title: [Usefulness of (18)F-fluorodeoxyglucose-positron emission tomography-computerized tomography in the identification of the primary tumor in patients with cancer of unknown origin].
abstract: OBJECTIVE
  We determined the utility of the (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)-computerized tomography (CT) in the localization of the primary tumor in patients with tumor of unknown origin (TUO).
  
  
  METHODS
  (18)F-FDG PET-CT scans, performed between November 2006 and November 2010, in search for the primary tumor in patients with TUO, were retrospectively evaluated. Patients underwent a standard PET-CT, 50-60minutes after intravenous injection of 296-370MBq (18)F-FDG. PET-CT studies were assessed as pathological, with/without identification of the primary tumour and no pathological. Final diagnosis was established by histological confirmation and/or clinical/radiologic follow-up longer than 6 months.
  
  
  RESULTS
  We studied 74 patients (59 males, 15 females), with ages ranging from 41-89 years. In 38 (51%) patients the PET-CT assessed the correct origin of the primary tumour. In 8 cases, a histological confirmation in the primary lesion was obtained. In 4 patients the PET-CT showed a false positive result.
  
  
  CONCLUSIONS
  PET-CT scanning identified 51% of the primary sites in our sample of patients.
authors.affiliation: Servicio de Medicina Nuclear, Hospital General Universitario de Ciudad Real, Ciudad Real, España. mdtalavera@hotmail.com
authors.forename: María del Prado
authors.initials: Mdel P
authors.lastname: Talavera-Rubio
authors.forename: Ana María
authors.initials: AM
authors.lastname: García-Vicente
authors.forename: Azahara María
authors.initials: AM
authors.lastname: Palomar-Muñoz
authors.forename: John Patrick
authors.initials: JP
authors.lastname: Pilkington-Woll
authors.forename: Víctor Manuel
authors.initials: VM
authors.lastname: Poblete-García
authors.forename: Angel
authors.initials: A
authors.lastname: Soriano-Castrejón
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005189:False Positive Reactions; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18