title: Performance of (18)F-FDG PET/CT as a postoperative surveillance imaging modality for asymptomatic advanced gastric cancer patients.
abstract: OBJECTIVE
  The purpose of this study was to investigate the diagnostic performance of postoperative fluorine-18 fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) as a surveillance modality for advanced gastric cancer patients who were asymptomatic and negative by conventional follow-up.
  
  
  METHODS
  We retrospectively collected 46 advanced gastric cancer patients who received approximately 1-year-postoperative (18)F-FDG PET/CT surveillance following curative resection (mean age 60.6 ± 11.5 years). (18)F-FDG PET/CT was interpreted by nuclear medicine physicians who were blind to the clinical information. Final confirmation was determined by clinical follow-up using tumor markers, conventional CT scan, upper gastrointestinal endoscopy and with/without subsequent histopathologic diagnosis.
  
  
  RESULTS
  Four patients developed recurrence (8.7 %; 1 local and 3 distant recurrences). For local recurrence, (18)F-FDG PET/CT found four hypermetabolic lesions and one was local recurrence. For distant recurrence, seven hypermetabolic lesions were found in six patients and true-positive was three lesions. False-positive cases were mainly turned out to be physiologic small bowel uptake. Regardless of the recurrence site, the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-FDG PET/CT were 100 % (4/4, 95 % confidence interval (CI) 39.6-100 %), 88.1 % (37/42, 95 % CI 73.6-95.5 %), 44.4 % (4/9, 95 % CI 15.3-77.3 %) and 100 % (37/37, 95 % CI 88.3-100 %), respectively in the patient-based analysis.
  
  
  CONCLUSIONS
  Our study showed good specificity of postoperative surveillance (18)F-FDG PET/CT for detecting recurrence. Careful caution should be made for interpreting some false-positive hypermetabolic lesions in postoperative (18)F-FDG PET/CT, especially at the local anastomosis site.
authors: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Dong Yun
authors: DY
authors: Lee
authors: Chang Hwan
authors: CH
authors: Lee
authors: Min Jung
authors: MJ
authors: Seo
authors: Suk Hyun
authors: SH
authors: Lee
authors: Jin-Sook
authors: JS
authors: Ryu
authors: Jong Jin
authors: JJ
authors: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000714:Anastomosis, Surgical; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D005743:Gastrectomy; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000737:chemistry; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18