[Assessment of recombinant human thyrotropin application in following-up patients with well-differentiated thyroid carcinoma].

Background/aim: The most sensitive indicators for detecting recurrence of well-differentiated thyroid cancer (DTC) are 131I whole body scintigraphy (WBS) and measurement of serum thyroglobulin (Tg). In order to perform it, it is necessary to raise the level of endogenous tiroid-stimulating hormon (TSH), which can be achieved by L-thyroxine withdrawal for 3-5 weeks or administration of recombinant human thyrotropin (rhTSH) without requiring the discontinuation of thyroid hormone therapy. The aim of this study was to assess the effect of rhTSH using in comparison to the traditional thyroid hormone withdrawal in the follow-up of patients with DTC.

Methods: This retrospective study included 44 patients, mean age 48.8 years, with DTC divided into 2 groups. The group I consisted of patients (n = 31) in which the analysis in the follow-up (WBS with 131I, TSH, Tg and antiTgAt) made in the hypothyroid state, and group II patients (n = 13) in which they made after the administration of rhTSH. The presence of 13 symptoms and signs of hypothyroidism was investigated on the day of giving 131I. Quality of life was evaluated using a modified form: the quality of life scale (SF-36) completed on the day of giving 131I.

Results: In both groups, serum TSH reached a very good stimulation level, but significantly higher in the group II (group I 30.3-101.5 microlU/mL, group II 68.6-192.0 microlU/mL, p < 0.05). In both groups, TSH-stimulated Tg was higher (group I 0.1-546.0 ng/mL, group II 0.1-7517 ng/mL) comapred to value during the L-thyroxine therapy (group I 0.1-495.0 ng/mL, group II 0.1-2785 ng/mL). There was no difference in technical quality of WBS obtained from both groups. The patients in the group I had attended 8-13 symptoms of hypothyroidism, while patients in group II did not have symptoms of hypothyroidism. The patients after application of rhTSH, showed statistically significantly better quality of life as compared with those who showed to have L-thyroxine withdrawal, (74-91 points vs 43-62 points; p < 0.05). The rhTSH was well tolerated, with nausea occurring in only one patient.

Conclusion: Administration of rhTSH in the follow-up of patients with DTC prevents the debilitating effects of hypothyroidism contributing to the maintenance of metabolic homeostasis of the organism and preserves the quality of life. RhTSH is safe, effective and easy to use, but is still an expensive product in our country.