A Comparison of Serum Thyroglobulin Measurements and Whole Body 131l Scanning in the Management of Treated Differentiated Thyroid Carcinoma

A comparison of serum thyroglobulin measurements and whole body 131l scanning in the management of treated differentiated thyroid carcinoma. J. P. Galligan, J. Winship, T. van Doom and R. H. Mortimer, Aust. N.Z. J. Med., 1982,12, pp. 248–254. Serum thyroglobulin levels were measured by a sensitive radioimmunoassay in 76 patients whose differentiated thyroid carcinoma had been treated by surgery with or without subsequent administration of radioactive iodine (131l). Examination of the results of 105 concomitant whole body 131l scan results and serum thyroglobulin levels showed a high degree (83 8%) of concordance between these two techniques. A significant correlation (r = 0.670, plt;0001) was found between serum thyroglobulin levels and quantitative 131l uptake in the neck and/or metastases in 42 patients in whom this was measured. Although a high degree of congruence was found between the results of 131l scans and the presence or absence of circulating thyroglobulin, 13 patients with negative scans using conventional doses of 1311 had measurable levels of thyroglobulin. Eight of these patients had or subsequently developed evidence of residual thyroid tissue or metastatic carcinoma. The measurement of serum thyroglobulin levels in patients previously treated for differentiated carcinoma offers a more convenient and more sensitive method of detecting residual normal or neoplastic thyroid tissue than does whole body scanning with 131l.