Efficacy and safety of salvage brachytherapy for local recurrence after radiotherapy for prostate cancer.

PURPOSE: To evaluate the efficacy and safety of salvage brachytherapy (SBT) as a curative treatment option for patients with locally recurrent prostate cancer after prior radiation therapy.

MATERIALS AND

METHODS

Between 2009 and 2023, we analyzed 108 prostate cancer patients with local recurrent after radiotherapy. SBT was performed as a sole treatment using either HDR (high dose rate) brachytherapy with a total dose of 30 Gy in three fractions (78.0 Gy EQD2 α/β=3 Gy) or PDR (pulse dose rate) brachytherapy with a total dose of 60 Gy in two sessions (71.5 Gy EQD2 α/β=3 Gy), with a three-week interval between sessions in both regimens.

RESULTS

Median follow-up was 41 months (range 6-173). Median interval between initial radiation and salvage brachytherapy was 66 months (range 18-214). The 5-year cumulative incidence of local recurrence was 17.0%. Local relapse was observed in 15 patients (13.8%). The 2- and 5-year biochemical disease-free survival according to the Phoenix definition were 83.6% and 59.9%. The 2- and 5-year progression-free survival were 77.0% and 53.2%; overall survival rates were 96.9% and 87.4%, respectively. Grade ≥ 3 urinary toxicity was uncommon, with 2/93 (2.1%) patients requiring transurethral resection and 6/93 (6.5%) long-term catheterization. Most patients had grade 0-1 incontinence; grade 2 and grade ≥ 3 occurred in 13/79 (16.5%) and 7/79 (8.8%) at 24 months. Proctitis was rare; no grade ≥ 3.

CONCLUSIONS

Salvage brachytherapy offers an effective and well-tolerated curative option for patients with locally recurrent prostate cancer after prior radiation therapy.