title: Role of 18F-FDG PET/CT in detecting recurrent gallbladder carcinoma.
abstract: OBJECTIVE
  The present study was aimed to determine the efficacy of integrated FDG PET/CT in patients with gallbladder cancer (GBC) with suspicion of recurrent disease.
  
  
  METHODS
  A total of 49 patients (male: 15, female: 34; median age: 52.5 years) with GBC underwent FDG PET/CT for suspected recurrence. A total of 62 PET/CT scans were acquired. Criteria for detection by PET/CT were both a positive FDG uptake and the correct anatomic localization of the tumor. The PET/CT findings were grouped as locoregional disease and metastatic disease. Results of PET/CT were compared with clinical and radiologic follow-up and/or histopathology. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Results of PET/CT were also compared with conventional imaging (CI) whenever available.
  
  
  RESULTS
  Of 62 PET/CT, 43 (69.4%) were positive and 19 (30.6%) were negative for recurrence. Of 43 positive scans, 41 were true positive and 2 were false positive. Among 19 negative PET/CT scans, 18 were true negative and 1 was false negative. PET/CT showed a sensitivity of 97.6% and specificity of 90% in detecting tumor recurrence. The positive predictive value, negative predictive value, and accuracy were 95.3%, 94.7%, and 95.1%, respectively. Locoregional disease was seen in 16 (37.2%) PET/CT studies, distant metastases were seen in 13 (30.2%), and 14 (32.5%) studies showed both locoregional disease and metastasis. When comparable CI was available, PET/CT showed a better specificity than CI for detection of recurrence.
  
  
  CONCLUSIONS
  Integrated FDG PET/CT can detect recurrence in GBC with high sensitivity and specificity. Routine use of PET/CT in these patients will detect recurrence early and change the subsequent management.
authors.affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Punit
authors.initials: P
authors.lastname: Sharma
authors.forename: Anita
authors.initials: A
authors.lastname: Kumari
authors.forename: Dhanapathi
authors.initials: D
authors.lastname: Halanaik
authors.forename: Arun
authors.initials: A
authors.lastname: Malhotra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D012015:Reference Standards; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18