Radioactive iodine therapy in Graves' hyperthyroidism: a prospective study from a tertiary referral centre in north India.

BACKGROUND: Radioactive iodine has gained widespread acceptance as the first-line therapy for Graves' hyperthyroidism and is the preferred treatment option in most situations. OBJECTIVE: A prospective study was conducted to look at the therapeutic practice of use of radioactive iodine in the treatment of Graves' hyperthyroidism, to determine whether the expected or desired therapeutic outcome is achieved. SETTINGS: A tertiary referral centre in north India, Delhi that caters to patients with thyroid disorders. METHODS: One hundred and seventy four consecutive subjects with Graves' hyperthyroidism, who were given radioactive iodine were followed up. RESULTS: There were 59 (33.9%) males and 115 (66.1%) females. The mean age was 41.8 +/- 9 years. The dose of radioactive iodine ranged from 2 mCi to 15 mCi and the mean dose administered was 5.2 +/- 1.9 mCi. After one year following radioactive iodine therapy, 29 (16.7%) subjects were euthyroid, 51 (29.3%) were hypothyroid and the remaining 94 (54%) had persisting hyperthyroidism. Those subjects with persisting hyperthyroidism at one year after radioactive iodine had received a significantly lower dose compared to the groups who had achieved cure (either euthyroidism or hypothyroidism). CONCLUSION: The study shows that the current practice of empirical low dose radioactive iodine therapy to avoid hypothyroidism results in majority of patients having persisting hyperthyroidism. There is a need to take a new look at the current practice to increase the cure rate.

Radioactive iodine therapy in Graves' hyperthyroidism.

Graves' disease is a common condition encountered in clinical practice. The available modes of therapy for Graves' disease are antithyroid drugs, radioiodine and surgery. Radioiodine therapy is indicated in patients with nearly all causes of hyperthyroidism and is considered the treatment of choice for most patients with Graves' hyperthyroidism who are beyond the adolescent years. Pregnancy and breast-feeding are absolute contraindications. Although there are many ways of calculating the dose of radioiodine, fixed dose regimens are gaining acceptance. Hypothyroidism follows sooner or later in nearly all patients treated with radioiodine. Available evidence suggest that patients are best treated by a single thyroablative dose, the aim being elimination of hyperthyroidism, with larger doses accomplishing it with more certainty, and the inevitable hypothyroidism develops under physician control. Radioiodine therapy can lead to exacerbation of infiltrative ophthalmopathy and this can be prevented by the concomitant administration of corticosteroids. Radioiodine therapy for Graves' hyperthyroidism has no adverse effects on the health of the offspring of treated patients. There are no definitive data that provide evidence for increased rates of thyroid cancer, leukaemia, infertility or neonatal abnormality in patients treated with radioiodine. Radioiodine therapy is safe, definitive and cost-effective.