Neck node metastases from nasopharyngeal carcinoma: MR imaging of patternsof disease

Background. The purpose was to use MR imaging to document the patterns of n odal involvement in the upper neck in nasopharyngeal carcinoma (NPC). Methods. The MR images of 150 patients with newly diagnosed NPC were review ed retrospectively. Nodes were considered abnormal on MR criteria of size, necrosis, and extracapsular spread. Results. Retropharyngeal nodes (RN) were more frequently involved than nonr etropharyngeal nodes (NRNs) (94% vs 76% in 115 patients with nodal metastas es). NRN involvement without RN was seen in only 7 of 115 patients (6%). in volvement of RN at the level of the oropharynx (82%) was as common as at th e nasopharynx (83%) level. internal jugular nodes were the most frequently involved NRN nodes (72%). Spinal accessory nodal involvement was also commo n (57%) but seldom in isolation (8%). Submandibular (3%) and parotid (2%) n odal metastases were uncommon and were always associated with advanced noda l metastases in the ipsilateral RN, internal jugular, and spinal accessory regions. Conclusion. Retropharyngeal nodes are the first echelons of nodal metastase s. Direct lymphatic spread to the neck without involvement of the RN nodes is uncommon. RN metastases at the level of the oropharynx are more common t han previously suspected, and this should influence radiotherapy planning. NRN outside the internal jugular and spinal accessory chains are rare and o nly occur when the usual routes of lymphatic spread have already been block ed by tumor. (C) 2000 John Wiley & Sons, Inc.