Endocrine Abstracts

Background: Although recombinant human TSH (rhTSH) is widely used to aid radioiodine treatment of differentiated thyroid cancer (DTC), however, there are data on its effectivness in children and adolescents with DTC.

The aim of our retrospective study was to evaluate effectiveness and safety of rhTSH aided radioiodine treatment in DTC patients 18 years of age or younger.

Material and Methods: Fifty five children/adolescents (median age 15 years, range 4–18 years) with the diagnosis of DTC were treated using the approved adult rh-TSH regimen (on 0.9 mg i.m. injection daily on 2 consecutive days) and therapeutic activity of ¹³¹I (median 3.7 GBq, range 2.2–3.8 GBq). Thyroglobulin was evaluated on 1st and 6 of stimulation, and whole body scan (WBS) on day 6th. Patients were followed-up on 6 months interval. The median follow up after the treatment is 43 months.

Results: Peak TSH concentration post-rhTSH exceeded 25 mU/l in all children. In all children the peak stimulated thyroglobulin was achieved on day 6 of stimulation (median 4 ng/ml, range 0.17-1080).

In children treated with radioiodine as an adjunct to total thyroidectomy (n=45), in 8(17%) second radioiodine treatment was performed due to persistent radioiodine uptake in thyroid bed and or elevated thyroglobulin concentration. There was one (2%) structural recurrence in thyroid bed during subsequent follow-up.

In ten patients (22%) distant metastases to lung/mediastinum were diagnosed. In all morphological (radiological or scintigraphic) remission was achieved, but in none thyroglobulin decreased below detection level during last 131-I therapy.

None side effects were observed after rh-TSH application.

Conclusions: rhTSH aided radioiodine treatment in children/adolescents with DTC is a safe and effective treatment. It allows to avoid hypothyroidism during L-thyroxine withdrawal without any significant side effects. The first results suggest that the treatment is effective both as an adjuvant and radical treatment but longer follow up is necessary.