Objective: To report 13-year biochemical disease-free survival results on 769 consecutive prostate cancer patients treated with brachytherapy alone.
Material and methods: Seven hundred sixty-nine patients with stage T1-T3, low to high Gleason grade prostate cancer underwent transperineal prostate implants with Iodine-125 (I-125) or Palladium-103 (Pd-103) as the sole treatment between January 1, 1987 and January 1, 1997. Median age was 69 years (range 43-92) and median follow-up was 71 months (range 18-156). Study cohort characteristics are summarized in Tables I and II and Figures 4-6. The patients were divided into two risk groups (low and high risk for extra-prostatic disease) based mainly on clinical stage and Gleason score. Group 1 consisted of 542 patients, who were considered at low risk and were treated with I-125. Group 2 comprised 227 patients, who were considered higher risk and were treated with Pd-103. No patient underwent pathological staging and none received androgen ablative therapy. Treatment failure was based on our modification of the American Society for Therapeutic Radiology and Oncology's (ASTRO) recommended failure criteria, defined as 3 consecutive serum Prostate Specific Antigen (PSA) rises (1). A critical component in our modification is that the value of the third PSA rise be above 0.5 ng/mL.
Results: One hundred thirty-seven patients were lost to follow-up. Thirteen patients expired of non-cancer causes within 18 months of the implant. This left 619 patients for evaluation, 441 in Group 1 and 178 in Group 2. The biochemical disease-free survival rates of the 619 patients at 3, 5, 10, and 13 years were 85%, 80%, 77%, and 77%, respectively (Fig. 1). The biochemical disease-free survival rates of the 441 "lower risk" I-125 treated patients at 3, 5, 10, and 13 years were 84%, 79%, 76%, and 76%, respectively (Fig. 2). The biochemical disease-free survival rates of the 178 "higher risk" Pd-103 treated patients at 3, 5, 10, and 13 years were 87%, 82%, 80%, and 80%, respectively (Fig. 3).
Conclusion: The excellent long-term results presented here, as well as the many advantages of prostate brachytherapy over other common treatments, demonstrate that brachytherapy is an effective treatment for clinical organ-confined prostate cancer in the long term.