Imagine experiencing severe pain when you brush your teeth or simply touch your face.

That is how one south Florida woman lived for years.

However, a high-tech tool to treat cancer got to the root of her pain.

The CyberKnife at the Memorial Cancer Institute is usually aimed at tumors, but its focused radiation beams are also being used to destroy the cause of disabling pain.

"It's like somebody's taking a knife and going right through on the bone,” says Marjorie Exantus, a sufferer of trigeminal neuralgia. “It's the worst pain you can ever have."

Marjorie was literally suffering from trigeminal neuralgia, an excruciating condition that causes facial pain. It affects women more than men, usually over age 50, and is often misdiagnosed.

"A lot of times, patients believe they're having dental problems and they have their teeth pulled and their pain doesn't get better," says Dr. Srinath Sundararaman, radiation oncologist.

Scans can pinpoint the root of the problem for treatment.

"We are aiming for where the nerve is coming out of the brain stem. That is the likely culprit where there is denuded or uncovered nerve that is very irritable," says Dr. Sundararaman.

CyberKnife can zero in on the nerve structure.

After one 90-minute treatment in February, Marjorie is now pain free after four years of failing to get relief from three surgeries and many medications.

"I am excited, I'm so grateful, I can't believe one treatment can make that difference," she says.

"We've seen success rates be at least 70 percent or higher, and that's complete symptom resolution," says Dr. Sundararaman.

Most insurance companies cover the CyberKnife treatment of trigeminal neuralgia.