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

OBJECTIVE: 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. DCE-MRI was performed. Three quantitative parameters, K(trans), v(e), and k(ep), were calculated for the largest node in each patient. Kruskal-Wallis 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. K(trans) 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.