Cost Effectiveness of ¹⁸F-FET PET for Early Treatment Response Assessment in Glioma Patients After Adjuvant Temozolomide Chemotherapy

In light of increasing health-care costs, higher medical expenses should be justified socioeconomically. Therefore, we calculated the effectiveness and cost effectiveness of PET using the radiolabeled amino acid O-(2-¹⁸F-fluoroethyl)-l-tyrosine (¹⁸F-FET) compared with conventional MRI for early identification of responders to adjuvant temozolomide chemotherapy. A recently published study in isocitrate dehydrogenase wild-type glioma patients suggested that ¹⁸F-FET PET parameter changes predicted a significantly longer survival already after 2 cycles whereas 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-that is, the probability to correctly identify a responder as defined by an overall survival of at least 15 mo. To determine the cost effectiveness, the incremental cost effectiveness ratio (ICER) was calculated-that is, 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 with MRI, ¹⁸F-FET PET increased the rate of correctly identified responders to chemotherapy by 26%; thus, 4 patients needed to be examined by ¹⁸F-FET PET to identify 1 additional responder. Considering the respective costs 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.