title: A sensitive Tg assay or rhTSH stimulated Tg: what's the best in the long-term follow-up of patients with differentiated thyroid carcinoma?
abstract: 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.
authors.affiliation: Department of Endocrinology, University Medical Centre Groningen, University of Groningen, The Netherlands.
authors.forename: Adrienne C M
authors.initials: AC
authors.lastname: Persoon
authors.forename: Pieter L
authors.initials: PL
authors.lastname: Jager
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Sluiter
authors.forename: John T M
authors.initials: JT
authors.lastname: Plukker
authors.forename: Bruce H R
authors.initials: BH
authors.lastname: Wolffenbuttel
authors.forename: Thera P
authors.initials: TP
authors.lastname: Links
mesh_terms: D000328:Adult; D001681:Biological Assay; D002277:Carcinoma / Q000175:diagnosis*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000175:diagnosis*; D013972:Thyrotropin / Q000494:pharmacology*
chemical_list: D013972:Thyrotropin; D013954:Thyroglobulin