title: 18F-fluorodeoxyglucose positron emission tomography to evaluate cervical node metastases in patients with head and neck squamous cell carcinoma: a meta-analysis.
abstract: BACKGROUND
  Positron emission tomography using 18F-fluorodeoxyglucose (18F-FDG PET) has been proposed to enhance preoperative assessment of cervical lymph node status in patients with head and neck squamous cell carcinoma (HNSCC). Management is most controversial for patients with a clinically negative (cN0) neck. We aimed to assess the diagnostic accuracy of 18F-FDG PET in detecting lymph node metastases in patients with HNSCC.
  
  
  METHODS
  We performed a meta-analysis of all available studies of the diagnostic performance of 18F-FDG PET in patients with HNSCC. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves using hierarchical regression models. We also compared the performance of 18F-FDG PET with that of conventional diagnostic methods (ie, computed tomography, magnetic resonance imaging, and ultrasound with fine-needle aspiration) by analyzing studies that had also used these diagnostic methods on the same patients.
  
  
  RESULTS
  Across 32 studies (1236 patients), 18F-FDG PET sensitivity was 79% (95% confidence interval [CI] = 72% to 85%) and specificity was 86% (95% CI = 83% to 89%). For cN0 patients, sensitivity of 18F-FDG PET was only 50% (95% CI = 37% to 63%), whereas specificity was 87% (95% CI = 76% to 93%). Overall, LR+ was 5.84 (95% CI = 4.59 to 7.42) and LR- was 0.24 (95% CI = 0.17 to 0.33). In studies in which both 18F-FDG PET and conventional diagnostic tests were performed, sensitivity and specificity of 18F-FDG PET were 80% and 86%, respectively, and of conventional diagnostic tests were 75% and 79%, respectively.
  
  
  CONCLUSIONS
  18F-FDG PET has good diagnostic performance in the overall pretreatment evaluation of patients with HNSCC but still does not detect disease in half of the patients with metastasis and cN0.
authors.affiliation: Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece.
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Kyzas
authors.forename: Evangelos
authors.initials: E
authors.lastname: Evangelou
authors.forename: Despina
authors.initials: D
authors.lastname: Denaxa-Kyza
authors.forename: John P A
authors.initials: JP
authors.lastname: Ioannidis
mesh_terms: D016001:Confidence Intervals; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008207:Lymphatic Metastasis; D009333:Neck; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18