Testing Shorter Duration Radiation Therapy Versus the Usual Radiation Therapy in Patients With High Risk Prostate Cancer

PRIMARY OBJECTIVE: I. To compare metastasis-free survival, determined using conventional imaging, between men with high-risk prostate cancer randomized to ultrahypofractionation (stereotactic body radiation therapy \[SBRT\]) to those randomized to moderate hypofractionation and conventional fractionation. SECONDARY OBJECTIVES: I. To compare physician-reported toxicity as measured by Common Terminology Criteria for Adverse Events (CTCAE) version (v)5 between treatment arms. II. To determine if ultrahypofractionation is non-inferior to moderate hypofractionation and conventional fractionation with respect to patient-reported urinary function (assessed by Expanded Prostate Cancer Index Composite \[EPIC\]-26 urinary domains). III. To determine if ultrahypofractionation is non-inferior to moderate hypofractionation and conventional fractionation with respect to patient-reported bowel function (assessed by EPIC-26 bowel domain). IV. To compare patient-reported fatigue (assessed by Patient Reported Outcomes Measurement Information System \[PROMIS\]-Fatigue) between treatment arms. V. To compare failure-free survival between treatment arms. VI. To compare metastasis-free survival based on molecular imaging between treatment arms. VII. To compare overall survival between treatment arms. EXPLORATORY OBJECTIVES: I. To compare patient-reported sexual function (assessed by EPIC-26 sexual domain) between treatment arms. II. To compare patient-reported quality of life (assessed by European Quality of Life Five Dimension Five Level Scale Questionnaire \[EQ-5D-5L\]) between treatment arms. III. To compare patient-reported treatment burden (assessed by COmprehensive Score for financial Toxicity (COST)) between treatment arms OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients undergo SBRT for a total of 5 treatments over 2 weeks in the absence of disease progression or unacceptable toxicity. Patients also undergo bone scan and/or computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)/CT during screening and CT and/or MRI on study. Additionally, patients may optionally undergo blood and urine sample collection on study. ARM II: Patients undergo external beam radiation treatment (EBRT) for 20-45 treatments over 4 to 9 weeks in the absence of disease progression or unacceptable toxicity. Patients also undergo bone scan and/or CT, MRI, or PET/CT during screening and CT and/or MRI on study. Additionally, patients may optionally undergo blood and urine sample collection on study. Patients are followed up every 6 months for 5 years.