title: [Comparison between PET/CT and MRI in diagnosing lymph node metastasis and N staging of nasopharyngeal carcinoma].
abstract: OBJECTIVE
  To compare the clinical significance of PET/CT and MRI in diagnosing lymph node metastasis and N staging of nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  116 NPC patients had undergone PET/CT and MRI before therapy. The findings of PET/CT and MRI in diagnosing lymph node metastasis and N staging were compared according to the results of follow-up.
  
  
  RESULTS
  A total of 614 lymph nodes in 116 patients were analyzed. 340 positive nodes and 274 negative nodes interpreted by image findings were verified during follow-up. The sensitivity, specificity and accuracy of PET/CT in diagnosing node metastasis was 93.2%, 98.2% and 95.4%, while that of MRI was 88.8%, 91.2% and 89.9%, respectively, with statistically significant difference in each between PET/CT and MRI (P < 0.05). Based on Fuzhou Staging System, 109 patients (94.0%) were correctly staged by PET/CT, and 103 patients (88.8%) by MRI, while according to UICC Staging System, 108 patients (93.1%) were correctly staged by PET/CT, and 100 patients (86.2%) by MRI.
  
  
  CONCLUSIONS
  PET/CT is superior to MRI in diagnosing lymph node metastasis and N staging of nasopharyngeal carcinoma. The false-positive and false-negative assessment based on PET-CT scan findings may be caused by: (1) inflammatory hyperplastic node; (2) node with large areas of necrosis; (3) node in diameter less than spatial resolution limitation of PET.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Gu-yi
authors.initials: GY
authors.lastname: Zhang
authors.forename: Wei-han
authors.initials: WH
authors.lastname: Hu
authors.forename: Li-zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Hu-bing
authors.initials: HB
authors.lastname: Wu
authors.forename: Yuan-hong
authors.initials: YH
authors.lastname: Gao
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.forename: Quan-shi
authors.initials: QS
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003951:Diagnostic Errors; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity