Evolution of Targeted Prostate Biopsy by Adding Micro-Ultrasound to the Magnetic Resonance Imaging Pathway

Background Although multiparametric magnetic resonance imaging (mpMRI) revolutionized the implementation of prostate biopsies, a considerable amount of clinically significant prostate cancer (csPCa) is missed when performing mpMRI-targeted biopsies only. Microultrasound (micro-US) is a new modality that allows real-time targeting of suspicious regions. Objective To evaluate micro-US of the prostate with real-time targeting of suspicious regions in patients suspected to have prostate cancer (PCa). Design, setting, and participants We examined 159 patients with prior mpMRI and suspicion of PCa with micro-US in the period from February to December 2018. Micro-US lesions were documented according to the prostate risk identification for micro-US (PRI-MUS) protocol, and were blinded to the mpMRI results and targeted independently of the mpMRI lesions. Outcome measurements and statistical analysis The main outcomes were cancer detection rate, additional detection of csPCa, and International Society of Urological Pathology (ISUP) grade group upgrading via micro-US. Results and limitations PCa was found in 113/159 (71%) men, with 49% (78/159) having clinically significant cancer (csPCa; ISUP ≥ 2). Micro-US–targeted biopsies resulted in a higher ISUP grade group than the nontargeted biopsies in 26% (42/159), compared with both nontargeted and MRI-targeted biopsies in 16% (26/159). In 17% (27/159) of patients, targeted mpMRI–guided biopsy was negative with cancer identified in the micro-US–guided biopsy, of whom 20 had csPCa. The comparison with only MRI-positive patients is the main limitation of this analysis. Conclusions Our data show an added benefit of micro-US in addition to mpMRI-targeted biopsies in a population of men at risk of PCa. A novel biopsy protocol with solely targeted biopsy with micro-US and mpMRI seems possible, replacing conventional ultrasound and omitting standard systematic biopsies. Patient summary In this report, we looked at the performance of microultrasound in the setting of diagnosing prostate cancer. We found that microultrasound is a good addition to magnetic resonance imaging (MRI) of the prostate and presents an alternative for men who may not undergo MRI.