Tumor control and morbidity following transperineal iodine 125 implantation for stage T1/T2 prostatic carcinoma

Purpose: To quantify disease progression and morbidity following computer tomography (CT)-based transperineal iodine 125 prostate implantation. Methods: Ninety-two patients with clinical stage T1 or T2, Gleason score 2 to 7/10, prostatic carcinoma had outpatient, CT-based transperineal I-125 prostate implantation and were monitored for 1 to 7 years (median, 3). The prescribed minimum radiation dose was 140 to 160 Gy. Lymph node dissection and postimplantation prostatic biopsies were not routinely performed. Results: In 46% of patients, radiation-related urinary symptoms were substantial enough at 1 month following implantation to require medication. Radiation-related urinary symptoms gradually resolved. Two years after implantation, 14% of patients had persistent urinary symptoms of Radiation Therapy Oncology Group (RTOG) greater than or equal to grade 2. Eight percent of patients underwent a transurethral resection of the prostate (TURF) within 2 years of implantation. Five patients developed radiation-induced rectal ulcerations. Of 56 patients who were sexually potent preimplantation, 86% retained potency at 3 years. Twenty-five patients had biochemical disease progression. The overall actuarial freedom from biochemical failure rate at 4 years following implantation was 63%. In Cox proportional hazards multivariate analysis, the strongest predictor of failure was prostate-specific antigen (PSA) level less than or greater than 10 ng/mL (P=.005), followed by Gleason score (2 to 4 v 5 to 7, P=.08) and stage (T1 v T2, P=.09). Conclusion: The 5-year biochemical freedom-from-progression rates following transperineal I-125 implantation are comparable with those achieved with prostatectomy. The morbidity has decreased with increased physician experience. (C) 1996 by American Society of Clinical Oncology.