Predictive factors for acute and late urinary toxicities after permanent prostate brachytherapy.

90 Background: To describe the frequency of acute and late Radiation Therapy Oncology Group (RTOG) urinary toxicity associated with predictive factors and International Prostate Symptom Score (IPSS) in consecutive prostate brachytherapy patients. Methods: From January 2004 to April 2011, 466 patients underwent permanent 125I-seed brachytherapy (median follow-up, 48 months). The IPSS and RTOG toxicity data were prospectively collected. The prostate volume, IPSS before and after brachytherapy and postimplant analysis were examined for an association with urinary toxicity which was defined as urinary RTOG toxicity 1 or more. Logistic regression analysis was used to examine the factors associated with urinary toxicities. Results: The rate of RTOG urinary toxicity Grade 1 or more at 1, 6, 12, 24, 36, 48 months was 67%, 40%, 21%, 31%, 27%, 28%, respectively. Grade 2 or more urinary toxicities were less than 1% at an each point. IPSS was highest at 3 months and returned to normal level at 12 months after brachyt...