title: How does magnetic resonance imaging influence staging according to AJCC staging system for nasopharyngeal carcinoma compared with computed tomography?
abstract: OBJECTIVE
  To analyze the degree and pattern of influence of magnetic resonance imaging (MRI) on staging according to the 6th edition of the American Joint Committee on Cancer staging system compared with computed tomography (CT).
  
  
  METHODS
  The MRI and CT scans and medical records of 420 consecutive patients with newly diagnosed nasopharyngeal carcinoma (NPC) were analyzed retrospectively. The tumors of all patients were staged according to the 6th edition of the American Joint Committee on Cancer staging system.
  
  
  RESULTS
  A significant difference (p <0.05) was found between CT and MRI in demonstrating involvement in the oropharynx (CT, 25.0% vs. MRI, 14.5%), prevertebral muscle (CT, 18.4% vs. MRI, 36.0%), parapharyngeal space (CT, 82.6% vs. MRI, 68.8%), skull base (CT, 31.0% vs. MRI, 52.6%), sphenoid sinus (CT, 13.6% vs. MRI, 16.7%), ethmoid sinus (CT, 7.1% vs. MRI, 3.3%), intracranial area (CT, 4.8% vs. MRI, 16.0%), and retropharyngeal lymph nodes (CT, 52.1% vs. MRI, 69.0%). The incidence of cervical lymph node metastasis and lymph node metastasis at each level was similar according to CT and MRI. MRI resulted in changes in 49.8% of T stage cases, 10.7% of N stage cases, and 38.6% of clinical stage cases.
  
  
  CONCLUSIONS
  MRI demonstrated early primary tumor involvement more precisely and deep primary tumor infiltration more easily. The use of MRI caused dramatic changes in the results of the T stage and clinical staging and should be preferred to CT in staging NPC. Patients would benefit from changes in treatment strategies resulting from the use of MRI.
authors.affiliation: Department of Radiation Oncology, Cancer Center, State Key Laboratory of Oncology in Southern China, Sun Yat-sen University, Guangzhou, People's Republic of China.
authors.forename: Xin-Biao
authors.initials: XB
authors.lastname: Liao
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Mao
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Ling-Long
authors.initials: LL
authors.lastname: Tang
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Lin
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Cui
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D002681:China; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D009367:Neoplasm Staging / Q000379:methods*; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014481:United States