Thallium-201 scan in evaluating thyroid nodules following equivocal fine-needle aspiration cytology.
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.
Lee
J K
JK
Department of Nuclear Medicine, Tri-Service General Hospital 325, Section 3, Cheng-Kung Road, Taipei, Taiwan 114 ROC.
Liu
R S
RS
Wu
S Y
SY
Huang
W S
WS
Chou
M C
MC
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*
D013794:Thallium Radioisotopes