Thyroid nodules with indeterminate cytology: molecular imaging with ⁹⁹mTc-methoxyisobutylisonitrile (MIBI) is more cost-effective than the Afirma gene expression classifier.

Purpose: To compare the cost-effectiveness of (99m)Tc-methoxyisobutylisonitrile (MIBI) thyroid scintigraphy and the Afirma gene expression classifier for the assessment of cytologically indeterminate thyroid nodules.

Methods: A decision tree model was used. Costs were calculated from the perspective of the German health insurance system. The robustness of the results was assessed with probabilistic sensitivity analyses using a Monte Carlo simulation.

Results: Life expectancy was 34.3 years (estimated costs per patient €1,459 - €2,224) for the MIBI scan and 34.1 years (estimated costs €3,560 - €4,071) for the molecular test. These results were confirmed by the Monte Carlo simulation.

Conclusion: MIBI thyroid scintigraphy is more cost-effective than the gene expression classifier.