Endocrine Abstracts

Introduction: Treatment of hyperthyroidism in older adults is crucial to reduce its morbidity and mortality. Radioactive iodine has been widely used in this age group due to its efficacy, safety and cost-effectiveness.

Aim: To determine the efficacy of ¹³¹I for treatment of hyperthyroidism in the elderly.

Methods: Retrospective study of 86 hyperthyroid patients aged ≥65 years who performed radioiodine therapy. We evaluated the following parameters: gender, age, thyroid disease, clinical, and laboratory situation at 1, 3, and 5 years after treatment. We excluded 22 patients who didn’t have a minimal follow-up of 1 year.

Results: We evaluated 64 patients (89% females) with a mean age (±S.D.) of 74.4±6.4 years (range 65–89 years) at the time of radioiodine treatment. Twenty-eight patients (44%) had toxic multinodular goiter, 27 (42%) had toxic adenoma and 9 (14%) had Graves’ disease. We documented hyperthyroidism, subclinical in most cases, in 27% (17/63), 12% (5/42), and 6% (2/32) of patients at 1, 3, and 5 years after radioiodine therapy, respectively. The prevalence of hypothyroidism was 10% (6/63), 24% (10/42), and 38% (12/32) at 1, 3, and 5 years after treatment with ¹³¹I respectively. Euthyroidism was observed in 63% (40/63), 64% (27/42), and 56% (18/32) after 1, 3, and 5 years of follow-up, respectively. Seven patients (11%) needed two and one patient (1.6%) needed three doses of radioiodine to solve the hyperthyroidism. One patient underwent surgery. There were no significant complications due to radioiodine therapy.

Conclusion: Radioiodine therapy has proved to be effective and safe to control hyperthyroidism in this age group. The cell necrosis induced by radioiodine occurs gradually hence its effect may not be achieved immediately.