Cost-utility of Focal HIFU vs Prostatectomy

Inclusion Criteria: * 45-75 yo male harboring a non-treated localized prostatic adenocarcinoma of maximum Gleason score 3+4, ISUP 2 unilateral on at most maximum 2 contiguous sextants (favorable intermediate risk),with or without ipsilateral or contralateral focus of score 3+3 (ISUP1). * Tumor visible on MRI and proven by systematic and/or targeted biopsies according to the center's practices, regardless of the route used (transrectal or transpirenal) * Or patients under active surveillance whose follow-up prostate biopsies reveal unilateral ISUP2 on at most 2 contiguous sextants (favorable intermediate risk), with or without ipsilateral or contralateral Gleason 3+3 focus (ISUP1) * Patients with several suspicious foci on MRI may be be included if only one of these foci is confirmed by targeted biopsies with an ISUP2 score. If more than one suspected site on MRI is confirmed by targeted biopsies, these should be unilateral ISUP2 on a maximum of 2 contiguous sextants (favourable intermediate risk), with or without an ipsilateral or contralateral site with a Gleason score of 3+3 (ISUP1). * stage T1c-T2, * with PSA \<20 ng/ml, * with prostate volume less than 150 ml, * patient clearly informed of the study and having agreed, with sufficient time for reflection to participate by signing the study's informed consent form, * patient affiliated to or benefiting from a social security scheme Exclusion Criteria: * Metastatic prostate cancer. * Gleason score \> 3+4 (ISUP\>2). * Adenoma prostate carcinoma Cribriform or intraductal. * Previous treatment anterior for the same cancer, whatever modality. * Contra-indication to pelvic MRI with gadolinium injection. * Contra-indication to surgery or general anesthesia. * Patient who refuse the one-year follow-up control biopsy after F-HIFU. * Presence of implant (stent, catheter) less than 1 cm from the treatment area. * Urinary or rectal fistula. * Anal or rectal stenosis or any other abnormality that may interfere with the Focal One® endorectal probe introduction. * Anatomic abnormality of the rectum or rectal mucosa. * Presence of a urinary artificial sphincter, a penile prosthesis or intraprostatic implant, i.e. urethral prosthesis. * Bladder neck and/or urethral stenosis or sclerosis. * Inflammatory bowel disease (colon or rectum). * Ongoing UTI (should be treated before the F-HIFU or the RP). * Previous anal or rectal surgery that may interfere with the anal probe introduction. * Latex allergy. * Rectal wall thickness \> 10 mm. * Tumor not accessible to a F-HIFU treatment (tumors located in the fibro-muscular anterior zone). * Previous not controlled cancer and/or treated since less than 5 years (except basocellular skin cancer). * Patient not able to understand the trial objectives or refusing to adhere to the trial instructions. * Patients under law-protection. * Patient in an ongoing research trial. * Patient with a severe health or psychologic problem that could impair the protocol pathway.