How Making Brain Tumors Glow Saves Lives
Aug. 27, 2012— -- It all started with a headache.
Back in 2010, Kelsey Stewart thought the new head pain he had been feeling was a sinus infection. He saw a doctor, who prescribed him some anti-inflammatory medication that he hoped would take care of the problem.
But once he started vomiting uncontrollably -- one day, he recalls, he vomited 21 times -- he went to the hospital for further evaluation.
There, a CT scan of his head and further testing revealed the bleak truth: Stewart had brain cancer. And it was not just any kind, but a grade 4 glioblastoma multiforme (GBM). GBM is a very aggressive kind of cancer known for its grim prognosis.
"We were terrified," Stewart says. "Everything you read about GBMs is just death everywhere, death, death, death. My neuro-oncologist said she's never seen anyone survive this."
Doctors told him that, without surgery, he was not expected to live more than a year. But even with surgery, risks were high. Operations to remove brain tumors are complicated. They are located in the delicate brain tissues, and a tumor often appears remarkably similar to healthy tissue in the brain. This means that the line between diseased and healthy tissue is almost indistinguishable, leaving surgeons few clues on where to cut.
Fortunately, his brain surgeon had been working on an innovative solution to address this challenge.
Neurosurgeon Dr. Aaron Cohen-Gadol at Indiana University Health Neuroscience Center had developed a method to make cancerous tumors glow, using a special new microscope filter and small amounts of a glowing compound called fluorescein.
"We wanted to find a way using this new technology to increase the safety for the patient and at the same time maximizing tumor resection," he explains.
In the operating room, Cohen-Gadol infused a small amount of a fluorescein into Kelsey's bloodstream. Within the baseball-sized brain tumor, microscopic breaks in the blood vessels allowed tiny amounts of fluorescein to leak out into the cancerous tissues to light up under the microscope. Through the filter of his microscope, the tumor glowed fluorescent yellow – almost like white clothing appears under a black light.
Cohen-Gadol says that the glowing tumor was "like a roadmap," helping him identify tumor more easily and facilitating a more thorough removal.
Currently, many neurosurgeons are seeking similar ways to remove brain cancers more easily and thoroughly. One emerging area of research involves an experimental compound that makes brain tumors glow, called 5-Aminolevulinic Acid (ALA). Other surgeons in Japan have tried using fluorescein, but without the newly invented filter that Cohen-Gadol used, they had to use precariously high doses of the glowing compound until they could see an effect.
In the United States, fluorescein is the only drug already approved by the U.S. Food and Drug Administration and available to all hospitals -- not just the few enrolled in the ALA trials. Therefore, this compound can theoretically be used by any neurosurgeon schooled in the techniques of the microscope filter Cohen-Gadol used.
