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)

Inclusion Criteria:

1. Adenocarcinoma of the prostate

2. Patient with one of the following cases:

   • Gleason 7 - 10 + T1c - T2b + PSA < 50 ng/mL or
   • Gleason 6 + T2c - T4 ou envahissement ≥ 50% sur les biopsies + PSA < 50 ng/mL or
   • Gleason 6 + T1c - T2b + PSA > 20 ng/mL

3. Risk of lymph node involvement> 15%

4. Patient N0, or Nx

5. Prostate volume estimated on MRI or ultrasound less than 60 cc.

6. Absence of pelvic lymphadenopathy ≥ 15 mm on CT or MRI extension assessment

7. Lack of bone and / or visceral metastasis on CT scan and bone scintigraphy

8. Hormonal treatment started maximum 90 days before the beginning of the irradiation,

9. IPSS score <12 without alpha blocker treatment

10. Absence of prior pelvic radiotherapy,

11. Lack of surgical treatment for prostate cancer except transurethral resection performed within 6 months before radiotherapy,

12. Age ≥ 18 years and ≤ 85 years,

13. WHO performance index ≤ 1,

14. Estimated life expectancy> 5 years,

15. Indication of treatment with radiotherapy and validated hormone therapy in a multidisciplinary consultation meeting

16. Affiliation to a social security scheme,

17. Signed informed consent.

Exclusion Criteria:

1. Prostate cancer of histology other than adenocarcinoma,

2. Patient diagnosed with N1 during imaging or pN1,

3. serum PSA level> 100 ng / ml,

4. IPSS score ≥ 12 or alpha blocker treatment,

5. Prostate volume estimated on MRI or ultrasound> 60 cc

6. History of cancer in the 5 years prior to entry into the trial,

7. History of trans-urethral resection of prostate less than 6 months old,

8. History of rectal surgery,

9. History of pelvic irradiation,

10. Patient with severe hypertension not controlled by appropriate treatment,

11. Contraindication to pelvic irradiation,

12. Patient not eligible for brachytherapy

    • Prostate volume> 60cc
    • Urine flow measurement with max flow <12 mL / s
    • Or curative anticoagulant treatment
    • Or contraindication to general anesthesia

13. Patient treated with antineoplastic or drug may include methotrexate,

14. Hormone therapy started> 90 days before the first irradiation,

15. Patient on immunosuppressant therapy

16. Contraindication to agonists or antagonists of LHRH,

17. Bilateral hip prosthesis,

18. Patient already included in another therapeutic trial with an experimental molecule,

19. Patient unable to cooperate during treatment,

20. Persons deprived of their liberty or guardianship,

21. Inability to undergo medical follow-up of the test.