Laser Interstitial Thermal Therapy & Stereotactic Laser Ablation

We are proud to be one of the first healthcare systems in the nation to pioneer laser interstitial thermal therapy (LiTT) in the treatment of lesions of the brain. LiTT is a minimally invasive procedure that uses heat to destroy areas of abnormal cells—such as tumors, radiation damage, or cells causing seizures—through a tiny incision smaller than the width of a pencil. LiTT also enables patients who have had complications of previous brain surgery; have comorbidities or a higher-than-normal medical risk; and those who are older to get safe treatment for their brain tumors.

LiTT is also sometimes called stereotactic laser ablation (SLA) or MRI-guided laser ablation (MRGLA).

Why Use LiTT?

LiTT destroys abnormal tissue in the brain using MRI-guided lasers which then heat and selectively damage normal tissues. Compared to traditional open skull surgery (craniotomy), it is minimally invasive surgery.

LiTT/SLA requires only a tiny incision (~ 3 mm), causing less pain and shorter recovery, with far fewer infections and fewer cognitive problems after treatment. Patients can typically go directly home a day after the procedure, rather than transferring to rehab after 3-5 days in the hospital, which is more typical after conventional craniotomy. Many people can return to work within days.

How Does LiTT Work? — An Overview

A LiTT device uses fiberoptic lasers, which are inserted through a small hole in the skull. Using MRI guidance, the surgeon positions the tips of the lasers in the problem area and activates the laser beams. The beams heat up and damage or kill the abnormal tissue. Special MRI sequences measure the temperature of the surrounding brain, helping ensure there is no damage to nearby healthy structures.

Who May Need the LiTT Procedure?

To determine if LiTT is the right approach for your condition, your care team will request and review all your medical records and tests including imaging studies of your brain and sometimes EEGs (brainwave tests). The doctors may recommend further lab work, biopsies and imaging to determine if LiTT is the most appropriate treatment for you. A biopsy can nearly always be performed at the same time as LiTT.

What Conditions Can Be Treated with LiTT?

Brain Tumors

LiTT can make it easier for neurosurgeons to gain access to some tumors that are located close to sensitive structures or deep in the skull, where they would be hard to reach and remove safely through traditional open craniotomy.

In some cases, LiTT may not completely destroy a larger brain tumor but may be able to shrink it or change the texture of the tumor tissue, making it easier and safer to remove through a craniotomy or more susceptible to chemotherapy or radiotherapy.

A large variety of tumors may be treatable with LiTT including primary brain tumors (those that originate in the brain) such as glioblastoma, a dangerously aggressive tumor that frequently recurs and can be life-threatening; certain low and intermediate grade gliomas; and lower grade gliomas and meningiomas located in areas where they would be difficult to remove with traditional surgery.

LiTT can also be used safely and effectively to treat brain metastases (cancer that spreads to the brain from other parts of the body), especially those that are small, located deep in the brain, or grow back after previous radiation treatment or radiosurgery.

Epilepsy

Some forms of epilepsy are caused by a lesion in the brain such as a scar or a malformation of brain tissue or blood vessels. These lesions can cause focal seizures, which may not be controlled with epilepsy medication. LiTT can be used to treat the problem lesions and reduce or eliminate the seizures they cause.

For example, one type of focal epilepsy called mesial temporal lobe epilepsy (MTLE) is often treated with surgery to remove the lesion. When the LiTT procedure is performed instead, studies have shown that the results are nearly as successful—with far fewer complications. If LiTT does not succeed, it does not appear to add any additional risk to more conventional craniotomy.

LiTT can also be used to treat focal epilepsy and other neurological problems caused by certain benign growths and malformations in the brain. LiTT can successfully treat growths such as:

• Periventricular nodular heterotopias – malformation of gray matter cells in the brain
• Hypothalamic hamartomas – benign growths on the hypothalamus
• Cavernous malformations – abnormal collections of blood vessels
• Focal cortical dysplasia – malformed areas in the top layer of the brain

Radiation Necrosis

After people receive stereotactic radiosurgery (sometimes called “gamma knife” or “cyberknife”) for brain cancer, the treatment often leaves behind areas of scar tissue, damaged blood vessels, and dead cells (necrosis). In some cases, radiation necrosis goes away on its own, but sometimes the necrotic areas in the brain can cause swelling, irritation, and a higher risk of infection in the brain. LiTT may be an effective alternative to current treatments to remove the dead tissue, such as surgery, hyperbaric treatments, steroids, blood thinners and other drug therapies. In fact, since 2012, data show that about 75% of people treated with LiTT have had relief from radiation necrosis symptoms.

What Happens During the LiTT Procedure?

• 1. The patient undergoes general anesthesia.
• 2. The surgeon makes a small hole in the scalp and skull at a location that makes it easier to access the affected area. Often, LiTT allows the surgeon to avoid regions where previous incisions were made and start with fresh tissue.
• 3. Using a computer system with MRI images that functions like “GPS for the brain,” the surgeon directs a needle-like fiberoptic laser probe toward the area in the brain where the problem lesion is located. The probe placement is confirmed by the MRI images.
• 4. The laser tip is heated, during which the temperature in the lesion and surrounding brain is carefully monitored with MRI thermometry to avoid overheating the surrounding area. During heating, the probe tip is cooled with saline, which confines the heat to the tumor rather than the surrounding brain.
• 5. Once the area has been treated, the neurosurgeon removes the probe and the incision is closed with one or two stitches.

Recovery After the LiTT Procedure

Patients typically spend only one night in the hospital for observation. Most people can begin to return to their normal activities in about a week—a much shorter time than after craniotomy. Rarely, the LiTT procedure may need to be repeated if, for instance, a brain tumor grows back. Repeated LiTT treatment may be less traumatic than repeated craniotomies for recurring brain tumors.

Side Effects and Complications

At the time of treatment there can be mild swelling of the area treated with LiTT. This swelling can usually be managed medically and will likely go away on its own. The swelling may cause symptoms such as headache.

Speech problems or other neurological changes may occur, but these go away on their own in the majority of cases. Conversely, LiTT rarely causes a cerebrospinal fluid leak, stroke, bleeding, or infection in the brain. The risk of these complications is much less with LiTT than it is with a craniotomy.

Other Cases for LiTT

• Because LiTT is much less invasive than craniotomy, it is also very useful in the treatment of older or debilitated patients, or for tissue that has been left or grown back after previous conventional surgeries.
• LiTT can be used to help shrink tumors as part of palliative care, addressing certain symptoms and improving the patient’s quality of life.