Quantitative SISCOM assessment for epileptogenic zone localization: insights from a multicenter study comparing two...

Area of Science:

• Medical Imaging
• Neurology
• Epilepsy Surgery

Background:

• Pharmacoresistant epilepsy affects one-third of epilepsy patients, necessitating accurate localization of the epileptogenic zone (EZ) for surgical planning.
• Functional imaging, like SPECT ictal-interictal subtraction coregistered to MRI (SISCOM), aids EZ localization but is limited by cost and complexity.
• Statistical Parametric Mapping (SPM) presents a potential cost-effective alternative for SISCOM analysis.

Purpose of the Study:

• To evaluate the efficacy of Statistical Parametric Mapping (SPM) for epileptogenic zone (EZ) localization using SISCOM in pharmacoresistant temporal lobe epilepsy.
• To compare the performance of SPM-based SISCOM with a proprietary software (Analyze) against a reference standard.

Main Methods:

• Retrospective study of 20 pharmacoresistant temporal lobe epilepsy patients who underwent pre-surgical SPECT imaging and had favorable surgical outcomes.
• SISCOM analysis performed using both SPM and Analyze software.
• Comparison of EZ localization results from both methods against anatomopathological findings and clinical outcomes.

Main Results:

• Both SPM and Analyze achieved 70% concordance with the EZ reference standard, showing no significant difference in sensitivity.
• SPM generated smaller, more localized clusters compared to the broader clusters from Analyze.
• Poor concordance (Kappa = 0.0179) was observed between the SPM and Analyze methods, indicating distinct methodological outputs.

Conclusions:

• SISCOM analysis using SPM demonstrates comparable sensitivity to proprietary software for EZ localization in epilepsy surgery.
• SPM-based SISCOM offers a practical, accessible, and cost-effective alternative for pre-surgical planning due to its rapid, semi-automated workflow.
• Further research with larger cohorts is recommended to validate these findings.