RecruitingRadiation therapyProton Radiation Therapy for the Treatment of Patients With High Risk Prostate CancerThis phase II trial investigates whether proton radiation therapy directed to the prostate tumor, pelvic, and para-aortic lymph nodes, is an effective way to treat patients with high-risk or lymph node positive prostate cancer who are receiving radiation therapy, and if it will result in fewer gastrointestinal and genitourinary side effects. Proton beam therapy is a new type of radiotherapy that directs multiple beams of protons (positively charged subatomic particles) at the tumor target, where they deposit the bulk of their energy with essentially no residual radiation beyond the tumor. By reducing the exposure of the healthy tissues and organs to radiation in the treatment of prostate cancer, proton therapy has the potential to better spare healthy tissue and reduce the side effects of radiation therapy.