Cost-effectiveness of ¹⁸F-FET PET for early treatment response assessment in glioma patients following adjuvant temozolomide chemotherapy

Abstract

Rationale: In light of increasing healthcare costs, higher medical expenses should be justified socio-economically. Therefore, we calculated the effectiveness and cost-effectiveness of positron emission tomography (PET) using the radiolabeled amino acid O-(2-[¹⁸F]-fluoroethyl)-L-tyrosine (¹⁸F-FET) compared to conventional magnetic resonance imaging (MRI) for early identification of responders to adjuvant temozolomide chemotherapy. A recently published study in isocitrate dehydrogenase-wildtype glioma patients suggested that ¹⁸F-FET PET parameter changes predicted a significantly longer survival already after two cycles while MRI changes were not significant. Methods: To determine the effectiveness and cost-effectiveness of serial ¹⁸F-FET PET imaging, we analyzed published clinical data and calculated the associated costs from the perspective of the German Statutory Health Insurance system. Based on a decision-tree model, the effectiveness of ¹⁸F-FET PET and MRI was calculated, i.e., the probability to correctly identify a responder as defined by an overall survival ≥15 months. To determine the cost-effectiveness, the incremental cost-effectiveness ratio (ICER) was calculated, i.e., the cost for each additionally identified responder by ¹⁸F-FET PET who would have remained undetected by MRI. The robustness of the results was tested by deterministic and probabilistic Monte Carlo sensitivity analyses. Results: Compared to MRI, ¹⁸F-FET PET increased the rate of correctly identified responders to chemotherapy by 26%; thus, four patients needed to be examined by ¹⁸F-FET PET to identify one additional responder. Considering the respective cost for serial ¹⁸F-FET PET and MRI, the ICER resulted in €4,396.83 for each additional correctly identified responder by ¹⁸F-FET PET. Sensitivity analyses confirmed the robustness of the results. Conclusion: In contrast to conventional MRI, the model suggests that ¹⁸F-FET PET is cost-effective in terms of ICER values. Considering the high cost of temozolomide, the integration of ¹⁸F-FET PET has the potential to avoid premature chemotherapy discontinuation at reasonable cost.