Recombinant human TSH in radioiodine treatment of differentiated thyroid cancer.
BACKGROUND
Recombinant human TSH (rhTSH) has been developed to facilitate the follow-up for persistent or recurrent differentiated thyroid cancer (DTC), avoiding the hypothyroid symptoms after the withdrawal of Levothyroxine (L-T4) suppressive therapy.


METHODS
To analyse the effect of rhTSH in providing stimulation of radioiodine uptake (RAIU) for the ablation of thyroid remnant and/or malignant thyroid tissue in patients with metastatic DTC. Ten subjects (4 women, 6 men), mean age 53 years, with DTC (7 papillary, 2 follicular and 1 Hürthle-cell), requiring radioiodine therapy (RIT) were studied. Nine of them had a positive diagnostic whole body scan (dWBS) or CT for thyroid remnant, lymph nodes and/or distant metastases. One patient with an invasive tall cell PTC had an increased serum Tg and a negative dWBS. Serum TSH was measured before and two days after the rhTSH injection. Thyroglobulin measurements were performed before the rhTSH administration, 3 and 6 months after RIT. There were no serious side effects of the rhTSH application.


RESULTS
Serum TSH after the rhTSH injection rose to 156.5 +/- +/- 60.9 mIU/L and induced RAIU in 8 out of 10 patients. Basal serum Tg was increased in 6 patients and decreased three months later in 2 of them. The post-therapy WBS (pthWBS) showed: 1) additional metastatic lesions in 3 patients with positive dWBS, 2) lung nodular metastases in 1 patient with negative dWBS, 3) similar image as the dWBS in 4 patients, 4) negative image in 1 patient with positive dWBS.


CONCLUSIONS
RhTSH is a safe and promising method for the stimulation of RAIU in patients with thyroid remnant and/or persistent or recurrent DTC, avoiding L-T4 withdrawal.
Kovatcheva
Roussanka D
RD
Department of Thyroid and Mineral Bone Diseases, Clinical Center of Endocrinology, Medical University, Sofia, Bulgaria. roussanka_kov@yahoo.com
Hadjieva
Tatjana D
TD
Kirilov
Georgi G
GG
Lozanov
Bojan S
BS
D000328:Adult; D000368:Aged; D017024:Chemotherapy, Adjuvant / Q000379:methods; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D013972:Thyrotropin / Q000008:administration & dosage* / Q000235:genetics; D016896:Treatment Outcome
D011838:Radiation-Sensitizing Agents; D011994:Recombinant Proteins; D013972:Thyrotropin