ABSTRACT
AIM: Withdrawal of levothyroxine with resultant hypothyroidism is still used in preparation for I-131 diagnostic whole-body scan (DWBS) and thyroglobulin (TG)-measurement in patients afflicted with differentiated thyroid cancer (DTC). Recombinant human thyroid-stimulating hormone (rhTSH) enhances TSH stimulation obviating the clinical and economical consequences of hypothyroidism. Primary aim of this study was an intraindividual comparison of diagnostic follow-up measurements under these two sets of conditions by taking clinical and socio-economic parameters into account. Second aim was to determine a clear patient preference for the one method or the other. METHODS: This non-interventional observational study included patients (n=192 signed informed consent, n=128 protocol compliant patients without need for therapeutic intervention) with DTC first treated by thyroidectomy and radioiodine ablation. Control visits including I-131 DWBS were planned at 3-6 months post-thyroidectomy after a phase (KU 1) of thyroid hormone withdrawal (THW) and again after 6-12 months later in a euthyroid state under exogenous stimulation with rhTSH (KU 2). Study design was open, prospective and multicentric. Data collected consisted of patient information (SF-12 (®) Health Survey), thyroid-specific results of clinical examinations and several aspects of daily life, e. g., employment, days of absence from work and other economic aspects. RESULTS: In contrast to KU 1, in KU 2 there is a highly significant improvement (p<0.0001) in all studied clinical symptoms and aspects of managing daily life. A significant increase of the SF-12 (®) health survey score could also be identified. Mental score showed a higher increase than physical score. Included patients were less absent from work before KU 2, (absent 4.5%, median 4 days in euthyroid state [range 2-5 d]), vs. before KU 1 (absent 47.8%, median 10 days in hypothyroid state [range 1-30 d]). After KU 2 7.7% of the euthyroid patients was absent from work (median 5 days) while 37.5% was after KU 1 (median 6 days). CONCLUSION: Included patients benefited subjectively and objectively from the use of rhTSH for diagnostic procedures in the treatment of DTC. A clear preference (127 of 128) of analyzed patients could be identified for exogenous stimulation with rhTSH.
