An update on imaging techniques to optimize active surveillance in prostate cancer.

Thanks to the higher diagnostic accuracy and safety, new imaging techniques provide future prospects in terms of patient management and follow-up in active surveillance (AS) protocols. Two of the aims of developing new imaging techniques are improving patient selection criteria and to improve follow-up with non-invasive tests. Another objective is to improve the diagnostic performance of biopsies; this would enable physicians to switch from blind systematic TRUS-guided biopsies to targeted biopsies to reduce the amount of biopsies required and reduce the diagnostic rate of clinically insignificant cancers. The notable advances of multi-parametric or functional prostatic imaging (mpMRI) have led to perceptible diagnostic improvements as it they does do not only provide information regarding size and location but also tumor aggressiveness. MRI has proven to be the most reliable non-invasive technique to be able to exclude patients with clinically significant cancer and thus gain acceptance in AS protocols during selection, confirmation and follow-up of AS patients. This chapter reviews the notable impact of multiparametric prostate MRI (mpMRI) on improving both diagnostic accuracy and follow-up. The second point describes the technical advances in the field of transrectal ultrasound imaging, aiming at improving the diagnostic accuracy of biopsies given their increased accessibility and real-time use.