Background: The objective of this study was to evaluate long-term treatment outcome of definitive irradiation by using temporary interstitial implant and limited dose of external beam radiotherapy in treatment of localized prostate carcinoma.
Methods: In total, 536 patients with biopsy-proven adenocarcinoma of the prostate, classification T1-T3, underwent staging pelvic lymph node dissection and brachytherapy delivering an average tumor dose of 30 grays (Gy), supplemented by external beam radiation therapy for an additional dose of 36 Gy delivered over 4 weeks. One hundred of 536 (18%) patients had pathologic D1 disease. A total of 181 patients had undergone transurethral prostatectomy before the treatment. Repeat prostate biopsy was performed on 132 patients 18 or more months after treatment. None of the patients received neoadjuvant or adjuvant hormone therapy.
Results: Cumulative disease free survival (DFS) including biochemical DFS at 10 and 15 years for classification T1B,C was 78% and 72%; for T2A, 78% and 78%; for T2B,C, 68% and 66%; and for T3A-C, 45% and 45%, respectively. Cause specific survival for the entire group at 10 and 15 years was 89% and 87%, respectively. Severe complications occurred only in the early developmental phase of the study.
Conclusions: In univariate analysis, the clinical stage, histologic grade, pretreatment PSA level, lymph node status, and results of repeat posttreatment biopsy were all independently significant prognostic factors. However, the authors' study indicates that in multivariate analysis, only two factors emerged with statistical significance-the status of pelvic lymph nodes and the results of posttreatment biopsy. This signifies the importance of local tumor control to achieve ultimate cure and the importance of assessment of pelvic lymph nodes before definitive local therapy other than radical prostatectomy, especially in the high-risk group.
Copyright 2001 American Cancer Society.