Salvage high-dose-rate interventional radiotherapy (brachytherapy) for locally relapsed prostate cancer after radical prostatectomy and subsequent external irradiation

Purpose: To report the use of high-dose-rate (HDR) interventional radiotherapy (brachytherapy, IRT) as a salvage treatment for macroscopic histologically confirmed local relapse of prostatic cancer after prostatectomy and subsequent external irradiation. Material and methods: A retrospective study of patients with prostate adenocarcinoma, treated with HDR-IRT for an isolated local relapse after prostatectomy and external irradiation at our institution (2010-2020). Treatment results and treatment related-toxicity were recorded. Clinical outcomes were analyzed. Results: Ten patients were identified. The median age was 63 years (range, 59-74 years), and the median follow-up time was 34 months (range, 10-68 months). Four patients had a biochemical relapse, and the mean time to prostate specific antigen (PSA) increase was 13 months. One-year biochemical failure-free survival (bFFS), 3-year bFFS, and 4-year bFFS were 80%, 60%, and 60%, respectively. Most of the treatment-related toxicities were grade 1-2. Two patients experienced grade 3 late genitourinary toxicity. Conclusions: HDR-IRT seems to be an effective treatment option showing acceptable toxicity for prostate cancer patients with isolated macroscopic histologically confirmed local relapse after prostatectomy and subsequent external irradiation.