Hypofractionated Stereotactic Body Radiation Therapy for Patients With Prostate Cancer That Was Removed by Surgery

This phase I trial studies the side effects and the best dose of hypofractionated stereotactic body radiation therapy (SBRT) in treating patients with prostate cancer that was removed by surgery. Hypofractionated SBRT delivers higher doses of radiation therapy over a shorter period of time and may kill more tumor cells and may have fewer side effects than standard radiation therapy.

PRIMARY OBJECTIVES: I. To determine maximum tolerated dose-per-fraction for SBRT to the prostate fossa following prostatectomy based on acute toxicity (\< 90 days). SECONDARY OBJECTIVES: I. To describe the acute (\< 90 days) toxicities and adverse events associated with hypofractionated SBRT when administered to the prostate bed in the post-prostatectomy setting. II. To describe the late (\> 90 days from treatment) toxicities and adverse events associated with hypofractionated SBRT when administered to the prostate bed in the post-prostatectomy setting. TERTIARY OBJECTIVES: I. To describe the patient-reported toxicity/quality of life (QOL) following hypofractionated SBRT treatment. OUTLINE: This is a dose-escalation study. Patients undergo 5, 10, or 15 fractions of hypofractionated SBRT daily over 1-3 weeks. After completion of study treatment, patients are followed up at 2, 6, and 13 weeks and then at 6, 9, 12, 18, 24, 30 and 36 months.