title: Thallium-201 scintigraphy in the evaluation of thyroid nodules. A retrospective study of 246 cases.
abstract: There is controversy at present concerning the value of Tl-201 scintigraphy in the diagnosis of malignant thyroid nodules. The usefulness of Tl-201 scintigraphy in differentiating benign from malignant nodules was evaluated retrospectively. Tl-201 scintigraphy was performed in 101 patients with malignant thyroid nodules and in 145 with benign nodules. Early and late images were examined to compare Tl-201 uptake in nodules and normal thyroid tissue. The visual method resulted in 74% of sensitivity and 58% of specificity for the detection of malignant nodules including incidental cancers. Excluding incidental cancers, 87% sensitivity and 58% specificity were achieved. Small cancers, including incidental cancers less than 1.5 cm in diameter and small number of viable tumor cells in a large tumor also gave negative Tl-201 scintigraphic results. Forty-two percent of the benign lesions gave false positive Tl-201 scintigraphic results. It is concluded that Tl-201 scintigraphy is a sensitive and useful method to use in diagnosing malignant thyroid nodules, but is not a specific method even with late scan, for the detection of malignant thyroid nodules.
authors.affiliation: Department of Radiology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Koizumi
authors.forename: H
authors.initials: H
authors.lastname: Taguchi
authors.forename: M
authors.initials: M
authors.lastname: Goto
authors.forename: T
authors.initials: T
authors.lastname: Nomura
authors.forename: T
authors.initials: T
authors.lastname: Watari
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging; D000236:Adenoma / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*
chemical_list: D013794:Thallium Radioisotopes