Phase II Study of Feasibility of Focal Therapy for Prostate Cancer of Good Prognosis With Permanent I125 Localized Implant.

Inclusion criteria

• Men of more than 18 years old
• Patient with localized prostate cancer with a good prognosis (AMICO classification), ie satisfying the following conditions according to the urologist medical record transmitted:

• Lesion classified T1c or T2a based on digital rectal exam
• histologically proven diagnosis of prostatic adenocarcinoma with a Gleason score ≤ 6
• Serum Prostatic Specific Antigen (PSA) <10ng/ml
• Patient for whom the Multidisciplinary Consultative Meeting (RCP) has adopted the following treatment options: active surveillance, brachytherapy, radical prostatectomy or external radiation
• Patient with good micturating function at inclusion, defined by IPSS score <10 (IPSS Questionnaire)
• Patient for whom the result of centralized PSA assay confirms a serum level < 10ng/ml
• Patient for whom the unique and intracapsular character of the target area (area to be treated) was confirmed on pre implantation multimodal MRI imaging (ESUR Score ≥ 9) and whose major axis has a size ≤ 20 mm
• Patient with a Gleason score on the target ≤ 6 (3 +3) confirmed on biopsies performed using KOELIS ® system and with no other derogatory criteria such as the invasion of the entire core or the presence of a grade 4 or perineural emboli
• Patients without history of transurethral resection that could have significantly modified the anatomy of the gland nor obstructive adenoma
• Patient who accepts, at the end of the study, the principle of active surveillance for the rest of the gland and the treated area according to the current standard protocol
• WHO ≤ 2
• Patient with life expectancy > 10 years
• Informed consent obtained and signed before any specific procedure in the study
• Patient affiliated to social security regimen

Exclusion criteria

• Image in favour of the crossing of the capsule, based on pre-implantation multimodal MRI (stage T2 MRI only)
• Image in favor of the invasion of the seminal vesicle, based on pre-implantation multimodal MRI (stage T2 MRI only)
• Multifocal lesions (ESUR ≥ 9/15) to the pre-implantation multimodal MRI and for which biopsies have shown the cancerous nature
• Lesion with larger diameter ≥ 20mm, to the pre-implantation multimodal MRI
• Patient who requires pre-implantation hormonal treatment in order to reduce prostatic volume
• Patient with current indication against prostate brachytherapy, including a significant limitation of the mobility of the hips, a prostate volume greater than 60 cm3 (measured by planimetry MRI) or a significant dysuria (IPSS ≥ 10)
• Patient unable to follow procedures, visits, examinations described in the the study
• Patient with absolute indication against imaging tests (significant claustrophobia, wearing a heart valve, pacemaker, ..)
• Man of childbearing age who do not want follow the instructions about sexual activities and condom use during the days following the treatment of brachytherapy and / or unwilling to hold (him or her partner) effective contraception for the duration of the study
• Any concomitant or previous malignant disease in the past five years with the exception of superficial basal cell carcinoma or non-metastatic of the skin
• Any prior systemic chemotherapy within 5 years prior to inclusion for malignant disease in the medical history
• Any coexisting medical condition that in the opinion of the investigator could be a risk in this study
• Patient protected by law