Relationship between PET metabolism and SEEG epileptogenicity in focal lesional epilepsy

• Published in: European journal of nuclear medicine and molecular imaging Vol. 47; no. 13; pp. 3130 - 3142
• Main Authors: Lagarde, Stanislas, Boucekine, Mohamed, McGonigal, Aileen, Carron, Romain, Scavarda, Didier, Trebuchon, Agnès, Milh, Mathieu, Boyer, Laurent, Bartolomei, Fabrice, Guedj, Eric
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2020; Springer Nature B.V; Springer Verlag (Germany) [1976-....]
• Subjects: Cardiology; Convulsions & seizures; EEG; Electroencephalography; Epilepsies, Partial - diagnostic imaging; Epilepsy; Epilepsy - diagnostic imaging; Fluorine isotopes; Fluorodeoxyglucose F18; Human health and pathology; Humans; Hypometabolism; Imaging; Life Sciences; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Metabolism; Neurology; Nuclear Medicine; Oncology; Original Article; Orthopedics; Performance evaluation; Positron emission tomography; Prognosis; Propagation; Radiology; Seizures; PET metabolism; SEEG; Focal epilepsy
• ISSN: 1619-7070; 1619-7089; 1619-7089
• DOI: 10.1007/s00259-020-04791-1

Purpose This study aims to evaluate the performance of 18 F-FDG PET for distinguishing the epileptogenic zone (EZ) from propagation and non-involved zones at brain area level, as defined using stereo-EEG (SEEG), in patients with pharmacoresistant epilepsy due to malformations of cortical development (MCD). Additionally, we seek to determine the relationship between 18 F-FDG-PET data and post-surgical seizure outcome. Methods Thirty-eight patients with MCD were explored with 18 F-FDG PET and SEEG. We compared PET metabolism of each patient to a control population of healthy subjects. Based on MRI and SEEG, we separated 4 distinct zones at individual level: lesional, epileptogenic non-lesional, propagation, and non-involved. Then, we analysed (1) difference of PET metabolism within these four distinct zones; (2) performance of PET in defining the EZ within the SEEG-sampled areas; and (3) relation between extension of PET hypometabolism and post-surgical seizure outcome. Results We found (1) a gradient of PET hypometabolism from non-involved to propagation, then to epileptogenic and lesional zones ( p  < 0.001); (2) good performance of PET in defining the EZ (AUC of ROC curve = 0.82); (3) poorer post-surgical prognosis associated with PET hypometabolism extension beyond SEEG sampling ( p  = 0.024). Conclusion 18 F-FDG-PET has good accuracy in determining EZ in patients with MCD even if the hypometabolism is not limited to the EZ. Furthermore, hypometabolic extension is unfavourably associated with post-surgical prognosis.