Management of high-risk prostate cancer with 5-treatment stereotactic body radiotherapy: Long-term results.

94Background: Stereotactic Body Radiotherapy (SBRT) is an emerging treatment modality with excellent control rates for low- and intermediate-risk prostate cancer. The role of SBRT for high-risk disease, however, is less studied. The standard treatment (RT) for high-risk prostate cancer entails 8-9 weeks of daily RT with long-term androgen deprivation therapy (ADT). In comparison to this, SBRT is completed in 5 sessions, and offers convenience, low toxicity, and equivalent biochemical disease control rates as standard RT in the low- and intermediate-risk setting. We now present long-term results for SBRT in a cohort of patients with high-risk disease. Methods: We evaluated patients treated from 2006-2010 with SBRT alone (n = 52) to dose of 35-36.25 Gy in 5 fractions, or pelvic radiation to 45 Gy followed by SBRT boost of 19-21 Gy in 3 fractions (n = 46). Androgen deprivation therapy was administered to 55% of patients. Quality of life and bladder/bowel toxicity was assessed using the Expanded Prostate Inde...