Title: Comparison of A1-Blockers for Acute Urinary Symptoms after Prostate Brachytherapy
Abstract: Acute urinary symptoms are very common complications resulting prostate brachytherapy for patients with clinically localized prostate cancer. The treatment of acute urinary symptoms has not yet been well established. In the present study, we aimed to assess the efficacy of 2 α1 -blockers (tamsulosin and silodosin) for the treatment of acute urinary symptoms resulting from prostate brachytherapy in Japanese patients. This single-institution prospective randomized controlled trial compared the efficacy of tamsulosin and silodosin in patients undergoing iodine-125 prostate brachytherapy. The patients were randomly grouped and received either tamsulosin or silodosin. The therapeutic dosages of tamusulosin and silodosin administered to the patients were 0.2 mg/day and 8 mg/day, respectively. This study included 70 patients between June 2006 and November 2011: 34 and 36 patients in the tamsulosin and silodosin groups, respectively. No significant differences in the pretreatment variables of the 70 patients were observed between both the groups. The α1 -blocker treatment was initiated 1 day after seed implantation and was continued for 1 year. The changes in the total International Prostate Symptom Score (IPSS), Quality of Life (QOL) index score, uroflowmetry (UFM) results, and residual urine (RU) values were estimated during the study (1, 3, 6, and 12 months). The median total IPSS at 1 month after prostate brachytherapy in the tamsulosin and silodosin groups were 17.6 and 18.9, respectively. Significant increases in IPSS within the 2 groups were observed at 1-3 months following prostate brachytherapy. Moreover, IPSS improved at 6 months and recovered to baseline at 12 months. No significant differences were observed in the changes of total IPSS, QOL index score, Qmax, and RU values in both the groups. Thus, this study indicates that α1 -blockers are a potential treatment for preventing radiation-induced acute urinary symptoms. Moreover, tamsulosin and silodosin may have an almost similar effect in patients with radiation-induced urinary toxicity.