What is Proton Therapy?

Proton beam therapy is a type of radiation that uses particles called protons, whereas traditional radiation therapy uses photons, or X-rays. Protons deliver radiation to a more targeted area than photons can achieve, which means it has the potential to spare more healthy tissue or organs as the radiation more precisely hits the tumor. This could mean fewer side effects for patients. Some physicians also believe proton therapy may allow higher doses of radiation to be used, but this has not been shown.

Loma LindaHenry Ford Health System

University of Michigan Health System

The technology has existed since 1954, but had very limited use outside of physics laboratories until 1990, when the first hospital-based proton treatment center opened at Loma Linda University Medical Center in California. Currently, five facilities across the country offer proton beam therapy, with at least a half dozen additional sites planned or proposed. Building a treatment center will cost an estimated $160 million and is 2.5 times more expensive than traditional photon therapy.

Proton beam therapy appears to be most promising for treating certain types of tumors where precision is of the utmost importance. It is also believed to be beneficial for some pediatric tumors, and may reduce the risk of the child developing a second cancer later in life. Currently, proton beam therapy is most commonly used for pediatric cancers, prostate cancer, ocular (eye) cancers and other skull-based tumors.

While the treatment is most often used for prostate cancer, scientific research to date has not shown this therapy provides any benefit for prostate cancer patients over the best standard treatment options. Essentially all of the conclusions have relied on non-controlled studies, meaning the results were not compared to similar patients receiving traditional therapy. Careful prospective trials are required to determine whether there is any measurable benefit to proton therapy, and if so, whether the benefit justifies the substantially increased cost over photon therapy.