Scott Webb (Host): Proton radiation therapy is being used to successfully treat some cancers in adults and children at the Proton Center of Arkansas, by targeting cancer cells and causing less collateral damage to surrounding cells and tissue for patients. And joining me today to tell us more about proton radiation therapy and the partnerships behind the center, is Dr. Sanjay Maraboyina. He's a Radiation Oncologist with UAMS.

 This is UAMS Health Talk, the podcast from University of Arkansas for Medical Sciences. I'm Scott Webb.

Doctor, thanks so much for your time today. We're going to talk essentially about the Proton Center of Arkansas. But before we get there, I want to talk about proton radiation therapy, which sounds like something out of Star Trek or Star Wars, but it's real, it's happening, and it's great to have your expertise today. So let's start there. What is proton radiation therapy?

Sanjay Maraboyina, M.D.: Thanks, Scott, great question. Before I answer that question about proton therapy, I think it's important to take a step back and really understand what is radiation therapy. Radiation therapy is a modality that is used to treat cancer. You have surgery, chemotherapy, radiation as important tools in the fight against cancer. And what radiation does on a cellular or molecular level, is as it enters the body and it causes ionizing radiation to interact with cells and it causes DNA damage. A normal cell has the capability of repairing and it survives.

But the cancer cell, because it's different, it's unable to repair itself and it subsequently dies. So that's the basic premise of how radiation works. So, radiation therapy is radiation and, and people have heard about radiation like, oh yeah, it causes cancer when you hear about nuclear accidents; but specifically, therapeutic radiation can be used to treat cancer, as I have mentioned.

 And so as radiation traverses the body, anything in the path, receives that and subsequently can be damaged, including the tumor and normal body. So the unique thing about proton therapy; and I can give an hour physics lecture about this, but I'll try to sum it up in a minute or so, is that proton therapy is a positively charged particle and it has very minimal entrance dose and it interacts with the tumor right at the tumor. And there is no exit dose. So what does that mean? That means that there is very minimal collateral damage. So that's the basic differentiating factor between photons or x-rays and proton therapy.

Host: It's so great to hear that limiting that collateral damage. It's amazing. So I think I know the answer to this. I think you've already answered it, but just go over a little bit when you compare standard x-ray radiation with proton radiation, why is proton better?

Sanjay Maraboyina, M.D.: As I mentioned, it's that physical characteristics of the proton that is able to precisely deliver the radiation to the target and minimize that low dose radiation. So from a patient perspective, what that translates into is that there is less side effects when compared to standard photon radiation.

So depending on if we're treating something in the brain or within the head and neck area, think about your throat. If there, if we have a tumor in the back of your throat, these patients get significant dry mouth, taste changes, trouble swallowing. And some of these patients need feeding tubes when they're getting radiation and chemotherapy. So with proton therapy, we're able to minimize those side effects to those structures that I just mentioned. And so they're able to get through the treatment, and some of them may not even require a feeding tube. And when you think about children, proton therapy is a major indication in the pediatric population.

If we're treating a brain or a spinal tumor, and that's actually, well, one of the techniques is called cranial spinal radiation. That's a fancy word of saying that we're radiating the brain and spinal cord. So, as that beam enters through the back in, let's say, photon therapy, that beam is going to go through the spinal cord and radiate the structures in the front of the body, anteriorly, such as the heart, lung, and abdomen; but with proton therapy, as I mentioned earlier, dose distribution stops right at your target, and so there's no exit dose.

Host: Yeah. I'm just shaking my head just thinking, you know, this is just so cool. Like, how can this be? But it is. Are there some instances or some types of cancer where as amazing as, you know, proton radiation is or proton therapy, that it's not the right fit that you still need sort of the, what was maybe the gold standard, the standard x-ray radiation?

Sanjay Maraboyina, M.D.: Proton therapy isn't some kind of magic tool that we have. And it's not indicated in every cancer patient. There are certain situations where photon therapy has a benefit when compared to proton therapy, especially when you're delivering very high doses and you know, you need like a conformal distribution.

So proton therapy is not going to replace a standard photon x-ray therapy.

Host: Let's talk about cancer outcomes for patients. You know, how is proton radiation improving those outcomes?

Sanjay Maraboyina, M.D.: When a patient thinks about like how they're going to do with treatment, they immediately think is it going to improve my survival? So it's very important how you define cancer outcome. To date, there are ongoing randomized studies comparing standard photon x-ray therapy to proton therapy.

And as those studies mature and get completed, you know, we're going to get more information. It's probably incorrect to say that proton therapy is going to improve survival point in time. But what it does is it's able to deliver, in certain situations, a higher dose so we get better tumor control.

And that can translate into better outcomes, but we have to wait for those studies to be completed and get that data. But as I mentioned in the example of head and neck cancer patients and not requiring the need for a feeding tube, these issues are related to quality of life. So, a patient can go through treatment and have better quality of life.

That's a very important outcome. These patients with radiation therapy, it's done as an outpatient. So, these patients can continue to live a normal life. They can work, go to school. And so, I think that's very important, but not everything is measured by how much longer you're going to live.

But, can we do a better job with proton therapy in terms of like local control and quality of life?

Host: Yeah, that's what I was thinking, this exact expression, the quality of life, right? So, survivorship or survival of respective cancers, the jury's still out, still more studies need to be done. But while you're here, for sure, your quality of life should be better, hopefully through the use of proton radiation. And I want to give you a chance to brag a little bit here. I know the Proton Center of Arkansas is the first of its kind in Arkansas and one of only 43 proton centers nationwide. So, I want you to talk a little bit about that and why proton radiation therapy is so essential for cancer care in Arkansas.

Sanjay Maraboyina, M.D.: I've been fortunate enough to be a part of this project from its inception. It's been almost three or four years ago where the decision was made from the various partners. So I'd like to mention UAMS, Proton International, Baptist Health and Arkansas Children's Hospital came together with the vision that we needed this very important cancer treatment in Arkansas.

 So fast forward two to three years, and here we are. So previously patients had to travel out of state, hundreds of miles to the nearest proton center. This is a game changer for cancer patients in Arkansas. They can receive this very important treatment close to home. They don't have to uproot their lives. They don't have to miss work, miss school. They can get this important treatment closer to home.

Host: Doctor, I love learning and I so wish we could stay on for that hour or more and talk more about this, but we've scratched the surface today, talked about the Proton Center of Arkansas, proton radiation versus standard x-ray radiation. All good stuff. Thank you so much. You stay well.

Sanjay Maraboyina, M.D.: Thank you, Scott.

Host: And to make an appointment, call 501-664-4568. I'm Scott Webb. And if you found this podcast helpful, please share it on your social channels and check out the full podcast library for additional topics of interest. This is UAMS Health Talk from the University of Arkansas for Medical Sciences. Thanks for listening.