Pretreatment Voiding Volume as a Predictor of Post-brachytherapy Urinary Quality of Life in Patients With Prostate Cancer: A Retrospective Study.

Introduction This study was performed to investigate the relationship between changes in urination-related quality of life (QOL) after brachytherapy and preoperative findings, including urinary function, urination scores, and patient background. Methods This retrospective study included 193 patients with localized prostate cancer who underwent brachytherapy at our institution. Urination-related QOL was assessed using the urinary domain of the Expanded Prostate Cancer Index Composite (EPIC) score, measured before treatment and 3, 6, and 12 months after treatment. Changes in EPIC scores from baseline were analyzed, and preoperative urination-related parameters - including prostate volume, maximum urinary flow rate, voiding volume, age, International Prostate Symptom Score (IPSS), and Overactive Bladder Symptom Score (OABSS) - were compared with post-treatment QOL outcomes. Results The urination-related EPIC score was lowest at three months post-treatment but gradually improved toward baseline levels. Patients with a preoperative voiding volume of <192 mL showed significantly greater declines in EPIC scores at 3, 6, and 12 months post-treatment. Additionally, those with an IPSS of <7 or an OABSS of <3 had significantly greater declines at six months, but these differences were not observed at 12 months. Prostate volume, maximum urinary flow rate, and age did not significantly impact changes in EPIC scores. Conclusion Preoperative voiding volume was significantly associated with changes in post-treatment urination-related QOL. These findings suggest that preoperative urination-related parameters may help predict post-treatment QOL, highlighting the importance of evaluating pretreatment urinary function when selecting treatments for patients with localized prostate cancer.