Comparison of multiparametric and biparametric magnetic resonance imaging protocols for prostate cancer diagnostics by radiologists with different experience

Abstract

Background: MRI can detect clinically significant prostate cancer, diagnose extracapsular extension and stage of the cancer. A scanning protocol including only T2-weighted and diffusion-weighted images represents a viable alternative to multiparametric MRI, provided that high diagnostic accuracy of the test is maintained. In recent studies, the diagnostic accuracy of bpMRI and mpMRI in detecting prostate cancer has demonstrated little difference. Objective: to compare the diagnostic accuracy of bpMRI and mpMRI for the detection of clinically significant prostate cancer using PI-RADS v2.1 with MRI-guided multifocal biopsy as the gold standard. Materials and methods: this study is retrospective. We initially processed the medical records of 126 patients. Inclusion criteria were the presence of a PI-RADS 2.1 mpMRI, clinical information on free and bound PSA blood levels, a multifocal prostate biopsy performed, and a time interval between MRI and biopsy of no more than 14 days. Three investigators (radiologists with less than 2 years' experience, 2 to 5 years' experience, and more than 5 years' experience) independently evaluated bpMRI of the prostate for the presence of pathological foci. After a period of 2 weeks, the researchers evaluated the dataset of mpMRI of the prostate. Each lesion detected, starting from PI-RADS category 3, was compared with the result of a multifocal fusion biopsy. The biopsy result was presented as a sum of Gleason scores, with a Gleason score of 7 or higher being considered clinically relevant biopsy findings. Findings meeting PI-RADS criteria 4 and 5 were considered as tumor foci according to MRI data. Conclusion: biparametric protocols of prostate MRI have a definite economic advantage over multiparametric protocols due to absence of costs for contrast media and significant decrease of MRI scanner loading time. Diagnostic accuracy of bpMRI to detect prostate foci is not inferior to mpMRI. At the same time, the use of DCE presumably allows reducing the number of biopsies.