Linear accelerator-based radiosurgery is a potential non-invasive alternative to the conventional surgical approach for managing focal epilepsies

Drug-resistant epilepsy types, such as mesial temporal lobe epilepsy (MTLE), are surgically managed through anterior temporal lobectomy (ATL). However, a significant proportion of patients with MTLE do not qualify for ATL owing to the risk of severe side effects, warranting the need for alternatives. Now, Mexican researchers have examined the therapeutic efficacy of non-invasive linear accelerator (LINAC)-based radiosurgery in MTLE. LINAC-based radiosurgery effectively decreased epilepsy and aura frequency but was associated with several side effects.

Epilepsy is a neurological disorder characterized by a sudden aberrant burst of electrical activity in the brain, temporarily disrupting consciousness, muscle control, and behavior. Mesial temporal lobe epilepsy (MTLE) is a type of epilepsy that originates from the deep structures of the temporal lobe, especially the hippocampus, amygdala, and parahippocampal gyrus. The histopathological manifestations of MTLE are neuronal cell loss and alterations in glial cells, which are collectively called hippocampal sclerosis (HS). A significant proportion of patients with MTLE presenting with HS develop drug-resistant epilepsy. Thus, surgical approaches, such as anterior temporal lobectomy (ATL), are adopted to treat these patients. However, several patients are not candidates for ATL owing to the risk of side effects, including cognitive dysfunction, visual field deficits (VFDs), and intracranial hemorrhage. These patients can be potentially managed through non-invasive surgical approaches, such as linear accelerator (LINAC)-based radiosurgery. In LINAC-based radiosurgery, high-dose focused radiation is delivered to the affected region without markedly damaging the surrounding healthy tissues. The therapeutic efficacy of LINAC-based radiosurgery in MTLE has not been evaluated.

To address this knowledge gap, a research team led by Dr. Clotilde Fuentes-Orozco from the Instituto Mexicano del Seguro Social, México, examined the anticonvulsant effects of LINAC-based radiosurgery in patients with MTLE. The findings were published in Volume 12 of the Chinese Neurosurgical Journal on September 8, 2026. “Various radiosurgery approaches, including laser interstitial thermal therapy, radiofrequency ablation, and stereotactic radiosurgery, have been demonstrated to be effective in epilepsy management. In this study, we aimed to harness the non-invasive and targeted nature of LINAC-based stereotactic radiosurgery in managing drug-resistant MTLE. The findings of this study can potentially provide a new tool for neurosurgeons to manage MTLE,” says Dr. Fuentes-Orozco.

The researchers recruited seven adult patients (age: 18–65 years) with drug-resistant unilateral MTLE. Before surgery, the patients underwent clinical evaluation, scalp electroencephalography, and high-resolution magnetic resonance imaging. The patients then underwent LINAC-based radiosurgery and were discharged on the same day. A structured follow-up was implemented with weekly telephone monitoring and monthly outpatient visits. Patients and their families were instructed to maintain a record of seizures and auras (aberrant electrical activity in an alert and conscious state). Clinical, electroencephalographic, and neuroimaging assessments were performed at 3-, 6-, 12-, and 24-months post-surgery.

LINAC-based radiosurgery decreased the seizure frequency by 75.6% but did not completely stop epilepsy. In four patients who had auras before the surgery, the auras decreased by 60.0% at 24 months post-surgery. Although LINAC-based radiosurgery decreased epilepsy frequency, it was associated with several adverse events. Three patients developed VFDs, while one patient developed recent memory impairment. Auras developed in three patients who did not have auras before the surgery. Psychotic episodes requiring intervention were noted in two patients. Headaches were the main systemic symptoms.

Thus, LINAC radiosurgery markedly reduced the frequency of epilepsy and auras. However, this approach is associated with several side effects. “LINAC radiosurgery can be an effective alternative to conventional ATL for patients with drug-resistant MTLE. To enable the clinical application of LINAC radiosurgery in MTLE treatment, controlled clinical trials are warranted with the incorporation of structural and functional neuroimaging biomarkers,” Dr. Fuentes-Orozco remarks.

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