Preimplant predictive factors of urinary retention after iodine 125 prostate brachytherapy

To assess the rate and predictive factors of urinary retention after iodine 125 brachytherapy for localized prostate cancer.

Between 1998 and 2006, 655 patients with localized prostate cancer (T1-2, Gleason score 7 or less) were treated with brachytherapy at our institution. 42% received neoadjuvant hormonotherapy for prostate downsizing or when brachytherapy was combined with external beam radiation (10%). They underwent real-time interactive implantation (79%) or a preplanned technique (21%). Clinical, treatment-related and dosimetric factors were evaluated for catheterization requirement because of urinary retention. All patients received alpha1-blockers before and throughout at least 30 days posttreatment.

Twenty-one (3.2%) patients required catheterization because of urinary retention. Median time to retention onset was 1 day postimplantation. Univariate and multivariate analyses demonstrated that preimplant ultrasound (US)-based prostate volume and preimplant international prostate symptom scores (IPSS) were significant independent predictive factors for urinary retention (odds ratio [OR] = 6.8 and 3.1, 95% CI = 2.3-11.4 and 0.2-5.9, P = 0.02 and P = 0.03, respectively). Eight catheterized patients were successfully relieved from their catheter by nonsurgical means and 13 underwent minimal (channeling) transurethral resection of the prostate (TUR-P) not earlier than 6 months postimplant. Mean volume of resected prostate tissue was 9.9 mL (range 4.5-15). The perioperative and postoperative courses were uneventful. There was no TUR-P-related incontinence.

Catheterization for acute urinary retention after brachytherapy is an uncommon event. Our data suggest that preimplant US-based prostate volume and IPSS are the strongest predictors for catheterization. Catheterized patients who are refractory to medical therapy can safely undergo a minimal TUR-P.