Multidimensional analysis of clinicopathological characteristics of false-negative clinically significant prostate cancers on multiparametric MRI of the prostate in Japanese men

Abstract

Purpose: To clarify clinicopathological features of false-negative clinically significant prostate cancer (csPC) at multiparametric prostate MRI (mpMRI).

Methods: 95 patients with 139 csPC undergoing 3T mpMRI before radical prostatectomy were included. Two radiologists were independently evaluated mpMR images using PI-RADS v2. Clinicopathological findings were compared between (a) detectable and undetectable lesions using overall mpMRI criteria (o-mpMRI criteria) and (b) lesions with early enhancement effect (EEE) and lesions without EEE at DCE-MRI.

Results: The detection rate of csPS using cutoff value of category 3 or more in PI-RADS v2 for positive lesion was 72.1% (98/136 lesions). In 38 false-negative lesions with less than PI-RADS v2 category 3, the DCE-MRI detected 14 lesions. 17 undetectable lesions on o-mpMR criteria had lower PSA and D'amico risk classification, and higher tumor apparent diffusion coefficient (ADC) than those of 118 detectable lesions (p ≤ 0.048). 89 lesions with EEE showed higher PSA, tumor size, prostatectomy GS grade, frequency of lesions with GS ≥ 4 + 3 and lower tumor ADC than those in 38 lesions without EEE (p ≤ 0.046).

Conclusion: Tumor detectability of csPC with PI-RADS v2 was limited compared with o-mpMRI criteria in Japanese men. Moreover, false-negative lesions on o-mpMRI criteria were characterized as small in size, low risk and low cellularity.

Keywords: Dynamic contrast-enhanced MR imaging; Magnetic resonance imaging; Prostate cancer; Prostate imaging and reporting data system version 2; Tumor detection.