Roland Piquepaille writes: "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. Read more for additional details and references."