PT - JOURNAL ARTICLE AU - David, Alessia AU - Blotta, Annabella AU - Bondanelli, Marta AU - Rossi, Roberta AU - Roti, Elio AU - Braverman, Lewis E. AU - Busutti, Luciano AU - Uberti, Ettore C. degli TI - Serum Thyroglobulin Concentrations and <sup>131</sup>I Whole-Body Scan Results in Patients with Differentiated Thyroid Carcinoma After Administration of Recombinant Human Thyroid-Stimulating Hormone DP - 2001 Oct 01 TA - Journal of Nuclear Medicine PG - 1470--1475 VI - 42 IP - 10 4099 - http://jnm.snmjournals.org/content/42/10/1470.short 4100 - http://jnm.snmjournals.org/content/42/10/1470.full SO - J Nucl Med2001 Oct 01; 42 AB - The use of recombinant human thyroid-stimulating hormone (rhTSH) has recently become available as an alternative diagnostic tool to assess the persistence and recurrence of differentiated thyroid carcinoma (DTC) in patients on thyroid hormone–suppressive therapy (THST) after near-total or total thyroidectomy and ablative doses of 131I. We report the results of rhTSH administration in patients who were monitored for DTC. Methods: Thirty-three adult DTC patients (13 men, 20 women; mean age ± SE, 45.6 ± 2.31 y; age range, 21–65 y) underwent diagnostic follow-up after rhTSH administration at a dose of 0.9 mg once a day for 2 d. Whole-body scanning and serum thyroglobulin (Tg) measurement were performed after rhTSH administration. Patients were divided into 2 groups depending on serum Tg concentrations on THST: 29 patients had Tg concentrations of &lt;2 ng/mL (group A) and 4 patients had Tg values of &gt;2 ng/mL (group B). Results: In group A, Tg values remained at &lt;2 ng/mL in 25 patients and increased from 1.1 ± 0.14 ng/mL to 22.0 ± 5.75 ng/mL (mean ± SE) in 4 patients after rhTSH administration. Whole-body scanning did not reveal any uptake of 131I in the 25 patients without an increase in Tg, whereas 131I uptake was evident in 2 of the 4 patients with a rise in Tg. In group B, Tg values increased in all 4 patients from 17.3 ± 6.35 ng/mL to 55.3 ± 12.75 ng/mL, and 131I uptake was evident in 3 of the 4 patients. No major adverse effects were reported after rhTSH administration. Conclusion: Our results show that the measurement of serum Tg concentrations after rhTSH has a higher diagnostic value than whole-body scanning in detecting the persistence of thyroid tissue. Therefore, rhTSH should be administered in TSH-suppressed patients with basal serum Tg concentrations of &lt;2 ng/mL because the increment in serum Tg concentrations may reveal the persistence of thyroid tissue in these patients.