title: Focal thyroid incidental uptake detected by ¹⁸F-fluorodeoxyglucose positron emission tomography. Meta-analysis on prevalence and malignancy risk.
abstract: OBJECTIVE
  To perform a meta-analysis of published data on the prevalence and risk of malignancy of focal thyroid incidental uptake (FTIs) detected by Fluorine-18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) or PET/CT.
  
  
  METHODS
  A comprehensive literature search of studies published up to and including December 2012 was performed. Pooled prevalence and malignancy risk of FTIs were calculated, including a sub-analysis for the geographic areas of origin of the studies.
  
  
  RESULTS
  34 studies including 215,057 patients were selected. Pooled prevalence of FTIs was 1.92% (95% confidence interval [95%CI]: 1.87-1.99%). Overall, 1522 FTIs underwent histopathology evaluation. Pooled risk of malignancy was 36.2% (95%CI: 33.8-38.6%), without significant differences among various geographic areas.
  
  
  CONCLUSIONS
  FTIs are observed in about 2% of 18F-FDG-PET or PET/CT scans and carry a significant risk of malignancy. Therefore, further investigation is warranted whenever FTIs are detected by 18F-FDG-PET or PET/CT.
authors.affiliation: Department of Nuclear Medicine and Thyroid Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Treglia
authors.forename: F
authors.initials: F
authors.lastname: Bertagna
authors.forename: R
authors.initials: R
authors.lastname: Sadeghi
authors.forename: F A
authors.initials: FA
authors.lastname: Verburg
authors.forename: L
authors.initials: L
authors.lastname: Ceriani
authors.forename: L
authors.initials: L
authors.lastname: Giovanella
mesh_terms: D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D015994:Incidence; D033162:Incidental Findings; D008297:Male; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals; D012307:Risk Factors; D017678:Sex Distribution; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18