Prostate-specific antigen relapse-free survival in patients with localized prostate cancer treated by brachytherapy.

Objective: To report the clinical outcome after permanent implantation of (125)iodine seeds (brachytherapy) for early prostate cancer, after 8.2 years of follow-up.
Patients and Methods: Between March 1995 and December 2001, 667 men (mean age 63 years, range 42-77) were treated with brachytherapy at the one cancer centre; 346 (51.9%) had a short course of neoadjuvant hormone therapy. The prescribed minimum peripheral dose was 145 Gy. No patient received external beam radiation.
Results: The median (range) follow-up was 31 (18-98.2) months; 41 patients were lost to follow-up. The actuarial biochemical relapse-free survival was 74.9%; 100 patients had biochemical relapse (international definition). In all, 20 patients had clinical relapse, and 24 died (10 from prostate cancer). The prostate-specific antigen (PSA) relapse-free survival was 78.3%, 66.5% and 56.4% for patients with Gleason scores of <7, 7 and > 7, respectively, and was 81.4%, 69.8% and 36.3% for those with PSA levels of <10, 10-20 and > 20 ng/mL, respectively (both P < 0.001). There was a strong cohort effect depending on year of implant, with progressive annual improvements in relapse-free survival (P < 0.001). Hormone therapy, tumour stage, prostate volume before implantation, age and D90 dose had no significant effect on the outcome.
Conclusion: The overall relapse-free survival for all patients was 75%; the initial PSA, Gleason score and risk group were significant factors predicting the outcome. Increasing clinical experience was associated with a better outcome but neoadjuvant hormone therapy had no effect.