ABSTRACT
PURPOSE: To retrospectively evaluate biochemical control and toxicity in patients who underwent 125I seed brachytherapy (BT) for intermediate-risk prostate cancer (PCa). MATERIALS AND METHODS: Between January 2004-December 2014, 395 patients with intermediate-risk PCa underwent 125I BT. Of these, 117 underwent preoperative planning (PP; 145â¯Gy) and 278 real-time intraoperative preplanning (IoP; 160â¯Gy). All patients were followed for ≥ 6 months (> 5 years in 48% of patients and > 7 years in 13%). Median follow-up was 59 months. RESULTS: Biochemical relapse-free survival (BRFS) rates at 5 and 8 years were, respectively, 91.7% and 82.1%. By treatment group, the corresponding BRFS rates were 93.5% and 90% for IoP and 89% and 76.8% for PP. The maximum dose to the urethra remained unchanged (217â¯Gy) despite the dose escalation (from 145 to 160â¯Gy), without any significant increase in treatment-related toxicity (pâ¯=â¯0.13). Overall toxicity outcomes in the series were excellent, with only 3 cases (0.76%) of grade 3 genitourinary toxicity. CONCLUSION: The real-time intraoperative planning technique at 160â¯Gy yields better biochemical controls than the preoperative planning technique at 145â¯Gy. Dose escalation did not increase urinary toxicity. The excellent results obtained with the IoP BT technique support its use as the first treatment option in this patient population.