Purpose: To evaluate the efficacy and morbidity of combined 3-dimensional conformal radiation therapy (3D-CRT) and brachytherapy for intermediate/unfavorable risk prostate cancer.
Materials and methods: Between May 1996 and November 1997, 65 patients with intermediate/unfavorable risk prostate cancer were treated with 3D-CRT (50.4 Gy) followed by a transperineal permanent Pd-103 implant. Patients with one or two adverse prognostic features (PSA > 10 and Gleason > or = 7) were classified as intermediate risk and unfavorable risk, respectively. Forty-seven patients (71%) had intermediate risk and 18 (29%) had unfavorable disease risk. The median age of this group was 65 years (range, 42-76 years), and the median pretreatment PSA level was 8.0 ng/ml (range, 1.7-42.0 ng/ml). The clinical stage of these patients was as follows: Tlc, 36 (55%); T2a, 27 (42%); T2b/T3, 2 (3%). Fifteen patients (23%) had a Gleason < or = 6, 41 patients (63%) were classified as Gleason 7, and 9 (14%) as Gleason > or = 8. Fifty-two (80%) received neoadjuvant androgen deprivation (NAAD) for cytoreduction. The median follow-up was 36 months (range, 24-42 months).
Results: The PSA relapse-free survival rate at 3 years was 87%, with a median PSA value at last follow-up of 0.25 ng/ml. The relapse-free survival was 90% for those who had an initial PSA < or = 10 ng/ml and 80% for patients who had an initial PSA > 10 ng/ml (p = 0.5). No difference in outcome was observed between patients with intermediate and unfavorable risk disease. Eight patients (13%) developed late Grade 2 rectal bleeding. Twenty-three patients (42%) required medication for urinary symptoms during the first 6 months after therapy. Three patients (5 %) noted rare stress incontinence at last follow-up. Of the 44 patients who were potent prior to therapy, 17 (26%) developed erectile dysfunction (ED).
Conclusion: Although the follow-up is short, the early biochemical outcome of combined 3D-CRT and brachytherapy for intermediate/unfavorable risk prostate cancer is promising. While rectal toxicity is minimal, urinary side effects are more common. Further follow-up is necessary to fully evaluate the efficacy of this combined therapeutic approach.