To estimate the negative predictive value (NPV) of prostate mpMRI in the detection of clinically significant (Gleason ≥7) prostate cancer (csPCa) at long-term follow-up (median 6.7 years, range 2. 6-10.7 years), in men with negative pre-MRI biopsy and to assess the diagnostic performance of mpMRI in detecting csPCa over this time.

Following Institutional REB-approval, men with prostate mpMRI following a biopsy between 2004-2009 were identified retrospectively from a cancer registry database and MRI reports. The mpMRI sequences comprised T2-weighted and dynamic contrast-enhanced series (2004-2005) with diffusion-weighted imaging 2006 onwards. Clinical outcomes were assessed up to July 2015 by review of subsequent pathology results, PSA levels and review of electronic patient records. The primary outcome was csPCa diagnosis by follow-up. We also estimated the sensitivity, specificity, PPV and NPV of all prostate mpMRI during the period.

502 mpMRI with a prior biopsy were included. 121 were in men with a prior negative systematic biopsy for cancer (median PSA 9.5; median age 60 years). Of these, 96% (70/73) of men with negative mpMRI remained free of csPCa at median follow-up of 6.7 years (range 2.6-10.7 years). The overall NPV and PPV of mpMRI in the entire cohort regardless of pre-MRI biopsy status was 86% (80-91%) and 54% (52-57%) respectively, in the time period.

Prostate mpMRI has high clinical NPV. In men with pre-MRI negative biopsy and a negative MRI, the risk of developing clinically significant prostate cancer at median 6.7 years is extremely low.

The Journal of urology. 2019 Jun 12 [Epub ahead of print]

Glen Lo, Kirsteen R Burton, Masoom A Haider, Neil Fleshner, Antonio Finelli, Sangeet Ghai

Sir Charles Gairdner Hospital, Diagnostic Imaging ( Perth , Western Australia , Australia )., Jt Dept of Medical Imaging, University Health Network – Mt Sinai Hospital – Women’s College Hospital, University of Toronto ( Toronto , Ontario , Canada )., Division of Urology, Dept of Surgical Oncology, University Health Network, University of Toronto ( Toronto , Ontario , Canada ).