Whole Pelvic Radiotherapy Versus Prostate Only Radiotherapy in the Management of Locally Advanced or Aggressive Prostate Adenocarcinoma

Purpose To determine whether whole pelvic radiotherapy (WPRT) or prostate-only radiotherapy (PORT) yields improved biochemical disease-free survival (BDFS) in patients with advanced or aggressive prostate adenocarcinoma. Methods and Materials Between 2000 and 2007, a consecutive sample of 277 patients with prostate adenocarcinoma and at least a 15% likelihood of lymph node involvement who had undergone WPRT ( n = 68) or PORT ( n = 209) at two referral centers was analyzed. The median radiation dose in both arms was 75.6 Gy. The outcome measure was BDFS, as determined using the prostate-specific antigen nadir + 2 ng/mL definition of failure. BDFS was calculated using the Kaplan-Meier method and compared with the log–rank test. A multivariate analysis was performed to assess for confounding. Treatment-related toxicity was assessed using the National Cancer Institute's Common Terminology Criteria for Adverse Events guidelines. The median follow-up was 30 months. Results WPRT patients had more advanced and aggressive disease at baseline ( p < .001). The 4-year BDFS rate was 69.4% in the PORT cohort and 86.3% in the WPRT cohort ( p = .02). Within the entire cohort, after adjustment for confounding variables, the pretreatment prostate-specific antigen ( p < .001), Gleason score ( p < .001), use of hormonal therapy ( p = .002), and use of WPRT (vs. PORT, p = .006) predicted for BDFS. Patients undergoing WPRT had increased acute gastrointestinal toxicity ( p = .048), but no significant difference in acute genitourinary toxicity was seen ( p = .09). No difference in late toxicity was found. Conclusion WPRT may yield improved BDFS in patients with advanced or aggressive prostate adenocarcinoma, but results in a greater incidence of acute toxicity.