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Home News From X-rays to CyberKnife: What is Noninvasive Radiosurgery?

From X-rays to CyberKnife: What is Noninvasive Radiosurgery?

Published: Tuesday, November 13, 2007

CyberKnife stereotactic radiosurgery—the noninvasive alternative to surgery—has treated more than 250 patients at the University of Tennessee Medical Center. But why has this technology revolutionized surgery? Why are patients so satisfied with their results?

In 1895, a German scientist by the name of Wilhelm Conrad Rontgen performed an experiment in his laboratory. He wanted to know the effects of running an electric current through a tube encased in a black box. Using his wife as the subject, he set up the experiment with her hand held near the tube. His results: a light was emitted on her skin that cast shadows of gray and black; yet the light penetrating through the skin cast a bright-white outlined image of her bones and wedding ring. Because the rays were not known at that time, Rontgen called them “X-rays.”

Fast forward 100 years. The advances over time have enabled us to harness X-rays for many purposes. Radiation therapy or radiotherapy involves high energy particles or waves that “collide” with cells the same way X-rays do. This “collision” causes the abnormal cells to be destroyed or to shrink from their original size. Now, we are able to deliver high energy X-ray beams at even greater energy levels while more accurately targeting the abnormal cells through radiosurgery.

Developed in 1951, radiosurgery is a procedure that allows a non-invasive approach (non-surgical or does not penetrate or break the skin) by means of a high-energy directed radiation source (linear accelerator) to destroy tumor cells. Radiosurgery delivers very precise beams of radiation from many angles outside the body that converge on the targeted area being treated. Radiosurgery can be used to treat tumors that otherwise would be inoperable or untreatable.

The newest state-of-art technology in radiosurgery is the CyberKnife Radiosurgery System. The accuracy of CyberKnife is so precise that radiation can be “matched” to the shape of small complex tumors, even those located near critical organs or those untreatable by conventional methods such as surgery or external beam radiation.

Compared to other radiosurgery systems, the CyberKnife offers several advantages to patients, including the ability to treat tumors anywhere in the body as well as using special techniques for treatment delivery. These advanced techniques allow treatments to be more accurate and less damaging to healthy tissue. The CyberKnife not only can precisely locate the tumor but it can adjust for patient movement during treatment.
Treatments are performed on an outpatient basis with each treatment lasting between 45 and 120 minutes. The number of treatments varies depending on the tumor size, location and shape but typically require one to five daily sessions. The CyberKnife allows patients to lie comfortably on the procedure table while the robotic arm moves, without touching them, to treat the entire targeted area with sub-millimeter accuracy. Most patients can return to their normal activities immediately after treatment.

UT Medical Center has treated more than 250 patients with tumors or conditions of the brain, spine, liver, lungs, prostate, head, neck and other areas of the body. The non-invasive (non surgical) method requires no anesthesia and does not present the same risks as traditional surgery. The CyberKnife provides hope for some patients who may have received the maximum allowable dose of conventional radiation or have been told their condition was untreatable.

Read CyberKnife Patient Stories.

Click here to learn more about the CyberKnife.