Correlation of Dynamic Contrast-Enhanced MRI Perfusion Parameters With Angiogenesis and Biologic Aggressiveness of Rectal Cancer: Preliminary Results

PurposeTo investigate whether quantitative parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are correlated with angiogenesis and biologic aggressiveness of rectal cancer. Materials and MethodsA total of 46 patients with rectal cancer underwent DCE-MRI. Using a two-compartmental model, quantitative parameters (K-trans, k(ep), v(e), and iAUC) were calculated from the whole-transverse region of interest (ROI) and high K-trans area ROI of entire tumors. Histological specimens were analyzed for tumor size; T/N stage; lymphatic, vascular, perineural invasion; expression of epidermal growth factor receptor (EGFR); and KRAS gene mutations. Tumor angiogenesis was evaluated based on the microvessel density (MVD) and the expression level of the vascular endothelial growth factor. Correlations of the DCE-MRI parameters with histological markers and angiogenesis were determined using Student's t-test and analysis of variance (ANOVA). ResultsThe mean k(ep) from high K-trans area ROIs showed a significantly positive correlation with MVD (P = 0.030, r = 0.514, R-2 = 0.264). The mean k(ep) from the whole-transverse ROIs showed a significant inverse correlation with T stage (T1 vs. T2-4, P = 0.021). EGFR-positive cancer displayed higher mean K-trans (P = 0.045) and k(ep) (P = 0.038) than EGFR-negative cancer in whole-transverse ROIs. ConclusionThese preliminary results suggest that the determination of k(ep) of high K-trans area permits the noninvasive estimation of tumor angiogenesis in rectal cancer and that DCE-MRI parameters can be used as imaging biomarkers to predict the biologic aggressiveness of the tumor and patient prognosis. J. Magn. Reson. Imaging 2015;41:474-480.(c) 2013 Wiley Periodicals, Inc.