SERUM THYROGLOBULIN CONCENTRATIONS AND131I WHOLE BODY SCANS IN THE DIAGNOSIS OF METASTASES FROM DIFFERENTIATED THYROID CARCINOMA (AFTER THYROIDECTOMY)

Abstract

Measurements of circulating thyroglobulin (hTg) and 131I whole body scan were performed in 101 patients with differentiated thyroid carcinoma who were subjected to surgical thyroidectomy and 131I ablation of remaining thyroid tissue. All 45 patients with positive scans (i.e., functioning metastases) had elevated hTg concentrations. Of 56 patients with negative scans, 42 had undetectable or very low hTg levels and were considered to be free of metastatic thyroid tissue, whereas 14 showed the presence of non-functioning metastases in the clinical and/or radiological examination. In this group of patients, 11 had elevated serum hTg levels, while the other 3 patients had detectable hTg concentrations within the normal range. Serum hTg measurements apparently correlate very well with scan findings and have the added advantage of detecting non-functioning metastases which would not be detected by scanning. Measurement of serum hTg may be used, together with scanning, as the 1st step in the follow-up of thyroidectomized patients with differentiated thyroid carcinoma.