title: The extent of resection of FDG-PET hypometabolism relates to outcome of temporal lobectomy.
abstract: A significant minority of patients undergoing surgery for medically refractory non-lesional temporal lobe epilepsy (TLE) continue to have seizures, but the reasons for this are uncertain. Fluorodeoxyglucose (FDG) PET shows hypometabolism in a majority of patients with non-lesional TLE, even in the absence of hippocampal atrophy. We examined whether the extent of resection of the area of FDG-PET hypometabolism influenced outcome following surgery for non-lesional TLE. Twenty-six patients who underwent temporal lobectomy for medically refractory TLE with at least 12 months follow-up were studied. The preoperative FDG-PET was compared with 20 non-epileptic controls using SPM99 to identify regions of significant hypometabolism (P < 0.0005, cluster > 200). This image was then co-registered to the postoperative MRI scan. The volume of the FDG-PET hypometabolism that lay within the area of the resected temporal lobe was calculated. The volume of temporal lobe resected was also calculated. Patients with a good outcome had a greater proportion of the total FDG-PET hypometabolism volume resected than those with a poor outcome (24.1% versus 11.8%, P = 0.02). There was no significant difference between the groups in the volume of temporal lobe resected (P = 0.86). Multivariate regression demonstrated that the extent of resection of the hypometabolism significantly correlated with outcome (P = 0.03), independent of the presence of hippocampal sclerosis (P = 0.03) and total brain volume of hypometabolism (P = 0.45). The extent of resection of the region of hypometabolism on the preoperative FDG-PET is predictive of outcome following surgery for non-lesional TLE. Strategies that tailor resection extent to regional hypometabolism may warrant further evaluation.
authors.affiliation: The Department of Medicine, The University of Melbourne, Royal Parade, Parkville, Victoria 3050, Australia. abvinton1@optusnet.com.au
authors.forename: Anita B
authors.initials: AB
authors.lastname: Vinton
authors.forename: Ross
authors.initials: R
authors.lastname: Carne
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Hicks
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Desmond
authors.forename: Christine
authors.initials: C
authors.lastname: Kilpatrick
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Kaye
authors.forename: Terence J
authors.initials: TJ
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D000368:Aged; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D001931:Brain Mapping / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D011379:Prognosis; D019275:Radiopharmaceuticals; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18