Long-Term Patient-Reported Rectal Bleeding and Bowel-Related Quality of Life After Cs-131 Prostate Brachytherapy

There is limited long-term data on outcome and side effects of Cs-131 prostate brachytherapy and minimal patient-reported data on rectal bleeding with any isotope. We aimed to describe the incidence, prevalence, and predictors of late patient-reported rectal bleeding after Cs-131 brachytherapy.

We reviewed a prospectively collected database of 620 men treated with Cs-131 prostate brachytherapy. Of 620 patients, 390 (62.9%) received brachytherapy as monotherapy; the remainder received combination therapy with external beam radiation therapy (EBRT). Patients were administered Expanded Prostate Cancer Index Composite questionnaires preoperatively and postoperatively at each follow-up visit. The primary outcome was late rectal bleeding, defined as rectal bleeding reported at the 6-month follow-up or later. Clinically significant rectal bleeding was defined as occurring more than "rarely," and clinically significant bother from rectal bleeding was defined as considering bleeding more than a "very small problem." Univariate and multivariate Cox regression were performed to identify factors predictive for rectal bleeding.

With a median follow-up time of 48 months, the cumulative incidence of clinically significant late rectal bleeding was 12.4%, with 15.2% reporting clinically significant bother from bleeding. At the time of last follow-up, the prevalence of clinically significant rectal bleeding and bother were 4.0% and 4.7%, respectively. On univariate analysis, acute clinically significant rectal bleeding, defined as occurring within the first 6 months (P = .001) and combination therapy with EBRT (P = .001) predicted for clinically significant late rectal bleeding. On multivariate analysis, both EBRT (P = .001; hazard ratio, 2.50; 95% confidence interval, 1.58-3.94) and acute rectal bleeding (P < .001; hazard ratio, 3.11; 95% confidence interval, 1.75-5.53) remained significant predictors for late rectal bleeding.

Prostate brachytherapy with Cs-131 is well tolerated in the long term. Although the incidence of clinically significant patient-reported late rectal bleeding was 12.4%, the prevalence at last follow-up was only 4.0%, suggesting that this problem tends to resolve.