Robotic arm delivers tumour-eradicating radiation

CyberKnife is a robotic radiosurgery system, manufactured by Accuray Inc., which is being used in 76 medical centres around the world to treat lung tumours in human patients.

At the 48th annual meeting of the American Association of Physicists in Medicine (AAPM), to be held in Orlando, Florida next month, Cihat Ozhasoglu, from the University of Pittsburgh Medical Center, will report on how the CyberKnife has been upgraded with a system called Synchrony.

untitled1.JPG (Accuray Inc.)

Using Synchrony, a lung tumour, and its movements, which are caused by breathing, can be tracked using X-rays in real time, with a sub-millimetre accuracy. Cyberknife can then be used to deliver 100-150 intense and focused X-ray beams to the tumour. Because of the accuracy of tumour tracking, healthy surrounding tissue is not irradiated.

Using the upgraded CyberKnife system, lung tumours can be eradicated with between 1-3 sessions, each lasting 60-90 minutes. Conventional radiotherapy requires up to 30 treatments, and delivers 10 times less radiation than the CyberKnife system.

The CyberKnife system consists of a linear accelerator, which produces the X-rays, mounted on a robotic arm, two flat panel cameras positioned perpendicular to ceiling-mounted X-ray sources, an array of three charge-coupled device (CCD) cameras, a Synchrony-tracking vest with external markers printed on it, and target-locating computers.

CyberKnife can also be used to irradiate tumours in the spine, liver, pancreas and prostate, as well as intra- and extracranial tumours. 62 more CyberKnife systems are due to be installed in medical centres around the world in the near future.