CyberKnife stereotactic radiosurgery (SRS) does not use a laser. The radiation is generated by a miniature (about 180 pounds) linear accelerator (linac). The linacs used by conventional radiotherapy devices are three to four thousand pounds and thus must be mounted on a gantry. Miniaturing the linac is what allows CyberKnife to place the linac on a robotic arm which, in turn, allows the CyberKnife to fire both isocentric (passing through the center of the tumor) and non-isocentric beams of collimated radiation at the tumor. CyberKnife also has an advanced imaging system which allows the computer to see the patient in real time and both hit the tumor from various angles and compensate for patient movement including respiration.

By firing from different angles, the CyberKnife is able to create a starburst pattern of radiation delivery such that each beam passes through healthy tissue only once but the sum total of all the beams intersect the tumor many times. This allows a sublethal dose level beam to accumulate a deadly concentration on the tumor without harming the surrounded healthy tissue. Gantry-mounted devices can only fire from a single plane and thus can never even come close to the complex treatment patterns generated by CyberKnife. Therefore they are not able to deliver the radiation as precisely or as effectively. It’s like a machete versus a scalpel.

CyberKnife technology is an amazing convergence of robotics, miniaturization, stereotactic imaging, guidance algorithms, geometry and treatment planning software all integrated into a completely non-invasive, Star Trek-like system which is literally able to abate tumors without surgery.

CyberKnife is experimental only in the sense that they keep expanding its use to more and more types of cancer and keep getting amazing results but the treatment is fully approved for use anywhere in the body by the FDA as well as the Japanese and
European authorities. There are about 135 Cyber Centers around the world and about 40,000 patients have been treated so far do date.

In the beginning, CyberKnife SRS was used only on the most hopeless (generally inoperable) cases but it achieved such tremendous results that its use has been greatly expanded primarily as patients refuse the traditional surgery, chemo, conventional radiation paradigm and demand CyberKnife SRS.

There are now randomized clinical trials underway that will compare CyberKnife SRS outcomes with conventional surgery for early-stage lung cancer as well as prostate cancer but the case-by-case clinical results are already well known within the industry. Patients are doing at least as well with CyberKnife SRS and they are avoiding the pain, risks and recovery times associated with open surgery as well as the side effects common with chemo and conventional radiation.

CyberKnife SRS, which is actually less expensive than conventional surgery, is covered by Medicare and most insurances companies. Further, many insurance companies that initially deny CyberKnife SRS come around and agree to pay after their decision is appealed. Why not? It’s saving them money. The CyberKnife Society works to help patients in this regard.

If you or someone you know is facing a cancer diagnosis, you owe it to yourself to learn more about CyberKnife. Unfortunately, you better not expect your physician to give you an unbiased or even an informed opinion. Many still don’t know about CyberKnife SRS and many others will not recommend it because they are in the business of selling some other treatment protocol. So, if you want to ensure that you are getting the best possible treatment, you are going to need to do your own research. Here’s a good place to start…

http://www.cksociety.org

http://www.accuray.com