An evaluation of thallium imaging for detection of carcinoma in clinically palpable solitary, nonfunctioning thyroid nodules.
OBJECTIVE
An evaluation of thallium imaging for differentiating benign from malignant lesions in clinically palpable solitary, nonfunctioning, thyroid nodules.


METHODS
Seventy-eight patients presenting with a clinically palpable solitary nonfunctioning thyroid nodule were imaged with 3 mCi thallium-201 with a pinhole acquisition at 20 minutes and 3 hours after injection. Thallium uptake was assessed as grade 1, less than the rest of the gland; grade 2, same as the rest of the gland; and grade 3, more than the rest of the gland. All patients underwent surgery and the histology was compared with the thallium scan results.


RESULTS
Of the 78 patients presenting with solitary thyroid nodule, 13 were malignant and 65 were benign. Twenty-four patients with benign disease showed no uptake of thallium at 3 hours (grade 1). Thirty-two patients with benign disease and 2 patients with malignant lesion had grade 2 uptake at 3 hours. Eleven patients with malignant disease and 9 with benign disease had grade 3 uptake at 3 hours.


CONCLUSIONS
All malignant lesions had at least grade 2 and most had grade 3 uptake at 3 hours. All lesions with grade 1 uptake at 3 hours were benign, enabling malignancy to be excluded in one-third of cases. Thallium imaging is a useful adjunct to fine-needle cytology in evaluation of solitary thyroid nodules especially when the latter is inconclusive.
Department of Surgery, Medway Maritime Hospital, Gillingham, Kent, United Kingdom.
P S
PS
Sinha
D I
DI
Beeby
P
P
Ryan
D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D001707:Biopsy, Needle; D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging; D003560:Cysts / Q000000981:diagnostic imaging; D005260:Female; D006042:Goiter / Q000000981:diagnostic imaging; D006801:Humans; D007700:Kinetics; D008297:Male; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics; D013959:Thyroid Diseases / Q000000981:diagnostic imaging; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D013967:Thyroiditis, Autoimmune / Q000000981:diagnostic imaging
D013794:Thallium Radioisotopes