Use of 5-alpha-reductase inhibitors as alternatives to luteinizing-hormone releasing hormone (LHRH) analogs or anti-androgens for prostate downsizing before brachytherapy

Introduction: Prostate hypertrophy, median lobe hypertrophy, and pubic arch interference (PAI) are relative contraindications to brachytherapy because of potential morbidity and technical considerations. GnRH analogs or non-steroidal anti-androgens are currently utilized to achieve prostatic downsizing prior to brachytherapy. However, such agents have been associated with effects on body habitus, metabolism, and quality of life. In contrast, 5-alpha reductase inhibitors (5-ARI) are far less frequently associated with these morbidities. Methods and materials: Patients with large gland size, median lobe hypertrophy, or PAI were offered 5-ARI therapy. Repeat transrectal ultrasound was performed at 3 or 4 months, followed by brachytherapy if resolution was achieved. If downsizing was inadequate, patients were offered continuation of 5-ARI for additional 3 months, gonadotropin-releasing hormone analog (GnRH) agonist or antiandrogen therapy, or other curative treatment. Results: Of 59 patients with follow-up available, 42 (71%) were deemed to have adequate downsizing; 37 (63%) after 3 to 4 months of 5-ARI and 5 (8%) after 7 to 8 months. Seventeen patients (29%) received other treatments because of inadequate effect. Median volume reduction was 20%. Of 41 patients undergoing brachytherapy, 4 (9.7%) required temporary catheterization because of obstruction. Median follow-up after implantation was 25 months (range, 1-64). Median time for return to International Prostate Symptom Score ≤5 of baseline score was 7 months (interquartile ratio, 6-13). All but 1 patient who received brachytherapy remain biochemically controlled. Conclusion: 5-ARI monotherapy is an alternative for downsizing in patients with hypertrophy or PAI, with more than 70% achieving adequate downsizing without use of GnRH analogs or antiandrogens. Patients who received brachytherapy experienced typical rates of postimplant urinary morbidity.