title: Thallium-201 scan in evaluating thyroid nodules following equivocal fine-needle aspiration cytology.
abstract: The AIM of this prospective study was to evaluate the usefulness of the thallium-201 ( (201) Tl) thyroid scan in the detection of malignancy in cold thyroid nodules whose status was equivocal following palpation fine-needle aspiration cytology (FNAC).
  
  
  METHODS
  Fifty-one patients with clinically palpable solitary cold thyroid nodules classified as non-diagnostic or suspicious following biopsy underwent (201) Tl thyroid scans. Each scan was performed 15 min (early scan) and 3 h (delayed scan) after an intravenous administration of 74 MBq (201) Tl. Thallium uptake in the nodules was visually assessed and scored on a three point scale, with a grade of three defining malignancy. All patients underwent surgery and the histopathology of nodule tissues were compared with results of the scans.
  
  
  RESULTS
  Fifty-one nodules were examined. Forty were benign and 11 were malignant. For early scans, the diagnostically relevant parameters were: sensitivity (100%), specificity (75%), and accuracy (80%). Corresponding findings for the delayed scan were: 91%, 98%, and 96%.
  
  
  CONCLUSIONS
  The (201) Tl scan is useful for detecting malignancy in cold thyroid nodules classified as nondiagnostic or suspicious lesions by FNAC.
authors.affiliation: Department of Nuclear Medicine, Tri-Service General Hospital 325, Section 3, Cheng-Kung Road, Taipei, Taiwan 114 ROC.
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: R S
authors.initials: RS
authors.lastname: Liu
authors.forename: S Y
authors.initials: SY
authors.lastname: Wu
authors.forename: W S
authors.initials: WS
authors.lastname: Huang
authors.forename: M C
authors.initials: MC
authors.lastname: Chou
mesh_terms: D044963:Biopsy, Fine-Needle; D005260:Female; D006801:Humans; D008297:Male; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D013794:Thallium Radioisotopes; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology*
chemical_list: D013794:Thallium Radioisotopes