The Role of Multiparametric MRI in the Local Staging of Prostate Cancer

Prostate cancer ranks as the second most frequently diagnosed cancer globally among men and stands as the fifth leading cause of cancer-related death in males. Hence, an early and precise diagnosis and staging are critical. Traditional staging is based on clinical nomograms but presents a lower performance than prostate multiparametric magnetic resonance imaging (mpMRI). Since tumor staging serves as the basis for risk stratification, prognosis, and treatment decision-making, the primary objective of mpMRI is to distinguish between organ-confined and locally advanced diseases. Therefore, this imaging modality has emerged as the optimal selection for the local staging of prostate cancer, offering incremental value in evaluating pelvic nodal disease and bone involvement, and supplying supplementary insights regarding the precise location and disease extension. As per the Prostate Imaging Reporting & Data System v2.1 guideline, a comprehensive and accurate mpMRI requires several key sequences, which include T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) for morphological assessment, with T2WI serving as the cornerstone for local staging. Additionally, diffusion-weighted imaging (DWI) and dynamic sequences acquired with intravenous administration of paramagnetic contrast medium (DCE) are crucial components. It is worth noting that while MRI exhibits high specificity, its sensitivity in diagnosing extracapsular extension, seminal vesicle invasion, and lymph node metastases is limited. Moreover, mpMRI has its own constraints and is not as effective in detecting distant metastases or evaluating lymph nodes, for which extended pelvic lymph node dissection remains the gold standard. This review aims to highlight the significance of mpMRI in prostate cancer staging and provide a practical approach to assessing extracapsular extension, seminal vesicle invasions, and the involvement of adjacent organs and lymph nodes.