title: Whole body 18F-FDG PET/CT imaging in the detection of primary tumours in patients with a metastatic carcinoma of unknown origin.
abstract: OBJECTIVE
  The aim of this study was to evaluate the role of whole body 18F-FDG PET/CT imaging in the detection of primary tumors in patients with a metastatic cancer from an unknown primary site.
  
  
  METHODS
  The study population consisted of 43 patients with a biopsy proven metastatic disease, negative conventional diagnostic procedures (including CT/MRI/endoscopic procedures) and a whole body 18F-FDG PET/CT examination. Patients' records were retrospectively analyzed. According to the final pathologic diagnoses, rate of detection of the primary tumor site was determined. Additionally, overall patient survival was calculated to evaluate the prognostic value of 18F-FDG PET/CT findings.
  
  
  RESULTS
  A primary tumor site was shown by 18F-FDG PET/CT in 24 patients (24/43; 55.8%). In 18 patients 18F-FDG PET/CT scans were negative (18/43; 41.8%). In a patient with an adenocarcinoma metastasis 18F-FDG PET/CT was falsely positive for an inflammatory lesion in the lung. Among the 18F-FDG PET/CT positive and negative groups median overall survival was not significantly different (log-rank p=0.573).
  
  
  CONCLUSIONS
  Whole body 18F-FDG PET/CT imaging has a high rate of detection of a primary tumor in patients with a carcinoma of unknown origin.
authors.affiliation: Gazi University, School of Medicine, Department of Medical Oncology, Turkey.
authors.forename: Ali Osman
authors.initials: AO
authors.lastname: Kaya
authors.forename: Ugur
authors.initials: U
authors.lastname: Coskun
authors.forename: Mustafa
authors.initials: M
authors.lastname: Unlu
authors.forename: Umit Ozgur
authors.initials: UO
authors.lastname: Akdemir
authors.forename: Nuriye Yildirim
authors.initials: NY
authors.lastname: Ozdemir
authors.forename: Nurullah
authors.initials: N
authors.lastname: Zengin
authors.forename: Mustafa
authors.initials: M
authors.lastname: Benekli
authors.forename: Ramazan
authors.initials: R
authors.lastname: Yildiz
authors.forename: Emel
authors.initials: E
authors.lastname: Yaman
authors.forename: Banu
authors.initials: B
authors.lastname: Ozturk
authors.forename: Mahmut
authors.initials: M
authors.lastname: Gumus
authors.forename: Aytug
authors.initials: A
authors.lastname: Uner
authors.forename: Deniz
authors.initials: D
authors.lastname: Yamac
authors.forename: Emel
authors.initials: E
authors.lastname: Ucgul
authors.forename: Suleyman
authors.initials: S
authors.lastname: Buyukberber
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000401:mortality / Q000556:secondary; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000556:secondary; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000556:secondary; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods; D051598:Whole Body Imaging / Q000379:methods
chemical_list: D019788:Fluorodeoxyglucose F18