This phase III trial tests the side effects of stereotactic body radiation therapy (SBRT) compared to hypofractionated radiotherapy for treating patients with prostate adenocarcinoma that has come back after a period of improvement (recurrent) or that has spread from where it first started (primary site) to a limited number of sites (oligometastatic). SBRT is a type of external radiation therapy that uses special equipment to position a patient and precisely deliver radiation to tumors in the body (except the brain). The total dose of radiation is divided into smaller doses given over several days. This type of radiation therapy helps spare normal tissue. Hypofractionated radiation therapy delivers higher doses of radiation therapy over a shorter period of time and may kill more tumors cells and have fewer side effects. SBRT may work just as well as hypofractionated radiation therapy at treating patients with biochemically recurrent or oligometastatic prostate cancer, but with a shorter treatment time and possibly fewer side effects.
Histologically confirmed prostate adenocarcinoma at the time of surgery
Pathologic stages T2-T3b, Nx or N0-1, M0-1 as staged by the pathology report (American Joint Committee on Cancer [AJCC] Criteria 8th edition [Ed.])
PSA post radical prostatectomy ≥ 0.1 and < 2.0 ng/mL ≤ 90 days prior to enrollment, obtained ≥ 6 weeks after surgery
Eastern Cooperative Oncology Group (ECOG) performance status 0, 1, or 2 assessed ≤ 90 days of enrollment
Previous pelvic radiation
Prior androgen deprivation therapy for prostate cancer and PSA ≥ 0.1 ng/mL
Active rectal diverticulitis, Crohn's disease affecting the rectum, or ulcerative colitis (non-active diverticulitis and Crohn's disease not affecting the rectum are allowed)
Prior systemic chemotherapy for prostate cancer