Lack of recruitment

The benefit of dose escalation in radiotherapy (RT) for biochemical control of prostate cancer is a clearly established fact based on the results of different published prospective trials. This benefit, acquired with three-dimensional conformal radiation technique is counterbalanced by an increase in urinary and gastrointestinal toxicity. The joint progress of dose planning systems and multileaf collimators (MLC) technology have enabled the Intensity Modulated Radiation Therapy (IMRT). Recently the contribution of "spacers" positioned in the septum between the rectum and the prostate could improve the functional results of IMRT in terms of rectal toxicity.

The aim of the investigators study is to assess the dosimetric gain from the contribution of the implantable BioProtect balloon on organs at risk.

Patients eligible for the trial and having signed their consent to participate will undergo a scan to verify the possibility of implantation of the balloon. Before and after implantation of the balloon, a dosimetric scan will be performed. Radiotherapy will be administered according to the habits of each centre : Intensity modulated radiotherapy : 2 Gy / session, 5 weekly sessions, total dose of 74-80 Gy (+/- associated with an hormone therapy).

Patients will have a clinical examination :

• prior to the start of treatment
• once a week during the radiotherapy
• at the end of the radiotherapy
• and at the end of the study.

They will also complete quality of life questionnaires :

• prior to the start of treatment
• at mid-treatment
• at the end of the radiotherapy
• and at 3, 6, 12 and 24 months after the end of the radiotherapy.

Finally, patients will undergo a laboratory examination :

• prior to the start of treatment
• 3 months after the end of the radiotherapy
• and then every 6 months.

Inclusion Criteria:

1. Patient over 18 years old

2. With a localized adenocarcinoma of the prostate

   • of intermediate risk of D'AMICO
   • and of stage MRI < T3

3. Requiring a treatment with Intensity Modulated Radiotherapy

4. PSA (Prostate-Specific Antigen) levels ≤ 20 ng/mL before external beam radiotherapy

5. Prostate volume > 15 cc

6. Short hormone therapy possibly associated (4-6 months)

7. Patient without clinical signs of progressive disease (Performing a bone scan and a CT scan is optional)

8. Performance status ECOG (Eastern Cooperative Oncology Group) ≤ 1

9. Life expectancy ≥ 10 years

10. Informed consent signed

Exclusion Criteria:

1. Incompatibility to the implantation of a Bioprotect balloon :

   • ongoing anticoagulant by vitamin K antagonist (VKA) or heparintherapy
   • patient with immunosuppression or with serious chronic diseases such as heart failure, cirrhosis, chronic kidney failure, colic or rectal digestive inflammatory disease
   • history of prostatitis or of lower gastrointestinal infection treated or ongoing
   • history of recto-colic inflammatory disease or of repeated prostatic resections
   • untreated perineal wound

2. Prior treatment with hormone therapy

3. History of another invasive cancer within 5 years prior to study entry (with the exception of a treated basal cell skin carcinoma)

4. History of pelvic radiotherapy

5. Severe hypertension non controlled by an adapted treatment (≥ 160 mm Hg in systole and/or ≥ 90 mm Hg in diastole)

6. Ongoing antineoplastic therapy

7. Person deprived of liberty or under tutorship

8. Inability to submit to the medical monitoring of the study for geographical, social or psychological reasons.

9. Conformal radiotherapy without intensity modulation