Long-Term Results in Three-Dimensional Conformal Radiotherapy of Localized Prostate Cancer at Moderate Dose (66 Gy)

Abstract

Biochemical control (bNED), disease-specific survival (DSS), overall survival (OS), and late gastrointestinal (GI) and urogenital (UG) side effects (EORTC/RTOG) of patients with long-term follow-up were evaluated. Three-dimensional radiotherapy up to 66 Gy with/without additional hormonal therapy was performed in 154 prostate cancer (T1-3 N0 M0) patients. According to T-stage, pretreatment prostate-specific antigen (PSA) and grading, patients were divided into a low-, intermediate-, and high-risk group. The 5-, 8-, and 10-year actuarial rates of bNED, DSS and OS and late side effects were calculated. Median follow-up was 80 months. Additional hormonal therapy was given in 57% of patients. Distribution concerning risk groups (low, intermediate, high) showed 15%, 49%, and 36% of patients, respectively. bNED 5-, 8-, and 10-year actuarial rates were 46%, 44%, and 44%. DSS 5-, 8- and 10-year rates amounted to 96%, 90%, and 82%. OS 5-, 8- and 10-year rates were 81%, 64%, and 56%. In uni- and multivariate analysis, only pretreatment PSA (<10 vs. >or=10 ng/ml; p<0.05) and PSA nadir (<0.5 vs. >or=0.5 ng/ml; p<0.0001) affected bNED significantly. Age, risk group, T-stage, grading, and hormonal therapy had no significant influence on bNED, DSS, and OS. Rates of late GI and UG side effects grade>or=2 at 5 years were 17% and 15%. Current dose escalation studies with better bNED rates may be able to further increase long-term clinical outcome.