title: Prediction of survival and evaluation of diagnostic accuracy whole body 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography in the detection carcinoma of unknown primary origin.
abstract: OBJECTIVE
  The aim of the current study was to determine the diagnostic accuracy of whole-body 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in detecting carcinoma of unknown primary (CUP).
  
  
  METHODS
  A total of 7,636 patients were investigated by FDG-PET/CT examinations at our Institution. We retrospectively evaluated the file records of 432 patients who were referred to FDG PET/CT imaging with a diagnosis of cancer of unknown primary, and included 316 of the patients with histopathologic verification at the final diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated. The Kaplan-Meier test was used for survival analysis. Median survival rate was calculated to evaluate the prognostic value of the FDG-PET/ CT findings.
  
  
  RESULTS
  In the search for a primary, FDG-PET/CT findings correctly diagnosed lesions as the site of the primary true positive in 238 cases, 10 findings diagnosed no site of a primary and none was subsequently proven true negative, 12 diagnoses were false positive and 56 were false negative. The sensitivity of FDG-PET/CT is 81% and the specificity 45%. Positive predictive value, negative predictive value and diagnostic accuracy were 95%, 15% and 78%, respectively.
  
  
  CONCLUSIONS
  Whole-body FDG-PET/CT imaging is proven to be useful method in the search for the primary focus and metastases in patients with cancer of unknown primary.
authors.affiliation: Department of Nuclear Medicine, Okmeydani Training and Research Hospital, Istanbul, Turkey. mugetamam@yahoo.com
authors.forename: M O
authors.initials: MO
authors.lastname: Tamam
authors.forename: M
authors.initials: M
authors.lastname: Mulazimoglu
authors.forename: T K
authors.initials: TK
authors.lastname: Guveli
authors.forename: C
authors.initials: C
authors.lastname: Tamam
authors.forename: O
authors.initials: O
authors.lastname: Eker
authors.forename: T
authors.initials: T
authors.lastname: Ozpacaci
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging* / Q000401:mortality; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18