New data from an ongoing study offers preliminary evidence that Monteris Medical's NeuroBlate System may be a viable solution for brain tumors that were previously considered inoperable.

Amanda Pedersen

New data from an ongoing study offers preliminary evidence that Monteris Medical's NeuroBlate System may be a viable solution for brain tumors that were previously considered inoperable.

The words "brain" and "tumor" are all too often accompanied by the word "inoperable," but a growing body of evidence suggests that laser ablation may be a viable solution for a lot of patients who don't have a lot of other options.

New data from three separate studies supporting Monteris Medical's NeuroBlate System for primary and metastatic brain tumors were presented recently at the annual meeting of the American Association of Neurological Surgeons (AANS) in Los Angeles.

The NeuroBlate was selected as a gold winning product in the "Surgical Equipment, Instruments, and Supplies" category of the 2015 Medical Design Excellence Awards. The system, which is FDA cleared, combines real-time MRI and software-based visualization to enable laser interstitial thermal therapy (LITT).

Andrew Sloan, MD, director of the Brain Tumor & Neuro-Oncology Center at the University Hospitals Cleveland Medical Center, was a principal investigator on the Laser Ablation in Stereotactic Neurosurgery (LAIS) study, which evaluated the clinical use of LITT with NeuroBlate for gliomas (the most common type of primary brain tumor), and metastatic brain lesions. Patients enrolled in the LAIS study had brain lesions ablated between 2011 and 2015 at one of nine U.S. centers.

Sloan told Qmed that he uses the technology to treat tumors he wouldn't normally be able to treat using conventional methods, either because they're too deep, or because it's too hard to tell if it is a recurrent brain tumor or a radiation injury from an earlier treatment (in which case the last thing a physician would want to do is give that patient more radiation, he said).

But LITT is effective at addressing both types of lesions, Sloan said, so it doesn't matter if it's a tumor or a radiation injury.

At AANS, Sloan presented a multicenter retrospective analysis of LITT for glioma, which described the results of 97 patients whose lesions were ablated with the NeuroBlate System. Of the lesions analyzed, 48% were deep-seated, 57.8% were considered inoperable, and 1% were not suitable for chemotherapy (because the patient was unable to tolerate additional chemo.

In other words, he said, the surgeons in 57.8% of those cases felt that "these were inoperable tumors, they would not dare to do this using a conventional therapy."

Sloan said about half of the patients in the glioma cohort of the LAIS study also had other significant medical problems, which means they may not have been good candidates for conventional brain surgery. A lot of these patients (about 52%) had also been treated for a brain tumor before, either with a craniotomy, radiation therapy, or LITT.

Sloan and his colleagues found that patients in the glioma cohort survived for about 18.5 months after the procedure, which is equal to or better than the survival outcomes associated with other interventions for gliomas.

The investigators also analyzed a second set of data from the LAISE study, which included 40 patients with brain metastasis (cases in which the tumor in the patient's brain was not their primary tumor). These patients survived about 13.8 months after the procedure, which also compares favorably to survival outcomes associated with other approaches for brain metastasis.

One particularly interesting finding from the analysis of this patient cohort, Sloan said, is that although the patients only lived for about 13.8 months after the procedure, 95% of them died because of their systemic tumor, rather than the tumor in their brain.

"Even 10 years ago, if you had a brain metastasis, the most likely cause of death was a brain metastasis," Sloan said. "We feel pretty good that 95% of them were saved from a neurologic death, although most of them did die of their cancer eventually. That's really a game changer for us in the brain metastasis group."

Again, he said, a lot of these patients had inoperable tumors, and/or were unable to tolerate additional radiotherapy or chemotherapy. And most of them (about 70%) had been treated for a brain tumor before.

"We've taken this very complicated patient group, who often doesn't have a lot of options, and we've treated them in a way that, for the most part, markedly extends survival and quality of life," Sloan said. "I wouldn't say it's risk free, but the risks are very manageable, and very reasonable for this very complicated, very ill sub-group of patients."

Other NeuroBlate data highlighted at AANS included results from the LAASR study (Laser Ablation After Stereotactic Radiosurgery), and the LAANTERN registry (Laser Ablation of Abnormal Neurological Tissue using Robotic NeuroBlate System).

Amanda Pedersen is Qmed's news editor. Contact her at [email protected].

[Image credit: Monteris Medical Inc.]