Study Evaluating the Efficacy and the Tolerance of Pelvic-prostatic Hypo-fractionated Radiotherapy Followed by Boost in Patients With Prostate Adenocarcinoma Adverse Intermediate Risk or High Localized Risk

The standard treatment of high-risk prostatic adenocarcinoma is based on pelvic-prostatic external radiotherapy combined with concomitant and adjunctive hormone therapy for a total of 3 years. Prostatic stereotactic radiotherapy in 5 sessions is a therapeutic option currently delivered and described in multiple cohorts of patients with a tolerance comparable to normo-fractional treatments. This therapeutic scheme makes it possible to deliver a higher equivalent biological dose than during a treatment carried out with a conventional fractionation. The results with a follow-up of 9 years are extremely encouraging and do not show any excess toxicity compared to other irradiation techniques. They confirm that urinary and digestive toxicities are acceptable. All these studies did not involve pelvic irradiation. Several trials have also demonstrated the feasibility of normofractionated pelvic irradiation associated with hypofractionated prostatic irradiation using an integrated boost technique. The primary objective is to evaluate, for localized high-risk prostate cancers (unfavorable intermediate or high risk), the rate of digestive and urinary toxicity cumulated at 3 months of the association of a pelvi-prostatic irradiation contracted in 5 sessions, with:To evaluate, for localized high-risk prostate cancers (unfavorable intermediate or high risk), the rate of digestive and urinary toxicity cumulated at 3 months of the association of a pelvi-prostatic irradiation contracted in 5 sessions, with: * a prostatic boost in brachytherapy with high dose rate (HDR) or * an integrated boost in stereotaxis (in case of contraindication to brachytherapy)