title: Nasopharyngeal carcinoma staging by (18)F-fluorodeoxyglucose positron emission tomography.
abstract: OBJECTIVE
  Nasopharyngeal carcinoma (NPC) has a high rate of neck lymph node and/or distant metastasis. We evaluated the value of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in staging NPC, especially in the detection of distant metastasis.
  
  
  METHODS
  A total of 95 patients, including 85 with primary and 10 with recurrent, NPC were enrolled. Dual-phase FDG-PET was used, in addition to the conventional workup. Eighty-one patients without distant metastases underwent repeat studies 3-4 months after initial radical treatment.
  
  
  RESULTS
  Of 14 patients with distant metastases, all had lesions detected by FDG-PET, and the conventional workup detected the metastases in only 4. Two patients had false-positive MRI findings for neck node metastasis, but the FDG-PET findings were accurate. Four patients without distant metastases on their initial workup were found to have new lesions on FDG-PET 3-4 months after initial treatment. Patients with advanced node disease had a significantly greater incidence of distant metastases on FDG-PET, especially for N3 disease. Of the 95 patients, the FDG-PET results for distant metastasis were true positive in 14 patients, false positive in 8, and true negative in 73. None of our patients had a false-negative result. For a patient base, the sensitivity and specificity of FDG-PET for distant metastasis was 100% and 90.1% (95% confidence interval 81.5-95.6%), respectively, in this study. The accuracy was 91.6% (95% confidence interval 84.1-96.3%), the positive predictive value was 63.6 (95% confidence interval 40.7-82.8%), and the negative predictive value was 100%.
  
  
  CONCLUSIONS
  FDG-PET stages N and M disease of NPC more accurately and sensitively than does the conventional workup. Patients with advanced node disease, particularly N3 disease, would benefit the most from FDG-PET.
authors.affiliation: Department of Radiation Oncology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Joseph Tung-Chieh
authors.initials: JT
authors.lastname: Chang
authors.forename: Sheng-Chieh
authors.initials: SC
authors.lastname: Chan
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Kun-Ju
authors.initials: KJ
authors.lastname: Lin
authors.forename: I-How
authors.initials: IH
authors.lastname: Chen
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Chang
authors.forename: Tsung-Ming
authors.initials: TM
authors.lastname: Chen
authors.forename: Chung-Jan
authors.initials: CJ
authors.lastname: Kang
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18