Proton Beam Therapy: The Futuristic Cancer Treatment That Could Improve Outcomes–If You Can Get It Approved
Breast cancer survivor Hauli Sioux Gray was prescribed proton beam therapy (PBT) after going through a single mastectomy and chemotherapy. Her doctor thought that the targeted therapy would reduce the chance that Gray, only 34, would experience radiation-related heart problems in the future.
But Gray’s insurance company did not think that PBT—more expensive than traditional radiation—was necessary. They denied her claim three times.
Proton beam therapy sounds like something straight out of Star Trek. But instead of sending photon torpedoes toward hostile alien ships, the therapy sends proton beams toward cancer cells. A machine delivers the beams to very specific parts of the body at specific speeds. The speed of the proton beam determines how deep it will travel so that once the beam hits its target depth, it delivers its dose of radiation. The radiation does not go beyond the tumor, does little damage to nearby tissue, and is painless.
Traditional radiation therapy, though effective, goes all the way through the body, which means it can damage healthy tissue on the way out and cause short-term side-effects and long-term risks. Radiation, both in the form of proton beams and standard x-ray radiation, works to destroy cell function so that they can’t repair themselves or maintain their normal functions. Because cancer cells are less able to repair themselves, radiation kills cancer cells while other cells, eventually, repair themselves.
But it’s a rough process. X-ray radiation has to be delivered in strong enough doses to ensure that all the cancer cells die, but most of the energy from one x-ray beam will end up in healthy tissue near the body’s surface.
Proton beams, however, slow down and stop at a targeted point: cancer cells. So the cancer cells get the biggest wallop of radiation from a proton beam, and the surrounding tissue gets much less. Patients are restrained on a table while the PBT machine aligns with specific spots on their body and delivers the beams. It’s not comfortable, but it’s an out-patient procedure that only lasts about 15 to 30 minutes per session.
But it’s not necessarily the obvious choice. While proton beam therapy is generally the standard for cancers around sensitive tissue (such as brain, head, nervous system, and lung cancers) as well as for cancer in children (to minimize the risk of damage to surrounding developing tissue), it’s not an inexpensive treatment. PBT usually costs about double what traditional radiation does. In some cases, it’s hard to determine how much of a benefit it provides over traditional radiation.
The American Society for Radiation Oncology recommends PBT for the types of cancer mentioned above, but only for other cancers (such as breast, prostate, and lung cancer) if a patient is also enrolled in a clinical trial. The National Comprehensive Cancer Network (a not-for-profit alliance of leading cancer centers) only recommends PBT for breast cancer unless other forms of radiation won’t work for a patient.
In Gray’s case, PBT was recommended because her tumor was near her heart, so radiation put her at greater risk of heart attack later on. Some studies have shown that PBT decreases the risk of a negative cardiac event by 0.4 percent over 20 years. Other studies have found that cardiac risk increased by 7.4 percent for every unit of traditional radiation.
“If it’s just going to be my skin that I have a problem with (because of radiation side effects), I can deal with that. I’m more worried about my heart,” Gray said.
Gray was able to have PBT through the Indian Health Service because she is a member of the Ponca and Tonkawa tribes in Oklahoma, but she is concerned that the same options might not be available for other patients.
According to NewsOK, for every 250 women in their fifties treated with PBT over traditional radiation, there will likely be about one fewer who experiences a serious cardiac problem. While the percentage of improvement seems small, increasing the odds in any way possible makes sense when you’re thinking of your heart. But the price of PBT means higher insurance premiums for everyone, and insurance companies are hesitant to approve the new and costly procedure.
Experts, both insurance companies and doctors, disagree about whether PBT is really effective enough to justify the cost. More data is coming, but it’s slow. Still, studies are happening as facilities are being built, and more patients are becoming interested in PBT. We can hope that a clearer idea of when PBT is advisable and when it’s not will be forthcoming—rather than just an idea of when it’s affordable or not.