title: Clinical applications of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in carcinoma of unknown primary.
abstract: BACKGROUND
  Carcinoma of unknown primary (CUP) encompasses a heterogeneous group of tumors with varying clinical features. The management of patients of CUP remains a clinical challenge. The purpose of this study was to evaluate the clinical applications of integrated (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) information in patients with CUP, including detecting the occult primary tumor and effecting on disease therapy.
  
  
  METHODS
  One hundred and forty-nine patients with histologically-proven metastases of CUP were included. For all patients, the conventional diagnostic work-up was unsuccessful in localizing the primary site. Whole-body PET/CT images were obtained approximately 60 minutes after intravenous injection of 350 - 425 MBq of (18)F-FDG.
  
  
  RESULTS
  In 24.8% of patients, FDG PET/CT detected primary tumors that were not apparent after conventional workup. In this group of patients, the overall sensitivity, specificity, and accuracy rates of FDG PET/CT in detecting unknown primary tumors were 86.0%, 87.7%, and 87.2%, respectively. FDG PET/CT imaging also led to the detection of previously unrecognized metastases in 29.5% of patients. Forty-seven (31.5%, 47 of 149) patients underwent a change in therapeutic management.
  
  
  CONCLUSIONS
  FDG PET/CT is a valuable tool in patients with CUP, because it assisted in detecting unknown primary tumors and previously unrecognized distant metastases, and optimized the management of these patients.
authors.affiliation: Department of Radiation Oncology and Shandong Province Key Laboratory of Radiation Oncology, Shandong Cancer Hospital, Shandong Academy of Medical Sciences, Jinan, Shandong 250117, China.
authors.forename: Man
authors.initials: M
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Pin-Liang
authors.initials: PL
authors.lastname: Zhang
authors.forename: Gui-Fang
authors.initials: GF
authors.lastname: Ju
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.forename: Guo-Li
authors.initials: GL
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Kong
authors.forename: Yan-Qin
authors.initials: YQ
authors.lastname: Yang
authors.forename: Yi-Dong
authors.initials: YD
authors.lastname: Ma
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011859:Radiography; D015203:Reproducibility of Results
chemical_list: D019788:Fluorodeoxyglucose F18