Abstract
Background: We proved recently that in children adjuvant radioiodine is effective in decreasing risk of locoregional recurrence even after radical surgery. The aim of our present study was as to evaluate the risk of late side-effects of radioiodine administration in children.
Material and Methods: There were 110 DTC patients (M/F:36/74) treated with 131-I before adulthood (median activity 100 mCi) and prospectively evaluated by radiological and biochemical examinations, with the median follow-up of 11 years. Seventeen of them were diagnosed with distant metastases at radioiodine administration. At the time of evaluation all of them were >18 years of age.
Results: At the evaluation, no case of DTC progression was stated (during the follow-up there was one case of local recurrence, treated by surgery). Chest x-ray was normal in 97,2% patients, in 2 fibrosis and in 1 metastases were visible. HRCT (high resolution CT) was performed in 42 patients. In 63,2% of patients with lung metastases and 69,6 % of non-metastatic group HRCT was normal. Single nodules of uncertain etiology were observed respectively in 15,8% and 17,4% patients. Signs of lung fibrosis were observed only in children without lung metastases (13%). Menstrual irregularities were stated in 25% of women, their gonadotropins were within normal range. FSH was elevated in 5/36 (14%) men, without any correlation with administered 131-I activity. 7 (out of 26 willing to) patients were not able to contribute to conception for > 1 year; and 5 women had miscarriage (19,2 % of all pregnancies).
Conclusions: Radioiodine therapy does not cause any increased risk of lung fibrosis even in children treated with repeated courses. Observed rate of miscarriages is not different from general population. Elevation in FSH in men is alarming and requires explanation.