Predictive factors of acute urinary retention requiring catheterization following ¹²⁵I prostate brachytherapy

Objective: To analyze predictive factors of acute urinary retention requiring catheterization after ¹²⁵I prostate brachytherapy. Methods: A group of 227 consecutive patients with localized prostate ca ncer were treated with 125 I prostate brachytherapy between September 2003 and December 2004. The clinical, treatment-related and dosimetric factors were evaluated for the need for catheterization owing to urinary retention. Results: Twelve patients (5.3%) required catheterization. The median time to onset was 2 days after implantation (range 1-7 days). Univariate analysis demonstrated that pre-implant ultrasound prostate volume, number of seeds, number of needles and neoadjuvant hormonal manipulation were predictive for catheterization. In multivariate analysis, the number of needles and neoadjuvant hormonal manipulation were significant independent predictive factors for catheterization (P = 0.002 and 0.025, respectively). The risk of catheterization in the cluster in which the number of needles was >24 was 4.07 times as high as that in the cluster in which the number of needles was ≤24 [11.3% versus 3.0%, P = 0.020; 95% confidence interval (CI) 1.24-13.36], and the risk in the hormonally manipulated patients was 7.05 times as high as that in the hormone-naïve patients (7.7% versus 1.2%, P = 0.034; 95% CI 0.89-55.64). Conclusion: Our data suggest that the number of needles and hormonal manipulation might be the strongest predictors for catheterization.