Proton therapy, a more targeted form of radiation, is gradually being introduced in the U.S. The first group of patients has recently completed treatment at the ProCure Proton Therapy Center (Oklahoma City), which is just the sixth center in the country to offer the alternative to standard radiation. Its chief known benefit is that proton therapy spares healthy tissue and results in fewer side effects.
"Proton therapy [also known as particle beam radiation] is very precise in terms of where it releases its radiation and you can stop your radiation on a dime," W.C. Goad, MD, medical director of the Center and a founder of Radiation Medicine Associates (RMA), which provides clinical care for the ProCure center, told Medical Device Daily. "You can treat an area with less risk to patients because less normal tissue gets exposed. Now the risk is that we have such a very precise way of treating people that we have to be very precise in defining where that tumor is. Now the demand on radiation oncologists is that you have to be very careful about defining which structures to treat and what not to treat. It challenges the way we think about planning areas to be treated.
"When you think in terms of tumors, what you see on an MRI or PET scan isn't always the exact margin of where that tumor stops and starts. There can be microscopic cells beyond what you can see."
Proton therapy uses a particle accelerator to generate a beam of protons that can be targeted in three dimensions and more precisely deliver a high dose of radiation to a tumor while sparing, or reducing, the damage to surrounding healthy tissue and organs.
The Oklahoma City center started treating patients in August and that first group has finished a round of treatments for several different cancers, including prostate.
"My patients have all done well and had no side effects that compromised their quality of life," Goad said. "My initial impression is we expected patients to have some mild symptoms with radiation proctitis or cystitis, but I don't think I've had to place any of those patients on medications to manage side effects."
Additionally, he's treated several patients with brain tumors who all reported good tolerance.
"But it's way too early to say that we're going to get better outcomes," he said. "But we're off to a very good start. There are fewer side effects."
Just the fact that these patients experienced no side effects is considered a huge advance by the patients themselves since radiation therapy can typically cause fatigue, nausea, vomiting, diarrhea and a host of other site-specific side effects.
One patient who was among the first to be treated for prostate cancer, Sam McElvany, said, "I always left the center feeling better than I came in. Few people can say that during cancer treatment."
Proton therapy is not intended for the entire spectrum of cancers. It's best used for localized tumors which can be well defined by computed tomography or MRI. In addition to prostate cancer, Goad said it can also be efficiently used for eye tumors and primary tumors of the brain.
"If a cancer metastasizes, the patient isn't a likely candidate for proton therapy," he said. "But it's an exciting time for proton therapy; a transformational time. We have an opportunity to combine proton therapy with other modalities such as chemotherapy and surgical management."
When combined with chemotherapy, the more precise radiation therapy provides a potential for better cure rates, he said.
And that potential is at the crux of a report recently issued by the Agency for Healthcare Research and Quality (AHRQ; Rockville, Maryland) on the comparative effectiveness of proton therapy. But instead of answering the question, the report presented a list of new questions dictating the need for broader study of the therapy.
The most important finding is that the majority of studies that were done to date are single arm. Of the available studies, investigators didn't use alternative care as a comparator (MDD, Sept. 18, 2009).
"Those questions have to be answered and we're committed to answering them for patients," Goad said. "Clearly not all patients will benefit from proton therapy. In radiation therapy we know there are different dose response curves. If you give a different dose you get a different response. What limits us in proving sometimes curative therapy is the size of a tumor. We haven't had the opportunity to treat patients with proton to doses that increase survival rate. I understand the need for answering if it's equally effective or comparable to photon therapy, but the other question is: What's the effect on quality of life? We have good studies that show fewer side effects and complications."
Goad said ProCure is in the midst of planning clinical trials focused on the use of proton therapy for prostate and brain cancers.
"We want to be a part of the process to answer those questions," he said.
In the meantime, patients with head and neck, brain, central nervous system, prostate and some pediatric cancers, among others, will be treated at the new 60,000-square-foot facility. It has four treatment rooms and will be at full capacity by next summer and able to treat 1,500 patients a year.
"ProCure was founded to increase access to proton therapy and provide exceptional patient care. Now that the first patients have completed treatment, we've officially realized our dream and are anxious to open more centers to make this important therapy closer to home for patients with cancer across the country," said Hadley Ford, CEO of ProCure Treatment Centers (Bloomington, Indiana).
The Oklahoma City location is the first in ProCure's network of proton therapy centers to provide this therapy, but construction is under way on a ProCure facility in suburban Chicago and ProCure has centers in development in suburban Detroit, South Florida, Seattle and Somerset, New Jersey.
Lynn Yoffee, 770-361-4789;