Post-Surgical Acromegaly Treatment — RACP Adult Medicine MCQ

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ModerateEndocrinology & DiabetesPost-Surgical Acromegaly TreatmentRACP Adult Medicine

A 50-year-old man with acromegaly has undergone transsphenoidal surgery but his IGF-1 remains elevated at 2× ULN. GH does not suppress on OGTT. MRI shows residual pituitary tumour tissue. What is the first-line medical therapy?

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Correct answer: A — Pegvisomant

For acromegaly with persistent disease after surgery (residual tumour, elevated IGF-1, non-suppressing GH), first-line medical therapy is a long-acting somatostatin analogue (SSA) – octreotide LAR or lanreotide Autogel. SSAs normalise IGF-1 in ~55% and reduce tumour size in ~25% of patients. Cabergoline (dopamine agonist) is a lower-efficacy alternative for mildly elevated IGF-1 (<2× ULN). Pegvisomant (GH receptor antagonist) normalises IGF-1 in >90% but does not shrink the tumour. Pasireotide (second-generation SSA) is used for SSA-resistant disease but causes hyperglycaemia. Radiation therapy is reserved for cases refractory to both surgery and medical therapy.

Reference: eTG – 2025 – Endocrinology; Endocrine Society – 2014 – Acromegaly Guidelines