Which hyperthyroid patient is the best candidate for radioactive iodine therapy?

• A. 30-year-old patient with toxic adenoma
• B. Over age 65 Graves' disease
• C. 50-year-old patient with subacute thyroiditis
• D. Pregnant woman with Hashimoto's thyroiditis

Answer: (B)

Radioactive iodine therapy is a definitive, non-surgical approach that's especially suited for older patients with Graves' disease. In those over around 65, the risks of thyroid surgery and general anesthesia are higher, making a single, outpatient treatment that destroys overactive thyroid tissue very appealing. Most patients end up hypothyroid after treatment, but that outcome is easy to manage with lifelong thyroid hormone replacement.

Subacute thyroiditis isn’t a good candidate because the hyperthyroidism comes from leaked preformed hormone and the gland’s uptake of iodine is low, so RAI won’t correct the problem. A pregnant patient is a contraindication due to fetal radiation exposure. A toxic adenoma can respond to RAI, but in an older patient with Graves' disease, the elderly patient’s overall treatment risk profile makes RAI the preferable option.