# Personalized neurometabolic signature predicts seizure outcomes of laser ablation in mesial temporal lobe epilepsy

## TL;DR

A new personalized neuroimaging tool called pNMS improves laser ablation outcomes for mesial temporal lobe epilepsy by predicting seizure freedom based on metabolic patterns.

## Contribution

The novel pNMS biomarker uses FDG PET imaging to personalize laser ablation planning and predict seizure outcomes in mTLE patients.

## Key findings

- The pNMS threshold of -0.06 metabolic asymmetry significantly predicted seizure outcomes (OR = 1.43, P = 0.02).
- A 39.79% hippocampal ablative rate was associated with seizure freedom (χ² = 10.16, P = 0.001; balanced accuracy = 0.83).
- Hippocampal atrophy most strongly contributes to pNMS expression (Shapley value = -0.026) and correlates with metabolic asymmetry (r = 0.47, P < 0.01).

## Abstract

Mesial temporal lobe epilepsy (mTLE) is a common form of drug-resistant epilepsy and seizure outcomes after minimally invasive laser ablation remain suboptimal. Current imaging-guided strategies often fail to capture individual variability in seizure foci. This study aimed to develop a personalized neuroimaging biomarker to improve surgical planning and predict outcomes.

Thirty patients with mTLE (16 women, 53.3%; age range 17–59 years) who underwent magnetic resonance-guided laser interstitial thermal therapy were retrospectively analyzed. The asymmetry index (AI) from [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET) defined the personalized NeuroMetabolic Signature (pNMS). Prognostic thresholds and optimal pNMS ablative rate were explored using restricted cubic spline (RCS) analysis and Youden’s index as statistical methods for identifying cutoffs. A generalized additive model (GAM) was applied to examine imaging-derived features associated with pNMS.

Here we show that the AI of PET metabolic values significantly predicted seizure outcomes (odds ratio = 1.43, P = 0.02), with −0.06 as the threshold for defining pNMS (P for non-linearity = 0.04). A hippocampal pNMS ablative rate of 39.79% is significantly associated with seizure freedom (Pearson χ2 = 10.16, P = 0.001; balanced accuracy = 0.83). Hippocampal atrophy contributes most to pNMS expression (Shapley value = −0.026), and correlates with metabolic asymmetry (Pearson’s r = 0.47, P < 0.01).

The pNMS provides an individualized imaging marker for guiding laser ablation and predicting postoperative seizure outcomes. This approach supports more precise surgical planning and may improve long-term prognosis in patients with mesial temporal lobe epilepsy.

Mo et al. develop a Personalized NeuroMetabolic Signature (pNMS) from [18F]FDG PET imaging to guide laser ablation in mesial temporal lobe epilepsy. The pNMS offers clinicians a practical tool for surgical planning and helps improve seizure outcomes for patients.

Mesial temporal lobe epilepsy (mTLE) is a common type of refractory epilepsy that does not improve with medicines. One treatment option is a minimally invasive procedure called laser ablation that destroys the brain tissue causing seizures. However, predicting who will benefit from this surgery remains difficult. In this study, we developed a Personalized NeuroMetabolic Signature (pNMS) using [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET) imaging, which shows areas of abnormal metabolism. We studied 30 patients and found that the pNMS could predict seizure outcomes after surgery and identify how much abnormal tissue needed to be removed. These findings suggest that pNMS may facilitate improved laser trajectory planning for clinicians and enhance patients’ surgical outcomes in the future.