Cost-effectiveness of [F]FDG PET/CT in follow-up after thermal ablation in patients with colorectal liver metastases in the Dutch healthcare setting.

Introduction: The ESMO and ECIO-ESOI consensus guidelines vary in their recommendations regarding the use of F-Fluorodeoxyglucose ([F]FDG) PET/CT in the follow-up after thermal ablation in patients with colorectal liver metastases. This is partly because studies providing data on long-term benefits of [F]FDG PET/CT are lacking. Therefore, a simulation model was developed to examine how follow-up with [F]FDG PET/CT impacts treatment planning, health and cost outcomes.

Methods: For an illustrative Dutch cohort, lifetime health and cost outcomes were simulated to assess the cost-effectiveness of performing a single additional [F]FDG PET/CT. Patients followed a standard surveillance schedule consisting of three-monthly serum CEA and contrast-enhanced CT, plus [F]FDG PET/CT 3-4 months after thermal ablation. Therapy could be repeated downstream the care pathway. Quality-of-life and survival estimates were based on disease stage and age. Costs were determined from a healthcare perspective incorporating costs related to diagnostics and treatments. The Consolidated Health Economic Evaluation Reporting Standards were followed.

Results: Health benefits of additional [F]FDG PET/CT were negligible, incremental QALYs < 0.001, whereas costs increased by €1,277, mainly due to the additional imaging. This lack of health benefits can be explained by the small subset of simulated patients (<5 %) in whom [F]FDG PET/CT affected treatment planning.

Discussion: Additional [F]FDG PET/CT 3-4 months after thermal ablation is unlikely to be cost-effective. More research is needed to determine if using [F]FDG PET/CT in subgroups of patients, or at alternative time points, is cost-effective. This requires collecting more (extensive) follow-up data across multiple centres to reflect heterogeneity between hospitals' clinical practices.