title: Evaluation of 18fluoro-2-deoxyglucose positron emission tomography in iodine scan negative, differentiated thyroid cancer recurrence.
abstract: BACKGROUND
  Follow up of patients with differentiated thyroid cancer is based upon anatomical imaging, thyroglobulin assay and functional imaging in the form of iodine uptake scanning. A significant cohort of such patients have rising thyroglobulin levels but negative iodine scans. In this group, 18fluoro-2-deoxyglucose positron emission tomography scans have been commonly employed. The aim of this study was to assess the usefulness of such investigation.
  
  
  METHODS
  The sensitivity of 18fluoro-2-deoxyglucose positron emission tomography for detecting recurrence of differentiated thyroid cancer was calculated from a retrospective review of scan results from patients with iodine scan negative recurrence.
  
  
  RESULTS
  Eighteen patients with rising thyroglobulin levels underwent 18fluoro-2-deoxyglucose positron emission tomography scanning. Fourteen patients had negative (and four equivocal) whole body iodine scintigraphy scans. Of these 14, six patients had a positive 18fluoro-2-deoxyglucose positron emission tomography scan, giving a sensitivity of 42.9 per cent.
  
  
  CONCLUSIONS
  When assessed in the clinical setting and restricted to patients with negative iodine scans, the sensitivity of 18fluoro-2-deoxyglucose positron emission tomography was found to be lower than in previous case series.
authors.affiliation: Department of ENT, St Mary's Hospital, Imperial College Hospitals NHS Trust, London, UK. edwardchisholm@doctors.org.uk
authors.forename: E J
authors.initials: EJ
authors.lastname: Chisholm
authors.forename: N S
authors.initials: NS
authors.lastname: Tolley
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000000981:diagnostic imaging*; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D013954:Thyroglobulin