Utility of Multiparametric Magnetic Resonance Imaging as a Predictor of Clinically Significant Prostate Cancer in a Sub-Saharan African Population

Abstract

Background: Traditionally, the diagnosis of prostate cancer was based on increased prostate-specific antigen level or an abnormal digital rectal examination and confirmed histologically following biopsy. Consequently, a proportion of men without cancer or with clinically insignificant disease undergo unwarranted prostate biopsies and experience resultant complications. Pre-biopsy multiparametric magnetic resonance imaging (MP-MRI) is vital in determining those with clinically significant cancer who need biopsy and those with a negative MRI who can safely avoid unnecessary biopsy.
 Methods: The diagnostic accuracy of MP-MRI using transrectal ultrasound-guided biopsy as the reference test was established for 133 men who had undergone MRI and biopsy. The MRI images were reviewed and reported by two independent consultant radiologists. Clinically significant cancer was defined as Prostate Imaging Reporting and Data System score ≥3 on multiparametric MRI and Gleason score ≥3 + 4 (grade group ≥2) on histology.
 Results: MP-MRI of the prostate was found to have 92% sensitivity, 47.8% specificity, 86.8% negative predictive value (NPV) and 62% positive predictive value for the diagnosis of prostate cancer.
 Conclusion: MP-MRI has a high sensitivity and a high NPV, validating its use in pre-biopsy evaluation of men at risk of prostate cancer to safely avoid unnecessary prostate biopsy and to guide biopsy of suspicious lesions.