Proton Beam Therapy

Mayo Clinic Hospital in Phoenix will soon open its proton beam center to treat cancer. In properly selected patients proton beam therapy is an advance over traditional radiotherapy. Mayo Clinic’s Proton Beam Therapy Program is unique, using pencil beam scanning, which allows closer targeting of a tumor. Dr. Sameer Keole (key-olee), the medical director of the Mayo Clinic Proton Beam Center in Arizona, will tell us more.

Transcript:

Ted Simons: Mayo Clinic hospital in Phoenix will soon open a new cancer treatment center. This one involves proton beam therapy, which in selected patients is a significant and more targeted advance over traditional treatments. Dr. Sameer Keole is the medical director of the Mayo Clinic proton beam center in Arizona joins us. Good to have you here.

Dr. Sameer Keole: Thank you for having me.

Ted Simons: This is pretty exciting stuff here, just researching this I'm thinking, what a brave New World we have. Give us a general description of proton therapy.

Dr. Sameer Keole: Sure. Most people have had an X-ray, a chest X-ray. And similar to chest X-rays, which go in one side and out the other, that's what we do with regular X-ray therapy. Which is very effective but it can travel into the right side of the head and come out the left with hair loss. Proton beam therapy is the H of H2O. We can put a set amount of gas in the car, it'll go a certain distance and stop. You can treat the ice cube but not the water around it.

Ted Simons: We have a video here, a graphic illustration of what we're talking about. This looks like it's very -- tell us what we're watching here.

Dr. Sameer Keole: Sure. With regular X-rays, radiation comes in one side and goes out the other. Treats the target and also good healthy tissues around it. Proton beam therapy, we take those hydrogen spots and we can drop them like a fine paint brush going around the stem of the glass. And we can paint it left to right, up to down, in distal to proximal. We can decrease the dose to the normal healthy brain by anywhere from 70 to 90% when we use this.

Ted Simons: My goodness. And these pencil beam scans as they say there, describe the machinery. There's like 100 yards of tubing where this stuff is hurtling at almost the speed of light. How does this work?

Dr. Sameer Keole: Well, you know, it's amazing. To the patient it doesn't look any different inside the room. When you go behind the curtain, so to speak, it's a whole different world. Protons are big. They have a big mass. So imagine a big semi-truck going down a freeway. It can't make a quick turn, it's got to take a very shallow turn. We accelerate the protons in a circle, and then send them down what's called a beam line, which is about 80 yards long. We peel them into four different treatment rooms. In each room we'll steer them into the patient. A gantry, for instance -- we have four of these, each gantry weighs 140 tons.

Ted Simons: My goodness gracious. What kind of building is responsible, a lot of concrete I would imagine.

Dr. Sameer Keole: Most of the viewers are familiar with the University of Phoenix football stadium where our Cardinals play each Sunday. Same construction company did our building as theirs. They used two thirds the amount of concrete for our building as they used for the entire Cardinal football stadium.

Ted Simons: That's a lot of stuff, a lot of technology, a lot of machinery. What does something like this cost?

Dr. Sameer Keole: Well, it's a big investment. The total building is roughly $180 million for the equipment, plus the building around it. And normally actually the way the government works, you're supposed to get reimbursed by practice expense. So you would say, boy, it should cost significantly more than regular X-rays. But because we raised a lot of money by philanthropies, and also because we wanted to put our money where our mouth is, we are charging the same price for proton beam therapy as we would for X-ray therapy.

Ted Simons: That's because it worked as well as it did. This is the only one in Arizona?

Dr. Sameer Keole: Correct. It's the first one in the five-state southwest.

Ted Simons: I have also read there are some folks not necessarily convinced this is the best treatment for different types of cancer. Do they have a point?

Dr. Sameer Keole: Yes and no. I think we're in a different era of health care now where a lot of emphasis on cost and cost-effectiveness. But also there's something to be said where no doctor goes to medical school to walk into the room and say, bad news, you have cancer. Good news, I have the second best treatment available. There are -- this is not a panacea. There's probably 15 to 20% of patients in whom this will offer a significant benefit over our best X-ray therapy.

Dr. Sameer Keole: Children, I would imagine?

Children are a great example. They are still growing and developing and there's data that shows -- I should say it strongly suggests that there is less of an I.Q. detriment when you use proton therapy versus regular X-rays. I don't think that's such a stretch, when you can decrease the dose to the brain by 70%, that's generally a good thing.

Ted Simons: The video that showed a brain tumor, I would imagine spine, areas hard to get to or around sensitive areas?

Dr. Sameer Keole: Great observation. Where we think it's really useful is in hard to target areas where there's really something to avoid. Something like breast cancer, on the right side may not be such a big advantage over advanced X-ray techniques. On the left side, because the heart is there, in certain cases we can decrease the dose to the heart by 90%.

Ted Simons: My goodness.

Dr. Sameer Keole: We treat our first patient in mid-March.

Ted Simons: Is the Valley becoming known for cancer care options? Seems like there's a lot going on here.

Dr. Sameer Keole: I think so. There's a lot of great physicians and great medical facilities. And I certainly would put us on that list.

Ted Simons: All right, good to have you here, very encouraging to hear, as well. Thanks for joining us.

Dr. Sameer Keole: Thanks for having me.

Ted Simons: Wednesday on Arizona Horizon, ASU Physicist Lawrence Krauss will talk about what's being called the science news of the century, the discovery of gravitational waves. And our weekly legislative update with the "Arizona Capitol Times," 5:30 and 10:00 on the next "Arizona Horizon." That is it for now. I'm Ted Simons. Thank you so much for joining us. You have a great evening.