This Article Full Text Full Text (PDF) Submit a related Letter to the Editor View responses Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Smallridge, R. C. Articles by Fatourechi, V. Search for Related Content PubMed PubMed Citation Articles by Smallridge, R. C. Articles by Fatourechi, V. Related Collections Thyroid Calcium and Bone Metabolism

Monitoring Thyroglobulin in a Sensitive Immunoassay Has Comparable Sensitivity to Recombinant Human TSH-Stimulated Thyroglobulin in Follow-Up of Thyroid Cancer Patients

Division of Endocrinology and Metabolism (R.C.S., S.E.M., M.A.M., G.S.G., T.P.F.), Mayo Clinic College of Medicine, Jacksonville, Florida 32224; and Department of Laboratory Medicine and Pathology (S.G.) and Division of Endocrinology (V.F.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905

Address all correspondence to: Robert C. Smallridge, M.D., Division of Endocrinology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida 32224. E-mail: smallridge.robert{at}mayo.edu.

Context: Most thyroglobulin (Tg) assays have a sensitivity of 0.5–1 ng/ml. A minority of patients with undetectable T₄-suppressed Tg levels have a recombinant human TSH (rhTSH)-stimulated Tg above 2 ng/ml and identifiable residual disease.

Objective: The objective was to determine whether a Tg assay with improved sensitivity could eliminate the need for rhTSH stimulation when baseline Tg is below 0.1 ng/ml.

Design: A retrospective study of two academic endocrine practices was conducted.

Population: A total of 194 patients undergoing rhTSH stimulation participated in the study.

Results: Of the 80 patients with Tg below 0.1 ng/ml, two (2.5%) had rhTSH-stimulated Tg above 2 ng/ml. One other patient with stimulation to 0.3 ng/ml and negative ¹²³I scan had an ultrasound-detected malignant lymph node resected. None had ¹³¹I/¹²³I imaging after rhTSH stimulation suggestive of local recurrence or distant metastasis. If T₄-suppressed Tg was 0.1–0.5 or 0.6–2.0 ng/ml, rhTSH Tg was above 2 ng/ml in 24.2 and 82.4%, respectively.

Conclusions: Patients with differentiated thyroid carcinoma and a T₄-suppressed serum Tg below 0.1 ng/ml rarely have a rhTSH-stimulated Tg above 2 ng/ml, and none of these patients had ¹³¹I or ¹²³I imaging after rhTSH stimulation suggestive of local recurrence or distant metastasis. We recommend monitoring such patients with a T₄-suppressed Tg level and periodic neck ultrasonography. An increase in T₄-suppressed serum Tg to a detectable level or the appearance of abnormal lymph nodes by physical or ultrasound exam should prompt further investigation.

This article has been cited by other articles:

				F. Pacini, M. G. Castagna, L. Brilli, G. Pentheroudakis, and On behalf of the ESMO Guidelines Working Group Differentiated thyroid cancer: ESMO Clinical Recommendations for diagnosis, treatment and follow-up Ann. Onc., May 1, 2009; 20(suppl_4): iv143 - iv146. [Full Text] [PDF]

				M. G. Castagna, L. Brilli, T. Pilli, A. Montanaro, C. Cipri, C. Fioravanti, F. Sestini, M. Capezzone, and F. Pacini Limited Value of Repeat Recombinant Human Thyrotropin (rhTSH)-Stimulated Thyroglobulin Testing in Differentiated Thyroid Carcinoma Patients with Previous Negative rhTSH-Stimulated Thyroglobulin and Undetectable Basal Serum Thyroglobulin Levels J. Clin. Endocrinol. Metab., January 1, 2008; 93(1): 76 - 81. [Abstract] [Full Text] [PDF]

				C. L. H. Snozek, E. P. Chambers, C. C. Reading, T. J. Sebo, J. W. Sistrunk, R. J. Singh, and S. K. G. Grebe Serum Thyroglobulin, High-Resolution Ultrasound, and Lymph Node Thyroglobulin in Diagnosis of Differentiated Thyroid Carcinoma Nodal Metastases J. Clin. Endocrinol. Metab., November 1, 2007; 92(11): 4278 - 4281. [Abstract] [Full Text] [PDF]

				M. Schlumberger, A. Hitzel, M. E. Toubert, C. Corone, F. Troalen, M. H. Schlageter, F. Claustrat, S. Koscielny, D. Taieb, M. Toubeau, et al. Comparison of Seven Serum Thyroglobulin Assays in the Follow-Up of Papillary and Follicular Thyroid Cancer Patients J. Clin. Endocrinol. Metab., July 1, 2007; 92(7): 2487 - 2495. [Abstract] [Full Text] [PDF]

eLetters: