Impact of Chronic Prostatitis on the PI-RADS Score 3: Proposal for the Addition of a Novel Binary Suffix.

Sascha Merat,Frank G Zöllner,Gad Singer,Daniel Hausmann,Rahel A Kubik-Huch,Theresa Blümlein,Stefan O Schoenberg,Dominik Nickel,Markus Klarhöfer,Lukas Hefermehl

doi:10.3390/diagnostics11040623

Abstract

We examined the impact of chronic prostatitis on the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI). In this retrospective study, 63 men underwent 3T mpMRI followed by MRI/ultrasound fusion biopsy to exclude/confirm clinically significant prostate cancer (csPCa). A total of 93 lesions were included for evaluation. Images were assessed by two radiologists. Prostatitis was graded visually on T2-weighted and contrast-enhanced sequences. The correlation of prostatitis features with the assigned Prostate Imaging Reporting and Data System (PI-RADS) and the presence of csPCa were assessed, and the clinical and functional imaging parameters for differentiating between prostatitis and significant tumors were examined. Histopathological analysis was used as the reference standard. The rate of PI-RADS 3 scores tended to be higher in the presence of radiologically severe prostatitis compared with no/discrete prostatitis (n = 52 vs. n = 9; p = 0.225). In severe prostatitis, csPCa was determined in only 7.7% (4/52) of PI-RADS 3 lesions. In severe chronic prostatitis, a binary prostatitis suffix (e.g., PI-RADS 3 i+ versus i−) within the radiological report may help assess the limitations of mpMRI interpretability because of severe prostatitis and avoid unnecessary biopsies. Mean apparent diffusion coefficient (ADCmean) was the best marker (cutoff 0.93 × 10−3 mm2/s) to differentiate between csPCa/non csPCa in severe prostatitis.

Highlights

Multiparametric magnetic resonance imaging is an important clinical tool for the detection and guidance of treatment for prostate cancer (PCa) [1,2,3,4]
The present study showed that a Prostate Imaging Reporting and Data System (PI-RADS) 3 score was frequently assigned in the setting of a severe and inflammatory active prostatitis, as defined by the presence of MRI features, while clinically significant PCa (csPCa) was rarely detected histopathologically in these PI-RADS 3 lesions (7.7% (4/52); Table 3)
We found that PI-RADS 3 lesions of the peripheral zone (PZ) often correspond to prostatitis and that after MRI/US-guided biopsy, these areas rarely show a csPCa

Summary

Introduction

Multiparametric magnetic resonance imaging (mpMRI) is an important clinical tool for the detection and guidance of treatment for prostate cancer (PCa) [1,2,3,4]. Advances in MRI scanner technology and sequence development have allowed the detection of even small PCa lesions with high accuracy. The mpMRI protocol is composed of native T1-weighted (T1W), T2-weighted (T2W), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) sequences [5,6]. These sequences are evaluated in a standardized fashion using the Prostate Imaging Reporting and Data System (PI-RADS) v2.1 classification to ensure good diagnostic quality of radiological reports and to increase interobserver agreement by reducing subjectivity in image evaluation [6,7,8]. Compared with conventional transrectal ultrasound-guided biopsies, MRI-guided targeted biopsies reduce the incidence of avoidable biopsies and improve the detection rate of clinically significant PCa (csPCa) [3]

Methods

Discussion

Conclusion