The ATC® serves as Radiorepository for PCORI COMPPARE. This study is a large, prospective, pragmatic, controlled comparison of patient-centric outcomes [quality of life (QOL), toxicity, and disease control] between parallel cohorts of men with prostate cancer treated simultaneously at proton therapy facilities and at geographically similar conventional (photon-based) radiation facilities using intensity-modulated radiation therapy (IMRT) techniques. This study includes a pre-specified randomized comparison of standard fractionation and moderate hypofractionation dose schemes within the proton therapy cohort. In addition, subgroup analyses will include a comparison of outcomes by race (Black vs. White), comorbidity score (0 vs. 1+), age (<65 vs. ≥65), and prostate cancer aggressiveness (low, intermediate, and high risk) for all endpoints.