Urinary morbidity after 125I brachytherapy of the prostate

To assess urinary morbidity within the first 6 months after transperineal prostate brachytherapy (TPBT) with 125I for localized prostate adenocarcinoma.

Between September 2000 and July 2001, 50 consecutive patients with favourable early-stage prostate cancer were treated with TPBT. Clinical and objective investigations, including uroflowmetry and postvoid residual urine measurements, were evaluated for short-term urinary morbidity; predictive factors were also sought.

Thirty-eight (76%) patients developed urinary disorders, but severe urinary complications were exceptional. The International Prostate Symptom Score (IPSS) changed significantly during the first and third month after implantation and then improved during the sixth month. Concomitantly, the maximum and the average urinary flow rate deteriorated significantly. The variations in postvoid residual were less significant. An initial IPSS of > 8 and previous alpha-blocker treatment were identified as significant predictive factors of urinary morbidity, as were the TPBT dose received by 90% of the target volume and by 30% of the urethra, and the volume of prostate receiving 144 Gy.

Urinary morbidity after TPBT is frequent but rarely exceptionally severe; patients must therefore be given full information. Patients with a higher initial IPSS or having had previous alpha-blocker treatment, with their associated dosimetric factors, are at greater risk of these urinary morbidity.