Outcomes of salvage high dose-rate brachytherapy with or without pelvic external beam radiotherapy in patients with palpable local recurrence of prostate cancer after radical prostatectomy.

PURPOSE

This study aims to evaluate the outcomes and toxicities in patients with palpable local recurrence of prostate cancer after radical prostatectomy (RP), who were treated with salvage high dose-rate brachytherapy (HDR-BT) with or without pelvic external beam radiotherapy (EBRT).

METHODS

This retrospective review included patients with palpable local recurrence of prostate cancer after RP who underwent salvage HDR-BT at a single institution between 2002 and 2020. HDR-BT regimens included 950 cGy x 2 (N = 4) or 1500 cGy x 1 (N = 2) combined with EBRT; or monotherapy with 950 cGy x 4 (N = 1) or 800 cGy x 2 (N = 1). Toxicity was graded according to CTCAE Version 5.0.

RESULTS

A total of 8 patients were included. Median follow-up was 49 months (range: 9-223 months). Median age at time of salvage brachytherapy was 68 years (range: 59-85 years). Seven out of 8 patients were alive at last follow-up. There have been no locoregional recurrences. Three patients developed distant metastatic disease. One patient developed acute grade 3 urinary obstruction requiring catheterization, which lasted for 1 day postbrachytherapy. One patient developed late grade 3 urinary incontinence 18 months after brachytherapy. There were no other grade 2+ toxicities.

CONCLUSIONS

This study demonstrates the safety and efficacy of salvage HDR-BT in the setting of palpable local recurrence of prostate cancer after RP, with durable locoregional control and acceptable rates of toxicity. HDR-BT should be further explored as an option for dose-escalated salvage radiotherapy after prior radical prostatectomy.