Permanent interstitial low-dose-rate brachytherapy for prostate cancer: institutional experience with implementation and predictive factors for outcome and side effects

Abstract Introduction: Low-dose-rate brachytherapy (LDR brachytherapy) with Iodine-125-seeds is an established treatment modality for low- and favourable intermediate-risk prostate cancer. Our single institution experience in this field was retrospectively studied. Methods: Two-hundred sixty consecutive patient records were reviewed for demographic, disease, therapy and side effect data. The patients were divided into subgroups by pre- and post-implant prostate-specific antigen (PSA) levels and by different LDR brachytherapy techniques used, that is, preoperative planning technique (PPT) versus intraoperative real-time planning (IOR). Data were analysed by Kaplan–Meier method and appropriate testing was conducted for PSA biochemical recurrence (BCR) and for toxicities. Results: After median follow-up of 65·0 months, 94·0% of all patients were free from BCR. This endpoint showed no significant differences by patient age, initial PSA, PSA decrease over time, Gleason score and implanted total activity. Patients with IOR were free of BCR in 98·9% (180/182) versus 76·9% (40/52) with PPT. All patients with a PSA nadir of <0·1 ng/mL were free from BCR. Six patients (2·5%) reported an incontinence grade 1. Transient nocturia/urge and dysuria appeared in 54·7% and 22·6% of patients. Conclusions: Consistent with literature, LDR brachytherapy for low- and intermediate-risk prostate cancer appeared highly effective for freedom from BCR with mild side effects.