Circulating tumor DNA (ctDNA) is a promising new biomarker with multiple potential applications in cancer care. As part of the “ctDNA on the way to implementation in the Netherlands (COIN)” project, an early, comprehensive Health Technology Assessment (HTA) is ongoing. Information about the costs of ctDNA testing is essential for implementation. Estimating the total cost associated with ctDNA-testing is challenging due to variation in the workflow, wide range in purchase and operational costs of the platforms, and the highly dynamic field. As a first step in the HTA, the aim of this study was to develop a flexible micro-costing framework and open-access model for consistent cost calculation of ctDNA-testing.

First, the complete diagnostic workflow of ctDNA-testing was mapped based on expert discussions. This step-wise workflow was used as the foundation of the framework. Second, the activity-based costing method was used and included costs for personnel, materials, equipment, overhead, housing, and test failures. Third, the framework was validated by experts and by applying the cost calculation model to six case studies.

The diagnostic workflow was mapped from blood sample collection to reporting the diagnostic findings. The framework was developed from a Dutch perspective and takes into account the testing volume. The total cost per sample for the case studies with different workflows and testing volumes ranged from EUR 168 to EUR 7,638.

The developed micro-costing framework can be used to calculate the costs for ctDNA-testing for different workflows. The results from the case studies show the wide range of costs for ctDNA-testing and that the costs are determined by the choice of platform, setting, and testing volume. The open access model allows users to adapt and specify parameters in the diagnostic workflow matching their setting and can be used to support investment decisions and future cost-effectiveness studies.