title: 18FDG-positron emission tomography/computed tomography (PET/CT) scanning in thyroid nodules with nondiagnostic cytology.
abstract: OBJECTIVE
  To assess the role of positron emission tomography/computed tomography (PET/CT) scans with (18) FDG ((18)FDG-PET/CT) in the evaluation of thyroid nodules with nondiagnostic cytology.
  
  
  METHODS
  Eighty-eight patients with a single euthyroid nodule and repeatedly nondiagnostic ultrasound-guided fine-needle cytology (US-FNC) were enrolled in the present study. Nodules concentrating (18)FDG were considered positive (i.e. suspicious for malignancy). Histological findings were obtained after surgery in all patients.
  
  
  RESULTS
  None of 41 patients with negative (18)FDG-PET/CT scan had a final histological diagnosis of malignancy (i.e. no false-negative results). Twenty-nine patients with final histological diagnosis of thyroid cancer had positive (18)FDG-PET/CT scan. Eighteen patients with final histological diagnosis of benign lesions (including four with follicular adenomas) also had positive (18)FDG-PET/CT scans. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 100%, 69%, 79%, 62% and 100%, respectively.
  
  
  CONCLUSIONS
  A negative (18)FDG-PET/CT scan accurately excludes malignancy in thyroid nodules with non-diagnostic US-FNC procedures. Histology is still necessary to distinguish benign from malignant disease in (18)FDG-PET/CT-positive nodules, but unnecessary surgery could have been reduced from 88 to 41 cases (46%) in our series.
authors.affiliation: Department of Nuclear Medicine and Thyroid Centre, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland. luca.giovanella@eoc.ch
authors.forename: Luca
authors.initials: L
authors.lastname: Giovanella
authors.forename: Sergio
authors.initials: S
authors.lastname: Suriano
authors.forename: Marco
authors.initials: M
authors.lastname: Maffioli
authors.forename: Luca
authors.initials: L
authors.lastname: Ceriani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003584:Cytological Techniques / Q000379:methods / Q000592:standards; D003951:Diagnostic Errors; D005260:Female; D019788:Fluorodeoxyglucose F18; D006652:Histological Techniques / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016606:Thyroid Nodule / Q000175:diagnosis / Q000000981:diagnostic imaging*; D019564:Unnecessary Procedures; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18