Diagnostic Accuracy of a Rapid Biparametric MRI Protocol for Detection of Histologically Proven Prostate Cancer

Abstract

Objective: To evaluate the performance of a rapid, low cost, noncontrast MRI examination as a secondary screening tool in detection of clinically significant prostate cancer.

Methods: In this prospective single institution study, 129 patients with elevated prostate-specific antigen levels or abnormal digital rectal examination findings underwent MRI with an abbreviated biparamatric MRI protocol consisting of high-resolution axial T2- and diffusion-weighted images. Index lesions were classified according to modified Prostate Imaging - Reporting and Data System (mPI-RADS) version 2.0. All patients underwent standard transrectal ultrasound-guided biopsy after MRI with the urologist being blinded to MRI results. Subsequently, all patients with suspicious lesions (mPI-RADS 3, 4, or 5) underwent cognitively guided targeted biopsy after discussion of MRI results with the urologist. Sensitivity and negative predictive value for identification of clinically significant prostate cancer (Gleason score 3+4 and above) were determined.

Results: Rapid biparametric MRI discovered 176 lesions identified in 129 patients. Rapid MRI detected clinically significant cancers with a sensitivity of 95.1% with a negative predictive value of 95.1% and positive predictive value of 53.2%, leading to a change in management in 10.8% of the patients. False negative rate of biparametric (bp) MRI was 4.7%.

Conclusion: We found that a bp-MRI examination can detect clinically significant lesions and changed patient management in 10.8% of the patients. A rapid MRI protocol can be used as a useful secondary screening tool in men presenting with suspicion of prostate cancer.

Conflict of interest statement

Conflict of interest: None of the authors declares a conflict of interest related to this manuscript.

Copyright © 2018 Elsevier Inc. All rights reserved.

Figures

Figure 1.. Study participant workflow.

A total of 133 patients with elevated PSA were enrolled in this study. Four patients were excluded; three because of extensive artefacts in the prostate region due to total endoprosthetic hip replacement (n=2) or due to excessive bowel gas causing sever distortion artefacts on diffusion weighted images (n=1). Another patient was excluded due to technical problems of the MRI scanner and the inability to obtain a full diagnostic MRI exam. The MRI exams of 129 patients scanned with the biparametric rapid MRI protocol were included in the statistical analysis. All 129 patients subsequently underwent TRUS biopsy. After systematic biopsy the Radiologists unblinded the Urologist to MRI findings. 84 Patients with a mPI-RADS lesion 3, 4 or 5 underwent further cognitive targeted biopsy in the same biopsy session. PSA = Prostate specific antigen; DRE = Digital rectal examination; MRI = Magnetic resonance imaging, TRUS = Transrectal ultrasound guided 12 quadrant prostate biopsy, mPI-RADS = modified Prostate Imaging Reporting and Data System