The MRI in Active Surveillance "MRIAS" Trial: Use of Baseline mpMRI and Saturation Biopsy to Reduce the Frequency of Surveillance Prostate Biopsies.

Prospective studies are lacking in assessing: (i) The diagnostic utility of serial mpMRI to predict biopsy-proven progression to csPCa in men on active surveillance (ii) The oncological safety of baseline MRI and saturation diagnostic biopsy in replacing early 'confirmatory' biopsy during active surveillance.

172 men were enrolled in this single arm prospective trial. Men with ≤cT2 histologically proven PCa (Gleason 3+3=6 or Gleason 3+4=7 with ≤10% Gleason pattern 4 overall and <2 cores of Gleason pattern 4) eligible for surveillance were included. Men underwent a baseline mpMRI and saturation biopsy followed by serial annual mpMRI until a three-year endpoint per protocol saturation biopsy. The standardized one-year confirmatory biopsy was omitted and biopsies during the protocol were triggered based on new abnormalities on mpMRI and PSA density.

We report the pre-specified interim analysis of the first 100 men at three years. At baseline, median age was 64.5 (IQR 57.25-69), PSA was 4.7 (IQR 3.4-6.6), 91% had Gleason 3+3=6 PCa and mpMRI was negative (PIRADS 1/2/3) in 88% of men. 21% experienced pathological progression within three years. The PPV, NPV, sensitivity and specificity for detection of csPCa by surveillance mpMRI was 45%, 89%, 61% and 80% respectively. Positive surveillance MRI (p=0.002) and PSA density>0.2 (p=0.042) had significant predictive value for csPCa.

Our novel active surveillance protocol incorporating mpMRI detected most cases of disease progression and may enable confirmatory biopsy to be deferred but should not replace 3 year surveillance biopsy altogether, due to occasional MRI-invisible tumours.

The Journal of urology. 2019 Dec 11 [Epub ahead of print]

Amer Amin, Matthijs J Scheltema, Ron Shnier, Alexandar Blazevski, Daniel Moses, Thomas Cusick, Amila Siriwardena, Brian Yuen, Pim J van Leeuwen, Anne Maree Haynes, Jayne Matthews, Phillip Brenner, Gordon O'Neill, Carlo Yuen, Warick Delprado, Phillip Stricker, James Thompson

St Vincent's Prostate Cancer Centre, Sydney, Australia., Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Sydney, Australia., I-MED Radiology, Sydney, Australia., School of Medicine, UNSW, Sydney, Australia., St Vincent's Clinic, Sydney, Australia., Douglas Hanly Moir Pathology, Macquarie Park, NSW, Australia.