What Is CyberKnife?
The CyberKnife Robotic Radiosurgery System is a non-invasive alternative to surgery for the treatment of both cancerous an non-cancerous tumors anywhere in the body, including in the prostate, lung, brain, spine, liver, pancreas, and kidney. The treatment—which delivers beams of high dose radiation to tumors with extreme accuracy—offers new hope to patients.
Though its name may conjure images of scalpels and surgery, the CyberKnife treatment involves no cutting. In fact, the CyberKnife System is the world’s first and only robotic radiosurgery system designed to treat tumors throughout the body non-invasively. It provides a pain-free, non-surgical option for patients who have inoperable or surgically complex tumors, or who may be looking for an alternative to surgery.
Multiple beams of high-energy radiation are delivered from multiple points outside of the body and converge precisely at the tumor or lesion inside the body. Each individual beam is not sufficient to cause harm, but the convergence of all the beams at the tumor results in the lesion receiving a very high dose of radiation while sparing nearby normal tissue.
Because CyberKnife radiosurgery is so precise, radiation beams can be sculpted to small, complex-shaped tumors near critical structures, such as hearing and vision nerves. This ability to accurately irradiate only the tumor and protect healthy tissue allows the CyberKnife to treat many lesions that may be considered inoperable or untreatable with other radiosurgery systems—giving many patients new hope.
Standard stereotactic techniques rely on a rigid metal frame fixed to a patient’s skull for head immobilization and target localization. However, such frame-based systems have numerous limitations, including:
Restricting treatment to the brain;
Limiting the possible angles at which radiation can be delivered
Causing considerable discomfort for the patient
In contrast to the standard frame-based radiosurgical instruments, the CyberKnife uses noninvasive image-guided localization and a robotic delivery system. This combination of technologies enables the CyberKnife to overcome the limitations of older frame-based radiosurgery such as the Gamma Knife and LINAC.
The CyberKnife belongs to a new class of radiotherapy techniques called image-guided radiotherapy (IGRT). The CyberKnife is unique in that it uses a compact linear accelerator (linac) mounted on an image-guided robotic arm to deliver multiple beams of high energy x-rays to a target. The ability of the CyberKnife to shape the profile of radiation to conform to the patient’s individual anatomy allows for maximum sparing of surrounding normal tissues.
The CyberKnife accomplishes this by accurately cross-firing approximately 150 beams of radiation at the target from multiple directions. The CyberKnife technology represents an improvement upon the most advanced conventional radiation therapy techniques: Intensity Modulated Radiotherapy (IMRT). Similar to IMRT, the CyberKnife can produce a highly conformal dose distribution that “matches” the shape of the tumor and spares adjacent normal anatomy (such as bladder and rectum for prostate cancer).