Multicenter Study of Hypofractionated Postoperative Radiotherapy in Patients Diagnosed With Prostate Carcinoma

What the investigators present in this study is a hypofractionation scheme of 62.5 Gy in 25 daily fractions of 2.5 Gy / day, which was chosen to provide a biological equivalent dose (BED) of 166.67 Gy, comparable to the 163 Gy administered with a scheme Normally divided up to 70 Gy in daily fractions of 2 Gy / day Version 2.0, March 27, 2019 (assuming an α / β ratio of 1.5 Gy for prostate cancer). The BED in risk organs (mainly rectum and bladder) will be governed by the ratio used and will differ depending on whether acute or late toxicity is calculated. If selected an acute α / β of 10 Gy and a conservative α / β for late toxicity of 3 Gy, the standard fractionation will result in an acute BED of 84 Gy versus 78 Gy in the hypofractionation scheme and a BED of 116.67 vs. 114.5 Gy for late toxicity. Therefore, what the investigators expect is a toxicity profile that is at least similar, if not slightly better, compared to the norm-fractionated scheme of 70 Gy in 35 fractions and similar rates of biochemical control and survival. To all this is added the use of intensity modulated radiotherapy and image-guided radiotherapy techniques (IGRT) that will allow the investigators to significantly reduce the dose administered to risk organs.