Presentation Authors: Matthew Roberts*, Peter Donato, Andrew Morton, Geoff Coughlin, Rachel Esler, Nigel Dunglison, Robert Gardiner, John Yaxley, Brisbane, Australia
Introduction: Multiparametric magnetic resonance imaging (mpMRI) of the prostate has been shown to improve prostate cancer detection by facilitating targeted biopsy and reducing negative biopsies due to high sensitivity. Reports on the feasibility of implementing a mpMRI-based triage system to guide patient selection for biopsy are limited, hence this study sought to describe the experience of the mpMRI-based triage pathway introduced in an academic, tertiary centre, including cancer diagnostic performance and avoiding unnecessary biopsies.
Methods: An observational retrospective cohort study of consecutive patients attending an academic, tertiary center between June 2014 and July 2017 who underwent mpMRI for investigation of prostate cancer were considered. Standard clinical, MRI-related and histopathological parameters were collected for analysis of biopsy-avoidance and diagnostic accuracy of biopsy approach.
Results: 653 men underwent mpMRI, of which 344 underwent prostate biopsy resulting in a 47% biopsy avoidance rate, of which 83.2% were reported as PIRADS 2. Demographics included median (with interquartile range) age (67; 62-72 years), prostate specific antigen (PSA; 8.6; 6-12 ng/ml), prostate volume (36.5; 30-51 ml) and PSA density (0.24; 0.15-0.32 ng/ml3) respectively. A trend toward higher PSA, PSA density and lower prostate volume and age was observed with higher PIRADS score. A 69.8% cancer detection rate was observed, 60.5% of which were considered to have clinically significant disease. Targeted biopsies resulted in a higher proportion of positive biopsies (70%) compared to template (4.2%) and combined targeted and template (36.4%) approaches. Higher PIRADS scores were associated with clinically significant disease, no matter the biopsy approach.
Conclusions: Introduction of a mpMRI-based triage system into a large public tertiary teaching hospital is feasible and leads to high rates of prostate cancer diagnosis whilst reducing unnecessary biopsies and detection of low risk prostate cancer.