Rôle de l'IRM prostatique dans le cancer de la prostate en 2016: mise au point et perspectives d'avenir

Prostate cancer is most commonly diagnosed on the basis of an increased serum prostate specific antigen (PSA) level, through individual screening, and is carried out following systematic transrectal ultrasound-guided prostate biopsies. This strategy is associated with risks of overdiagnosing clinically non significant cancers, as well as missing clinically significant ones. Performing a prostate magnetic resonance imaging (MRI) prior to prostate biopsies modifies the way of diagnosing prostate cancer. It increases the detection rate of clinically significant cancers by using targeted biopsies focused on lesions that are detected on MRI. It enhances the estimation of grade, size, location and boundaries of the lesions. It may be used to reduce the detection rate of clinically non significant cancers if the systemic biopsies were not performed in patients without any suspect MRI lesion. Therapeutic use of MRI includes screening of patients eligible for active surveillance or focal treatment. MRI protocols and interpretation have been published in 2016 as an update of the PI-RADS score (Prostate Imaging Reporting and Data System version 2). Standardising the acquisition, interpretation and reporting of prostate MRI is useful for urologists and radiation oncologists in order to diagnose and treat prostate cancer.