title: The role of FDG-PET/CT in detecting unsuspected and unknown distant metastasis in the initial staging of NSCLC.
abstract: OBJECTIVE
  Our purpose in this retrospective study was to determine the ratio of unexpected [metastases within the coverage area of thorax computed tomography (CT)] and unknown (metastases out of the coverage area of thorax CT) metastases by positron emission tomography/CT (PET/CT) in patients with newly diagnosed non-small cell lung cancer (NSCLC) who had no defined metastatic lesion, and to investigate the contribution of fludeoxyglucose (FDG)-PET/CT in metastasis staging.
  
  
  METHODS
  A total of 567 patients (489 males and 78 females, mean age 60.9 ± 10.7 years) were enrolled in this study. Among the 567 patients, a total of 156 patients who underwent PET/CT for metabolic characterization (group 1) and had solitary pulmonary nodules (group la, n = 39) or solitary pulmonary masses (group lb, n = 117) and the remaining 411 patients (group 2) with NSCLC who had PET/CT performed for staging formed the basis of this study
  
  
  RESULTS
  In group 1, 5/39 (12.8%) patients with a solitary pulmonary nodule and 29/117 (24.8%) patients with a solitary pulmonary mass had distant metastases. In group 2, 129 patients of 411 (31.4%) had distant metastasis.
  
  
  CONCLUSIONS
  FDG-PET/CT is proven to be an effective method in detection of unsuspected-unknown metastasis, either in patients with solitary pulmonary lesion or in the initial staging of patients with NSCLC.
authors.affiliation: Department of Nuclear Medicine, İstanbul University, Turkey. metin.halac@yahoo.com
authors.forename: Metin
authors.initials: M
authors.lastname: Halaç
authors.forename: Meftune
authors.initials: M
authors.lastname: Özhan
authors.forename: Sabire
authors.initials: S
authors.lastname: Yilmaz Aksoy
authors.forename: Betül
authors.initials: B
authors.lastname: Vatankulu
authors.forename: Anar
authors.initials: A
authors.lastname: Aliyev
authors.forename: Sertaç
authors.initials: S
authors.lastname: Asa
authors.forename: Ersan
authors.initials: E
authors.lastname: Atahan
authors.forename: Muhammet Sait
authors.initials: MS
authors.lastname: Sağer
authors.forename: Kerim
authors.initials: K
authors.lastname: Sönmezoğlu
mesh_terms: D000328:Adult; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18