Does F-18 FDG-PET substantially alter the surgical decision-making in drug-resistant partial epilepsy?

Ramshekhar N Menon; Ashalatha Radhakrishnan; Ramanathapuram Parameswaran; Bejoy Thomas; Chandrashekharan Kesavadas; Mathew Abraham; George Vilanilam; Sankara P Sarma

doi:10.1016/j.yebeh.2015.07.004

Does F-18 FDG-PET substantially alter the surgical decision-making in drug-resistant partial epilepsy?

Epilepsy Behav. 2015 Oct:51:133-9. doi: 10.1016/j.yebeh.2015.07.004. Epub 2015 Aug 11.

Authors

Ramshekhar N Menon¹, Ashalatha Radhakrishnan², Ramanathapuram Parameswaran³, Bejoy Thomas¹, Chandrashekharan Kesavadas¹, Mathew Abraham¹, George Vilanilam¹, Sankara P Sarma¹

Affiliations

¹ R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
² R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India. Electronic address: drashalatha@sctimst.ac.in.
³ Department of Nuclear Medicine and Imaging, Manipal Hospital, Bangalore, India.

PMID: 26276413
DOI: 10.1016/j.yebeh.2015.07.004

Abstract

Objective: There is a dearth of information on the critical utility of positron emission tomography (PET) in choosing candidates for epilepsy surgery especially in resource-poor countries where it is not freely available. This study aimed to critically analyze the utility of FDG-PET in the presurgical evaluation and surgical selection of patients with DRE based on the results obtained through its use in our comprehensive epilepsy program.

Methods: From 2008 to 2012, 117 patients with drug-resistant epilepsy underwent F-18 fluoro-deoxy-glucose (FDG) PET in our center. We utilized their data to audit the utility of PET in choosing/deferring patients for surgery.

Results: Of the 117 patients (age: 5-42years) who underwent F-18 FDG-PET, 64 had normal MRI, and 53 had lesions. Electroclinical data favored temporal ictal onset in 48 (41%), extratemporal in 60 (51.3%), and uncertain lobar localization in 9 (7.7%). The topography of PET hypometabolism was localizing in 53 (45.3%), lateralizing in 12 (10.3%), and 52 (44.4%) had either normal or discordant results. In the nonlesional group, focal hypometabolism was concordant to the area of ictal onset in 27 (41.5%) versus 38 (58.5%) in the lesional group (p=0.002). Greater concordance was noted in temporal lobe epilepsy (TLE) (78.0%) as compared to extratemporal epilepsy (ETPE) (28.6%) (p<0.001). Positron emission tomography was more concordant in patients with mesial temporal sclerosis than in those with other lesions (82.8% versus 50%) (p=0.033). Positron emission tomography helped in surgical decision-making in 68.8% of TLE and 23.3% of ETPE cases. Overall, 37 patients (31.6%) were directly selected for resective surgery based on PET results.

Conclusions: Positron emission tomography, when utilized judiciously, remained an ancillary tool in the surgical selection of one-third of patients with drug-resistant partial epilepsy, although its utility as an independent tool is not very promising.

Keywords: Cost-effectiveness; Drug-resistant; Epilepsy surgery; FDG-PET; Presurgical evaluation; Surgical outcome.

MeSH terms

Adolescent
Adult
Child
Child, Preschool
Decision Making*
Drug Resistant Epilepsy / diagnostic imaging*
Drug Resistant Epilepsy / surgery
Epilepsies, Partial / diagnostic imaging*
Epilepsies, Partial / surgery
Female
Fluorodeoxyglucose F18*
Humans
Male
Positron-Emission Tomography / methods*
Radiopharmaceuticals*
Seizures / diagnostic imaging
Young Adult

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18