This article is more than 5 years old. Information may no longer be current.
MD Anderson treats inoperable brain, spinal tumors with refined laser interstitial thermal therapy
Click Here to Manage Email Alerts
The University of Texas MD Anderson Cancer Center is one of a few select cancer centers in the United States offering a refined version of laser interstitial thermal therapy to treat patients with brain and spinal cord tumors.
Laser interstitial thermal therapy (LITT) is designed to heat and destroy tumor cells safely, regardless of tumor size and location.
“Previously, we would have to make a very large incision, take off part of the skull, and open and dissect through the brain to get to the lesion. In some very deep-seated areas of the brain, it is very difficult to do this and sometimes impossible,” Ganesh Rao, MD, associate professor of neurosurgery in the department of neurosurgery at The University of Texas MD Anderson Cancer Center, told HemOnc Today. “[Laser interstitial thermal therapy] gives us the ability to laser probe into the tumor, and the thermal energy that is deployed by the laser is destructive to the tumor tissue.”
HemOnc Today spoke with Rao about the unique nature of the technique, the patient population that benefits most, and whether more widespread use is anticipated in the near future.
Question: What make s this technique unique?
Answer: Lasers in medicine have been used a lot over the past few years, and use of laser technology to treat tumors has been happening for a while. What is unique about this technique is that, in the brain, we finally have the tools and software to control how the heat is distributed throughout the brain so we do not damage functioning normal brain.
Q: How does the technique work?
A: LITT requires a trip to the operating room and a general anesthetic. The technique is performed in an MRI scanner. For hospitals that have an MRI scanner built into the operating room, we can easily perform this procedure in one setting. Some hospitals do not have an MRI scanner built into the operating room and, in this case, the patient will have the probe placed in the operating room and then they are transported to a MRI scanner in the radiology department. The work flows by first having the patient admitted to the operating room, then they go under anesthesia. We roughly estimate where the probe can go (we do have to shave a little bit of the hair so that we can see the scalp). At MD Anderson, we place the patient in the MRI scanner so that we can get a registration scan that allows us to use the navigation system to be very precise with where we are placing the laser probe. The patient is then taken out of the MRI scanner and we register their head to the computer system. There are a couple of ways to put the laser fiber in. We usually create a trajectory on a workstation that gives us a point and a target and then we make a very small incision in the scalp, maybe 2 mm to 3 mm in length, with a very narrow drill bit. Then, using this navigation system, we place the fibers to the target. This is all essentially done by viewing what we are doing on a monitor. The screen shows the position. We do a final scan to verify placement and then we start heating up the tumor in real time. Once we are satisfied that we treated the whole tumor, we withdraw the probe, close the incision and wake the patient.
Q: Are there certain patients who benefit most from the technique?
A: Yes. The most common patient population we are seeing — and those who are having the best results — are patients who have had prior radiation to the brain. For some patients who have metastases from other cancers that have spread to the brain, they often are treated with radiation and have had some type of stereotactic radiation — the most common radiation used for metastatic disease. What can happen over time is that patients can develop necrosis, a reaction to that radiation. We do not fully understand why this is happening, but we think that the immune system or inflammatory cells in the brain are just trying to clear the dead tissue and it ends up almost looking like a tumor or massive inflammation in the brain. This can be very debilitating. We have to put people on steroids and try to suppress the necrosis. Sometimes this works, but there are some cases where either the steroids are not working or the patient has been prescribed immunotherapy and the oncologists do not want to use steroids. In this circumstance, LITT is an excellent option for these patients. The other population of patients that benefit most from this are those who have primary brain tumors, such as gliomas or glioblastomas that start in the brain. This technique seems to offer the patient an ablative treatment before they go under radiation and chemotherapy.
Q: What have outcomes been like so far?
A : We, along with several other groups, have published on our different patient populations. At least from my perspective, patients with post-radiosurgery necrosis are the patients who have benefited the most from this technique. It is a way to treat the malignant necrosis so that they can get off of steroids and get back on chemotherapy. We really had no other options for these patients before other than putting them through an operation. This has been a very useful technique for these patients. The majority of patients are demonstrating a significant reduction in the size of the mass after this treatment. For the gliomas, use of the technique is still pretty new. Others have shown a reduction in the size of the tumor, but it takes more time to show this reduction. So, I think the jury is still out on this technique for gliomas, but it certainly is something that we have been doing more and more of. Before, we did not have an option for them.
Q: W hat other major cancer centers offer the technique?
A: Other than MD Anderson, institutions offering LITT include Cleveland Clinic, Washington University in St. Louis, University of Florida, University of California, San Diego, and others. It is becoming more prevalent throughout the country. A lot of the first studies assessing LITT were conducted at MD Anderson back in 2009. But, it really started to take off in 2011 — my first case was in 2011. After this, I did not perform any procedures with the technique for a long time, until recently. It has only been within the past couple of years that the system has been refined and is able to be used more easily. Within the past year and a half it has been used quite a bit.
Q: How hopeful are you that this will become mainstream and more centers will offer the technique ?
A: We are already seeing this. It is becoming more widely used. At MD Anderson, we have a fellowship program where we train neurosurgeons to perform cancer surgeries after they have finished residency. Many of them, when they get hired, are asking for this as a tool because they have seen how effective this is. My guess is that within the next few years, we will see LITT become much more available across the country.
Q: Is there anything else that you would like to mention ?
A: Oncologists should reach out to centers that have had a lot of experience with performing this technique. There is some value in the experience of knowing what to treat and how to treat because it is still a very new technique. Until LITT becomes more mainstream, the larger centers that perform it are probably the best bet. – by Jennifer Southall
For more information:
Ganesh Rao, MD, can be reached at The University of Texas MD Anderson Cancer Center, Blvd., FC7.2000, Unit Number: 442, Houston, TX 77030; email: grao@mdanderson.org.
Disclosure: Rao reports no relevant financial disclosures.