Dynamic Contrast-Enhanced Magnetic Resonance Imaging In The Detection Of Intratumoral Hypoxia And Angiogenesis In Nasopharyngeal Carcinoma

Objective:To evaluate the value of gadopentetate dimeglumine (Gd- DTPA) based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of intratumoral hypoxia and angiogenesis by investigating the relationship between the parameters of MR dynamic enhancement and microvascular density (MVD) as well as expression of hypoxia induced factor-la (HIF-la) and vascular endothelial growth factor (VEGF)Methods:14 patients with nasopharyngeal carcinoma underwent dynamical contrast enhanced MR imaging before nasopharyngoscopy. A time-intensity curve for each ROI is obtainted. The semiquantitative dynamic parameters were calculated. Dynamic MR parameters were correlated with histopathologic results. The strength of correlations was tested by Spearman correlation test.Result:Statistically significant positive correlations existed between slope, MS, SImax of biopsy region and expression of VEGF(r=0.889,0.882,0.619, respectively,p<0.05), HIF-1α(r=0.870,0.825,0.665, respectively, p<0.05), MVD(r=0.627,0.755,0.693, respectively, p<0.05)Statistically significant negtive correlations existed between T1 on set,TTP of biopsy region and expression of VEGF(r=-0.909,-0.829, respectively, p<0.05), HIF-1α(r=-0.687,-0.690, respectively, p<0.05),MVD(r=-0.578,-0.852, respectively, p<0.05). Statistically positive correlations also existed between Ktrans, kep and expression of VEGF(r=0.540,0.691, respectively, p<0.05), HIF-1α(r=0.536,0.677, respectively, p<0.05).Another statistically positive correlation existed between kep and MVD(r=0.635, p<0.05),but it did not happen on Ktrans. Statistically negtive correlations existed between ve of biopsy region and expression of VEGF(r=-0.624, respectively, p<0.05), HIF-1α(r=-0.595, p<0.05), MVD(r =-0.667, p<0.05).Conclusion:Statistically correlations existed between semiquantitative or quantitative parameters of MR dynamic enhancement of biopsy region and MVD as well as expression of VEGF and HIF-1α. The dynamic enhanced MRI may be a non-invasive method for detection of intratumoral hypoxia and angiogenesis in nasopharyngeal carcinoma.