José Tomás1,2, Francesca Pittau1,3, Alexander Hammers4,5, Sandrine Bouvard6, Fabienne Picard1,3, Maria Isabel Vargas3,7, Francisco Sales2, Margitta Seeck1,3, Valentina Garibotto8,9. 1. EEG and Epilepsy Unit, Neurology Department, University Hospitals of Geneva, Geneva, Switzerland. 2. Neurology Department, Coimbra Hospital and University Centre, Coimbra, Portugal. 3. Faculty of Medicine of Geneva University, Geneva, Switzerland. 4. The Neurodis Foundation, CERMEP Imagerie du Vivant, Lyon, France. 5. King's College London & Guy's and St Thomas' PET Centre, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK. 6. Translational and Integrative Group in Epilepsy Research, Lyon Neuroscience Research Center, INSERM - U1028, CNRS - UMR5292, University Claude Bernard Lyon 1, Lyon, France. 7. Neuroradiology Division, Diagnostic Department, University Hospitals of Geneva, Geneva, Switzerland. 8. Faculty of Medicine of Geneva University, Geneva, Switzerland. valentina.garibotto@hcuge.ch. 9. Nuclear Medicine and Molecular Imaging Division, Diagnostic Department, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland. valentina.garibotto@hcuge.ch.
Abstract
PURPOSE: FDG PET is an established tool in presurgical epilepsy evaluation, but it is most often used selectively in patients with discordant MRI and EEG results. Interpretation is complicated by the presence of remote or multiple areas of hypometabolism, which leads to doubt as to the true location of the seizure onset zone (SOZ) and might have implications for predicting the surgical outcome. In the current study, we determined the sensitivity and specificity of PET localization prospectively in a consecutive unselected cohort of patients with focal epilepsy undergoing in-depth presurgical evaluation. METHODS: A total of 130 patients who underwent PET imaging between 2006 and 2015 matched our inclusion criteria, and of these, 86 were operated on (72% with a favourable surgical outcome, Engel class I). Areas of focal hypometabolism were identified using statistical parametric mapping and concordance with MRI, EEG and intracranial EEG was evaluated. In the surgically treated patients, postsurgical outcome was used as the gold standard for correctness of localization (minimum follow-up 12 months). RESULTS: PET sensitivity and specificity were both 95% in 86 patients with temporal lobe epilepsy (TLE) and 80% and 95%, respectively, in 44 patients with extratemporal epilepsy (ETLE). Significant extratemporal hypometabolism was observed in 17 TLE patients (20%). Temporal hypometabolism was observed in eight ETLE patients (18%). Among the 86 surgically treated patients, 26 (30%) had hypometabolism extending beyond the SOZ. The presence of unilobar hypometabolism, included in the resection, was predictive of complete seizure control (p = 0.007), with an odds ratio of 5.4. CONCLUSION: Additional hypometabolic areas were found in one of five of this group of nonselected patients with focal epilepsy, including patients with "simple" lesional epilepsy, and this finding should prompt further in-depth evaluation of the correlation between EEG findings, semiology and PET. Hypometabolism confined to the epileptogenic zone as defined by EEG and MRI is associated with a favourable postoperative outcome in both TLE and ETLE patients.
PURPOSE: FDG PET is an established tool in presurgical epilepsy evaluation, but it is most often used selectively in patients with discordant MRI and EEG results. Interpretation is complicated by the presence of remote or multiple areas of hypometabolism, which leads to doubt as to the true location of the seizure onset zone (SOZ) and might have implications for predicting the surgical outcome. In the current study, we determined the sensitivity and specificity of PET localization prospectively in a consecutive unselected cohort of patients with focal epilepsy undergoing in-depth presurgical evaluation. METHODS: A total of 130 patients who underwent PET imaging between 2006 and 2015 matched our inclusion criteria, and of these, 86 were operated on (72% with a favourable surgical outcome, Engel class I). Areas of focal hypometabolism were identified using statistical parametric mapping and concordance with MRI, EEG and intracranial EEG was evaluated. In the surgically treated patients, postsurgical outcome was used as the gold standard for correctness of localization (minimum follow-up 12 months). RESULTS: PET sensitivity and specificity were both 95% in 86 patients with temporal lobe epilepsy (TLE) and 80% and 95%, respectively, in 44 patients with extratemporal epilepsy (ETLE). Significant extratemporal hypometabolism was observed in 17 TLEpatients (20%). Temporal hypometabolism was observed in eight ETLE patients (18%). Among the 86 surgically treated patients, 26 (30%) had hypometabolism extending beyond the SOZ. The presence of unilobar hypometabolism, included in the resection, was predictive of complete seizure control (p = 0.007), with an odds ratio of 5.4. CONCLUSION: Additional hypometabolic areas were found in one of five of this group of nonselected patients with focal epilepsy, including patients with "simple" lesional epilepsy, and this finding should prompt further in-depth evaluation of the correlation between EEG findings, semiology and PET. Hypometabolism confined to the epileptogenic zone as defined by EEG and MRI is associated with a favourable postoperative outcome in both TLE and ETLE patients.
Authors: Kun Guo; Bixiao Cui; Kun Shang; Yaqin Hou; Xiaotong Fan; Hongwei Yang; Guoguang Zhao; Jie Lu Journal: Eur Radiol Date: 2021-02-27 Impact factor: 5.315
Authors: Maarten Haemels; Donatienne Van Weehaeghe; Evy Cleeren; Patrick Dupont; Johan van Loon; Tom Theys; Koen Van Laere; Wim Van Paesschen; Karolien Goffin Journal: Acta Neurol Belg Date: 2021-02-05 Impact factor: 2.396
Authors: Eric Guedj; Andrea Varrone; Ronald Boellaard; Nathalie L Albert; Henryk Barthel; Bart van Berckel; Matthias Brendel; Diego Cecchin; Ozgul Ekmekcioglu; Valentina Garibotto; Adriaan A Lammertsma; Ian Law; Iván Peñuelas; Franck Semah; Tatjana Traub-Weidinger; Elsmarieke van de Giessen; Donatienne Van Weehaeghe; Silvia Morbelli Journal: Eur J Nucl Med Mol Imaging Date: 2021-12-09 Impact factor: 10.057