Hypofractionated SBRT For Prostate Cancer

The purpose of this study is to determine, in both low-risk and intermediate-risk cohorts, the rates of acute and late grade 3 or higher gastrointestinal and genitourinary toxicity observed during a 24 month follow up and to estimate the rate of biochemical Disease-Free Survival, Phoenix and American Society for Therapeutic Radiology and Oncology definitions, at 2 years following hypofractionated stereotactic body radiation therapy for low and intermediate risk prostate cancer.

Radiosurgery should be ideal for treating prostate cancer because: * targeting accuracy for static targets is excellent, with an error of about 1mm, * it can adjust for intra-fractional organ motion, reducing the volume of the target PTV and therefore the dose to surrounding organs, * by using over one-hundred non-conplanar beams, the dose gradient between the prostate and surrounding tissues may be superior to that achieved with conventional linear accelerators, * the radiobiology of prostate cancer may favor large dose per fractions.