Introduction: 36 fibers were placed in 28 patients for Laser Interstitial Thermal Therapy (LITT). Outcomes were assessed to optimize methods.
Methods: Visualase probes were placed using MRI guidance (4), frameless stereotaxy (FS, 7), frame-based placement (23), and directly (2). LITT was performed in MRI. Patients had tumors(11), medial temporal lobe epilepsy (MTLE, 15) and hypothalamic hamartomas (HH, 2).
Results: For MTLE, favorable Engel (1+2) outcome was seen in 14/15, 8/11, 4/9 and 1/2 at 3 months, 6 months, 1 year and 2 years, with one failure undergoing temporal lobectomy. 6/9 tumor patients had progression-free survival, with one requiring subsequent craniotomy.
Malposition in an MTLE patient occurred once when a 1.8mm alignment rod was not used to create a track. In tumor patients, 2/7 probes were malpositioned when using FS, but none using a frame. Two nonoperative hematomas occurred in patients with MTLE: one intraparenchymal secondary to twist drill plunging at a non-orthogonal entry resulting in superior quadrantanopsia. An intraventricular hemorrhage occurred in a patient with excessive movement in MRI under local anesthesia.
Two complications resulted from the LITT itself. One patient with a glioblastoma of the deep vermis developed bilateral CN 6 and 7 palsies. A patient with a filum terminale ependymoma developed paraparesis the day after treatment.
Conclusions: LITT may be used to treat brain tumors, HH and MTLE with comparable outcomes to open procedures.
To optimize outcome, we suggest:
1. Use of an alignment rod to create a tract for deep structures
2. Use of frame-based techniques
3. Orthogonal entry of the laser probe
4. General anesthesia to reduce movement during occipital bolt placement
5. Caution for spinal tumors
6. Maintain a margin beyond the treatment region near critical structures (e.g. the brain stem)
Patient Care: Laser ablation is an minimally invasive option for neurosurgical treatment that is an alternative to craniotomy. We show good results in patients who suffer from epilepsy and brain tumors in disease control. Our experience also can provide guidance for compication avoidance.
Learning Objectives: Understand indications for laser ablation
Improve clinical outcome of patients undergoing laser ablation
Reduce complications related to the laser ablation procdure