To evaluate the relationship between pretreatment postvoid residual urine (PVR) less than 100 mL and brachytherapy-related urinary morbidity.

A total of 204 patients with a pretreatment PVR measurement underwent permanent prostate brachytherapy with urethral-sparing techniques (100% to 140% minimal peripheral dose) for clinical Stage T1b–T2c (2002 American Joint Committee on Cancer staging system) prostate cancer. The median follow-up was 11.7 months. Evaluation of urinary morbidity consisted of the time to International Prostate Symptom Score (IPSS) resolution, length of catheter dependency, and the need for postimplant surgical intervention. IPSS resolution was defined as a return to within 1 point of the score at baseline. In all patients, an alpha-blocker was initiated before implantation and continued at least until the IPSS returned to baseline. Statistically significant predictors of urinary morbidity were determined using Cox regression analysis of multiple clinical, treatment, and dosimetric parameters.

For the entire cohort, the mean time to IPSS resolution was 2.5 months. The urinary catheter was removed on the day of implantation in 171 patients (83.8%), with no patient remaining catheter dependent for more than 3 days. To date, no patient has required postimplant surgical intervention. On multivariate analysis, pretreatment PVR predicted for clinically irrelevant differences in IPSS resolution and did not influence catheter dependency.

The selection of patients with a pretreatment PVR of less than 100 mL was associated with rapid IPSS resolution, the absence of prolonged (more than 3 days) catheter dependency, and the elimination of postbrachytherapy surgical intervention for bladder outlet obstruction.