Combination of IG-IMRT and Permanent Source Prostate Brachytherapy in Patients with Organ-Confined Prostate Cancer: GU and GI Toxicity and Effect on Erectile Function

PURPOSE: To assess toxicity outcomes of image-guided intensity-modulated radiation therapy (IG-IMRT) combined with permanent prostate seed implant in a cohort of patients with localized prostate cancer.METHODS AND MATERIALS: A retrospective analysis was performed on 67 patients with the median pretreatment prostate-specific antigen level of 5.4. The Gleason score was less than 7 in 7 patients, 7 in 52 patients, and greater than 7 in 8 patients. The median followup was 28.2 months (range, 12-89.5 months). Treatment consisted of 45 (n = 65) or 50.4 Gy (n = 2) at 1.8 Gy/fraction of IG-IMRT to the prostate and seminal vesicles. Eight patients had simultaneous irradiation of pelvic lymph nodes to 45 (n = 65) or 50.4 Gy (n = 2). After IG-IMRT, patients received transperineal prostate implant boost with either (103)Pd (n = 65, the prescribed D(90) of 100 Gy) or (125)I (n = 2, D(90) of 110 Gy). Eleven patients received androgen deprivation therapy with radiotherapy.RESULTS: Toxicity higher than Grade 3 was not observed. The combined incidence of acute and late Grade 3 genitourinary toxicity was 6%. The combined incidence of acute and late Grade 3 gastrointestinal toxicity was 3%. At least one episode of gastrointestinal bleeding on followup, which could be attributed to radiation, was recorded in 14.9% of patients. For patients achieving erections before radiation, the 3-year Kaplan-Meier potency preservation rate was 66.5%.CONCLUSIONS: The early toxicity of the combination of IG-IMRT and low-dose rate brachytherapy boost in this study was favorable. (C) 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.