title: 18F-FDG PET/CT as a diagnostic tool in patients with extracervical carcinoma of unknown primary site: a literature review.
abstract: BACKGROUND
  Carcinoma of unknown primary (CUP) represents a heterogeneous group of metastatic malignancies for which no primary tumor site can be identified after extensive diagnostic workup. Failure to identify the primary site may negatively influence patient management. The aim of this review was to evaluate (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) as a diagnostic tool in patients with extracervical CUP.
  
  
  METHODS
  A comprehensive literature search was performed and four publications were identified (involving 152 patients) evaluating (18)F-FDG PET/CT in CUP patients with extracervical metastases. All studies were retrospective and heterogeneous in inclusion criteria, study design, and diagnostic workup prior to (18)F-FDG PET/CT.
  
  
  RESULTS
  (18)F-FDG PET/CT detected the primary tumor in 39.5% of patients with extracervical CUP. The lung was the most commonly detected primary tumor site (∼50%). The pooled estimates of sensitivity, specificity, and accuracy of (18)F-FDG PET/CT in the detection of the primary tumor site were 87%, 88%, and 87.5%, respectively.
  
  
  CONCLUSIONS
  The present review of currently available data indicates that (18)F-FDG PET/CT might contribute to the identification of the primary tumor site in extracervical CUP. However, prospective studies with more uniform inclusion criteria are required to evaluate the exact value of this diagnostic tool.
authors.affiliation: Department of Oncology 5073, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark. anne.kirstine.moeller@rh.regionh.dk
authors.forename: Anne Kirstine Hundahl
authors.initials: AK
authors.lastname: Moller
authors.forename: Annika
authors.initials: A
authors.lastname: Loft
authors.forename: Anne Kiil
authors.initials: AK
authors.lastname: Berthelsen
authors.forename: Karen
authors.initials: K
authors.lastname: Damgaard Pedersen
authors.forename: Jesper
authors.initials: J
authors.lastname: Graff
authors.forename: Charlotte Birk
authors.initials: CB
authors.lastname: Christensen
authors.forename: Katharina
authors.initials: K
authors.lastname: Perell
authors.forename: Bodil Laub
authors.initials: BL
authors.lastname: Petersen
authors.forename: Gedske
authors.initials: G
authors.lastname: Daugaard
mesh_terms: D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods*; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D019788:Fluorodeoxyglucose F18