AUTHOR=Khamwan Kitiwat , Sukprakun Chanan , Limotai Chusak , Jirasakuldej Suda , Jantarato Attapon , Hemachudha Thiravat , Tepmongkol Supatporn 

TITLE=Dynamic 18F-FDG-PET kinetic parameters for epileptogenic zone localization in drug-resistant epilepsy

JOURNAL=Frontiers in Physics

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2023.1233059

DOI=10.3389/fphy.2023.1233059

ISSN=2296-424X

ABSTRACT=<p><bold>Objective:</bold> Precisely localizing the seizure onset zone remains a challenging task in drug-resistant epilepsy (DRE) patients especially given its critical role in successful surgery and effective management. This study aimed to investigate the kinetic parameters of regional <sup>18</sup>F-fluorodeoxyglucose (FDG) uptake in DRE patients, aiming to identify the kinetic parameters best enabling the identification of the epileptogenic region.</p><p><bold>Methods:</bold> Consecutive DRE patients with clinically mandated interictal <sup>18</sup>F-FDG PET/CT were recruited from October 2019 to September 2020 for pre-surgical evaluation. Immediately after injecting <sup>18</sup>F-FDG of 112–179 MBq, dynamic data were acquired for 90 min. The motion correction and resampling to the Montreal atlas was performed in order to generate a transformation matrix. 116 volume of interests (VOIs) and regional time-activity curves (TACs) were generated by employing the automated anatomical labeling (AAL) template using PMOD software. Kinetic parameters of FDG unidirectional blood-brain clearance (<italic>K</italic><sub><italic>1</italic></sub>), efflux (<italic>k</italic><sub><italic>2</italic></sub>), phosphorylation (<italic>k</italic><sub><italic>3</italic></sub>), and net metabolic flux (<italic>K</italic><sub><italic>i</italic></sub>) were derived using irreversible 2-tissue-compartment model with an image-derived input function (IDIF). The kinetic parameters values obtained from all regions were ranked and compared with the presumed epileptogenic zone (EZ).</p><p><bold>Results:</bold> Eleven DRE patients (5 males, 6 females, mean age 35.1 ± 10.2 years) were analyzed. We found that the region with the lowest values of <italic>K</italic><sub><italic>i</italic></sub> provided correct lateralization in 7/7 (100%) of patient with temporal lobe epilepsy (TLE) and the region with the lowest <italic>K</italic><sub><italic>i</italic></sub> and <italic>k</italic><sub><italic>3</italic></sub> parameters showed concordance with the EZ in 100% and 71.4% of patients, respectively.</p><p><bold>Conclusion:</bold> The present parametric approach to the evaluation of FDG-PET may be more sensitive than semi-quantitative approaches for the detection of pathophysiology in the EZ of patients with medically unresponsive TLE in addition to the routine clinical investigations.</p>