High-Dose-Rate Brachytherapy As Monotherapy For Favorable-Risk Adenocarcinoma Of The Prostate Delivered In A Single 19 Gy Fraction: Preliminary Results Of A Prospective Pilot Study

INTRODUCTION: We evaluated the acute genitourinary (GU) and gastrointestinal (GI) toxicities, health-related quality of life (HRQOL) factors, biochemical control rates, and technical feasibility of high-dose-rate (HDR) brachytherapy as monotherapy for favorable-risk prostate cancer delivered in a single 19 Gy fraction. METHODS: A single-institution, prospective pilot study was performed by evaluating 6 patients with low- and intermediate-risk prostate cancer treated with high-dose-rate (HDR) brachytherapy as monotherapy. Patients received a single 19 Gy fraction as HDR monotherapy without the use of a transperineal hyaluronic acid injection. Patients were assessed according to the Common Terminology Criteria for Adverse Events version 4.0 and Health-Related Quality of Life (HRQOL) questionnaires. Additionally, prostate specific antigen levels have been followed for evidence of biochemical failure. RESULTS: All 6 patients tolerated the implant well and were all discharged home the same day. Median follow-up was 15 months with all subjects followed for at least 12 months. No grade 3, 4, or 5 toxicities were observed. Two of the 6 patients experienced grade 2 GU toxicity. One patient experienced grade 2 GI toxicity. HRQOL bowel and urinary assessments revealed peak complaints at 3 months which returned to baseline at 6 months. There have been no biochemical relapses. CONCLUSION: This is the first study using HDR brachytherapy as monotherapy for favorable-risk prostate cancer using one implant delivered in a single 19 Gy dose in the United States. All patients demonstrated acceptable acute toxicities and were pleased with their cost-effective treatment choice. Citation Format: Scott Dahlbeck, Chase C. Hansen, Werner deRiese, A. Robert Kagan, Carlos Torres, Maurizio Chiriva-Internati, Everardo Cobos, Jose A. Figueroa, Diane Nguyen, Lukman Tijani, Jaden D. Evans. High-dose-rate brachytherapy as monotherapy for favorable-risk adenocarcinoma of the prostate delivered in a single 19 Gy fraction: Preliminary results of a prospective pilot study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3440. doi:10.1158/1538-7445.AM2015-3440