Frequently Asked Questions

What is MRI-guided laser interstitial therapy?

MRI-guided laser interstitial therapy uses real-time imaging to deliver a laser probe to a specific area deep within the brain. This energy from the laser then “cooks” the damaged area of the brain, leaving the surrounding tissue unharmed.

Find out more about brain laser ablation technology

What conditions does this therapy treat? 

Conditions the MRI-guided laser interstitial therapy targets include:

  • Inoperable tumors that are newly diagnosed or after treatment (biopsy, radiation, and/or chemotherapy)
  • Recurrent tumors (high grade primary brain tumors and metastases)
  • Recurrent metastatic tumors after stereotactic radiation (e.g. Gamma Knife or Cyber Knife therapy)
  • Radiation necrosis (after radiation such as Gamma Knife therapy or whole brain radiotherapy)
  • Certain forms of epilepsy (e.g. amygdalohippocampectomy candidates) For more information, visit Barnes-Jewish Hospital and Washington University’s Epilepsy Center.
  • Pediatric cases that share similar indications as adults

For more information, please visit our Conditions Treated section.

How many procedures has the Brain Laser Center performed? 

Nearly 250 cases have been performed, making the Washington University Brain Laser Center one of the busiest centers in the world.

What should I keep in mind when considering brain laser therapy?

Main factors to keep in mind include:

  • A multidisciplinary team with experienced clinicians: At the Brain laser center our team of experts collaborates across disciplines and are leaders in their fields.
  • Advanced technology: We are constantly testing and improving on the technologies we use. Please also visit our Research & Trials section for more information or to get involved in ongoing research.
Who do I call to make an appointment? 

For a referral to the Brain Laser Center, or to make an appointment, please call:

What do I need to bring to my appointment? 

If possible, please provide

  • A demographic sheet with a contact name, phone number, complete medication list, copy of insurance card(s), office notes from the treating physician/oncologist (that document a formal diagnosis/grade, exact location of tumor, symptoms and treatment type/start date/schedule, etc.).
  • CT/MRI scans (in DICOM format) and associated radiology written reports. Any biopsy/pathology reports would also be helpful.
  • CDs of any imaging/scans.
  • Medical records for any previous treatments of the condition for which you are being treated.

See Your Visit page for information about what to expect when you come to the Brain Laser Center.

Where do I go for my appointment? 

The Brain Laser Center is located at:
Center for Advanced Medicine
4921 Parkview Place, Suite 6C

Brain Laser Center Map

View full map here.

For more information on getting to the Center for Advanced Medicine and parking, visit the Washington University Physicians site.

Mailing address:
Washington University School of Medicine
660 S. Euclid Ave., Campus Box 8057
St. Louis, MO 63110-1093

Phone: 314-747-6146
Fax: 314-362-2107

See Your Visit page for information about what to expect when you come to the Brain Laser Center.

Who will perform my surgery?

Your surgery will be performed by one of our team of physicians, which includes highly skilled health care professionals from a range of disciplines such as surgery, interventional neurology, oncology and many others.

Once you have scheduled your appointment you will see Eric C. Leuthardt, MD, professor of neurological surgery and director of the center, who will discuss treatment options with you and help determine who is best suited to perform your surgery.

Please see a list of our physicians for more information on the Brain Laser Center’s team.

Video Frequently Asked Questions

Eric C. Leuthardt, MD, director of the Brain Laser Center, provides more in depth information about brain laser therapy. View videos* and/or read the transcripts below:

What is laser ablation therapy?

Laser ablation therapy is a seamless integration of a number of different modern technologies ranging from a laser to intraoperative robotics to intraoperative MRI. When you look at the device, it looks like a crochet needle. Basically it’s a small probe and, at the tip, there’s a laser. And we insert that laser into a very small incision in the scalp and a hole through the skull and we insert it into the center of the tumor. Then an intraoperative robot basically controls the position of that laser tip so that when the patient’s in the intraoperative MRI, we can control the laser so that we can shape and mold the heating to kill that tumor in a very conformal fashion. And then, at the end of it, we pull that probe out and you have a single incision – that’s about the length of my fingernail – that we can close with a single stitch.

What are the different types of brain tumors?

When we think about brain tumors, we often distinguish them into two broad categories. Primary brain tumors, which are tumors that are coming from the brain, and what I mean by that is that some cell in the brain has become genetically altered and it has uncontrolled growth. So, again, it’s a tumor that has derived from some cell in the brain. That’s a primary brain tumor. The second category is a metastatic brain tumor and these are tumors such as lung cancer, breast cancer, colon cancer that have grown from some other part of the body outside the brain, but have metastasized or spread to the brain.

For what indications do you use laser ablation therapy?

There are a number of clinical diagnoses and patient populations who I feel are great candidates for this type of approach. One of the most common ones that we see are patients with primary brain tumors. These include tumors that are difficult to access, meaning tumors that are deep in the brain and cannot be reached through open surgical procedures (such as thalamic glioblastomas or insular gliomas, which are two common names that you’ll hear).

Another category of primary brain tumor where I think this offers a great therapy is for recurrent glioblastomas or recurrent malignant primary brain tumors. These are often patients who have had quite a number of therapies previously, meaning previous surgery, previous radiation, previous chemotherapy. When these patients have a small recurrence, it becomes very risky to go through another open surgery because they’re already somewhat frail and the ability to go in and precisely treat just those that are of local recurrence provides a nice alternative.

Another category is brain metastases. These are tumors that have spread from a different part of the body and have been treated with radiation and have now come back and are no longer candidates for radiation.

Another category is when radiation itself causes an inflammatory, irritating process known as radiation necrosis. That sometimes can also be treated with laser therapy.

Finally, and a growing indication of brain laser therapy, is for epilepsy. These are patients who have some part of their brain that is irritating the rest of the brain by creating a lot of noise and pathologic signals. And so by placing the laser in that zone and killing that irritating lesion, we can significantly impact their epilepsy.

Does it matter where a brain lesion/abnormality is located in the brain?

The location of a brain tumor plays an important role in how we decide on what the surgical strategy is for treating that tumor. If it’s superficial or not terribly close to any critical structures, open surgical procedures are commonly employed. This involves making a larger incision in the scalp, a window into the skull, and making a small hole in the brain. Now, as the tumor becomes deeper in location – meaning closer to the center of the brain or close to critical locations such as motor and speech areas – then the risk profile of open surgical procedures increases and that’s where minimally invasive approaches – such as laser therapy – become an optimal approach to treating some of these types of tumors.

What has been your experience with laser ablation therapy?

My experience with laser ablation therapy has been overwhelmingly positive – whether it is the low morbidity with the procedure, the short hospital stays, the ability to control the patient’s cancer if they’ve got a tumor diagnosis, or the ability to cure their epilepsy. All of these things combine together, I think, to give a high quality of life option with a very low risk treatment, which I think has really made it the “go-to” choice at my institution for a number of different diagnoses.

What should a patient expect after the procedure?

The procedure itself often takes several hours under general anesthesia and patients will – to a degree – wake up groggy and that’s normal. Most patients go home around 1-2 days after surgery. The pain tends to be minimal. It’s usually a single stitch. They have to keep the incision dry for about a week, but otherwise they’re able to get back to normal activities by around 1-2 weeks. 

What is the advantage of a minimally invasive approach?

A minimally invasive procedure has a number of advantages for the patient. First off, when you think about having to make a large incision in the scalp, making a hole in the skull, the bigger it is the more trauma it puts that patient’s body through. When you think about the brain itself, if you’ve got to make a larger surgical pathway in the brain, there’s a higher likelihood that there’s some level of brain recovery that needs to happen – meaning that they have to have some level of cognitive recovery. So oftentimes with classical surgical procedures, it often takes weeks, really, for the patients to start feeling like themselves. Now if you have a smaller surgical footprint, meaning small incision, small hole in the skull, then it’s a lot less to put the patient through in terms of global stress to their body, pain after surgery, and – if you’re just treating the tumor and not significantly damaging the brain to get there – then you’re also having a reduced likelihood for surgical morbidity. Meaning it’s less likely that they’re going to need cognitive rehab after surgery.

What are some of the risks associated with laser ablation therapy?

Anytime we do surgery, I’m always going to give a standard list of complications that can happen anytime you cut the skin and penetrate the brain. Those risks include: bleeding (with any surgery), infection (with any surgery), the risk of something catastrophic happening with surgery (including coma, death, or paralysis). And that’s true whether it’s an open surgery or a laser surgery. Now when I think about laser surgery in particular, some of the things we can sometimes see with the laser is that we can have swelling after surgery that takes approximately 7-10 days to resolve and this tends to be self-limited and improves with steroids. And anytime we’re treating close to a functional area, there are always risks that we could injure one of those areas, even though we’re using a minimally invasive approach that gives us a tailored treatment.

What does a craniotomy procedure involve?

craniotomy is a very classic surgical approach that we use to treat brain tumors. Typically this involves making an incision in the scalp, making a window in the bone – where we take a bone flap out – and exposing the surface of the brain to get access to the tumor that’s deeper in the brain. That often involves making some type of hole in the brain so that we can then take that tumor out. After the tumor’s been taken out, the bone is placed back, and then we close the scalp.

Is laser ablation therapy a new technology?

Interestingly, laser therapy is both a technology that’s been around, but that’s also new. It’s old in the sense that people have been using lasers to treat tumors for quite some time – close to 10-20 years. Where it’s new is in its application in the brain, where we’re combining it with advanced imaging using the intraoperative MRI or an MRI scanner to image in real time so that we can do very precise therapy to kill the tumor cells in a very specific anatomic way, and do it in real time, so the surgeon has very specific control over this therapy while it’s happening.

Define the term “Progression Free Survival.”

Progression free survival is a term that’s commonly used in the scientific and medical literature. What that is a measurement of is the time interval from the time of treatment to the time that the tumor comes back. So it’s an important measure to know how effective that therapy is in controlling the cancer disease.

How can laser therapy address epilepsy?

There’s a number of different types of epilepsy. Specifically, there’s what we call lesional epilepsy where a part of the brain – or an area of the brain – is behaving abnormally. Essentially it’s creating disruptive noise – which we call a seizure – that causes people to lose consciousness, causes people to have abnormal behavior, alterations of awareness and be very disruptive to people’s lives. Removing that lesion in the brain – that abnormal part of brain – can significantly impact their epilepsy. The laser provides a minimally invasive option to treat and ablate that lesion.

If you were advising a member of your own family, what would you say?

This is a common question for me: What would I do if it was a family member of mine? And also, a lot of times, we are dealing with diagnoses that are not curable. These are sometimes malignant brain tumors that we cannot fully cure, but we can only slow down with all the therapies that we have. And that’s where quality of life becomes critical, because for the time that these people have left, we need to make sure that every moment is as good as it can be. That they can spend the time they want with their family, they can do the things that they enjoy, that really give them a high quality for the moments that they have. And so I think that’s where laser therapy plays a critical role, because oftentimes we can kick the can further down the road by treating the recurrence, by treating the tumor upfront, in a minimally invasive fashion that has minimal morbidity and allows them to return to their lifestyle as soon as possible versus open surgeries which could potentially take a lot longer to recover from.

Your visit to the Brain Laser Center

See Your Visit page for information about what to expect when you come to the Brain Laser Center.


For a list of complex terminology, view the Glossary or visit the National Cancer Institute’s Dictionary of Cancer Terms.

*Videos produced by Monteris