A Retrospective Review of the Effectiveness of Recombinant Human TSH-Aided Radioiodine Treatment of Differentiated Thyroid Carcinoma

Abstract

Background: The aim of the study was to evaluate the biochemical effects of recombinant human thyroid stimulating hormone (rhTSH) as an adjunct to radioiodine (RI) treatment of a differentiated thyroid carcinoma (DTC). We retrospectively reviewed the clinical response rates of DTC patients treated with RI after thyroid hormone withdrawal and compared with those after rhTSH stimulation. Method: We included the patients treated with RI for locally recurrent DTC from February 1, 2002 to August 31, 2005 and followed with diagnostic studies at our hospital. Forty totally (or near totally) thyroidectomized adults were included in this study. Nine patients underwent RI treatment after rhTSH stimulation while euthyoid on L-thyroxine (LT4), and 31 patients were treated with RI after thyroid hormone withdrawal. The clinical response was defined as > 25% decrease in serum thyroglobulin (Tg) level on LT4 3 months after the RI treatment. Results: In each group, serum Tg levels were significantly decreased 3 months after the RI treatment. And we found that 77.8 and 71.0% of those prepared by rhTSH and LT4 withdrawal, respectively, had clinical responses 3 months after the RI treatment by our criteria and there was no significant difference in response rates between two groups (P = 0.238). Conclusions: Given the biases that exist in retrospective studies, at the current time we cannot recommend the routine use of rhTSH to prepare RI treatment of DTC. However, our study provided preliminary evidence that rhTSH effectively aided RI treatment of DTC at least to an equivalent degree as LT4 withdrawal. (J Kor Soc Endocrinol 21:274~280, 2006)