AUA 2020: Comparison of Micro-Ultrasound and Multiparametric MRI Imaging for Prostate Cancer: A Multicenter Prospective Analysis

(UroToday.com) The novel micro-ultrasound system operating at 29 MHz operates at a higher level than the conventional 6-9 MHz systems. This results in 300% improvement in resolution, both axial and laterally down to 70 microns, allowing visibility of suspicious areas using the prostate risk identification using a micro-ultrasound (PRI-MUS) system.1 Micro-ultrasound may be used to image suspicious lesions and target biopsies in real-time with or without additional MRI-based targets. This approach offers the benefits of simplicity, a single intervention for imaging and biopsy, leveraging the low cost of ultrasound.  At the American Urological Association (AUA) 2020 virtual annual meeting, Dr. Giovanni Lughezzani and colleagues presented results of their study comparing the sensitivity, specificity, negative predictive value, and positive predictive value of mpMRI with the novel high-resolution micro-ultrasound imaging modality.   

For this study, data from nine sites were aggregated, totaling 866 subjects presenting for ExactVu micro-ultrasound guided biopsy with available mpMRI studies.  Samples in all subjects were taken from mpMRI targets and micro-ultrasound targets, with up to 12 systematic samples filled in.  Various strategies were used for mpMRI target sampling including cognitive fusion with micro-ultrasound, separate software-fusion systems, and software-fusion using the micro-ultrasound FusionVu system.  Clinically significant cancer was considered any Gleason sum > 6 and targeted samples were taken for PI-RADS > 2 or PRI-MUS > 2 lesions. 

Overall, 39% of all biopsy cases were positive for clinically significant prostate cancer. mpMRI demonstrated 89% sensitivity and a negative predictive value of 77%.  Compared to mpMRI, micro-ultrasound sensitivity (95%) and negative predictive value (87%) were higher.  Micro-ultrasound was less specific (21% vs 23% for mpMRI) with similar positive predictive value (44% vs 43%) compared to mpMRI. A summary of the findings is found in the following table:

AUA2020_Lughezzani__1.png

The aggregate effect demonstrates higher sensitivity for clinically significant prostate cancer with micro-ultrasound compared to mpMRI (p<0.01). 

Dr. Lughezzani concluded his presentation with the following take-home points:

  • Micro-ultrasound is an attractive option for screening and targeted biopsy
  • Sensitivity and negative predictive value appear superior to mpMRI, but specificity is mildly reduced
  • Further larger-scale studies are required for validation of these findings

 

Presented by: Dott. Giovanni Lughezzani, Department of Urology, Humanitas Clinical and Research Center, Humanitas University, Rozzano, Italy

Co-Authors: Davide Maffei, Marco Paciotti, José Gregorio Pereira, Andrea Sánchez, Frédéric Staerman, Hannes Cash, Laurent Lopez, Jean Rouffilange , Richard Gaston, Rafael Sanchez-Salas, Xavier Cathelineau, Eric Klein, Robert Abouassaly, Laurence Klotz, Gregg Eure

Written by: Zachary Klaassen, MD, MSc – Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, Twitter: @zklaassen_md at the 2020 American Urological Association (AUA) Annual Meeting, Virtual Experience #AUA20, June 27- 28, 2020

References:

  1. Ghai S, Eure G, Fradet V, et al. Assessing Cancer Risk in Novel 29 MHz Micro-Ultrasound Images of the Prostate. J Urol. 2016 Aug;196(2):562-569. 
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