Which investigation is used at baseline and at regular intervals during adjuvant trastuzumab therapy to detect its principal dose-limiting toxicity?

• A Serial measurement of left ventricular ejection fraction by echocardiography ✓
• B Monthly serum troponin I estimation
• C Serial pulmonary function tests
• D Quarterly liver elastography

Explanation

Trastuzumab causes reversible, non-dose-dependent cardiac dysfunction through HER2 blockade in myocardium, unlike the cumulative, often irreversible anthracycline cardiomyopathy. Guidelines require baseline assessment of left ventricular ejection fraction by echocardiography or MUGA scan, with repeat assessment every three months during therapy; a significant fall mandates interruption. Troponin monitoring is not standard, and neither pulmonary function testing nor liver elastography relates to trastuzumab toxicity.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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