The CyberKnife radiosurgery system is mostly used for blasting tumors, but it can also zap away a type of facial nerve pain without causing major complications, according to a study published Thursday in the Journal of NeuroInterventional Surgery.

Although the study was small, the results were promising enough to warrant further investigation, according to the paper's authors, led by Dr Orland Ortiz, a radiologist with Winthrop-University Hospital in Mineola, N.Y.

Trigeminal neuralgia is a type of nerve disorder that causes electric shock-like pains and spasms in the face, and involves a three-branched nerve (the trigeminal nerve) that carries sensations from the face to the brain. The condition affects four or five out of 100,000 people, generally those in middle age or older, according to the study. At its most severe, it can debilitate sufferers with pain, dread of future attacks and even depression.

It's usually treated at first with drugs, and resilient cases can go on to surgery, the authors said. Since the mid-1990s, certain radiation therapy platforms have been used, with long-term pain relief (lasting more than one year) experienced by about 59 to 83 percent of patients, according to the study's authors. But a side effect, facial numbness, has been an issue, afflicting up to half of patients, according to a handful of studies cited by the authors.

In the current study, the doctors said they wanted to see if they could get good results with the CyberKnife, a radiosurgery platform made by Accuray Inc., and released in the United States in 2001, which uses real-time imaging and a robotic arm to deliver precise doses of radiation.

For the study, the researchers recruited 17 patients whose TN wasn't responding to medications or previous surgery.

The doctors then used the CyberKnife to irradiate a 6-millimeter section of the offending nerve, giving an average total dose of about 73 Gy.

Of the 16 patients treated for whom they had follow-up data, 88 percent (14) had complete or partial pain relief. Eleven had full pain relief at one time during the post-treatment period, and seven had full relief up until their last follow-up visit, on average 5 months later.

However, pain did recur in four patients, 3, 4, 9 and 18 months after treatment. Still, side effects were minimal, with only two patients reporting problems: one complained of a "bothersome feathery dysesthesia" (dysesthesia is when a normal stimulus inflicts pain) about a year after treatment, and another of a "non-bothersome" mild loss of sensation in the area after two months.

"Our cohort of patients treated with Cyberknife radiosurgery for TN targeting a consistent nerve length and dose demonstrated effective and safe outcomes in terms of initial pain relief and incidence of sensory loss. Non-isocentric radiosurgery can be used as an alternative to more invasive treatments and warrants further follow-up and investigation," the authors wrote.

More Industry Headlines