Results of IMRT Following Neoadjuvant Hormone Therapy for Clinical Stage C Prostate Cancer

We report the 5-year prostate-specific antigen (PSA) relapse-free survival outcome and incidence of toxicity for patients with clinically Stage C prostate cancer treated with intensity-modulated radiation therapy (IMRT) in our institute. A total of 35 patients with Stage C prostate cancer were treated with IMRT between July 2003 and November 2007. All patients were treated to a dose of 74Gy prescribed to the planning target volume and received neoadjuvant hormone therapy. The median age was 71 years (range: 50 to 80 years). 3 patients (8.6%) had Gleason scores or=8. The median pretreatment PSA level was 28.0 ng/mL (range: 5.1 to 160.0 ng/mL). Patients were characterized as having high risk disease if their pretreatment PSA level was >20ng/ml and Gleason score >or=8. PSA relapse-free survival rate were calculated and toxicity data were scored according to the Common Terminology Criteria for Adverse Events Version 3.0. The median follow-up time was 58 months (range 7 to 84). 11 patients (31.4%) developed a PSA relapse, and the 5-year PSA relapse-free survival rate was 66.3%. The 5-year PSA relapse-free survival rates for high risk patients and others were 39.2% and 85.7%, respectively (p=0.0098). The likelihood of acute grade 2 urinary and rectal toxicity was 14.2% and 11.4%. No grade 2 late complications have been observed. These results indicated that 74Gy IMRT is well tolerated and is associated with good PSA relapse-free survival outcomes in patients with Stage C prostate cancer, especially non-high risk patient.