I knew who you were, because I'm a member.
I've been a follower for years. I was like, that's Peter Ratti over there. So luckily, we met, but it was totally random. Well, I knew who you were, because I've been a member, I've been a follower for years.
I was like, that's Peter Ruti over there.
So luckily we got paired up in the same group,
and that's kind of where it started.
It was totally random.
I was actually just, it was a last minute thing.
That was actually a level two,
so I was like, you hadn't done the level one.
So I was like, man, how did this guy get in here
without even doing the level one?
So having done that, I agree, especially those cars
with the automatic transmissions and the turbo lag,
not the greatest for drifting.
Yeah, yeah.
You've been kind of a car nerd your whole life.
What is it about cars that has you as excited as you are?
You know, I think whenever anybody asks me that, I kind of think about it in terms of
every three or four-year-old boy is enamored by cars, but normal people just grow out of
it and some of us never do.
My dad certainly liked cars.
He taught me how to change my oil and whatnot, but he wasn't a fanatic like I am. So it just kind of started there and
then it got to a point where like my parents will tell you the story. I was that four year
old who could tell you at a car driving by if it was an Oldsmobile that had Cadillac
hubcaps on it. Like how the hell does this kid know this thing? Yeah, I don't know where
it just kind of clicked. Over the years, it was always just a nice release. I guess being
a mechanically oriented type person, I think if I didn't do medicine, I would have done
engineering, which is why it's so impressive.
What did you study in college?
I was actually biology.
I did a BA with art, so I did a lot of jazz studies at UT.
So I was a music guy.
Engineering just seemed fascinating to me.
I was always interested in medicine from day one.
But I think that really the mechanical side of things,
like knowing that every car's five gear ratios
and what their torque converter lockup is
and what their horsepower and torque is.
It's just-
And what posters of cars did you have on your wall?
The same as everybody.
Actually, no, because everyone had a Countach, right?
I never had a Countach.
See, I had a Countach.
What did you have?
I mean, they're cool.
I would have like a Callaway Corvette, Miami Vice, Testa Rosa, 928, which I'm almost done
with my old 928, getting it back on the road.
More the domestic stuff and the stuff that's more attainable,
Fox Body Mustangs, the five liter Mustangs of that era
are really cool.
C4 Corvettes, back in that era when they were state of the art.
I mean, I loved watching Knight Rider,
so I thought Pontiac Firebirds were super cool.
It's funny, I just bought my youngest
his first Lamborghini poster.
He's mostly got sports posters on his walls,
which is great, but I was like,
you gotta have like a Lamborghini poster,
so let's go pick one out.
So we scrolled Etsy for hours,
because I wanted to figure out what his taste was.
Did he wanna go retro?
Did he want like a Countach?
But in the end, I think we went with,
I can't even remember now, actually, we just ordered it.
I think we went with an Huracan.
Huracan, a modern car, great car.
Yeah, it was gonna be an Aventador or a Huracan.
But get the color right and get the angle right.
Have you driven a Countach yet?
I've never driven a Countach, have you?
I have, it's one of those don't meet your heroes
kind of things.
It's cool, but it's kind of a POS too, you know?
The bar has moved a long way since then.
It's for the experience.
I mean, you clearly don't expect the bar has moved a long way since then. It's for the experience.
I mean, you clearly don't expect it to perform like a modern car, but even if you judge it
for what it was in the 80s, is it still not enjoyable?
It's enjoyable because of the 80s campiness in retrospect, but even compared to its contemporaries,
you look at an 80s 928 Porsche or even a Testerosa, those cars are beautifully driving long distance
cruisers, super comfortable, compliant suspensions, you got good ergonomics.
The Countach is so awesome because it has none of that.
It's awesomely bad.
Yeah, yeah.
I've driven a Testerosa.
Have you ever driven an F40?
I have not.
I would love to have ridden in one, but I haven't driven one.
It's a race car.
You're basically just sitting on the ground with a carbon tub around you. So if you could have three road cars, but you can't sell them. You're not making the
decision based on economics. What are the three you want?
Three road cars, not daily drivers. Are we talking about just three cars that's all you
can have in your garage?
No, no, no, no, no. These are your three Grail cars.
Okay. I would probably say, man, there's too many to choose from,
but to go with, it's gonna sound like a cliche,
but McLaren F1, I mean, how do you not pick that?
If I could only have one, that's the one I want.
It's gotta be there.
I sent you the picture of me sitting in that one.
Yeah, I was jealous, I was jealous.
Oh my God.
That would have to be number one,
but then there's at least 10 that I could pick from,
be happy, but I would probably say,
and one of them is one that I have a lot of experience with, the Ford GT.
I just think that's one.
Gen one.
Gen one, one of the all-time greats.
I would probably pick stuff that's manual and somewhat analogs.
I'd probably have to say Carrera GT, Porsche Carrera GT with an NA V10.
They're unobtainable now, but they were reasonable of just a few years ago, and there's plenty
of faster cars out there.
A Carrera GT today is going for about $17, $18.
Ten years ago it was half that.
Yep.
And what's an F40 going for today?
It's got to be three.
I think at least.
Yeah.
I mean, six, seven years ago it was half that.
Yeah, it was half that.
Do you think this is a bubble or do you think these things are not coming down in value?
They're never making any more of those.
Limited supply, demand is never going to wane for those, at least.
I think when you look at other collector cars,
like some of the pre-war stuff, it's
going down because the target market is all,
unfortunately, dying off.
Those people aren't around and we appreciate that.
And that may happen at some point,
I suppose.
There's going to be a point where nobody cares about this.
We'll probably be long gone by then.
But the McLaren F1 is unattainable.
And there's so few of them.
That's in a completely different league than the other cars. But even like is unattainable. And there's so few of them.
That's in a completely different league than the other cars.
But even like something like the Ford GT, they made 4,000 of them.
It's not that rare.
Well, a few of them are gone.
A lot of them are gone thanks to, yeah, lack of traction control.
But still, I don't think they'll ever go down just because that era, I think the Gen 2,
the current Ford GT, which is a twin-turbo automatic car, will ultimately be eclipsed
in value by the old one, even though right now there's still more. They're almost double or triple,
but I think it's going to go the other way.
So, where would you put the 959 on this list?
We talked about that a little bit. It's right up there. The only downside to the 959 is
that it was so ahead of its time. That essentially is what a modern Porsche is now. So yeah,
it's super cool. You've got the 80s campiness, the looks,
but it's basically like driving a 993 turbo
for the most part.
It doesn't have that NA V8 or V10 sound.
It's a turbocharged flat six, like everything was after it.
At that time, there was nothing like it.
Did it have four wheel steering as well?
You know what?
I think they did.
It was so modern.
So modern.
Sequential turbos and even water-cooled
heads even though those were all air-cooled Porsches back then they managed
to water cool the heads. And now Kniep does a really cool version, the Restomod
version, but those never came to the US. I think you know about that right? It was
the Bill Gates rule. Did you hear about that? I did know about this. Say more. I don't know all the
details I should have read up but essentially he was able to get the gray
market to passage for these cars for some loophole. I don't know all the details I should have read up, but essentially he was able to get the gray market to passage for these cars for some loophole.
I don't know the details of it.
And only after that were they able to import them into the US.
Of course, now that they're older, you can get anything under a 25-year rule.
I like the oddball stuff like that that should sound available.
The 959, I would still put a click below the Carrera GT just because of that naturally
aspirated F1 drive V10 that just sings and the 959's motor doesn't have that level of character.
I'll tell you what's interesting about the Carrera GT, which by the way would be on my
list of three as well.
Most people listening to us now, if they're not car nerds, wouldn't spot a Carrera GT
if it ran over their toes.
Yeah.
That's like a bigger Boxster, right?
It's just like so-
They're like, what is that a Porsche?
What is that car?
That doesn't even look, it doesn't stand out at all.
Whereas if you saw a McLaren F1,
you don't need to know anything about a car
to know you saw something special.
For sure, for sure.
And I think the same is true with the GT.
The GT is absolute head turner, no matter what.
And the interesting thing there
is it's really based on a 60s design.
It was a tribute, but Camilo Pardo, absolute head turner, no matter what. And the interesting thing there is it's really based on a 60s design.
It was a tribute.
But Camilo Pardo, who was the designer for Ford, who basically reinterpreted it for the
21st century, kept that original character, but made it aero-friendly and was able to
use all these hard points from the old car, but make it modern and basically upsize the
car.
It's like 110% size of the original that you could actually fit two people in because the original GT40s were tiny.
And they apparently generated tremendous front end lift in Le Mans.
And the modern one, I've actually run the Texas Mile on an airstrip over 200 miles an hour. It's dead straight.
They did everything right without resorting to the modern cars with all the big wings and all the big downforce. It's just well balanced.
It is a beautiful, beautiful car.
OK, now of the modern cars, anything
that you really, really fancy, let's
define that first wave of hypercars in the 2015.
So when the LaFerrari, the P1, and the 918 came out,
which is 2014, 2015.
So 10 years ago.
They call it the Holy Trinity for some reason.
Yeah.
Golly, that was staggering, right?
It was.
So from that era forward, what do you fancy the most?
Those cars, again, at that time, I liked them more than I do now just because, again, the
hybrid technology is leaving those kind of... They're a little outdated now.
I think out of those three, I was personally, maybe I'm sounding like a Porsche fanboy,
but the 918 was just stunning.
Part of it was just the design, forget about the performance.
And it had an NAV8, high revving, bespoke to that car, not in any other platform.
And the electric component was just the gee whiz thing of the moment, which of course
made it ungodly fast.
But that NAV8 and the way the exhaust sticks out of the back. Well, that's why, by the way, I've got a friend who has all in silver, 959, Carrera GT, 918.
That's the Trinity right there.
That's a Trinity.
That's like having, you know, F40, F50, Enzo, LaFerrari, same sort of thing.
I mean, all of those cars were amazing, but since then, the interesting thing about that
era a decade ago was that was probably the inflection point after which performance doesn't matter
anymore.
Who cares?
We've saturated performance.
Who cares?
Your traction limited at this point.
Right.
And not only that, you can buy a used EV.
You can buy a Tesla Plaid that'll do 60 in two seconds flat.
50 grand, that'll smoke everything.
Tell everybody about the time you took your Tesla Plaid to Kota.
How long did it take you to smoke the brakes on that?
So when it was stock, one stop.
Incredible.
Make sure people understand this, because they don't know.
So that means you came out of pit lane, right?
So you're going up to turn one.
I didn't outlap, so I didn't outlap.
But the first coming down.
So the first hard brake.
First hard brake.
Is going into turn one.
Going to turn one, and my buddy was in an SF90, which is a thousand horsepower Ferrari
hybrid, which is basically the fastest Ferrari you could ever buy.
I was catching up with him in 20 and coming down the front straight, I caught an SF90
in my daily driver, but I nearly rear ended him because the car was able to stop just
barely for turn one, but the brake fluid boiled at that point.
The car was not designed to do that, unfortunately.
And what's interesting thing is you would say, okay, it's an electric car, it's heavy,
blah, blah, blah.
Other electric cars don't do that.
The Lucid, the Taycan, they actually have really good brakes.
But at the time, I didn't realize this because they had been advertised as being track ready
or at least able to run a – like we're talking about how it ran so good at the Nurburgring.
But the factory brake fluid is DOT 3.
I find out after the fact, which is low boiling point, just boiled it.
The car is designed for efficiency, low drag.
By the way, I didn't even use DOT 3 in my simulator.
Right?
I was running DOT 4 in the sim.
Probably boiler simulator.
Yeah, yeah, yeah.
So a 5,000 pound machine stopping from 100 and I probably did 160 on the front straight.
I bet more.
Yeah, well, that's about it. I think it was limited actually that time. I didn't have a track.
The amount of BTUs that you're trying to shed off of those brakes, just forget about it. So,
thankfully it had to be... So the brakes are fine if you put better fluid in?
Well, they're better. They're less terrible. But if you want to track a plaid, you're going to
need new brakes. Did I tell you what I did? I ended up having a full Wilwood setup put on the car. So,
all new rotors, custom ducting, Mike Dusoul, Dusoul Designs, actually he bought a plaid
for himself.
He's the guy that built the Z06 I'm driving now.
But he ducted into the front brakes, basically custom brake ducts.
That car is sealed.
The whole front end is sealed.
It's not meant for that.
It's meant to just be low drag.
So you weren't getting any air on them?
Nothing.
Nothing at all.
So he actually made custom ducting.
And after that, the car was unbelievable
because you could actually late brake
and do really well.
So what lap time can you do in a tripped Plaid now?
Here's the problem.
You can only get one solid lap
before it starts pulling power due to heat to the battery.
But my best was a 224.
And so that's at a 5,000 pound car that's no weight taken out.
This is a stock car.
Didn't do any mods to it other than just the brakes.
But you do one lap, just to re-answer your previous question.
I don't know how much time we have, but I'll just keep it brief.
That one stop, turn one, brakes gone.
Thank God I have regen, so I just literally nursed it.
But I was already, I couldn't turn off, so I go through the S's,
and I'm just 30 miles an hour, whatever I got down through the regen
is enough to keep the car from completely just going off the tracks.
30, 40, 50, so coming through 9, 10, coming into 11, again, I'm not on the throttle at all. I'm
just maybe going 40 miles an hour. But the regen is coming down the hill towards 11. The regen has
kept me from gaining any more speed. My right foot is on the floor. The fluid is boiled. So I had to
go wide in 11 into the gravel, completely around. And then, you know, that's when I found out about
all that and the McLaren Senna both taught me
where all those orange squares are spray painted
on the Armco where you can have the emergency offs.
So I literally went through the gravel,
came within inches of the Armco at 11
and then just hobbled in.
But then after that, the next time out,
we put dot four, put Castrol brake fluid in it
and changed the pads.
Then it was good for maybe a lap.
So then ultimately that still wasn't good enough.
So we did the big brakes.
Now I see guys out there with Teslas,
they're clearly not pushing as hard as you.
Or they're mostly model threes.
The model three is 800 pounds lighter.
It's not as fast, but it's a way better track car.
So I've got dozens of laps in model threes.
They do fine because they're not making a thousand horsepower
and they don't weigh 5,000 pounds.
They still will boil their brakes. But if you just do pads and fluid, that's actually a very desirable,
especially if it's a little bit damp outside, not much can keep up with you in a Model 3.
And autocrossers, they've won national championships with just coilovers in a 4,000-pound sedan.
That's where EVs have gotten. But just to answer the previous question, we did the brakes on the
Model S and then once that was done, the only thing that eliminated the brakes as the weak link
But the battery the cooling is still not there. So you've got guys spending tons of money
I actually was looking at doing a really heavily modified aero Tesla Model 3 like Randy Pope's drives
It'll only do a lap at coda such a high speed and high braking
But you can hot pit and go right back out and you can keep hot pitting but you'll never get a full lap time
But it'll do just fine if you do that hot pit and go right back out and you can keep hot pitting, but you'll never get a full lap time. You'll never get a full lap.
But it'll do just fine if you do that.
But the next gen cars, the Porsche, Taycan, even the Lucid Sapphire, now those cars, they're
just as heavy, just as powerful, and they can do it.
Have you taken the Taycan Turbo S out?
I did when it first came out in 2020.
And what'll that lap at?
At the time I was on stock tires and everything, probably a 230-ish, right around there.
I think I probably sent you that video.
At John Hennessy's track, I had the Taycan, the Lucid, and the Plaid all lined up on the
drag strip.
I'm in a 750 horsepower Porsche that can run 10s in the quarter mile, and the Plaid
and the Lucid walked away from me like I was on foot.
You just didn't have the traction control?
No, it didn't have the power.
750?
750 horsepower versus 1100.
How much does the Lucid have?
This was the old Lucid.
Now the new Sapphire Lucid has more, has 1200,
but this was 1100 and it's still a tenth or two
behind the thousand horsepower Tesla.
Because they all have great traction.
And they're all all wheel drive.
The traction is a non-issue.
All the same tire.
It's literally just power to weight at that point.
Power to weight.
So I didn't realize that.
So the Taycan Turbo S was only 750.
When you stand on a Turbo S and if there's a plaid next to you, he will leave you like
you're not moving.
That's like the Audi.
It's a super fast car in the real world, but that's why horsepower doesn't matter anymore.
But that was more horsepower limited.
The Taycan would happily do, and actually I had a Turbo before the Turbo S, which had
steel brakes.
Turbo S had ceramics, and even the Turbo would do it on all-season tires, the very first Taycan that came out.
This was in the early days when Porsche was,
VW was having to respond to Dieselgate.
You remember Dieselgate, that whole deal?
So they had to build these electric cars,
and they had to go to states that were CARB,
basically the California Air Research Board,
emissions compliant,
because of all the diesel penalties they had.
So the first cars didn't come to Texas,
they only went to New York. So I got a non-turbo S, a
regular Taycan, one all-season tires out of New York. And on steel brakes, Porsche
is Porsche. I mean it was squealing in the corners with an all-season tire, but it
lapped 20 minutes. No problem, brakes were solid. There's just something about the
German engineering there. But having said that, the Lucid is now equally good if
not better, despite being a brand new non-legacy company
who is again, not trying to build a track car.
But the Lucid Sapphire is faster than a Plaid now.
It runs eights in the quarter mile,
but it can actually track.
And even my old Lucid, which I was expecting to-
It can run eights in the quarter mile?
Eight nineties, yeah, it can crack in sub nine now.
It's several car lengths ahead of a Plaid,
which is beyond bonkers.
You have to warn passengers.
These cars now, you can't just accelerate on them.
You have to say, hang on, just put your head against the headrest before I concuss you.
By the way, we failed.
You very, very briefly mentioned it, but my favorite car post the Holy Trinity of 2014
and 2015 is, of course course the McLaren Senna.
The Senna, yep.
How does the Senna stack up for you and what was your fastest lap time in a Senna?
My best, again, the biggest limitation-
The tires are limited.
The non-GTR, the Senna GTR can probably, I've seen guys run like I think two flats in those
things.
I know a coach of mine had run a 208 just barely even trying, but the street Senna on
the Trofeo R, it understeers. It's really
just not meant for that. But it'll still, and it got tons of downforce, tons of braking,
but it just doesn't have the grip. So I think the best I did was a 215. And again, when
you're driving a car that value-
That's insane for a street car with street tires. That is insane.
But at the same time, I'm sure a pro could do better. I was still thinking, you know,
that Armco gets really close to a car of this value. It could be a really bad day. Where are you breaking into turn 12?
150, even on Trofeo Rs. McLaren doesn't want you to put slicks on it. And so I violated
all the rules. I ended up putting a set of Pirelli tires off the Ferrari Challenge cars
on it. When I first put it in, again, slicks need camber. You can't get much camber out
of a street center, which to me was the most disappointing thing. Whereas the GTR, you've
got four degrees. Even without camber, when I first stopped, which to me was the most disappointing thing, whereas the GTR you got four degrees.
Even without camber, when I first stopped on that back straight, completely stock center
with just slicks on it, at the 150 mark, I almost parked it in the corner.
It was incredible.
Even with the Trofeo R, to stop at 150 in a car, in a tire that drove me to Houston
and back, the bandwidth of today's tires, that's a whole nother topic.
It's incredible what even an all season Michelin
can generate at one G, one G is nothing anymore.
All my old car and drivers, I have a library
of thousands of magazines,.8,.9 was a huge deal
30 years ago, now you got minivans that do that
and even all season shod sports cars that are heavy
can do that on a regular tire.
The chemistry of these tires these days is unbelievable.
Yeah, and the Pro Mazda, we're 2.3, 2.1.
Yeah, right.
I mean, that's just-
And that's not even on a Pirelli.
I'm a cheap guy, so I run hard.
AMG GT3, I was running Handcooks,
which would at least last me two weekends.
And even then, that car was running
two 11s on Handcooks with just me driving it.
So the Pros are running faster than that.
Yeah.
I think Senna GTR, not a street car, of course, but just-
The problem with the Senna street car is it's two track for the street and it's two street
for the track.
The 720S, which is mechanically identical without all the downforce, is a beautiful
GT car.
Drive it cross country.
You can store stuff in it.
Super comfortable.
And on Hoosiers, not on Slicks, but on Hoosiers, and I changed out to steel brakes, that's a 216, 217 car.
It's not that much slower.
So faster than your old GT4.
Yes, the McLaren GT4.
McLaren GT4.
Yeah, that one, I'm sure, I think Randy Popes
could probably run close to that.
But driver to driver.
Driver to driver, three seconds probably.
And that's all in the straights,
because the GT4 car has half, not half the power, but it it has and actually my GT4 I cheated, I tuned it. The 570S GT4
was already detuned from the street car, but you can tune the street cars as well. So when
I was, I pushed an extra 150 wheel just by tuning it because stock turbos can handle
that. So that would go 175 on the back straight, whereas a regular GT4 can do 20 miles an hour
less than that. But even then the 720S, actually 720S and Senna are identical in the back straight, whereas a regular GT4 can do 20 miles an hour less than that. But even then, the 720S, actually the 720S and Senna are identical on the back straight.
The Senna can stop later though.
Stop later.
Yeah.
The Senna, you can stop on, you can wait until 100.
Stop by later.
Yeah.
In the 720 with the aftermarket steel brakes, pads, and a Hoosier, which is still a DOT
tire, you can still break it a little bit after 200.
It's not bad at all for a car that you can go shopping at the outlet malls in because it's got a massive frunk.
And the ride compliance, that's the biggest thing about McLaren. So the Senna is more tied down but they all have that active suspension that doesn't use sway bars or springs.
It's all hydraulic. It's all fully active. There's hydraulic lines that diagonally connect the front right to the left rear wheel.
So the pressure in those lines combats body roll. So you can have it be a plush highway ride or you can have it be a stiff track car.
The bandwidth is almost unobtainable in any other car.
Do you think McLaren is somehow underperforming relative to what they should be doing given
both their quality as an automotive brand and as a racing brand?
Underperforming in terms of sales, is that what you're talking about primarily?
They are, yeah, they truly are.
And a big problem is, I think, is the perceived,
I mean, actually, it's not just perceived,
the actual lack of reliability.
I love the cars, but they're always,
it's all the jokes about British electronics,
they all come to bear.
Even the Senna would go into limp mode on,
between nine and 10, if you floored it,
it wasn't just mine.
We had SennaFest going on with 20,
I think we had 20 on track at one time. Some guys were just kind of tooling around, so they were fine. But if you were
hauling ass between nine and 10, when you get a little bit of suspension droop, you're going to
limp mode. If you're accelerating through that, I would literally-
Even a GTR?
No, no. I'm sure the GTR is fine. I haven't tracked one of those, unfortunately.
Is that a mode issue?
No.
Like if you were in track mode-
That was in track mode. I think it happened to me even
one time I forgot to put it in track mode. I think it still did it. It's a G-Force related
to suspension droop issue. They just freaked out the computer and they had a McLaren guys on site
who were actually working on patches. And they could patch it? They did. I think it made it less
frequent, but I think it still happened after the patch. I have to ask the McLaren guys about that.
Well, I think it's safe to say nobody's listening to us
anymore now anyway.
But in case anybody still is, this
has been an awesome discussion.
I really appreciate the offer to come out.
This is a true privilege.
Peter, what you have done in this community
is unparalleled in terms of, I think
I told you when I first met you, I was like, dude, how do I
get CME for this stuff?
Your lectures are better than almost all, not lectures,
but your podcasts are better than almost all, not lectures, but your podcasts,
are better than almost all the CMEs
because you get the right quality people on here,
much better than me by far.
And the way you phrase the questions
and the way you parse everything,
it's so understandable for a wide bandwidth.
I got my non-medical friends and family
all the way to the colleagues.
Everybody gets something out of them,
and that's hard to do.
Well, hopefully today we delivered a lot of insight,
both to people who are obviously interested
in radiation therapy for cancer,
which unfortunately is gonna be a lot of people.
And then of course this other application
around the treatment of inflammatory conditions,
which again, inflammation lies at the root
of so many other things.
And just in case anybody cares about a little drumming
in cars, hopefully we got something too.
I think we have a whole indication for a whole separate series here that truly is the drive.
Truly is the drive.
We can do that.
All right.
Well, thank you, man.
Awesome.
Thank you, Peter.
Thank you for listening to this week's episode of The Drive.
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