Alpha 1-Adrenoceptor Blocker May Improve Not Only Voiding But Also Storage Lower Urinary Tract Symptoms Caused by 125I Brachytherapy for Prostate Cancer

Purpose. To assess changes in lower urinary tract symptoms (LUTS) within 1 year after brachytherapy in patients receiving alpha 1-adrenoceptor antagonists. Methods. We retrospectively evaluated 116 patients who underwent 125I prostate brachytherapy in our institute. Seventy-one patients were treated with a combination of external beam radiation therapy and brachytherapy. Alpha 1-adrenoceptor antagonists were prescribed to all patients after brachytherapy. International Prostate Symptom Score (IPSS) forms and postvoid residual urine volume were recorded at all follow-up visits. Results. Forty-nine patients were given tamsulosin hydrochloride, 32 were given silodosin hydrochloride, and 35 were given naftopidil for up to 6 months after seed implantation. Patients given tamsulosin or naftopidil tended to show a higher peak IPSS and slower recovery to baseline values than those given silodosin. The patients given naftopidil showed an insufficient recovery in storage symptoms in naftopidil group in comparison with tamsulosin group at 3 months and with silodosin group at 6 and 9 months. Conclusions. In the management of LUT after brachytherapy, silodosin may provide a more favorable improvement. Silodosin and tamsulosin may have an advantage in improving not only voiding but also storage lower urinary tract symptoms after brachytherapy. 1. Introduction Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer death in men over the age of 40 years in the United States [1], and its incidence has been increasing in Japan. Since its approval in September 2003, interest in the use of 125I prostate brachytherapy for localized prostate cancer has increased, and the Japan-Prostate Cancer Outcome Study Group has estimated that more than 18,000 patients have received this therapy up to March 2011. This increase has been accompanied by growing recognition that lower urinary tract symptoms (LUTS) after seed implantation are a major complication of brachytherapy [2–6]. Management of this complication remains ineffective, however, substantially impacting quality of life after treatment. Alpha 1-adrenoceptor antagonists are well known to provide relief from LUTS caused by benign prostate hyperplasia (BPH) and are recommended for patients complaining of LUTS after seed implantation [7–9]. 1-adrenoceptors are generally subdivided into alpha 1A-, alpha 1B-, and alpha 1D-adrenoceptor subtypes [10]. The alpha 1A-adrenoceptor subtype predominates in the prostatic stroma at the mRNA and protein level and is responsible for the dynamic component of