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The Planet Money podcast from npr. I think that we talk about carbon as the next machine, but I really think of it as the first step in personalized radiation oncology.
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When it comes to cancer treatment, a lot of people hear the word radiation and think of one thing, a beam of energy aimed at a tumor. But radiation is rapidly advancing in real time. And now doctors and researchers are entering a new frontier called carbon ion therapy, a form of heavy particle therapy. It's designed to hit some of the most aggressive and treatment resistant cancers with greater precision and force. And this new innovation targets tough cancers more effectively than traditional radiation. Mayo Clinic just opened the Duan Family building in Jacksonville, Florida, home to the first carbon ion therapy program in the US it's the most advanced form of radiation, with carbon ion treatment expected to begin in 2028. This is where physics meets medicine in a new era of radiation therapy. And it raises big questions. What could this mean for patients? What still needs to be proven? And how do you turn a massive physics platform into better care? That's what we dive into on this episode of Tomorrow's Cure from Mayo Clinic, a podcast that brings the future of medicine to the present. I'm Lindsay Siever, and it's great to have you with us. Joining me today are Dr. Adam Holtzman, a radiation oncologist at Mayo Clinic in Florida, and Dr. Paige Taylor, an assistant professor in the department of Radiation Physics outreach at UTMD Anderson Cancer Center. Thank you so much for being here today. Before we really dive into carbon ion therapy, I wanted to zoom out a little bit and try to understand this larger landscape of what is heavy particle therapy. I know if you work in your space or if you've been on a cancer journey, that might be a Term that a lot of people understand, but I wasn't familiar with it. So what is heavy particle therapy? I'd love to hear it.
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So in heavy particle therapy, we're using particles or ions to treat cancer. And what we do is we can put these particles into an accelerator and speed them up, and this raises the energy of the particles and then we can direct them into a patient. And the nice thing about heavy particles is that they deposit energy in a very small, focused space. So if we can direct them in the right way, we can be very targeted with where we send the particles in the patient to try to kill cancer cells.
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So within heavy particle therapy is carbon ion therapy. And this is used, this is the new frontier used to really target treatment, resistant, difficult, the toughest of cancers. And that's where you come in, Dr. Holtzman, is that you're sitting literally in the frontier of this, in Jacksonville, Florida, about to deploy this with patients.
C
So you're painting a picture of a patient maybe with a radio resistant tumor. And so imagine you have a, a challenging location. So something that's surrounding the optic nerves, so things that control vision or motor, which is kind of your ability to move your body or to feel sensations, you can have tumors in these really delicate areas. And to Dr. Taylor's point, particle therapy, you're able to control a little bit better how, where the radiation stops and where it could be directed. And then carbons also has a biologic difference. So for things that may be a little bit more resistant to other types of treatments, it may pack a little bit more punch or be able to cause a little bit more damage to the tumor itself while still trying to protect that healthy, normal surrounding tissue. And so in the head and neck space, it could be something around a visual pathway, an optic or apparatus. It could be tumors that are recurrent, that have come back in the head and neck, the spine, near the spinal cord, in the pelvis or abdomen, Something like a pancreas tumor that may not be surgically resectable. And it's a way of delivering that radiation precisely to the targeted area, but also being able to give it a little bit more biologic impact to meaningfully increase the chance of a cure for that particular patient.
A
So more of a personalized radiation treatment. I also understand that you both work on this issue from, from different sides, Dr. Holtzman, on, on the clinical side, Dr. Taylor, more on the, the research side. But you do know each other. You both have, have worked on this issue together.
C
Yeah. So Dr. Taylor and I both are on the PTCOG NA board. And so Dr. Taylor's, you know, an expert physicist out at MD Anderson who does a lot of work and sort of commissioning research and sort of the technical side, you know, they're the kind of the. The geniuses and brains that we look to to help us give kind of safe and accurate treatment.
B
Yeah, so we've met through the proton therapy community. So proton therapy has become really popular in the United States for radiation therapy treatment. And we have a couple decades of experience now under our belt in that space.
A
And so you both have been in this field for some time, and carbon ion therapy has been available in Asia and Europe. But did you both think that you would be working in this field at a time it'd be available for the first time in the Western Hemisphere?
C
I'd like to be an optimistic thinker, but, you know, you just never know with a project of this magnitude. So I think that, you know, anytime when you're developing on the cutting edge or a new frontier, there's more than just the potential clinical need for a patient. It's how do you build this center? How do you get the technology, the right people? There are so many factors that. That come into play. You know, it's been one of the highlights of my career to be able to see all of that come together and be a part of it. Anytime when you have a project of that magnitude, it's always incredible, and I'm always inspired when I get up and I could go to work each day to be able to see. So I'm still in awe. It's something that doesn't change, and it's exciting to see it come to fruition.
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Dr. Taylor, what about you? To see this unfold for your eyes
B
after working on it for so long, it's very exciting. So a lot of people who've been anticipating carbon ion therapy in the US have been collaborating with some of those international carbon centers. So I know folks at Mayo Clinic and here as well have been traveling to Germany and Italy and Japan to do experiments there so that we can help get the baseline research and build the data to justify having one in the United States now. So that's been really important in getting the information we need to prove that this is a good investment for us.
A
So I understand you both worked on this unveiling of the Duan center that has been under construction for several years. I would love to start from the patient experience and then sort of zoom out to what the building looks like. But, Dr. Holtzman, when you have a patient that is a candidate for this carbon ion therapy. How do you first approach them and describe this new radiation treatment to them?
C
So I think, you know, Dr. Taylor alluded a little bit about some of the physics behind it, of how particles are different. So carbon is 12 times the mass of protons. So from a scientific basis and clinical application, the way radiation works is it causes DNA damage, and, and so by having a bigger particle, it can cause more dense damage within the tumor cell. So when that tumor goes to divide, the machinery doesn't work, and then that stops the growth. And that's how radiation works to be targeted to kill cancer cells. And so when we're approaching patients, we're really looking for those scenarios where it's going to be the highest value for that patient. So oftentimes with treatments, patients may be coming from all around the country, all around the world. And so we really want to be using it, as Dr. Taylor mentioned, you know, judiciously, to get the best return for that patient. So I'd say probably 99.5% of patients will probably even maybe a little bit higher, will still be really well treated with either photon or proton radiation. And where we're focusing on, on those radioresistant areas, and I think what radioresistant, that means that maybe regular radiation isn't strong enough to cure that patient, but it's really personalizing it. So in the future, will we have biologic models where we can actually predict which patient may need carbon, may need a higher dose of radiation Clinically? Right now, we use surrogates. So we use things like pancreas, cancer, some liver tumors, some recurrent tumors that have already been irradiated, or maybe you need more biologically potent, precise radiation. But those are just surrogates of what we really want to know. What we really want to know is biologically how that tumor is going to respond. And so those are things that are currently in development. That's what we're using as clinicians to decide is this an appropriate candidate for carbon radiation or for any other type of radiation? Maybe they're a good candidate for proton therapy, where we just want to spare normal tissue, or maybe x ray radiation because of the anatomic location, the distribution, that's a great treatment option for them. Behind the scenes, when we're presenting it to a patient, that's how we're describing the value of carbon and then its place within the treatment options for any particular patient.
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Dr. Taylor, I saw a visualization from Mayo Clinic of the photons, protons, and the carbon and it looked like with photons and protons, the beam sort of moved through in a more like a slice through the DNA. And then when the visualization came of carbon, it almost looked like a dynamite had, had like splintered it. And so I was just wondering if you can describe to us scientifically how it works like that. It was, it was helpful for me to see. And, and how would you describe it?
B
Yeah. So the key for the carbon ion therapy, as Dr. Holtzman mentioned, is that the carbon ions are very massive and, and they can cause a lot of really dense ionization and damage within the DNA of the tumor cells. So if you want to use an analogy, it might be like if you shoot a ping pong ball into a table of pool balls, that's not going to be as effective in breaking apart that initial configuration. But if you're taking a pool ball and shooting it and then you see those balls move farther apart and they're going to be harder to put back together. So it's this transfer of energy and using those kind of basic physics principles to really cause that irreparable harm.
C
I tend to use that reference. So I'm glad that I feel validated that.
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Dr. Taylor, I know that you both worked on all of the treatment availability within the duan Center. So Dr. Holtzman, you're within that center right now. Could you be our tour guide for a minute? If we're a patient question going for carbon ion treatment there, what would we see?
C
What does it look like in terms of the investment, what the facilities look like. So, you know, all down to the composition of the concrete is all tested in certain parts right behind the beam. The walls are 13ft thick. In order to shield the patients outside of the room and the staff members who be around, around those patients. There's 1700 tons of steel, which is about seven statues of liberty. And then in terms of the magnets, there's about 180, 190ft of magnets, and that's used to help accelerate the particles. So oftentimes the particles, you know, usually they'll, they'll transverse the accelerators about 8 million times before being sped up to about the speed of light where they're carefully delivered through the nozzles into each of the treatment rooms. So that's sort of the structural elements that go in. And then aesthetically, you know, I think the building has a lot of symbolic artwork. So there's a sculptor who's Florida based who built the Guiding Light. So it's actually a photon beam. So it's not a particle, it's not a proton or a carbon atom, but there's a photon beam. And so as you walk around it, the shape of it changes. So as we reflect, you're going through cancer care, it really is meant to symbolize a lot of the challenges that our patients are facing on a daily basis. So it's really neat to have these artistic renderings that have a lot of symbolic reference to what's being done here. So That's a brief 360 degree overview of what it's like.
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And I just wanted to reflect back the. The steel amounting to seven statues of liberty, which is incredible. And then the other nugget I took out of what you said, Dr. Holtzman, is that the carbon ions move at, is it nearly the speed of light? Dr. Taylor, can you talk about that?
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Yeah. So we speed them up in accelerators, typically called synchrotrons. And so they start off very low energy, and then the faster they go, the higher energy they have. So we want to get them to an energy that will travel a certain distance in the patients, and the higher energy, the farther the carbon ion can travel in the patients. So we use information from medical imaging, like CT scans to figure out how far we want those carbon ions to go into the patient to treat the tumor. And then we can tune these magnets in the machine that help speed, speed it up to get the really precise distance we want there From a patient perspective.
A
If a doctor told me these carbon ions will move at the speed of light inside you, do you feel anything? I mean, what is it? Does it feel any different than the other forms of radiation therapy?
B
No. So these carbon ion machines are interesting because when we are delivering them, the machine is on. But once you turn off the machine, once a treatment is done, there's no radioactivity or any extra radiation. It's just these chemical reactions then happening in your body. So the patients don't feel anything. The machines are relatively quiet while they're delivering the treatment. And so a lot of times the patients are treated laying down, and so they get to have some quiet reflective time. We have radiation therapists who help set up the patients for treatment. And they often turn on music for the patients or have light or image displays to kind of create a calming environment for those treatments.
C
I always joke, you're not going to glow in the dark. You don't become radioactive. As soon as the machine is off, there's no radiation being delivered.
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Hey, do you have about 20 minutes? I know you're busy, but what if
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help improve your life?
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That's what we aim to do on each episode of Life Kit.
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Now more than ever, technology is a dominating force in our lives. Then there's the threat of AI everywhere. And yet tech can be inspiring and help level playing fields. I mean, a YouTuber with a self funded debut movie just dominated the box office.
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I thought, hey, if you interview me,
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it'd be good for your publication.
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And that's not ego, I just have a lot of followers.
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But it's that stigma. It's like YouTubers, they're not real.
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Join me, Lizzie O', Leary, the host of what Next TBD, Slate's podcast focused on technology, power and the future. Follow what next TBD now, wherever you get your podcasts. And Dr. Taylor, it's sort of your basic science class and I found myself going back what is the difference between a photon, a proton, and a carbon ion? Just. Just as we move forward in this conversation, I think it's great just to remind us.
B
Yes, great. So for conventional therapy that most patients receive in radiation oncology, it's photon based, which are X rays. And X rays travel through the body and they excite or move electrons around in the body, which are what end up depositing dose to our tumors. The tricky thing about X rays is that they will continue to move through our body even beyond the tumor we're trying to target. So we have a lot of techniques to try to minimize the amount of X rays that go outside of the tumor. But we're always going to have some X rays beyond where we're trying to target the beam. Proton therapy is sort of a step in between. It's similar to carbon ions, where protons, because they are massive, have a finite range when they're traveling inside the patient's body. So just like carbon ions, we can control how far the proton beam travels, and then they deposit a lot of dose in one focused spot and typically no dose beyond their range. So that's really beneficial for tumors where we don't want to get extra dose beyond where we're treating. And then carbon ions are very similar to protons where they're also depositing dose in a very small finite area. And we can control where that goes. But carbon ions, as Dr. Holtzman mentioned, have this increased biological effect because they are more massive, so they cause more severe damage to the DNA of the tumor. Cells that's hard for those tumor cells to repair and overcome.
A
So, Dr. Holtzman, essentially just a more personalized, precise blast of this type of invasive cancer. What does it mean to be able to offer this to a patient? I imagine it's such a moment of hope, not just for you as a clinician, but for the patients themselves.
C
Oh yeah, of course. And, and I think most of the times that we're considering, and as I mentioned, this is probably for a select number of patients with those really difficult to treat tumors. Either they've come back for a second time, they've already received radiation potentially, or it's a tumor that can't be removed surgically and maybe doesn't respond the best to conventional lower L E T and let is the physics term. But it kind of causes less dense damage. So to Dr. Taylor's pool ball versus ping pong ball example, when that hits it, it just breaks the DNA in such a way it's kind of like if your 3 year old took a puzzle and rather than taking a nice scissors that kind of cut cleanly down the middle, just took it and threw it off the table. The body just can't actually put all the pieces together. So the cancer dies because it can't divide, just doesn't have the machinery to be able to put it back together. So really we're using it in situations like unresectable pancreatic cancer or we're trying to get a pancreatic cancer patient to surgery or those really hard to treat sarcomas. And so a sarcoma is a tumor of bone or soft tissue and it's typically very rare and they can occur throughout the body. And oftentimes the locations where a surgeon they a surgery might be feasible, but it might require removing a limb or an extremity. You might have a, you know, a high school athlete who doesn't want to have an amputation because he or she wants to have a chance for college sports. And so it really is offering hope for those patients as a sometimes a non operative alternative to what may be a morbid or have high complication surgical operation or for patients where maybe surgery isn't an option because it's inoperable. So it's kind of, it's really giving hope to those patients in those situations where the current treatment options aren't up to what we would hope they would be at this time.
A
And right now, Dr. Holtzman, your patients, in order to pursue this treatment would have to go across the world.
C
Yeah. So I think most of the Carbon centers are concentrated in Asia, particularly Japan, Germany, China, Italy, so mainly the Eastern Hemisphere.
A
So, Dr. Taylor, what does it mean to be able to offer it, this carbon ion therapy, right in the US can you talk about the significance of this moment?
B
Yeah, this is a really exciting advancement for us in the United States because it will give us a chance to have another tool in our toolbox for some of these really hard to treat tumors. And I think we're ready for it. We certainly have been doing the research and the preparation, so this will be an exciting time for us in the field.
A
And Dr. Holtzman, when will you be able to offer it right here in the US where you are at the Dewan Center?
C
The center initially had an agreement with Hitachi, which is one of the large particle center manufacturers worldwide. They have several proton centers and carbon centers, both here in North America for protons and then internationally for carbon as well. We've received all of the equipment, everything's installed, and so really, it's undergoing that commissioning and testing. So that will be done for the next year. So our plans is. Is the first half of 2027, we'll start treating with proton therapy, and then the first half of 2028 is when we anticipate carbon will come online. Currently, our colleagues are discussing carbon with the fda. So before we treat a patient. And patients have been treated in the United States before, previously at the Berkeley lab in California. So patients were treated in the research setting. And so now after it goes to the FDA process, we look to initiate probably about 2028 is the. Is the timeline for that. But there's a lot of steps and work. Even though we have the equipment, there's really a lot of things that need to come into play even behind the scenes before it's operational.
A
So, Dr. Taylor, are you. Are you scrambling in real time to collaborate with what Dr. Holtzman is outlining here?
B
Yeah. So we've been preparing for carbon ions in the US for quite a few years. Starting back in 2019, I started traveling over to a carbon center in Europe to characterize our radiation sensors or radiation detectors that we use to audit different radiation therapy facilities in the US So we've been building that infrastructure for a long time.
A
So your trips to Europe, you really studied the best practices and protocols. What was working well? Is there anything that you took away that was working really well, or were there any changes that you made from what you saw in Europe?
B
Yeah, so one tool that we use to test radiation therapy is called an anthropomorphic phantom, and it's a patient surrogate that we use to mimic patient treatment. And we use radiation detectors or radiation sensors inside this patient's surrogate. And we have clinics go through the entire treatment process like they would a real patient. So they take an image of these phantoms, they create a treatment plan, and then they deliver that treatment plan to this phantom. And then with the radiation sensors inside, we can measure to see if what they delivered matched what they intended to deliver. So we can test that entire process of how the information is flowing and how the machine is delivering as a double check of that dose. So for the carbon ion therapy, we actually developed a new phantom that we thought was appropriate for testing carbon therapy. So a phantom is like a patient surrogate that mimics a different type of anatomy. So we have phantoms that simulate brain tumors or lung tumors or liver tumors. And we can use different materials, like different density plastics to try to mimic human tissue. And then we create a target or tumor that we treat within these phantoms, and we put radiation detectors or radiation sensors inside of the phantoms so that we can measure the radiation dose delivered. So we developed a pancreas phantom, so it simulates or mimics a pancreas tumor so that we can test out what the dose would be to the pancreas if we were to treat one without having to test on a real patient.
A
This is really a feat of physics, engineering, medicine. But I think from a patient perspective, it's really reassuring the amount of testing that has gone into this. By the time you visit the Duan center, years and years have gone into this before it is unveiled here, right, Dr. Holtzman?
C
Oh, yeah. I mean, that's kind of a lot of the commissioning. The treatment planning system is also being designed from bottom up. So a lot of the models to, to biologically determine what the effects of carbon were based on some Japanese and European data. And so with. When you apply carbon to any specific patient, our physicists are working to actually design some of the treatment planning software system with a software engineering company. By having our own treatment planning planning software system, we'll be able to have a lot of control over which models we're using within that, and we'd be able to modify it based on what we're seeing clinically. So it's we, we verify multiple times, then we deliver, and then follow up to, to inform all of the future treatments as well.
A
Dr. Taylor, I'm wondering if you could revisit what biological effect means.
B
Sure. So there's a physical aspect of the dose that's delivered which we can measure very clearly. But then there's also the way that the radiation interacts with DNA and cells, which is our biological effect. And carbon ions are thought to have two to three times greater biological effect than our conventional photons or X rays. And we've talked a little bit about how they cause greater DNA damage. So we have colleagues called radiation biologists who do really extensive studies to look at the impact of different types of radiation on different types of cells. So they might design an experiment where they take tumor cells in a petri dish, essentially deliver carbon ion beams, and then count to see how many cells survive that irradiation and how many cells are killed by it. So when we talk about the greater biological effect, if you were to design an experiment where you give one petri dish photons and one petri dish carbon ions, we see more cells killed with the carbon ions than we do with the conventional photons.
A
So, Dr. Holtzman, some of your patients could receive both of those types of radiation treatment because it is so personalized. Talk about that, how you use both of these tools together.
C
We've talked a lot about the biology. There's also the technical delivery to patients. And so anytime when you deliver radiation, oftentimes patients are laying flat on a table. And as I described further, often these magnets are flying £40,000 that are used to help direct the carbon radiation into the room. So when we initially start treating patients, it will be with a fixed gantry. And so that means that we'll have sort of creative solutions to be able to create the target or geometric distributions and beam angles that we want to deliver for patients. Because the geometry may be fixed with carbon, we really want to give it to patients where we're treating gross disease. And what that means is a tumor that we can see that hasn't been removed. But anytime we give radiation, there may be parts of the tumor or areas that we want to treat that don't need the same biologic intensity. So, for instance, in the head and neck area, oftentimes we treat the cancer at the area where it started. But there may be some lymph nodes, which we know there's a chance they may be harboring tumor cells, but we can't see any with our eyes or on any of the scans or tests that we're looking at. So there may be an opportunity for mixed modality treatment options where we can treat X ray or proton therapy to certain areas of the body or the tumor and then really cone down carbon to the areas of the tumor that are most resistant and most in need of that treatment option. Behind the scenes, there's some engineering tricks that can be done. And so oftentimes the transition speed between one particle to another is one of the factors. And so with our system we'll be able to transition between one or the other very quickly such that the patient won't be very inconvenienced. It's not a long period. It really will be almost imperceivable to the patient when that's being done.
A
I imagine Dr. Holtzman, for the work that you do when you are trying to help a patient that's really sick, the opportunity to give them this new lifeline with carbon ion therapy is just so meaningful.
C
Of course, I think that's what we all get up in the morning to do. That's one of, I think the most rewarding parts of my job is being able to follow these patients and follow up and really be able to give or give them opportunities, hope and a chance for a cure. I think that that's something that we all strive for. Our physicists, they do an awesome job of making sure that the radiation supposed to go where it's supposed to go. And so I know behind the scenes they're working to make sure it's as accurate as possible. And then for us to be able to meet with patients, offer that in clinic is really kind of what drives us throughout the day. And I think that's what one of the reasons why I'm always so excited to come to work and work in this field is that oftentimes people think that, you know, cancer and certainly it has its down moments being an oncologist, but you know, there really are those bright moments and when you have a chance to offer cure to a patient, or when you cure a patient that you know, was in a difficult situation, that could be, you know, many fold rewarding when you get to see that outcome. So that's what drives me throughout the day.
A
And Dr. Taylor, as you work on the rollout of carbon ion therapy, what is the, the big wow for you? What is what drives you?
B
I'm really excited about carbon ion therapy because it is really a technical feet. It's a lot of different people coming together to put all this machinery together and then treat such a very small point in the body. So it's amazing that you go from this giant machine to a sub millimeter treatment point and the accuracy of it is really impressive. The increased biological effect is really exciting and, and I think carbon ion therapy is coming at a time where A lot of other technologies we have in radiation therapy are advancing simultaneously, like adaptive therapy and image guidance for radiation therapy. So to see them all kind of coming to fruition at the same time makes me really hopeful about what we can do with all of them together. Adaptive planning is when we use images of the patient during their treatment to update the radiation that they're receiving. So we have a student who created a great metaphor here of you're trying to hit a pinata at a birthday party. So typically with a pinata, you get a good look at it at the beginning, but then you're blindfolded while you're swinging at it. And historically, radiation therapy has been like that as well. We get a really good image of it at the beginning, and maybe we get little glimpses while we're treating, but we're not actually updating our swing as we're going along. But with adaptive radiation therapy, it's like taking off the blindfold. And so you can watch the tumor shrink or the anatomy change, and you can update the field of radiation that you're delivering while you're treating that patient,
A
just from a patient perspective. Because I'm not in the field of science, I think of radiation as more of this static treatment, the beam. You know, I think of it as more limited. And now what you're saying is that you can really personalize radiation with protons, photons, and carbon?
B
Yeah, absolutely. And Dr. Holtzman mentioned doing multimodality treatment. And what's cool about the accelerator that they'll have at Mayo Clinic is that it can deliver both protons and carbon ions from the same machine. So you could potentially have a combined treatment that's sort of like a paint by numbers, where you paint this part of the tumor with protons and you paint this part with carbon ions. And we can use advanced medical imaging, or biomarkers, to give us the information about where we want to target each of those particles within the same course of treatment.
A
What do you think this means for the field of radiation oncology?
C
I think that we talk about carbon as the next machine, but I really think of it as the first step in personalized radiation oncology. So it's really melding the technical and biologic impact of our treatment, and it's forcing us to really give the right treatment to the right patients. So as Dr. Taylor mentioned, adaptive radiation, the way radiation's been done for 60 years, is when we map the radiation out, it's static. We know on a day to day basis your stomach, based on what the last Meal you ate is at a different volume. The body is not fixed. And when we design a radiation plan, historically the way it was done is when that CT scan is done, that's fixed and static in time. And as a patient goes through several weeks of treatment, they may lose weight, the tumor may shrink, their body or anatomy may be the bowel or which is kind of their, you know, in their abdomen, their intestines may shift around a little bit. And so when you're giving really precise treatment to small areas of the body, you want to be able to adapt, live for that day. And so if you imagine a radiation treatment could take several really high trained, specialized physicians, physicists and other technical people within a department to make a radiation plan. And so to have the technology to be able to shift or maybe make a new treatment that day, or adapt the radiation based on a biologic response, that's, I think, some of the really exciting translational work that's being done and where the future is going. So maybe you can get a special image that can see where the most resistant areas of the tumor are. Oftentimes those are the areas, areas that lack oxygen. Maybe we can on a day to day basis target that or use that mid treatment. But that all requires many specialized people in different domains. And then also the calculation speeds the synthesis of all that information all at once. And so I think carbon is leading that sphere. But the whole field of radiation oncology will be moving with it.
A
And just as Dr. Taylor went to Europe to study carbon ion therapy, do you expect to host people and patients from around the world that will now come to Florida for this treatment?
C
Yeah, I mean, just like a lot of the proton centers, there's agreements with countries and other places around the world that are seeking proton therapy. And so I know that MD Anderson is probably a large international center, Mayo Clinic is a large international center for proton therapy. I expect the same will, will be with carbon. Currently, to date, only about a few dozen at most patients within the United States have been treated with carbon ion therapy. And we know that the potential need is on, you know, several magnitudes larger than that. So I imagine both within the US and other patients internationally who don't have access to maybe some of the Asian and European centers would look to Mayo Clinic as a potential treatment option based on the type of cancer and potentially some of the innovative clinical trials we'll have ongoing.
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I love thinking about all the people all around the world that have studied in, in this field for years and the true team sport it takes and the 40,000 pound magnet and the seven Statue of Liberties of steel to help the one person who needs it most. It's really just a beautiful thing to think about, all the gears turning behind the scenes to be able to offer it to a patient soon enough.
C
Worldwide, there have been about 40 to 50,000 patients treated with carbon. So it's not that there hasn't been a large amount of patients treated with this type of treatment. Probably about 400 to 500,000 patients treated worldwide with proton therapy, about a tenth of that volume with carbon. So many patients have been treated with particle therapy, just not particularly a carbon in the U.S. proton therapy is, is, is pretty more widely available within the United States.
A
Dr. Taylor, what will you be watching closely for next in these crucial next few years, and what keeps you hopeful as we get closer?
B
I'm really excited about the integration of advanced imaging with a lot of these technologies. So we're able to now image the patient right before they're being treated or during treatment. And that helps us keep track of how the tumor is responding to treatment and how the patient anatomy is changing, which can help us make the treatment delivery more accurate.
A
I imagine there's people out there listening that are wondering if they're a candidate for carbon ion radiation treatment or if their loved one is. And so how do you know? Where do you begin?
C
Somebody who's a candidate for carbon radiation therapy really take a step back. And so any patient where they've been recommended radiation therapy is a potential patient who could be a candidate from a very generic standpoint. What we're looking for though, is those patients where the tumor may be in a very sensitive area or a type of cancer that may not typically respond to regular courses of radiation. So oftentimes that'll be tumors of the head, neck, brain and skull base where the tumor may be sitting right next to a sensitive structure like a nerve going to the eye or the parts of the spinal cord or parts of the brain stem. Or it could be something in the abdomen like a liver or pancreas tumor, which can't be removed with a surgery, or as we mentioned, some of the types of aggressive sarcoma types tumors, bone or soft tissue tumors that also may be a little bit more resistant to other forms of radiation. So I think that I kind of went into some of the clinical criteria that we think about, but I think any patient where they've been recommended radiation, a good person to ask would be their radiation. Dr. There's always ways for patients to reach out, see if there's a clinical trial that would be ongoing. I expect that we'll have several clinical trials looking at those high need focus areas. And then certainly any patient who's considering proton radiation is another potential option. Now of those, it'll certainly be a select number of patients selecting the best candidates. But it's, I think it's something for, you know, any patient to, to consider. And the reason is, is that oftentimes patients won't know. As a clinician who's been doing this for 10 years in medical school, it's so hard to be able to, to distill. Dr. Taylor does a really good job of explaining the physics and a layman's perspective, but I think as a patient, it's so hard to know what you don't know. So I think the easiest thing is to, to reach out, especially if you're somebody who is considering radiation. And usually it could be determined pretty quickly by the clinical team.
A
Your future patients, many of them just have very difficult, treatment resistant answers and this could be their greatest hope.
C
Exactly. Now the patient, you know, it's hard for them to make that determination. They may not know, but it's always easy to reach out and always the clinical teams and they do a really good job of, you know, helping those patients identify quickly if it would be something helpful. Also the ability to give a third type of ion. So there are other types of ions like helium, oxygen, which might have different masses and have different properties. So there is potential, the possibility of even introducing another ion within therapy as well, which could further enhance those effects.
A
With the carbon ions as the new superhero of radiation oncology, where does that put us in 20 years or 50 years, are we going to be able to cure some sort of cancers or just make immense progress?
C
I think that the whole field of radiation oncology, whether it's carbon or proton or photon, I think we're learning a lot about how radiation could affect the immune system, how we can enhance the immune system and we can give precise targeted treatments. So oftentimes when you get a chemotherapy or any type of systemic therapy that goes throughout your entire body. And what's so neat about the field of radiation oncology is we have these really neat and cool tools to be able to deliver directly to the tumor. And so I think the future of radiation oncology will be a meld of everything that we've talked about in being able to select the best treatment option for any particular patient, whether that's photon, proton or even carbon. And we'll have both ways of detecting a patient's blood and their tumor itself, as well as ways to better image and guide where the radiation goes. I think at 20 years, I think that that will be the field, is that we will have these signatures from people, all of that information, to be able to give the right modality to the right patient in the right amount. So that way we're not causing more side effects than we want to cause. We're giving them exactly what they need, but no more.
A
That's beautiful, Dr. Taylor.
B
I think carbon ion therapy is driving a lot of innovation, and currently it's very expensive, so it's not accessible to every clinic that might like to have it. But because of that, there are a lot of engineers and physicists working together to design future generations of systems, and that would be more compact and more affordable so that we can get this technology out to more patients around the world.
C
So one of my mentors and colleagues, Dr. Hoppe, the Director of the Particle center here in Florida, is saying, we'll judge the success of the carbon program if in 20 years, we're not the only carbon center, I'm sure with, you know, fantastic colleagues and centers at MD Anderson throughout the Mayo enterprise, I think that's how we'll be judged by our success, is that this has been able to be scaled and we've been able to bring down the accessibility and cost so that we really can access people and make it convenient for patients to be able to receive treatments that could be preferential for them.
A
Well, thank you so much to you both. I learned so much today and I have on my list a tour of a heavy particle treatment center. That sounds amazing. I've learned a lot through both of your analogies. From pinatas and pool balls.
C
I think they were mainly Dr. Taylor's excellent analogies.
A
Well, you dropped the knowledge of the seven statues of Liberty and the 40,000 ton magnets.
C
That is true.
A
And really the patients that are the best candidates for this. So I learned so much from you both. So, Dr. Holtzman and Dr. Taylor, thank you for your critical work and for giving patients much hope.
B
Thanks for having us.
C
Thank you.
A
Tomorrow's Cure is a production of Mayo Clinic with production help from the Podglomerate. Be sure to follow Tomorrow's Cure wherever you get your podcasts. And if you like today's episode, please like and subscribe. I'm Lindsay Siebert. Thank you so much for being with us.
B
Mayo Clinic Key into Quality is a podcast focused on healthcare quality, safety and patient experience, offering actionable insights and strategies to help organizations address quality challenges Dr. Timothy Margenthaler and co host Sherry Nemec invite Mayo Clinic experts to share insights about innovative work to drive excellence and explore some of the biggest challenges in healthcare quality, safety and experience. Podcasts are released twice per month on Tuesdays. Tune in to learn more by listening to Mayo Clinic Key into Quality on your favorite streaming services.
Date: June 24, 2026
Host: Lindsay Siebert
Guests: Dr. Adam Holtzman (Radiation Oncologist, Mayo Clinic, FL), Dr. Paige Taylor (Assistant Professor, Department of Radiation Physics Outreach, UTMD Anderson Cancer Center)
This episode explores carbon ion therapy, an emerging, highly precise form of radiation treatment for some of the most treatment-resistant, hard-to-reach cancers. As the Mayo Clinic prepares to launch the first U.S. carbon ion therapy program, Dr. Adam Holtzman and Dr. Paige Taylor share insights on the significance of this technological leap, its unique biology, clinical applications, patient experience, and the innovative collaborations making it possible. The conversation covers the science behind heavy particle therapy, who stands to benefit most, milestones in the technology's journey to the U.S., and what the future of personalized, adaptive radiation oncology might look like.
On the impact for difficult-cancer patients:
"It really is offering hope for those patients...a non-operative alternative to what may be a morbid...surgical operation or for patients where maybe surgery isn't an option because it's inoperable." — Dr. Holtzman (19:30)
On adaptive therapy's significance:
"With adaptive radiation therapy, it's like taking off the blindfold [at a pinata party]. And so you can watch the tumor shrink or the anatomy change, and you can update the field of radiation..." — Dr. Taylor (34:42)
On the global milestone:
"This is a really exciting advancement for us in the United States because it will give us a chance to have another tool in our toolbox for some of these really hard to treat tumors." — Dr. Taylor (22:02)
On the scale of engineering:
"There's 1,700 tons of steel, which is about seven Statues of Liberty. And then in terms of the magnets, there's about 180, 190 ft of magnets." — Dr. Holtzman (12:26)
On personalized treatment vision:
"In 20 years...we will have these signatures from people...to give the right modality to the right patient in the right amount. So that way we're not causing more side effects...We're giving them exactly what they need, but no more." — Dr. Holtzman (44:31)
This episode underscores carbon ion therapy as a transformative leap in cancer care for patients with the most challenging diagnoses, marrying advanced physics, engineering, and medicine. It will usher in an era of highly personalized and adaptive radiation treatment, offering new hope when conventional options are exhausted. The episode brings forward the sense of awe, hope, and global collaboration powering this breakthrough, while reminding listeners that as the technology advances, the drive is always to serve the patient with ever greater precision and compassion.