Technology being developed by a company with a Kalamazoo office is helping to foster a new way to attack brain tumors.
The AutoLITT (Laser Interstitial Thermal Therapy) system from Monteris Medical Inc. uses high-intensity laser energy to heat and destroy difficult-to-treat tumors with the assistance of specialized computer software.
The technology is undergoing clinical trials on 10 patients at the Cleveland Clinic and University Hospitals at Case Western Medical Center in Cleveland.
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The company announced Wednesday that it had received U.S. Food and Drug Administration clearance for commercial sales of the system for wider use in neurosurgery.
Monteris, which has a facility in Winnipeg, Canada, and an office in Kalamazoo, will now begin expanding its Kalamazoo operations, which could employ 100 workers in manufacturing, sales and administration by 2011, said James Duncan, president and chief executive officer. Research and development will stay in Winnipeg.
The AutoLITT system combines three technologies: a laser-induced thermal therapy, real-time MRI (magnetic resonance imaging) heat monitoring and minimally invasive MRI-guided surgical procedures.
Traditionally, brain tumors are treated by either surgical removal or noninvasive stereotactic radiosurgery, in which the tumor is treated with a precise dose of radiation that destroys it, said Dr. Andrew Sloan, a neurosurgeon at University Hospitals who, along with neurosurgeon Dr. Gene Barnett of Cleveland Clinic, is leading the investigation.
However, those treatments do have limitations, Sloan said. Radiosurgery is not effective on brain metastasis or tumors generally larger than about 4 centimeters across. Also, traditional surgery cannot be used in certain areas of the brain, such as the thalamus or the corpus callosum, he said. In those cases, the interstitial thermal therapy may provide an alternative, Sloan said.
"We don't know what the ultimate outcomes will be, but this is very promising," Sloan said.
Rotating laser probe
With the AutoLITT system, a surgeon uses MRI scans to plan the trajectory for the approach to the tumor. A hole about the size of a dime is made in the skull, and a guide to hold the laser probe is inserted into the brain.
The probe, which can rotate 360 degrees, is then inserted through the guide into the tumor. The surgeon fires the laser to heat up and destroy the cells of the tumor, at temperatures between 57 and 85 degrees Celsius (between 134. 6 and 185 degrees Fahrenheit).
Using the MRI, the surgeon can carefully monitor the temperature of the tumor cells and the surrounding brain cells. While the laser is heating the tumor cells, the remainder of the brain is being cooled, using a line of carbon dioxide, to prevent the heat from spreading, Sloan said.
None of the technologies used in the AutoLITT system are new, Sloan said. The laser and MRI technology have been in existence for several years, he said. "What makes this unique is the combination of the two and integrating them in real time," he said.
"If I do Gamma Knife (radiosurgery), I can plan the surgery based on anatomical images, but I don't know what the effect is for months. With this, I know more or less in real time, within seconds, what I've done," Sloan said.
The new technology also allows a new degree of control to the treatment, he said.
"The key thing to understand is that the laser does not fire continuously the whole time," Sloan said. "The laser fires only when I turn it on. I can turn it on for half a second at a time. I can turn it on and off in sub-second increments."
That precision is critical, because it is impossible to predict how a tumor -- or different parts of a tumor -- will conduct heat. "Every patient and every tumor appears to be different," Sloan said.
The precise control of the laser and the MRI thermal readings also allow the surgeon to sculpt the treatment to the shape of the tumor, which is usually irregular.
"I don't know that this is as good as surgical removal. I think resection is still the standard," Sloan said. "But this is something very interesting."