title: [MRI in exploring the spread pattern of retropharyngeal lymp node metastases in nasopharyngeal carcinoma].
abstract: OBJECTIVE
  The purpose of this study is to investigate the incidence, distribution and spread pattern of retropharyngeal lymph node (RLN) metastasis in the patient with nasopharyngeal carcinoma (NPC) using magnetic resonance imaging (MRI).
  
  
  METHODS
  MRI data of 294 patients with newly diagnosed NPC were reviewed retrospectively. Criteria for RLN metastasis were the minimal axial dimension of > or = 6 mm, or the presence of nodal necrosis.
  
  
  RESULTS
  RLN involvement was detected in 165 (56.1%) patients. The incidence of metastatic lateral RLN decreased gradually from C1 to C3 level. A significantly higher incidence of metastatic RLN was observed in the patients with cancerous involvement of oropharynx, nasal cavity, pre-styloid parapharyngeal space, post-styloid parapharyngeal space or with cervical lymph node metastasis. Thirty-one patients (10.5%) had metastatic RLN only, and 54 (18.4%) showed metastatic cervical lymph nodes only, but 134 (45.6%) exhibited an involvement of both the RLN and cervical lymph node. A significantly lower incidence of metastatic RLN was found in T1, N0, and stage I disease.
  
  
  CONCLUSIONS
  The incidence of metastatic lateral retropharyngeal lymph node decreases gradually from C1 to C3 level. Metastatic retropharyngeal lymph node is associated with cancerous involvement of surrounding tissue by primary tumor or with cervical lymph node metastasis. Retropharyngeal lymph node or cervical level II node can be considered equally as the first station of nodal metastasis in nasopharyngeal carcinoma.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Imaging Diagnostic and Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Cui
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Xue-Wen
authors.initials: XW
authors.lastname: Liu
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D009333:Neck; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010614:Pharynx; D012189:Retrospective Studies; D055815:Young Adult