Worse Prostate Cancer Outcomes With 5-Alpha-Reductase Inhibitors

96. Background: To investigate the impact of 5-alpha-reductase inhibitors (5-ARIs) usage on radiotherapy outcomes for localized prostate cancer.Methods: From our institutional database of over 2500 patients, we identified 203 patients on a 5-ARI. They were all treated with either external beam radiotherapy (EBRT) or brachytherapy for localized prostate cancer.