Date of Award
5-2019
Document Type
Dissertation
Degree Name
Master of Medicine (MMed)
First Supervisor/Advisor
Sudihir Vinayak
Second Supervisor/Advisor
Samuel Gitau Nguku
Third Supervisor/Advisor
Edward Chege
Department
Imaging and Diagnostic Radiology (East Africa)
Abstract
Background: Traditionally, the diagnosis of prostate cancer has been based on an elevated prostate specific antigen or an abnormal digital rectal examination and confirmed histologically following prostate biopsy. This has led to a number of men without cancer or with clinically insignificant disease undergoing unwarranted prostate biopsies and suffering consequent complications. Pre-biopsy multi-parametric MRI plays a vital role in determining men with clinically significant cancer who need biopsy and those with a negative MRI who can safely avoid an unwarranted biopsy. Whereas studies on the value of multi-parametric MRI have been done elsewhere, there is variation in prevalence of prostate cancer in different populations which affects the predictive value, varying thresholds in defining clinically significant cancer as well as possible differences in tumour biology with our population.
Objective: To determine the diagnostic accuracy of multi-parametric MRI in differentiating clinically significant and clinically insignificant prostate cancer using histopathology as the reference standard.
Methods: The diagnostic accuracy of multi-parametric MRI using transrectal ultrasound guided biopsy as the reference test was established for 133 men who underwent multi-parametric MRI and biopsy between January 2016 – March 2019. The multi-parametric MRI images were reviewed and reported by two independent consultant radiologists. Clinically significant cancer was defined as PI-RADS score of ≥3 and Gleason score ≥3 + 4 (grade group ≥2).
Results: Multi-parametric MRI of the prostate was found to have 92% sensitivity, 47.8% specificity, 86.8% negative predictive value and 62% positive predictive value.
Conclusion: Multi-parametric MRI has a high sensitivity and a negative predictive value 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.
Recommended Citation
Obino, M. (2019). Diagnostic accuracy of multi-parametric MRI in diagnosis of clinically significant prostate cancer (Unpublished master's dissertation). Aga Khan University, East Africa.