Clinical Scorecard: A Stepwise Approach to Robot-Assisted Stereotactic Biopsy and Laser Interstitial Thermal Therapy for Epilepsy Linked to Brain Tumors

At a Glance

Key Highlights

• LITT produces controlled spheroid-shaped thermal lesions via a 980 nm laser fiber with real-time MR thermometry monitoring.
• Robot-assisted stereotactic biopsy enables precise histomolecular diagnosis prior to LITT in deep-seated or difficult-to-access brain tumors.
• Thermal barriers such as fissures, sulci, blood vessels, and CSF spaces affect heat diffusion and must be considered during planning.

Guideline-Based Recommendations

Diagnosis

• Perform presurgical evaluation including MRI to identify tumor characteristics and epileptogenic focus.
• Use robot-assisted stereotactic biopsy with intraoperative histological smear to confirm diagnosis and minimize sample number.

Management

• Employ a stepwise approach: first robot-assisted biopsy, then placement of laser fiber for LITT.
• Use MR thermometry for real-time temperature monitoring to achieve irreversible thermal ablation at 52 °C threshold.
• Plan surgical trajectory considering anatomical thermal barriers and sinks to optimize ablation extent.

Monitoring & Follow-up

• Confirm fiber positioning and absence of hemorrhage or air bubbles with T1-weighted MRI post-biopsy.
• Monitor ablation zone and brain temperature in real-time using MR thermometry during LITT.
• Use diffusion-weighted and T2-FLAIR MRI sequences post-ablation to confirm cytotoxic edema and contrast-enhanced T1 to assess blood–brain barrier disruption.

Risks

• Air bubbles from biopsy can cause signal dropout and interfere with MR thermometry monitoring.
• Thermal sinks such as blood vessels and CSF spaces may reduce ablation efficacy.
• Potential for hemorrhage or tissue damage if trajectory or temperature control is inadequate.

Patient & Prescribing Data

Patients with drug-resistant focal epilepsy linked to deep-seated brain tumors, including dysembryoplastic neuroepithelial tumors

LITT combined with robot-assisted biopsy offers a minimally invasive option when craniotomy is challenging, enabling targeted ablation with histological confirmation.

Clinical Best Practices

• Use skull-mounted fiducial markers and intraoperative CT for accurate registration and robotic guidance.
• Secure head in Mayfield clamp and use ROSA robotic system for precise instrument alignment.
• Perform minimal hair shaving and use progressively smaller reducers for burr hole drilling and dura opening.
• Obtain two tissue samples with rapid suction for intraoperative histology to confirm diagnosis.
• Calculate and mark catheter length precisely to match target depth minus reducer height.
• Advance cooling sheath and secure fiber with guidance bolt before MRI transport.
• Monitor for air bubbles and hemorrhage post-biopsy and adjust procedure accordingly.
• Deliver multiple adjacent spheroid ablations by retracting fiber to cover entire target volume.

References

• Laser Interstitial Thermal Therapy in Neurosurgery
• ROSA Robotic System for Stereotactic Neurosurgery