Purpose: Survey the rate and distribution of retropharyngeal lymph node metastasis, the suitability between Magnetic Resonance and computed tomography in the evaluation of nasopharyngeal tumor and the ability to detect retropharyngeal lymph node.
Methods and Materials: Cross-sectional descriptive study conducted on 35 patients with nasopharyngeal carcinoma diagnosed and treated at Hue Central Hospital from April 2018 to July 2019. The patient underwent Magnetic Resonance Imaging and Computed Tomography. Data processed with SPSS 20.0 for Windows. Investigate the level of correlation between the two techniques based on the Kappa coefficient. Results: 14 patients had retropharyngeal lymph node metastasis with a total of 25 lymph nodes, all of which in the lateral position, none in the middle. 76% the lymph nodes are at the level of C1 vertebra. 48% of lymph nodes have heterogeneous enhancement. There is a close match between Magnetic Resonance Imaging and Computed Tomography in assessing the invasion at anatomical positions: Rosenmuller fossa, Eustachian tubes, nasal cavity, pharynx, and paranasal sinuses; There is a moderate match between the two methods in assessing the invasion of the cranial base and the sphenomaxillary suture. In 14/35 cases where the retropharyngeal lymph node was detected on Magnetic Resonance Imaging (accounting for 40%), Computed Tomography identified only 6 cases (17.1%).
Conclusions: There are differences on many levels between Magnetic Resonance Imaging and Computed Tomography in the diagnosis of tumor invasion and retropharyngeal lymph node metastasis in nasopharyngeal carcinoma. In particular, Magnetic Resonance Imaging is better in detecting retropharyngeal lymph node metastasis due to high structural contrast, these lymph nodes are often difficult to detect on Computed Tomography because it is difficult to distinguish from posterior pharyngeal structures or tumors.
Retropharyngeal Lymph Node Metastasis in Nasopharyngeal Carcinoma: Prognostic Value and Staging Categories
