Evaluation of extracapsular extension in prostate cancer using qualitative and quantitative multiparametric MRI

Purpose To investigate the value of multiparametric magnetic resonance imaging (mpMRI) for extracapsular extension (ECE) in prostate cancer (PCa). Materials and Methods In all, 292 patients who received radical prostatectomy and underwent preoperative mpMRI at 3T were enrolled retrospectively. For determining the associations with ECE, the likelihood of ECE was assessed qualitatively on T 2 ‐weighted imaging ( T 2 WI) and combined T 2 WI and diffusion‐weighted imaging (DWI) or dynamic contrast‐enhanced imaging (DCEI). Quantitative MRI parameters were measured in PCa based on histopathological findings. Two models for detecting ECE including imaging and clinical parameters were developed using multivariate analysis: Model 1 excluding combined T 2 WI and DWI and DCEI and Model 2 excluding combined T 2 WI and DWI, and combined T 2 WI and DCEI. Diagnostic performance of imaging parameters and models was evaluated using the area under the receiver operating characteristics curve (Az). Results For detecting ECE, the specificity, accuracy, and Az of combined T 2 WI and DWI or DCEI were statistically better than those of T 2 WI ( P < 0.05), and all quantitative MRI parameters showed a statistical difference between the patients with and without ECE ( P < 0.05). On multivariate analysis, significant independent markers in Model 1 were combined T 2 WI and DWI, combined T 2 WI and DCEI, and K trans ( P < 0.05). In Model 2, significant markers were combined T 2 WI and DWI and DCEI, K trans , K ep , and Ve ( P < 0.05). The Az values of models 1 and 2 were 0.944 and 0.957, respectively. Conclusion mpMRI may be useful to improve diagnostic accuracy of the models for determining the associations with ECE in PCa. Level of Evidence : 4 Technical Efficacy : Stage 2 J. MAGN. RESON. IMAGING 2017;45:1760–1770