Late urinary morbidity with high dose prostate brachytherapy as a boost to conventional external beam radiation therapy for local and locally advanced XXXX .

@entity1 @entity263
PURPOSE: Late urinary retention (UR) is a known complication that may occur when using high dose rate brachytherapy (HDR-B) to boost external beam radiation therapy (EBRT) when treating @entity263 . However, the dosimetric, treatment and clinical factors associated with this complication are not well-known. MATERIALS AND METHODS: From March 1997 to March 2000 a total of 108 @entity1 with local or locally advanced @entity263 were treated with EBRT (45 Gy) and HDR-B as a boost, when 16 to 20 Gy was given in 4 fractions twice daily. Median @entity1 age was 68 years and median followup was 44 months (range 36 to 72). Each implant was performed using 8 to 18 needles with a median active length of 3 cm. Planning ultrasound target volume ranged from 23 to 65 cc. RESULTS: Biological effective doses for the urethral region ranged from 107 to 138 Gy3 (median 113). Crude and 5-year actuarial UR-free survival were 95.4% and 86.2%, respectively. Predictive factors for UR on univariate analysis were age more than 65 years (p = 0.0416), planning ultrasound target volume greater than 35 cc and active length of needles more than 3.5 cm (p = 0.0158). On multivariate analysis by Cox regression age was the only predictive factor (p = 0.027). CONCLUSIONS: HDR-B appears to offer a safe, reproducible and effective method of boosting conventional EBRT in @entity1 with locally advanced @entity263 . Results with this technology reveal late urinary morbidity rates paralleling those achieved with other forms of treatment, but further long-term followup is still needed to warrant a definitive conclusion.
