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What is robotic stereotactic radiosurgery, e.g. Cyberknife?

Stereotactic radiosurgery is a medical procedure that utilizes very accurately targeted, large “killing” doses of radiation. This noninvasive “operation” has proven to be an effective alternative to surgery or conventional radiation for treating many small tumors and a few other select medical disorders.  see video and here and read reviews here and here.

There is evidence that giving the radiation in large single doses and fewer treatments or fractions (called hypofractionation) may be more effective than conventional treatment (multiple fractions of small doses, called fractionated radiation) The safe and proper dose is much different. See the tables for brain here and tables on doses for single fraction or three fractions or five fractions

more videos here, here, here, here, here, here, here, here, here, here, here

Conditions treated with Cyberknife:

 

Best Web Sites:

 

 

 
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:

1) restricting treatment to the brain,
2) limiting the possible angles which radiation could be delivered,
3) 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. (see patient manual page 1 and page 2.

The CyberKnife belongs to a new class of radiotherapy techniques called IGRT (image-guided radiotherapy. Go here for an update on new radiation techniques.)  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 which 'matches' the shape of the prostate and spares adjacent normal anatomy (bladder and rectum).
  Other Cyberknife centers with good information: