CHARACTERIZATION OF THE NEOPLASTIC POTENTIAL OF SOLITARY SOLID THYROID LESIONS WITH TC-99M-PERTECHNETATE AND TC-99M-SESTAMIBI SCANNING

Background: Radionuclide scans that use Tc-99m-pertechnetate or I-123 currently lack the specificity to assess the malignant potential of so litary solid lesions of the thyroid gland. Tc-99m-sestamibi scanning w as used to determine the neoplastic potential of thyroid lesions. Meth ods: Patients with lesions of the thyroid underwent Tc-99m-sestamibi i maging to assess the neoplastic potential of their thyroid lesions, id entified as solitary and cold by radionuclide imaging with Tc-99m-pert echnetate. Tc-99m-sestamibi uptake was correlated with fine-needle asp iration cytology or surgical pathology. Results: Twenty-seven patients were evaluated using Tc-99m-pertechnetate and Tc-99m-sestamibi scans: 14 had right thyroid lesions, and 13 had left thyroid lesions. Of 27 patients, 10 had a positive Tc-99m-sestamibi scan: one Hurthle cell ad enoma, one papillary carcinoma, six follicular adenomas, and two nodul ar goiters, Of 27 patients, 17 had a negative Tc-99m-sestamibi scan: o ne follicular carcinoma, one papillary carcinoma, two follicular adeno mas, one Hurthle cell adenoma, one metastatic adenocarcinoma, one medu llary carcinoma, four nodular goiters, and six colloid nodules. Positi ve Tc-99m-sestamibi scan identified neoplasms with a sensitivity of 53 %, a specificity of 83%, and a positive predictive value of 80%. Concl usions: Tc-99m-sestamibi scanning lacks sufficient sensitivity for dia gnosis of solitary thyroid nodules. Future work may define a role for its use in recurrent or metastatic thyroid neoplasms.