Long-term results in three-dimensional conformal radiotherapy of localized prostate cancer at moderate dose (66 Gy)

Purpose: 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. Patients and Methods: Three-dimensional radiotherapy up to 66 Gy with/without additional hormonal therapy was performed in 154 prostate cancer (T1-3 NO MO) 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. Results: 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. >= 10 ng/ml; p < 0.05) and PSA nadir (< 0.5 vs.>= 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 >= 2 at 5 years were 17% and 15%. Conclusion: Current dose escalation studies with better bNED rates may be able to further increase long-term clinical outcome.