Value of preoperative 3T multiparametric MRI for surgical margin status in patients with prostate cancer

PurposeTo examine the value of preoperative multiparametric magnetic resonance imaging (MRI) as a predictor of surgical margin (SM) status in patients with prostate cancer (PC). Materials and MethodsThe Institutional Review Board approved this retrospective study; the requirement for informed consent was waived. Fifty-six male patients with histologically proven PC underwent preoperative 3T multiparametric MRI including high b value (0, 2000 s/mm(2)) diffusion-weighted imaging. In each patient, clinical data, such as biopsy Gleason score and D'Amico clinical risk score, and multiparametric MRI findings, such as tumor location, tumor size, tumor extension in the apical or proximal region, tumor apparent diffusion coefficient (ADC), and the presence or absence of MRI findings of extracapsular extension (ECE) were evaluated. Statistical evaluations included the Fisher's exact test, (2) test, Mann-Whitney U-test, and logistic regression analysis. ResultsOn histopathological evaluation, 15 patients (27%) were SM-positive (SMP group), and 41 (73%) were SM-negative (SMN group). The tumor ADC was significantly lower in the SMP group than in the SMN group (P=0.001). The frequency of tumor extension in the apex or base and suspected ECE on MRI were significantly higher in the SMP group than in the SMN group (P=0.037 and 0.011, respectively). On multivariate analysis, tumor ADC was the only predictor of SM status in PC (P=0.003). ConclusionPC with positive SM was characterized by tumor extension in the apical and proximal regions, lower tumor ADC, and tumors with positive MRI findings of ECE, compared to tumors with negative SM. J. Magn. Reson. Imaging 2016;44:584-593.