A 42-year-old woman is found to have a suppressed TSH of 0.02 mIU/L with a free T4 of 2.6 ng/dL and free T3 of 9.8 pg/mL. She has a multinodular goitre and no exophthalmos. Technetium scan shows multiple autonomous hyperfunctioning nodules. Which treatment is most appropriate as first-line definitive therapy?
- A Propylthiouracil for 18 months
- B Radioactive iodine (I-131) ablation ✓
- C Subtotal thyroidectomy only after beta-blockade
- D Methimazole lifelong
Correct answer: B. Radioactive iodine (I-131) ablation
Explanation
Toxic multinodular goitre (Plummer's disease) with autonomous nodules is best treated definitively with radioactive iodine (I-131), which selectively destroys hyperfunctioning thyroid tissue. Unlike Graves' disease, antithyroid drugs do not induce remission in toxic MNG—they only control symptoms temporarily. Surgery is reserved for very large goitres causing compressive symptoms or when malignancy is suspected. Definitive ablative therapy is preferred over long-term antithyroid drug use.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.