Oct 5, 2006 9:34 pm US/Central
'Gamma Knife' Brain Surgery Helps Texas Patient
by Shannon Hori
DALLAS (CBS 11 News) ―
Brain surgery, the words conjure frightening images. For one Texas college student, who says she had a ticking time bomb in her head, there was no other choice.
That young student was able to go out dancing with friends just a week after her second brain operation because of a surgical tool called a Gamma Knife… a tool that seems like it came straight out of a Star Wars movie.
Katherine Coit suffered from debilitating headaches for years, but thought they were just migraines. Then right before she graduated from high school, Coit realized her problem was much bigger than a simple headache.
"I woke up my senior year and had numbness in my hand and my mouth," she explains, "so I went to the doctor and they did an MRI."
Doctors discovered Coit had a dangerous cluster of abnormal blood vessels, called an AVM, buried deep inside her brain. She had to have brain surgery.
A week after her high school graduation, surgeons cut Coit's skull open. "I was pretty much in denial about it until about five minutes before I had surgery," Coit remembers. "I ended up having a craniotomy where they found that I also had an aneurysm."
The aneurysm, an enlarged and very weak blood vessel, had been leaking blood into Coit's brain, which was responsible for the numbness she felt in her hand and mouth. She had basically suffered a small stroke.
During surgery, doctors removed the dangerous tangle of blood vessels and placed a metal clip on the aneurysm to keep it from bleeding again.
Slowly, Coit recovered from the surgery, but it was a long haul. "It's tough to be in bed for as long as I was in bed," Coit said.
Three years later, a routine follow-up scan showed the problem had returned... this time in a part of the brain where it was too dangerous to operate.
Dr. Tony Whitworth of UT Southwestern Medical Center knew they couldn't operate again, at least not in the traditional way. "It was felt that the remainder of the AVM would be too small, and too deep, to get to surgically, without putting her at significant risk for harm," he says.
So doctors performed a non-surgical procedure using a tool called a Gamma Knife. It uses 201 beams of weak radiation instead of surgical steel and computer mapping defines the target.
A large helmet called a collimator focuses the beams so they zap the problem area.
"Each beam converges on the same point and the addition of all the different beams makes a very potent dose," says Dr. Robert Timmerman, UT Southwestern Medical Center. "Each beam converges on the same point and the addition of all the different beams makes a very potent dose."
Dr. Whitworth says there's no cutting and no blood loss. "We do not have to open the skull and we do not have to disrupt normal neural tissue."
One of the most important steps in a Gamma Knife procedure is determining exactly where the radiation will go. Doctors used MRI scans and a frame that immobilized Coit's head to fix the exact location of the problem spot.
"Basically you're trying to hit the abnormality and miss the normal tissues," Dr. Timmerman explains.
It's hard to believe, but Coit was back home with her family in Midland the same day, and a week later she celebrated her 21st birthday. It was a day she thought she might never see. "I'm just happy to be alive and to have the friends I have," Coit says. "I should be in a wheelchair or disabled or something and I'm fine."
It will take two to three years for the radiation to completely resolve the AVM, but doctors expect Coit to make a full recovery.
(CBS 11 News)
