A robotic Cyberknife to fight cancer

The Cyberknife is not a real knife. This is a robot radiotherapy machine which works with great accuracy during treatment, thanks to its robotic arm which moves around a patient when he breathes. According to BBC News, the first Cyberknife will be operational in February 2009 in London, UK. But other machines have been installed in more than 15 countries, and have permitted to treat 50,000 patients in the first semester of 2008. And the Cyberknife is more efficient than conventional radiotherapy devices. The current systems require twenty or more short sessions with low-dose radiation. On the contrary, and because it’s extremely precise, a Cyberknife can deliver powerful radiation in just three sessions. …

As you can see above, “the CyberKnife System uses image guidance software to track and continually adjust treatment for any patient or tumor movement. This sets it far ahead of other similar treatments. It allows patients to breathe normally and relax comfortably during treatment.” And it “uses pencil beams of radiation which can be directed at any part of the body from any direction via a robotic arm;” (Credit: various Accuray pages). Here is a link to a larger version of thie picture above.

The Cyberknife is a product of Accuray, who has deployed a corporate CyberKnife website and many other local sites in various locations. Speaking about locations, here is a link to a page where you can check if you live in a place not too far from a medical institution using such a system.

Here is an excerpt from the BBC News article. “At first sight the Cyberknife looks like one of those robots used in the TV car commercials. It is a compact linear accelerator mounted on a robot arm. The cyberknife works by delivering multiple beams of high dose radiation from a wide variety of angles using a robotic arm. X-ray cameras monitor the patient’s breathing and re-position the radiotherapy beam in order to minimise damage to healthy tissue. This accuracy enables tumours to be treated that are in difficult or dangerous to treat positions, such as near the spinal cord.”

Of course, such a treatment is expensive. “Treatment will cost between £20,000 and £25,000.”

Now, let’s look at the new CyberKnife Centre in London to discover what is CyberKnife and how it works.”The vast array of different angles/trajectories from which pencil beams of radiation converge upon the tumour lead to an extremely high cumulative dose of radiation therapy at the convergence point (the target/tumour) and yet a very fast ‘fall-off’ of dose at the periphery of the carefully mapped target. The surrounding normal tissues/organs only receive a small fraction of the high central dose of therapy.”

You’ll also find explanations about why the Cyberknife is about to replace surgery — at least in some cases. “The treatment is so accurate that it’s now possible to treat tumours previously thought to be inoperable. Although the results of treatment do not always show immediately, in most cases the procedure will initially stop the growth of tumours before gradually reducing their size. As there is no open surgery, the complications normally associated with an operation are eliminated, as is the need for a long recovery time. This makes treatment suitable for those who are not well enough to cope with the side-effects of surgery and most patients leave the clinic the same day as their treatment.”

For even more information, you can read this overview or the Cyberknife brochure (PDF format, 20 pages, 1.85 MB).

Sources: Fergus Walsh, BBC News, December 30, 2008; and various websites

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