Low-Dose-Rate Brachytherapy for Prostate Cancer: Outcomes Beyond 10 Years of Follow-Up

To examine biochemical control, survival, and late morbidity with definitive low-dose-rate brachytherapy (LDR-BT) for prostate cancer patients surviving ≥10 years post-treatment.

We identified 757 men with localized prostate cancer who underwent definitive LDR-BT in the period 1990-2006 and were followed for ≥10 years at our institution. Biochemical failure-free survival (BFFS), distant metastases-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were selected as study endpoints. Survival was examined using the log-rank test, Kaplan-Meier method, and Cox regression modeling. Urinary, quality of life (QoL), and potency scores at baseline and last follow-up were recorded.

Median follow-up was 12.5 years (range, 10.1-21.8 years). At the time of analysis, 88.6% of patients were alive, 1.5% died of PC, and 13.9% developed biochemical failure, with 82% of failures occurring in the first decade of follow-up. Overall, 2.3% developed distant metastases (DM). On multivariate analyses, stage T3a-T3b, PSA >20, intermediate-risk and high-risk disease predicted worse BFFS, whereas age >70 years at diagnosis and stage T3a-T3b - worse OS. Total BED ≥150Gy and ADT were associated with improved BFFS, but not OS. The overall 17-year rates for BFFS, DMFS, PCSS, and OS were 79%, 97%, 97%, and 72%, respectively. Respective 17-year BFFS rates for low-risk, intermediate-risk, and high-risk patients were 86%, 80%, and 65% (p<0.00001), whereas OS rates for the same groups were 82%, 73%, and 60% (p=0.09). Among those patients who were potent at baseline, 25% remained potent by the last follow-up. Urinary function and QoL were mainly unaffected.

LDR-BT yields excellent survival rates, with 17-year PCSS of 97%. 18% of patients with biochemical relapse fail ≥10 years post-implantation which justifies their continued follow-up. This article is protected by copyright. All rights reserved.

BJU international. 2018 Jan 10 [Epub ahead of print]

S Lazarev, M R Thompson, N N Stone, R G Stock

Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY., Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY.