Proton therapy is simply using a beam of protons to deliver precision radiation therapy. In a fashion identical to intensity modulated radiation therapy (IMRT), patients are treated daily on an outpatient basis. A typical treatment session lasts 15 to 20 minutes with most of that time devoted to patient positioning. The treatment delivery—beam-on-time—is usually less than 60 seconds. Unlike the photon radiation used in IMRT, protons come to an abrupt stop at their target point within the body. Photons, and thus IMRT, expose a larger volume of healthy tissue outside the target area; men who are considering IMRT might want to consider proton therapy instead. 

Recent Advances

A recent development in proton treatment is the development of intensity-modulated technology for protons. Intensity modulated proton therapy (IMPT) permits coverage of the pelvic lymph nodes. The Scripps Proton Treatment Center, which opened in San Diego in 2014 is the first center in the United States to use IMPT.

Clinical Trials

Initial clinical data published in 1994 confirmed the safety and efficacy of proton beam therapy. A subsequent publication that looked at over 1,200 patients was published in 1997, revealing that proton beam therapy could achieve cure rates equal to radical prostatectomy with a lower rate of toxicity. Using proton therapy, greater dose-specificity and better normal tissue sparing can be achieved over the results achievable with the older proton techniques.





Carl Rossi, MD is a radiation oncologist specializing in proton beam therapy, specifically for prostate cancer and lymphomas. He is also the current medical director for the Scripps Proton Therapy Center, which will provides treatment to target tumors with high control and precision. In addition to treating a variety of cancers with radiation, it is also used to treat some non-cancerous conditions. Dr. Rossi has a research focus on the quality of life and cure rate in prostate cancer and lymphoma treated with proton beam radiation.