A Stereotactic LITT Strategy to Flank Calcifications within Epileptogenic Lesions
Abstract number :
3.407
Submission category :
9. Surgery / 9B. Pediatrics
Year :
2025
Submission ID :
1081
Source :
www.aesnet.org
Presentation date :
12/8/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Nicole De La Pena, MD – Mayo Clinic
Bryan Neth, MD, PhD – Mayo Clinic
Brian Lundstrom, MD PhD – Mayo clinic, Rochester, Minnesota
Timothy Kaufmann, MD, MS – Mayo Clinic
Kai Miller, MD, PhD – Mayo Clinic
Rationale: Laser interstitial thermal therapy (LITT) is an increasingly utilized minimally invasive surgical technique for treating identified lesions or brain regions that are determined to be epileptogenic foci. Calcified lesions pose a significant challenge given the inability to position a laser filament within these calcifications. We present a surgical technique of flanking calcified lesions with laser filaments to encompass the lesion within the thermal ablation zone, illustrated by a case of a patient with a calcified polymorphous low-grade neuroepithelial tumor of the young (PLNTY).
Methods: A 20-25 year old male presented with medically refractory epilepsy with daily focal aware seizures with semiology consisting of episodes of heartburn and a rising sensation that occasionally progressed to brain fog and decreased responsiveness and rare focal impaired awareness seizures. Imaging demonstrated a T2 hypointense, minimally enhancing lesion that was radiographically consistent with a PLNTY tumor in the right posterior parahippocampal/lingual gyrus of the temporal lobe (Figure 1); EEG was concordant with this being the focus of his seizures, with demonstrated maximal right temporal onset. The decision was made to proceed with LITT ablation of this lesion; however, it was noted to be densely calcified on CT imaging (Figure 1). Therefore, two laser filaments were stereotactically positioned to flank the centrally calcified portion of the lesion in the anterior and posterior aspects (Figure 2A). Two laser ablations were then performed, beginning with the anterior trajectory. The two laser filaments were activated to 9.0 Watts ranging from 136 – 143 seconds for treatment.
Results: The thermal ablation zone covered the entirety of the lesion while also demonstrating a thermal shield to the surrounding normal brain parenchyma (Figure 2A). Post-procedure MRI demonstrated peripherally enhancing and overlapping ablation zones within the right posteromedial temporal lobe, which subsumed the calcified mass (Figure 2B). The patient tolerated the procedure well and was discharged on postoperative day 1 without any neurologic or visual field deficits. Follow-up imaging at two months demonstrated a mildly contracted peripherally enhancing ablation zone that continued to encompass the calcified lesion (Figure 2C). The patient has remained seizure free at 6 month follow-up.
Conclusions: Utilizing stereotaxy to position laser filaments to flank epileptogenic lesions that are calcified, as demonstrated in this case, is a strategy to effectively encompass lesions within the ablation zone while also providing a thermal shielding effect to the surrounding normal brain parenchyma. This technique can be utilized in cases where positioning the catheter within the lesion is not viable.
Funding: None
Surgery