Radio-iodine therapy of hyperthyroid Graves' disease - The Bloemfontein experience

Objectives. The aim of this study was to investigate effectiveness, action rate and eventual complications of radioactive iodine (RAI) therapy in our patients with hyperthyroid Graves' disease. Design. Retrospective analysis of clinical results. Setting. Departments of Internal Medicine, Nuclear Medicine and Biostatisti cs at the University of the Orange Free State, Bloemfontein. Subjects and outcome measures. Forty-three patients with Graves' disease (3 8 women and 5 men) aged 19 - 67 years, mean body mass index 25.0 kg/m(2), w ere treated with 10 - 15 mCi RAI between 1994 and 1997. Response to the the rapy was monitored clinically (complications, body mass index) and biochemi cally (serum free thyroxine (T-4), thyroid stimulating hormone (TSH) levels ) at regular intervals. Results recorded at 6, 12, 16 and 52 weeks were sta tistically evaluated. Results. All patients had diffuse enlargement of the thyroid gland. Iodine- 131 (131-I) uptake was increased (6 hours 67.3%, 24 hours 79.9%). After RAI therapy 35/43 patients (81.4%) were cured with a single dose of RAI (34 pa tients became hypothyroid, 1 patient remained euthyroid) and 8/43 patients (18.6%) needed a second dose of RAI. Hypothyroidism occurred 6 - 52 weeks a fter the ICAI therapy, in most eases after 3 - 4 months (94% of finally hyp othyroid patients). Replacement therapy with Eltroxin was started on averag e 13 weeks after RIA therapy. Transient central hypothyroidism was present in 15/34 finally hypothyroid patients (44.1%) Graves ophthalmopathy was cli nically diagnosed in 13/43 patients (30.2%) before RAI therapy and worsened in 2/13 patients (4.6%) who required corticosteroid treatment. No other co mplications of RAI therapy were found. The mean weight gain of patients was 4.0 kg within 3 months after RAI therapy. Conclusions. A single dose of 10 - 15 mCi of RAI was effective in 81.6% of patients with Graves' disease. A second dose of RAI should be considered if patients are still hyperthyroid 4 months after RAI therapy. We did not obs erve any complications of therapy except moderate worsening of ophthalmopat hy in 2/13 patients.