Extending Resection to Adjacent MRI-Normal PET Hypometabolism May Improve Postoperative Seizure Freedom
Abstract number :
3.414
Submission category :
9. Surgery / 9B. Pediatrics
Year :
2025
Submission ID :
661
Source :
www.aesnet.org
Presentation date :
12/8/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Nicole Arvanitis, MD – Ann and Robert H Lurie Children's Hospital of Chicago
Nitin Wadhwani, MD – Ann and Robert H Lurie Children's Hospital of Chicago
Jeffrey Raskin, MS, MD – Ann & Robert H. Lurie Children's Hospital of Chicago
Enrique Rojas, CCRC – Ann and Robert H Lurie Children's Hospital of Chicago
Sandi Lam, MD, MBA – Ann & Robert H. Lurie Children's Hospital of Chicago
Elysa Widjaja, MD, MPH – Ann and Robert H Lurie Children's Hospital of Chicago
Joyce Wu, MD – Ann and Robert H Lurie Children's Hospital of Chicago
Rationale: In epilepsy surgery, concordance between Magnetic Resonance Imaging (MRI)-visible lesions and Positron Emission Tomography (PET) hypometabolism is used to guide resection. However, often PET abnormalities extend beyond the MRI lesion. This study investigates whether incomplete resection of PET hypometabolism—when larger than the MRI lesion—is associated with breakthrough seizures, and whether pathological findings differ between MRI–PET concordant regions.
Methods: At a single center children’s hospital, we prospectively followed 10 patients with drug-resistant focal epilepsy who underwent surgical resection and had preoperative video-encephalography (EEG), MRI and PET imaging. MRI+ PET+ and MRI- PET+ tissue samples were marked on BrainLab by neurosurgeons and separately sent to neuropathology, and one neuropathologist read all samples in a blinded fashion. Pre- and postoperative MRI, as well as preoperative PET, were reviewed by a neuroradiologist, and children were categorized into three groups based on lesion concordance and resection extent: (1) Concordant group — complete resection of overlapping MRI and PET abnormalities; (2) MRI-only resection group — resection of MRI lesion only, with PET hypometabolism extending beyond the resected area; (3) Incomplete resection group — incomplete resection of both MRI and PET abnormalities. Seizure outcomes and histopathological findings from resected tissue were analyzed.
Results: All (2/2) patients in the concordant group remained seizure-free postoperatively. 20% (1/5) of patients in the MRI-only resection group experienced postoperative seizures despite complete resection of the MRI lesion. None (3/3) of the patients in the incomplete resection group achieved seizure freedom. Pathology from resected MRI–PET concordant and discordant regions were identical for each patient. Diagnoses from the resected lesions included focal cortical dysplasia, cortical tubers, tumor (glioma and ganglioglioma), as well as ischemia. Postoperative follow-up ranged from 3 to 21 months.
Conclusions: Histopathological similarity between concordant and discordant regions suggests that adjacent unresected PET hypometabolic tissue represents undetected microscopic spatial extension of the MRI abnormality and may contain epileptogenic pathology.Incomplete resection of PET hypometabolism, even when MRI lesions are fully removed, is associated with postoperative seizures. Furthermore, patients with incomplete resection of both MRI and PET abnormalities have the poorest outcomes. These findings highlight the importance of incorporating PET imaging into surgical planning, particularly when MRI lesions are smaller in extent or discordant with PET.
Funding: None
Surgery