Dose escalation for localized prostate cancer: substantial benefit observed with 3D conformal therapy.

Purpose: To determine the effect of radiation dose escalation on biochemical and/or disease failure in patients with localized prostate cancer treated with three-dimensional conformal radiotherapy (3D-CRT).

Methods And Materials: Between May 1987 and December 2000, 1473 patients were assessed after treatment with 3D-CRT. The mean patient age was 70.4 +/- 6.8 years, 1316 patients had T1-T2 disease, and 1150 had Gleason score
Results: At a median follow-up of 35.2 months, 395 failures (26.8%) had occurred. Adjusting for dose as a continuous variable, the hazard ratio for failure was 2.03 (p < 0.0001) for 569 intermediate-risk patients (stage T1-T2 and Gleason score 7 or PSA 10-20 ng/mL) and 5.16 (p < 0.0001) for 456 high-risk patients (stage T3-T4 or PSA >20 ng/mL or Gleason score >or=8) compared with 448 low-risk patients (stage T1-T2 and Gleason score
Conclusion: Dose escalation using 3D-CRT significantly reduces the risk of biochemical/disease failure among intermediate-risk prostate cancer patients.