The CyberKnife is not actually a knife at all. It's a state-of-the-art piece of equipment that allows specialist oncologists to treat tumours and other medical conditions painlessly without the need for an operation.

CyberKnife uses pencil beams of radiation which can be directed at any part of the body from any direction via a robotic arm. The robotic arm tracks the tumour's position, detects any movement of the tumour or patient, and automatically corrects its positioning before targeting the tumour with multiple beams of high-energy radiation, destroying abnormal tissue without damaging surrounding areas.

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.

The advanced technology also eliminates the need for patients to be fitted with a brace or restraining device during the treatment phase, making the whole procedure less stressful for patients.

How the CyberKnife 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.

Whilst any tumour may be destroyed by a very high dose of radiation therapy, it has very often been the case, with orthodox radiotherapy, that it has not been possible to deposit the required dose on a tumour without also depositing a toxically high dose of radiation on the surrounding organs. Cyberknife often overcomes this problem by its capability to so accurately target and achieve a fast dose gradient ('fall-off') at the perimeter of the tumour/target.