title: Change in presurgical diagnostic imaging evaluation affects subsequent pediatric epilepsy surgery outcome.
abstract: OBJECTIVE
  Since 2008, we have changed our presurgical diagnostic imaging evaluation for medically refractory focal epilepsy to include high-resolution epilepsy protocol on 3 T magnetic resonance imaging (MRI), and combined magnetoencephalography and 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) in selected patients with normal or subtle changes on MRI or discordant diagnostic tests. The aim of this study was to evaluate the effectiveness of the change in imaging practice on epilepsy surgery outcome in a tertiary pediatric epilepsy surgery center.
  
  
  METHODS
  The change in practice occurred in early 2008, and patients were classified based on old or new practice. The patient characteristics, surgical variables, and seizure-free surgical outcome were compared, and the trend in seizure-free outcome over time was assessed.
  
  
  RESULTS
  There was a trend for increased abnormal MRI (92% vs. 86%, respectively, p = 0.062), and increased utilization of FDG-PET (34% vs. 3% respectively, p < 0.001) with new relative to old practice. There were no statistically significant differences in invasive monitoring, location, and type of surgery and histology between the two periods (all p > 0.05). During the old practice, there was no statistically significant change in yearly trend of seizure-free outcome (odds ratio [OR] 0.960, 95% confidence interval [CI] 0.875-1.053, p = 0.386). The change in practice in 2008 was associated with a significant improvement in seizure-free outcome (OR 1.535, 95% CI 1.100-2.142, p = 0.012). During the new practice, there was a significant positive trend in yearly seizure-free outcome (OR 1.219, 95% CI 1.053-1.411, p = 0.008), after adjusting for age at seizure onset, invasive monitoring, location and type of surgery, histology, MRI, magnetoencephalography, and FDG-PET.
  
  
  CONCLUSIONS
  We have found an improvement in seizure-free surgical outcome following the change in imaging practice. This study highlights the importance of optimizing and improving presurgical diagnostic imaging evaluation to improve surgical outcome.
authors.affiliation: Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Rubinger
authors.affiliation: Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Carol
authors.initials: C
authors.lastname: Chan
authors.affiliation: Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Felice
authors.initials: F
authors.lastname: D'Arco
authors.affiliation: Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Rahim
authors.initials: R
authors.lastname: Moineddin
authors.affiliation: Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada.|Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Osama
authors.initials: O
authors.lastname: Muthaffar
authors.affiliation: Department of Neurosurgery, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: James T
authors.initials: JT
authors.lastname: Rutka
authors.affiliation: Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: O Carter
authors.initials: OC
authors.lastname: Snead
authors.affiliation: Department of Psychology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: Smith
authors.affiliation: Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada.|Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Elysa
authors.initials: E
authors.lastname: Widjaja
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D021621:Imaging, Three-Dimensional; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D019635:Neurosurgical Procedures / Q000379:methods*; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: 18-Fluorodeoxyglucose-positron emission tomography; Magnetic resonance imaging; Magnetoencephalography; Seizure-free outcome