MRI-Guided Laser Appears Promising in Study

A minimally invasive, MRI-guided laser system appears promising for treating malignant brain tumors, a first-in-human study has found.

The NeuroBlate thermal therapy system, developed by Monteris Medical and the Case Comprehensive Cancer Center — comprising the University Hospitals’ Case Medical Center, Cleveland Clinic and Case Western Reserve University School of Medicine — provides a safe procedure for treating recurrent glioblastomas, a malignant type of brain tumor, by “cooking” them in a controlled way to destroy them.

The technique, part of a Phase I clinical trial investigating the safety and performance of the specially designed laser probe system, uses an MRI-guided laser system to coagulate, or heat and kill, brain tumors. The procedure is done in an MRI machine, enabling surgeons to plan, steer and see in real time the device, the heat map of the area treated by the laser, and the tumor tissue that has been coagulated.

“This technology is unique in that it allows the surgeon not only to precisely control where the treatment is delivered, but the ability to visualize the actual effect on the tissue as it is happening,” said co-principal investigator Dr. Andrew Sloan, director of the Brain Tumor and Neuro-Oncology Center at UH Case Medical Center and Case Comprehensive Cancer Center. “This enables the surgeon to adjust the treatment continuously as it is delivered, which increases precision in treating the cancer and avoiding surrounding healthy brain tissue.”

An investigatory device exemption was issued by the FDA to study the system in patients with glioblastomas. The investigators treated 10 patients, with a median age of 55, who had tumors diagnosed to be inoperable or high risk for open surgical resection because of their location close to vital areas in the brain. The NeuroBlate system received FDA clearance based on the results of this study.

“Overall the NeuroBlate procedure was well-tolerated,” Sloan said. “All 10 patients were alert and responsive within one to two hours postoperatively, and nine out of the 10 patients were ambulatory within hours. Response and survival was also nearly 10½ months, better than expected for patients with such advanced disease.”

“Previous attempts using less invasive approaches such as brachytherapy and stereotactic radiosurgery have proven ineffective in recent meta-analysis and randomized trials,” said Dr. Gene Barnett, director of the Brain Tumor and Neuro-Oncology Center at Cleveland Clinic and Case Comprehensive Cancer Center. “However, unlike therapies using ionizing radiation, NeuroBlate therapy results in tumor death at the time of the procedure.”

A larger national study is under development.

Drs. Sloan and Barnett are paid consultants for Monteris Medical and are members of the company's medical advisory board. Researchers from Cleveland Clinic Florida, Case Western Reserve University and the University of Manitoba also contributed to the study.

The study appeared online in the Journal of Neurosurgery (doi: 10.3171/2013.1.JNS1291).

For more information, visit: www.uhhospitals.org