Case Study: Laser Probe Destroys Aggressive Brain Tumor

The use of laser interstitial thermal therapy is helping doctors reach and treat formerly inoperable tumors, including deep-seated brain tumors.

Presentation

A 27-year-old patient was 28 weeks pregnant when she had a first seizure, followed by five more. The diagnosis was an astrocytoma, an aggressive tumor of the brain.

Her doctors observed the tumor during her pregnancy; she was no longer having symptoms and the tumor remained stable in size and appearance on MRI. After she delivered her baby, she underwent an open craniotomy with intraoperative MRI. The resection appeared to be complete.

The recurrence, approximately 16 months later, was a grade III astrocytoma on the right side of the brain. It was located in an area that allows for sensation on the left side of the arm and face. Treatment alternatives were a repeat craniotomy, chemotherapy and/or targeted radiation.

Each has drawbacks. Craniotomies do not lead to durable control and have a relatively long recovery period. A new chemotherapy may not work and may be highly toxic, and targeted radiation has an inconsistent response rate.

Gene Barnett, MD, Director of Cleveland Clinic’s Burkhardt Brain Tumor and Neuro-Oncology Center and Gamma Knife Center, says that reducing the number of cancer cells would likely allow the patient’s subsequent treatments to have the best chance of maintaining tumor control. “The tumor was small, and ideally suited to targeting with a laser probe,” he says.

Treatment

The NeuroBlate™ System uses laser interstitial thermal therapy (LITT) to ablate brain tumors from the inside out. Inserted into the brain through a small hole in a patient’s skull, it enabled doctors to better manage this aggressive brain tumor.

The MRI-guided system has been FDA-cleared since 2009. The tip of the probe emits laser energy that heats (up to 160 degrees) and destroys brain tumor tissue and can even be used directionally to protect normal tissue in surrounding areas. Each burst of laser energy lasts from 30 seconds to a few minutes.

The primary risk is some temporary swelling around the treated area. It is usually managed with medication. Manmeet Ahluwalia, MD, Director of Cleveland Clinic’s Brain Metastasis Research Program and Section Head of Neuro-Oncology Outcomes, says the laser surgery has benefits that include shorter recovery time and a faster hospital discharge.

It also allows surgeons to reach formerly inoperable tumors. “Deep-seated brain tumors that may not be amenable to surgical resection can be removed with NeuroBlate,” he says. However, the system can’t currently be used to treat tumors larger than 4.5 cm.

Outcome

After the original craniotomy, the patient had radiation and chemotherapy, with subsequent chemotherapy treatments until the time of recurrence.

The NeuroBlate™procedure was performed on August 27, 2013. It took 3 hours (from skin incision to skin closure). The patient was discharged two days later with temporary foot numbness only. This was followed by chemotherapy that was necessary to try to prevent or retard recurrence.

Treatment was successful. “Today she is neurologically normal with no evidence of tumor recurrence,” says Dr. Barnett.

Conclusion

According to Dr. Barnett, these types of tumors are rarely cured with contemporary treatments. “We focus on obtaining remissions,” he says. Tumor control is typically about 1 to 1.5 years, and survival 4 to 5 years. If the tumor does recur, which Dr. Barnett says is likely, the surgical team would again consider NeuroBlate™ as part of its management strategy.