Simultaneous irradiation for prostate cancer: Intermediate results with modern techniques

Purpose: In this study of men with early stage prostate cancer we evaluated treatment outcome after modern simultaneous irradiation, comprising transp erineal implantation followed by external beam radiation. Disease-free surv ival rates were calculated according to an undetectable prostate specific a ntigen (PSA) nadir. Materials and Methods: From 1992 to 1996, 689 men with clinical stage T1-T2 , N0, Nx prostate cancer were treated with ultrasound guided transperineal (125)iodine seed implantation followed 3 weeks later by external beam radia tion. Disease-free status was defined as the achievement; and maintenance o f a PSA nadir of 0.2 ng./ml. or less. Median followup was 4 years (range 3 to 7). None of these men received neoadjuvant or adjuvant hormonal therapy. Results: Overall 5-year disease-free survival was 88%. The 5-year rate acco rding to PSA 4.0 ng./ml. or less, 4.1 to 10.0, 10.1 to 20.0 and greater tha n 20.0 was 94%, 93%, 75% and 69%, respectively. Multivariate analysis revea led that pretreatment PSA was the strongest indicator of subsequent disease -free status in regard to Gleason score or clinical stage. Conclusions: Intermediate treatment outcome analysis of modern simultaneous radiation supports the principles of radiation dose intensification for in tracapsular disease plus the treatment of potential microscopic capsular pe netration.