The aim of this study is to test the safety and efficacy of Stereotactic Body Radiation Therapy (SBRT) in localized prostate carcinoma in patients for whom the standard treatment is the irradiation of the entire prostate gland with or without seminal vesicles accompanied or not by hormonal therapy. In light of the accumulating clinical evidence favoring the use of hypo fractionation, SBRT regimen might constitute a much more convenient non-invasive and highly efficient outpatient therapy.