DCE-MRI quantitative transport mapping for noninvasively detecting hypoxia inducible factor-1alpha, epidermal growth factor receptor overexpression, and Ki-67 in nasopharyngeal carcinoma patients.

BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has the potential to noninvasively detect expression of hypoxia inducible factor-1-alpha (HIF-1alpha), epidermal growth factor receptor (EGFR), and Ki-67 in nasopharyngeal carcinoma (NPC) by quantitatively measuring tumor blood flow, vascularity, and permeability. PURPOSE: We aim to explore the utility of DCE-MRI in detecting HIF-1alpha, EGFR, and Ki-67 expression levels using traditional Kety's/Tofts' modeling and quantitative transport mapping (QTM). MATERIALS AND METHODS: Eighty-nine NPC patients underwent DCE-MRI before treatment were enrolled. DCE-MRI was processed to generate the following kinetic parameters: |u| and D from the QTM model, tumor blood flow (TBF) from Kety's model, and K(trans), V(e), and K(ep) from Tofts' model. Pretreatment levels of HIF-1alpha, EGFR, and Ki-67 were assessed by immunohistochemistry and classified into low and high expression groups. RESULTS: |u| (p < 0.001) and TBF (p = 0.015) values were significantly higher in the HIF-1alpha high-expression group compared to low-expression group. Only K(trans) (p = 0.016) was significantly higher in the EGFR high-expression group. Only |u| (p < 0.001) values were significantly higher in the Ki-67 high-expression group compared to low-expression group. Multiple linear regression analyses showed that |u| independently correlated with HIF-1alpha and Ki-67 expression, and K(trans) independently correlated with EGFR. The areas under the ROC curves of |u| for HIF-1alpha and Ki-67, and K(trans) for EGFR were 0.83, 0.74, and 0.70, respectively. CONCLUSION: |u| and K(trans) derived from DCE-MRI may be considered as noninvasive imaging markers for detecting hypoxia and proliferation in NPC patients.