Dynamic Contrast-Enhanced Magnetic Resonance Imaging of Regional Nodal Metastasis in Nasopharyngeal Carcinoma: Correlation with Nodal Staging

To determine if the perfusion parameters by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of regional nodal metastasis are helpful in characterizing nodal status and to understand the relationship with those of primary tumor of nasopharyngeal carcinoma (NPC). Materials and Methods. Newly diagnosed patients imaged between August 2010 and January 2014 and who were found to have enlarged retropharyngeal/cervical lymph nodes suggestive of nodal disease were recruited. DCEMRI was performed. Three quantitative parameters, 𝐾trans, Ve, and 𝑘ep, were calculated for the largest node in each patient. KruskalWallis test was used to evaluate the difference in the parameters of the selected nodes of different N stages. Spearman’s correlation was used to evaluate the relationship between the DCE-MRI parameters in nodes and in primary tumors. Results. Twenty-six patients (7 females; 25∼67 years old) were enrolled. 𝐾trans was significantly different among the patients of N stages (N1, 𝑛=3; N2, 𝑛 = 17; N3, 𝑛=6), 𝑃 = 0.015. Median values (range) for N1, N2, and N3 were 0.24 min−1 (0.17∼0.26 min−1), 0.29 min−1 (0.17∼0.46 min−1), and 0.46 min−1 (0.29∼0.70 min−1), respectively. There was no significant correlation between the parameters in nodes and primary tumors. Conclusion. DCE-MRI may play a distinct role in characterizing the metastatic cervical lymph nodes of NPC.