A sensitive Tg assay or rhTSH stimulated Tg: what's the best in the long-term follow-up of patients with differentiated thyroid carcinoma?

• Published in: PloS one Vol. 2; no. 8; p. e816
• Main Authors: Persoon, Adrienne C M, Jager, Pieter L, Sluiter, Wim J, Plukker, John T M, Wolffenbuttel, Bruce H R, Links, Thera P
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.08.2007; Public Library of Science (PLoS)
• Subjects: Adult; Assaying; Biochemistry; Biological Assay; Carcinoma; Carcinoma - diagnosis; Diabetes and Endocrinology/Thyroid; Diagnosis; Diagnostic systems; Endocrinology; Evidence-Based Healthcare/Methods for Diagnostic and Therapeutic Studies; Follow-Up Studies; Humans; Hypothyroidism; Imaging techniques; Laboratories; Localization; Lymphatic system; Medical imaging; Methods; Middle Aged; Neck; Neoplasm Recurrence, Local - diagnosis; Oncology/Head and Neck Cancers; Patients; Positron emission; Positron emission tomography; Radiology and Medical Imaging; Radiology and Medical Imaging/PET and SPECT Imaging; Radiology and Medical Imaging/Ultrasonography; Sensitivity and Specificity; Stimulation; Therapy; Thyroglobulin; Thyroglobulin - blood; Thyroid; Thyroid cancer; Thyroid carcinoma; Thyroid diseases; Thyroid Neoplasms - diagnosis; Thyrotropin - pharmacology; Tomography; Tumors; Ultrasonic imaging; Ultrasound
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0000816

Sensitivity of thyroglobulin (Tg) measurement in the follow-up of differentiated thyroid carcinoma (DTC) can be optimized by using a sensitive Tg assay and rhTSH stimulation. We evaluated the diagnostic yield of a sensitive Tg assay and rhTSH stimulated Tg in the detection of recurrences in the follow-up of DTC. Additionally the value of imaging techniques for the localization of recurrences was evaluated. We included 121 disease free patients in long-term follow-up for DTC (median 10 years, range 1-34). Tg during thyroid hormone suppression therapy (Tg-on) and rhTSH stimulated Tg were measured with a sensitive Tg assay. Patients with rhTSH stimulated Tg > or =1.0 ng/ml underwent imaging with neck ultrasound, FDG-PET and post therapy 131I WBS. Sensitive Tg measurement resulted in 3 patients with Tg-on > or =1.0 ng/ml, recurrence could be localized in 2 of them. RhTSH stimulation resulted in Tg > or =1.0 ng/ml in another 17 of 118 patients. Recurrence could be localized in only 1 additional patient (1 out of 118 patients). Recurrence was localized by neck ultrasound in 1 of 3, by FDG-PET in 2 of 3 and by post therapy 131I WBS in 2 of 3 patients. In the detection of recurrences in DTC, rhTSH stimulation had very limited additional value in comparison to Tg-on measurement with a sensitive Tg assay. We consider this too low to justify rhTSH stimulation in all patients during long-term follow up. Neck ultrasound, FDG-PET and post therapy 131I WBS showed complementary value in localization of disease, but were only positive in a small fracture of all procedures.