Cyberknife is an exciting new tool for the eradication of benign and malignant tumours (cancers that are localised in one place). With other radiotherapy techniques the dose is limited by the damage that could be done to the surrounding normal tissue if higher dosage was delivered. Cyberknife uses the same type of radiation that is used in conventional radiotherapy, but unlike conventional radiotherapy, Cyberknife can safely place a huge dose of radiation on the target without over-irradiating the surrounding normal body tissues. Such a high dose of radiation delivered to the tumour can destroy it as effectively as removal by a surgical operation.
The technique employs a device called a Linear Accelerator (Linac) that generates a beam of radiation. This is mounted on a robotic arm which can manoever the Linac to direct its 'pencil' beam from any angle with a high degree of accuracy, utilising sophisticated computer control. The tumour is scanned and every point in the tumour is located precisely by three dimensional co-ordinates which are stored in the computer (this is called Strereotactic Mapping). The patient lies on the therapy couch/table in the treatment room and the on-table imaging facility allows the tumour to be localised (located by the hardware). After the target tumour has been localised, the robotic arm automatically lines up the Linac to deliver beams of radiation from many different directions. The direction of the beam is controlled by advanced planning software so that the tumour is slowly obliterated by a radiation dose that is built up over a period of time from one to several hours.
Many cancers may be effectively treated by Cyberknife, which forms a non-invasive alternative to many surgical options, without the inherent risks that are always present with surgical procedures. Cancers and tumours in the head, brain, spine, lung, liver, pancreas, prostate and sarcomas may all respond well to this new technique. The Cyberknife can also treat metastases, where the primary cancer has spread to other parts of the body.
Cyberknife at the Harley St Clinic