Presentation Authors: Daniel Costa*, Alberto Diaz de Leon, Takeshi Yokoo, Claus Roehrborn, Brad Hornberger, Kenneth Goldberg, Naveen Subramanian, Julia Lotan, Neil Rofsky, Franto Francis, Ming Zhou, Yuval Freifeld, Ivan Pedrosa, Dallas, TX
Introduction: The standard multiparametric MRI (mpMRI) of the prostate includes dynamic contrast-enhanced (DCE), T2- and diffusion-weighted (DWI) imaging. DCE affects PI-RADS v2 score only in a small group of lesions in the peripheral zone (PZ) with DWI score of 3. Emerging data suggest comparable diagnostic performance of biparametric (bp) vs. mpMRI, the former forgoing DCE. Potential advantages of bpMRI include reduced cost, no need for a venous access and reduced risk of contrast-related side effects. However, the value of DCE for lesions other than PZ lesions with a DWI score of 3 is currently unknown. This study aims to assess the impact of DCE status for discrimination of clinically significant PCa in lesions for which the current scoring approach is not influenced by DCE findings (i.e., all but PZ lesions with a DWI score of 3).
Methods: This single-center, retrospective study of prospectively collected data included all men with abnormal 3T mpMRI examinations (PIRADS v2 score â‰¥3), without prior treatment, who subsequently underwent targeted biopsies between 5/2017-5/2018. During routine clinical interpretation, 1 of 9 radiologists prospectively assigned a lesion score for each MRI sequence according to PI-RADS v2 criteria, including DCE status (+ or -). Targeted biopsy outcome (negative, clinically insignificant [GG1 PCa] or significant [GG2+] PCa) on a per-lesion basis served as the standard of reference. Logistic regression with mixed effects adjusting for clustered data and chi-square test were used to analyze the association between DCE status and biopsy outcome in the PZ, transition zone (TZ), and whole gland.
Results: A total of 324 men (mean PSA: 9.0 ng/mL, age: 66 y, prostate volume: 51 cc) with 449 lesions were eligible (mean size: 14 mm, PI-RADS 3: 8%(34/449), 4: 59%(263/449), 5: 34%(152/449), PZ: 58%(261/449), DCE+:76%(340/449)). A strong association between DCE status and the presence of clinically significant PCa was identified (OR: 5.1; p < 0.001). Most DCE+ lesions (62%,211/340) represented GG2+ PCa for every category in both zones. Largest differences in the biopsy yield were found for PIRADS 4 TZ lesions (DCE+: 62% vs. DCE-: 23%; p=0.005) (Fig.1).
Conclusions: DCE status helps discriminate clinically significant PCa on targeted biopsies - even in lesions where DCE does not influence overall PIRADS v2 score. This information may help refine future versions of PI-RADS and raise awareness among those opting for an abbreviated, bpMRI protocol.