Purpose: Prostate brachytherapy has been reported to have less morbidity for patients than radical prostatectomy or external beam irradiation. However, to date there have been no long-term data to support these claims. With radiation doses in excess of 140 Gy required to control the tumor, disabling chronic urinary symptoms and associated quality of life (QOL) changes might be expected to occur. This study prospectively assessed the long-term effects of (125)I prostate brachytherapy on urinary morbidity.
Methods and materials: A total of 248 patients with a median age of 67 years (range, 43-83 years) who presented with T1-T2 prostate cancer were treated with (125)I seed implantation and followed up for a minimum of 18 months after treatment (range, 18 to 108 months; median, 31 months). There were 177 T1b-T2a cases and 41 patients with prostate-specific antigen >10 ng/ml; 20.2% were treated with hormonal therapy. All patients prospectively reported their urinary symptoms and QOL assessment on American Urological Association symptom score records before treatment and at each follow-up visit. Urinary symptoms at last follow-up were compared with pretreatment scores. Radiation doses to the prostate (dose delivered to 90% of the gland; D(90)) and urethra (D(30)) were determined by CT-based dosimetry.
Results: The median prostate D(90) was 165 Gy (range, 16.5-260 Gy), and the median urethra D(30) was 192 Gy (range, 23.5-306 Gy). Mean individual scores and QOL ranged from 0.31 to 1.65 before implantation and 0.39 to 1.73 afterward. There were no significant differences between pretreatment and last mean scores for any of the categories except for a small but significant increase in urgency (p=0.01) and weak stream (p=0.03). The cohort of patients who initially presented with marked urinary symptoms (initial score >or=3) had improvement in individual scores by 31.4% to 58.2%, total score by 31.1% (p=0.0005), and QOL by 40.6% (p<0.0001).
Conclusions: This study suggests that prostate brachytherapy is associated with minimal long-term urinary morbidity. The subgroup of patients who present with marked urinary symptoms before implantation has improvement in symptoms and QOL after implantation. These data substantiate the favorable long-term QOL outcomes associated with modern brachytherapy techniques.