Laser Thermal Ablation

What is laser thermal ablation (LTA)?

In 2015, UPMC Presbyterian became the first hospital in western Pennsylvania to perform LTA (also known as Laser Interstitial Thermal Therapy, or LITT) for epilepsy. LTA is a procedure, like open resection, that may potentially cure a patient’s epilepsy. Rather than removing the seizure focus, however, the focus is ablated, using heat generated from laser light concentrated at the tip of a very thin probe.

How is LTA performed?

Dr. Richardson now routinely employs the Monteris NeuroBlate® System for LTA via an interventional-MRI approach. Procedurally similar to the placement of electrodes during asleep DBS surgery, MRI scans are used to guide alignment of the trajectory and insertion of the probe in real time. Additionally, the ablation itself occurs under MRI guidance: special MRI scans are used to report the temperature of the target tissue and to create a continuous visual representation of the ongoing ablation. In mesial temporal lobe epilepsy, for instance, the ablation is confined to the hippocampus and amygdala, without affecting adjacent brain tissue (see image below).

ROSA-MRI
Postoperative MRI image demonstrating selective ablation of the hippocampus. The contrast-enhancing border of the ablated tissue is delineated with red arrows

Who is a candidate for LTA?

Patients who have had a thorough work up through our comprehensive epilepsy center may be offered LTA once we have localized their seizure focus to a well-defined area. These patients may have temporal lobe epilepsy with an MRI finding of mesial temporal sclerosis (MTS), or they may have a seizure focus in another brain region that has been well pinpointed by intracranial monitoring. We also offer LTA as a treatment for gelastic seizures caused by a hypothalamic hamartoma. LTA also can be used to treat a variety of brain tumors in patients with or without epilepsy.

Ablation of hypothalamic hamartoma

What makes LTA minimally invasive?

The surgery is performed through an incision that is about the size of a pencil’s eraser and is closed with a single absorbable stitch. Many of our patients leave the hospital the day after surgery and quickly resume normal activities, including returning to work. What are the advantages of LTA over traditional resection? LTA offers similar seizure freedom rates as traditional resections such as temporal lobectomy, but LTA’s minimally invasive approach leads to a shorter hospitalization and recovery time. Although the rates of cognitive side effects in our resection cases are low, an additional benefit of LTA over traditional open resection is to further reduce the chance of cognitive side effects from surgery.