MRI-guided Focal Laser Ablation

Inclusion criteria: * MRI visible index lesion (on T2-weighted MR imaging or diffusion weighted imaging); * Maximum MRI visible lesion size is ≤ 15 mm large axis; * Life expectancy at inclusion of more 10 years; * Diagnosis of prostate cancer confirmed by targeted biopsy using TRUS-MRI fusion or in-bore MRI guided biopsies; * Criteria of low and intermediate risk of progression and eligibility for focal therapy (clinical stage of maximum T2c, maximum biopsy Gleason score of 4 + 3 on targeted biopsies, serum prostate specific antigen \< 15 ng/ml); * Patient accepting to be included in an active surveillance protocol at the end of the study, in accordance with the recommendations of good practice. Exclusion criteria: * History of prostate surgery; * History of radiation therapy or pelvic trauma; history of proved acute or chronic prostatitis; * History of tumor in the preceding 5 years (excluded: non-metastatic basal cell skin cancer); * Severe urinary symptoms associated with benign hyperplasia of the prostate, and defined by an IPSS score \> 18; * Tumor with MRI signs of extra-capsular extension or invasion of the seminal vesicles; * Maximum cancer core length \>3 mm and/or maximum Gleason score of 3+4 on systematic biopsies outside the visible tumor area on mpMRI; * Impossibility to obtain a valid informed consent; * Patients unable to undergo MR imaging, including those with contra-indications; * Contra-indications to MR guided focal laser therapy (colitis ulcerosa, rectal pathology or abdomino perineal resection); * Metallic hip implant or any other metallic implant or device that distorts local magnetic field and compromises the quality of MR imaging; * Patients with evidence for nodal or metastatic disease; * Patients with an estimated Glomerular Filtration Ratio (eGFR) \< 40 mL/min/1.73 m2.