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Toxic MNG Treatment — RACP Adult Medicine MCQ

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ModerateEndocrinologyToxic MNG TreatmentRACP Adult Medicine

A 70-year-old man with a toxic multinodular goitre and AF with rapid ventricular response (HR 140) presents with thyrotoxicosis (free T4 42 pmol/L). He has ischaemic heart disease and is not a surgical candidate. TRAb is negative. What is the most appropriate definitive treatment?

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Correct answer: E — Radioactive iodine (I-131)

Toxic multinodular goitre (TMNG) does not remit with ATDs (unlike Graves). Definitive treatment is required. For elderly patients who are poor surgical candidates, RAI is the preferred definitive treatment. Pre-treatment with carbimazole to achieve euthyroidism before RAI is standard (withdrawn 3-7 days before RAI). Ophthalmopathy is not a concern in TMNG (TRAb negative). Rate control with beta-blocker.

Reference: ESA – 2024 – Thyroid; ATA 2016 Hyperthyroidism