Prostate high dose-rate brachytherapy as monotherapy for low and intermediate-risk prostate cancer: Efficacy results from a randomized phase II clinical trial of one fraction of 19 Gy or two fractions of 13.5 Gy: A 9-year update

•Long-term outcomes of HDR brachytherapy for low and intermediate prostate cancer.•Treatment given as single 19 Gy fraction or two 13.5 Gy fractions, with 9-year follow-up.•We observed that two fractions of 13.5 Gy led to a robust, long-term PSA response with acceptable toxicity.•In contrast, a single fraction of 19 Gy yielded poor oncologic outcomes and is not recommended.•Contributes to the ongoing debate on optimal HDR monotherapy strategies to manage low and intermediate-risk prostate cancer. High dose-rate (HDR) brachytherapy as a monotherapy is an accepted treatment for localized prostate cancer, but the optimal dose and fractionation schedule remain unknown. We report on the efficacy of a randomized Phase II trial comparing HDR monotherapy delivered as 27 Gy in 2 fractions vs. 19 Gy in 1 fraction with a median follow-up of 9 years. Enrolled patients had low or intermediate-risk disease,