Radioiodine therapy for pediatric patients with thyroid cancer

From 1986 to 1998, 753 patients under the age of 16 were operated on for thyroid cancer. A metastatic disease was diagnosed in 110 (14.6%) cases. In 108 patients (14.3%), there were lung metastases, and in 2 lung and bone metastatic lesions. In 22 of 110 patients (20%), metastases were detected by routine X-ray before therapy. Two patients died without treatment and 108 were selected for radioiodine therapy. Tumor histology was as follows: papillary carcinomas - 104, follicular - 3 and medullary - 1. Sex ratio was 1.2f/1m. Most of the patients had an extended disease. Neck lymph nodes were positive in 103 (95.4%) of cases and in 76 (70.4%) neck metastases were bilateral (pN1b). In 86 patients tumour involved the thyroid capsule and surrounding extrathyroid tissues (pT4). All the patients underwent thyroidectomy with either unilateral or bilateral radical neck dissection. Diffuse lung metastases were diagnosed in 88 cases. A single dose activity of sodium-iodine-131 varied from 3 to 5 GBq. In several advanced cases, the activity of radioiodine in following courses was enhanced up to 7 GBq. The total delivered activity for patients varied from 1.25 up to 43.7 GBq. Response was noted in 107 patients. There were 79 complete responders and in 28 patients partial response was reached. Cancer progression was seen only in one patient with medullary carcinoma, after three courses of radioiodine therapy. All the patients were alive from 6 to 56 months after surgery. (author)