A Clinical Debate: What Is the Therapeutic Choice for Recurrent Graves’ Hyperthyroidism?

Ms. E.A. is a 36-year-old woman who has been referred for the management of recurrent hyperthyroidism. She was always healthy with no significant medical history until about 30 months ago when she developed signs and symptoms of hyperthyroidism with a 45-gm diffuse goiter. Laboratory test results were as follows: thyrotropin (TSH) < 0.01 mU/L, free thyroxine (fT4): 42 pmol/L (normal range, 10 - 23 pmol/L), TSH receptor antibodies (TRAb): 15.6 IU/mL (normal range, < 1.75 IU/mL). She was treated with methimazole (MMI) via titration method, and thyroid hormone concentrations became normal within six weeks. She continued MMI 5 mg daily for 18 months; one year ago, she had a goiter weighing 30 gm and following thyroid-related tests: TSH: 1.8 mU/L, fT4: 18 pmol/L, serum TRAb = 1.6 IU/mL; MMI was discontinued, and she did well until one month ago (nearly eleven months after MMI discontinuation) when she experienced palpitation, tremor, anxiety, and insomnia and lost 3 kg of weight. Now, a diffuse goiter is evident; there are no symptoms or signs of Graves’ orbitopathy. Recent serum TSH concentration is 0.06 mU/L, serum fT4 is 42 pmol/L, and serum TRAb is 11.6 IU/mL. According to this history and results of laboratory tests, she wants to know which therapeutic modality is recommended.