RESUMO
OBJECT: The aim of this study was to assess the dynamic contrast enhanced magnetic resonance imaging (DCE-MRI)-derived pharmacokinetic parameters between two contrast agents in a murine orthotopic pancreatic cancer model and to evaluate the tumor heterogeneity and the potential association between kinetic parameters and angiogenic markers such as the microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression by immunohistochemistry. MATERIALS AND METHODS: Human pancreatic adenocarcinoma cell line MIAPaCa-2 was injected into the pancreas of BALB/C nu/nu mice. DCE-MRI was performed using Gd-DTPA and Gd-EOB-DTPA. Quantitative and semi-quantitative vascular parameters (K(trans), Kep, Ve and AUC) were calculated by using a dedicated postprocessing software program. Values were compared with tumor rim, tumor core and the entire tumor. The MVD and VEGF expressions between tumor rim and tumor core were also compared. RESULTS: There were no significant differences in K(trans), Kep, Ve, and AUC values of the three groups when using Gd-DTPA. However there were significant differences in K(trans), Kep, and AUC values of the three groups when using Gd-EOB-DTPA (P=0.014, 0.022, 0.007, respectively), in addition, the K(trans) and Kep values of tumor core were significantly lower than those of the entire tumor (adjusted P=0.014 and 0.027, respectively), the AUC values of core were significantly lower than those of the entire tumor and rim (adjusted P=0.039 and 0.009, respectively). Immunohistology results revealed that MVD and VEGF expression in the tumor rim was significantly higher than that in the core. There was positive correlation between AUC and MVD, VEGF. CONCLUSION: The murine orthotopic pancreatic cancer model provides an ideal animal model to study human pancreatic cancer. It can more sensitively semi-quantitatively and quantitatively analyze tumor angiogenesis through selecting the albumin-binding contrast agent.