Cost-effectiveness of [¹¹C]Choline PET/CT as first-line imaging in primary hyperparathyroidism

We performed a cost-utility analysis, using prospectively gathered trial data, comparing two imaging strategies for localizing parathyroid adenomas in primary hyperparathyroidism (pHPT) to determine the most cost-effective approach. Additionally, we provide customizable open-source R-script enabling other centres to identify their optimal imaging strategy based on local diagnostic accuracy and cost data.

An evaluation of the diagnostic accuracy was performed for five imaging modalities: first-line cervical ultrasound (cUS) and [^99mTc]Tc-methoxy isobutyl isonitrile-single-photon-emission-computed- tomography/computed-tomography (MIBI SPECT/CT), and second-line [¹¹C]choline positron-emitting-tomography/CT (PET/CT), [¹¹C]methionine PET/CT, and 4 dimensional (4D)-CT. A decision-tree-model, constructed in R-studio, compared two diagnostic pathways: (1) The comparator pathway: a stepwise approach starting with cUS and MIBI SPECT/CT escalating to one of three second-line imaging modalities if needed, and (2) use of only one second-line imaging. Costs and quality-adjusted life years (QALYs) were evaluated across pathways, and cost-utility ratios (€/QALY) were calculated for a centre specific perspective with a 24-year time horizon based on life expectancy. In addition, to test the joint parameter uncertainty of the model, a probabilistic Monte-Carlo analysis was performed. One- and two-way sensitivity analyses were conducted to assess model robustness.

[¹¹C]choline PET/CT had a total costs of €10,394 and a QALY gain of 16.66. In contrast, the current standard, cUS + MIBI SPECT/CT with, when necessary, second-line imaging, costs €10,907 and yields 16.63 QALYs. The incremental cost-utility ratio (ICUR) for [¹¹C]choline PET/CT was -€18,846/QALY, indicating dominance with lower cost and greater effectiveness. Sensitivity analyses showed that cost-effectiveness was most sensitive to variations in costs of [¹¹C]choline PET/CT.

This centre-specific model supports first-line [¹¹C]choline PET/CT as a cost-effective first-line strategy for localization of parathyroid adenomas, depending on [¹¹C]choline PET/CT costs. Additionally, the provided cost-utility model, enables other centres to determine their optimal imaging strategy.