Prostate carcinoma detection: Moving from multiparametric to bi-parametric magnetic resonance imaging

ABSTRACT

Background: Prostate carcinoma screening tests usually include digital rectal examination (DRE) and prostate-specific antigen (PSA) levels. If these tests detect some abnormality, further evaluation is recommended using transrectal ultrasound (TRUS), TRUS guided biopsy, or magnetic resonance imaging (MRI). MRI is a preferred tool among three as its noninvasive and has high sensitivity and specificity. In MRI, most of the medical centers perform multi-parametric MRI. The present study is an endeavor to evaluate the feasibility of using biparametric study for detection of prostate cancer; thereby reducing the scan time and avoiding the use of contrast. Objective: The objective of the study was to compare the diagnostic efficacy of using biparametric MRI (T2-weighted imaging [T2WI] and Diffusion-weighted images [DWI]) for detection of carcinoma prostate as compared to multiparametric MR study which in addition also includes dynamic contrast-enhanced (DCE) and spectroscopic MRI sequences. Materials and Methods: This prospective cross-sectional study included 60 patients suspected to have prostate cancer on the basis of PSA levels and DRE. All the patients underwent pre-treatment MRI on 1.5 T scanner followed by TRUS guided biopsy. MRI protocol included T1-weighted images, T2W, DWI, DCE MRI, and MR spectroscopy. The diagnostic performance of T2WI + DWI and multi-parametric MRI for diagnosis of prostate cancer was determined and compared with each other using histopathology as the gold standard. Results: The sensitivity for detection of carcinoma prostate for biparametric MRI (T2WI + DWI) is 63.3%, specificity 78.95%, positive predictive value (PPV) 86.6%, and negative predictive value of (NPV) 50.00%. The sensitivity of multiparametric MRI was 78.05%, specificity 68.42 % with PPV 84.2%, and NPV of 59.09%. Conclusion: For the detection of prostate cancer biparametric (DWI/T2WI) and multi-parametric MRI both showed comparable results. Multi-parametric MRI involves the administration of intravenous contrast and requires longer acquisition time; T2/DWI is faster and non-contrast sequences and is workhorse sequence in the detection of prostate cancer.