title: Clinical value of whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with carcinoma of unknown primary.
abstract: BACKGROUND
  The purpose of the study is to investigate the clinical value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in detecting the primary sites in patients with carcinoma of unknown primary (CUP).
  
  
  METHODS
  The reports of FDG PET/CT scans of 164 patients with CUP syndrome in consecutive 2589 patients referred to our department from January 2006 to June 2010 were retrospectively reviewed. The final results were obtained from the pathologic reports, other imaging modalities diagnoses and clinical follow-up data.
  
  
  RESULTS
  There were 142 cases in the results analysis, as 19 patients were lost to follow-up and three patients were excluded. FDG PET/CT successfully detected primary tumours in 67 (47.2%) out of 142 patients. Among this group, 53 were pathologically proved and 17 patients were confirmed by clinical follow-up. The primary sites of 38 (56.7%) were in lung, eight (11.9%) in nasopharynx and 13 (19.4%) in digestive system. Six patients were misdiagnosed by FDG PET/CT scan. FDG PET/CT could not detect the primary lesion in 66 patients, and three primary tumours were identified by conventional work-up after negative FDG PET/CT scan. The accuracy, sensitivity and specificity of FDG PET/CT scan in detecting the primary site in this study were 93.7%, 95.7% and 91.7%, respectively. FDG PET/CT scan changed the medical management of about 33.8% of 142 CUP patients.
  
  
  CONCLUSIONS
  FDG PET/CT whole-body imaging is a valuable tool in detecting the primary tumour of patients with CUP site.
authors: Department of Medical Imaging and Interventional Radiology, Cancer Center and State Key Laboratory of Oncology in South China, Sun Yat-sen University, Guangzhou, China.
authors: Guohui
authors: G
authors: Wang
authors: Yaopan
authors: Y
authors: Wu
authors: Weidong
authors: W
authors: Zhang
authors: Jiayao
authors: J
authors: Li
authors: Peihong
authors: P
authors: Wu
authors: Chuanmiao
authors: C
authors: Xie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000706:statistics & numerical data*; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D051598:Whole Body Imaging / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18