Stepwise Robot-Assisted Biopsy and LITT for Epilepsy-Linked Brain Tumors

Overview

This report details a combined robot-assisted stereotactic biopsy and laser interstitial thermal therapy (LITT) approach for treating drug-resistant epilepsy associated with deep-seated brain tumors. The technique enables precise histological diagnosis followed by minimally invasive thermal ablation, with real-time MRI thermometry ensuring controlled lesioning.

Background

Laser Interstitial Thermal Therapy (LITT) is a minimally invasive technique that produces controlled thermal lesions to treat focal brain pathologies, including tumors and cortical malformations. It is particularly useful for lesions located in eloquent or deep brain regions where open surgery poses high risks. Real-time MR thermometry allows precise monitoring of tissue temperature to achieve effective ablation while sparing surrounding structures. Robot-assisted stereotactic systems facilitate accurate targeting for both biopsy and laser fiber placement.

Data Highlights

The procedure was performed on a 39-year-old patient with drug-resistant focal epilepsy linked to a right posterior cingulate dysembryoplastic neuroepithelial tumor (DNET). Two biopsy samples measuring 10 mm × 1 mm were obtained. Intraoperative MRI confirmed correct fiber placement and absence of hemorrhage. Three air bubbles were noted within the lesion but did not interfere with MR thermometry. Two adjacent spheroid-shaped ablations were delivered along the fiber axis to encompass the entire target volume, confirmed by post-ablation diffusion-weighted and T2-FLAIR imaging.

Key Findings

• LITT produces a spheroid-shaped thermal lesion via a 980 nm laser fiber positioned at the target's deepest point.
• Fissures, sulci, blood vessels, and CSF spaces act as thermal barriers or sinks, influencing ablation extent.
• Robot-assisted stereotactic biopsy allows precise sampling with minimal tissue disruption, confirmed by intraoperative histology.
• MR thermometry provides real-time temperature mapping to control ablation and avoid damage to adjacent structures.
• Air bubbles from biopsy can cause localized MRI signal dropout but did not affect ablation monitoring in this case.
• Two adjacent ablations along the fiber axis effectively covered the tumor volume without procedural delay.

Clinical Implications

This combined robot-assisted biopsy and LITT approach offers a minimally invasive option for patients with deep-seated, difficult-to-access brain tumors causing epilepsy. Real-time MRI guidance ensures precise targeting and controlled ablation, potentially reducing surgical morbidity. Awareness of anatomical thermal barriers and sinks is critical for planning effective treatment zones.

Conclusion

Robot-assisted stereotactic biopsy followed by LITT under MR thermometry guidance is a feasible and precise technique for treating epilepsy linked to deep brain tumors. This stepwise approach enables safe histological diagnosis and effective minimally invasive ablation.

References

1. Article Source 2024 -- A Stepwise Approach to Robot-Assisted Stereotactic Biopsy and Laser Interstitial Thermal Therapy for Epilepsy Linked to Brain Tumors