Washington University School of Medicine in St. Louis
Introduction: Prostate multiparametric magnetic resonance imaging (pMRI) has emerged as a valuable tool in the diagnostic pathway for prostate cancer. The recent introduction of high-resolution micro-ultrasound (microUS) guided prostate biopsy aims to further improve the detection of clinically significant prostate cancer (CSCaP). The correlation between these two imaging modalities is poorly understood. We investigated correlation in lesion identification between microUS and pMRI. Methods: We reviewed our prospectively maintained database of 200 consecutive patients who underwent transperineal microUS-guided biopsy with the ExactVu™platform (Exact Imaging, Markham, Canada) between February 2021 and April 2022. The Prostate Risk Identification using MicroUS (PRI-MUS) protocol was utilized to risk stratify prostate lesions, with PRI-MUS 3-5 defined as positive. pMRI lesions were classified according to PI-RADS version 2. Clinicopathologic outcomes were analyzed. Spearman correlation testing was computed to assess the relationship between PRI-MUS and PI-RADS. Patients with sufficient data for analysis were included. Results: A total of 159 patients met inclusion criteria. Of these, 117 were biopsy-naïve, 19 had a prior negative biopsy and 20 were on active surveillance. Mean ± standard deviation (SD) age was 66.6 ± 7.7 years and PSA was 10.1 ± 4.4 ng/mL. A total of 112 patients underwent multiparametric magnetic resonance imaging (mpMRI) prior to biopsy, of which 56 were found to have PIRADS 3-5 lesions. There was a weak positive correlation between PRI-MUS and PI-RADS (r = 0.23, P = 0.013) (Figure 1). Conclusions: This preliminary comparison between PRI-MUS and PI-RADS scoring demonstrates a weak positive correlation between the two modalities. This may be attributable to a significant number of patients with negative pMRI who were found to have PRI-MUS 3-5 lesions. Given the rising utilization of micro-US-guided prostate biopsy and widespread use of pMRI, further prospective studies are needed to compare their ability to detect clinically significant prostate cancer. SOURCE OF Funding: Midwest Stone Institute
