Presentation Authors: Giovanni Lughezzani*, Rozzano, Italy, Ander Astobieta, Bilbao, Spain, Frédéric Staerman, Reims, France, Eric A. Klein, Robert Abouassaly, Ahmed El-Shefai, Cleveland, OH, Eure Gregg, Virginia Beach, VA
Introduction: Multi-parametric MRI (mpMRI) is growing as a screening approach for prostate cancer due to trials such as PROMIS and PRECISION demonstrating high sensitivity and negative predictive values. Unfortunately, implementation of mpMRI programs is complicated in practice due to additional costs, complexity, learning curve, procedure time, and experience required for adequate interpretation and reproducible results. Many men are also contraindicated to MRI due to concerns with renal function, claustrophobia, or ferromagnetic implants. This work aims to compare the sensitivity and specificity of mpMRI with the novel high-resolution micro-ultrasound imaging modality, which maintains the workflow, simplicity and low cost of ultrasound and can be used to target biopsies in real-time without the need for MRI.
Methods: Data from 5 sites was aggregated, totaling 280 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. mpMRI targets were sampled cognitively at 4/5 sites using the micro-ultrasound system and with either a software-fusion system or cognitively using micro-ultrasound at the 5th site. Clinically significant cancer was considered any Gleason Sum > 6 and targeted samples were taken for PI-RADS > 2 or PRI-MUS1 > 2 lesions.
Results: mpMRI demonstrated strong sensitivity (83%), with slightly weaker NPV (69%). Micro-ultrasound sensitivity (95%) and NPV (82%) were both higher. However, micro-ultrasound was considerably less specific (17% vs 25% for mpMRI) and both modalities showed a relatively poor PPV of 43-44%.
Conclusions: Micro-ultrasound's high sensitivity makes it an attractive option for both screening and targeted biopsy, even relative to the more widely studied mpMRI. Further larger-scale studies are required to ensure these early results are repeatable. The relatively lower specificity suggest micro-ultrasound is not yet able to exclude biopsy in as many men, though the higher sensitivity indicates the confidence may be higher in the men it does exclude._x000D_
1. Ghai, S. et al., â€œAssessing Cancer Risk in Novel 29 MHz Micro-Ultrasound Images of the Prostateâ€, Journal of Urology, 2016 Aug;196(2):562-9