The Cost-Effective Use of ¹⁸F-FDG PET in the Presurgical Evaluation of Medically Refractory Focal Epilepsy

Abstract

This study applied decision tree analysis to evaluate the sensitivity, specificity, and cost-effectiveness of clinical algorithms that incorporate 18 F-FDG PET. Methods: A cohort of 176 patients was studied. The localization rate, accuracy, therapeutic impact on the presurgical decision-making process, and correlation with the postsurgical outcome were assessed for the tests commonly performed for seizure localization. Decision tree sensitivity analysis compared 3 imaging strategies with a baseline strategy of medical therapy for all: video-electroencephalography monitoring (VEM)/MRI strategy, in which patients underwent VEM and brain MRI only, and 1SPECT and 1PET strategies, in which patients with an indeterminate VEM/MRI result underwent ictal SPECT or interictal 18 F-FDG PET, respectively. Results: The localization rates for VEM, MRI, 18 F-FDG PET, ictal SPECT, and intracranial electroencephalography (EEG) were 62.2%, 35.8%, 75.0%, 60.0%, and 93.8%. The VEM/MRI strategy had the lowest cost per class I/II outcome, but the additional costs per class I/II outcome for the 1PET and 1SPECT strategies were always below the minimum reported cost savings for a class I/II outcome. There were no valid conditions in which the 1SPECT strategy had a lower cost per class I/II outcome than the 1PET strategy. Within the range of cost savings estimated to be associated with a class I/II outcome, all decision strategies produced net cost savings; however, these were significantly higher for the 1PET and the 1SPECT strategies. Conclusion: 18 F-FDG PET is cost-effective in the presurgical evaluation, particularly when used in patients with a nonlocalizing or nonconcordant VEM or MRI result.

The clinical effectiveness and cost-effectiveness of technologies used to visualise the seizure focus in people with refractory epilepsy being considered for surgery: a systematic review and decision-analytical model.

“…The O'Brien et al study 78 was the only published study found in the review process that was considered to be in line with the scope of this assessment. The study was conducted from the viewpoint of an Australian health-care provider.…”

“…78 The following section provides an overview of this paper and assesses its relevance to the scope of this technology assessment.…”

“…Review of O'Brien et al 78 This study by O'Brien et al 78 evaluates the cost-effectiveness of a range of presurgical strategies for the lateralisation of temporal lobe epilepsy in patients; a summary of the paper is provided in Table 12. The costs of the strategies are evaluated over the lifetime of the patient from the perspective of the Australian health-care sector.…”

“…In addition to F-FDG-PET all patients had initially undergone interictal EEG, prolonged video-EEG and MRI (16 of the 176 also received iEEG but the results and impact of undertaking this test are not reported). Although some patients in O'Brien et al 's sample 78 had ictal and interictal SPECT (n = 15), given the small numbers the data that inform the decision tree are taken from an alternative study (Won et al 79 ). However, this highlights that patients may have had a sequence of tests, which influences the decision to proceed to surgery and surgical outcomes; the implications of this sequencing are not well considered by the author or incorporated into the decision tree.…”

“…The data collected by O'Brien et al 78 was derived from a cohort of 176 patients who received FDG-PET scans at the Royal Melbourne Hospital as part of a presurgical evaluation for chronically refractory focal epilepsy from November 1996 to July 2001. In addition to F-FDG-PET all patients had initially undergone interictal EEG, prolonged video-EEG and MRI (16 of the 176 also received iEEG but the results and impact of undertaking this test are not reported).…”