Comparison of radical prostatectomy and iodine 125 interstitial radiotherapy for the treatment of clinically localized prostate cancer: A 7-year biochemical (PSA) progression analysis

Objectives. To evaluate the relative efficacy of brachytherapy to radical prostatectomy, we compared biochemical progression rates from a published series of men who underwent iodine 125 (I-125) interstitial radiotherapy for localized prostate cancer to a similar group of men who underwent anatomic radical prostatectomy using appropriate end points. Methods. Seventy-six men who underwent anatomic radical prostatectomy between 1988 and 1990 were carefully matched for Gleason score and clinical stage to a recently reported contemporary series of patients treated at another institution with I-125 brachytherapy without adjuvant treatment. The definition of biochemical progression was a serum PSA level greater than 0.2 ng/mL after anatomic radical prostatectomy and greater than 0.5 ng/mL for brachytherapy-treated patients. Results. The 7-year actuarial PSA progression-free survival following anatomic radical prostatectomy was 97.8% (95% confidence interval [CI], 85.6% to 99.7%) for this group of men selected to match the brachytherapy group, compared to 79% (95% CI not published) for men treated with I-125 interstitial radiotherapy. Conclusions. Using comparative end points for biochemical-free progression, failure rates may be higher following I-125 interstitial radiotherapy compared to anatomic radical prostatectomy. These data provide a better comparison of biochemical progression than previously published studies and emphasize the need for caution in interpreting the relative efficacy of brachytherapy in controlling localized prostate cancer. (C) 1998, Elsevier Science Inc. All rights reserved.