Phase 3, Multicenter, Randomized Study, Evaluating the Efficacy and Tolerability of Focused HIFU (High Intensity Focused Ultrasound) Therapy Compared to Active Surveillance in Patients With Significant Low Risk Prostate Cancer

HIFU treatment will be conducted with the Focal One® device. The treatment area will be defined using MRI data and 3D biopsies. A safety distance of at least 9 mm will be defined around the tumor. An intraoperative contrast echocardiographic control will be performed to evaluate the necrotic area. If necessary, additional HIFU lesions will be performed during the same session. In case of residual tumor demonstrated during control biopsies, additional treatment of this tumor with focal HIFU may be proposed.

PSA dosage will be regularly performed during patient follow up thanks to blood sampling.

MRI exam will be regularly performed during patient follow up.

Patients will have to complete five questionnaires during their follow up : QLQ-C30 (Quality of Life questionnaire), EPIC-26 (The Expanded Prostate Cancer Index Composite), IPSS (International Prostate Score Symptom), IIEF-5 (The International Index of Erectile Function), STAI-YB (State-Trait Anxiety Inventory)

Prostatic biopsies will be regularly performed during patient follow up.