Endocrine Abstracts

We treated 4150 patients, aged 30–70 years; 1950 patient with toxic multinodular goitre (TMNG), and 2200 patient with autonomous toxic nodule (ATN). Qualification of these patients was based on high levels of serum fT₃ and fT₄, low levels of serum TSH. Malignant changes were excluded in all nodules by fine needle aspiration biopsy. All the patients had serum TSH levels ≤0.1 mU/l and the effective T-half was ≥3 days at the time of treatment. The activity dose was calculated by the use of Marinelli’s formula and ranged between 200 and 800 MBq. The absorbed dose (Gy) for TMNG ranged between 150 and 260, and for ATN 200–300. Follow up control was done every 6 weeks in the first year, then every 6 months for 9 years.

Results: In general the success of treatment after 1 year was: 97% of patient with ATN and 91% of patient with TMNG achieved euthyroidism. 2% of patient with ATN and 8% of patient with MNG develop hypothyroidism. 1% of the patients had persistent or relapse of hyperthyroidism and received second dose of radioiodine therapy. After 3 years of radioiodine therapy 4% of patient with ATN and 10% of patient with TMNG develop hypothyroidism. After 5 years of radioiodine therapy 6% of patient with ATN and 11% of patient with TMNG develop hypothyroidism. After 8 years of radioiodine therapy 8% of patients with ATN and 11% of patients with MNG develop hypothyroidism. After 10 years of radioiodine therapy 9% of patients with ATN and 12% of patients with TMNG develop hypothyroidism. The volume of thyroid glands decreased about 55% average.

Conclusions: The achievement of euthyroidism and the remission of the symptoms and signs of hyperthyroidism, were due to good diagnosis, well preparation of the patients; accurate measurement of administered activity, effective half-life, and well-organised follow up.