What is Gamma Knife?
Gamma Knife Radiosurgery is a well established method of treating selected tumours or lesions in the brain. Gamma Knife is not a knife in the normal sense of the word. No incisions are made in your head. Instead, very precisely focused beams of radiation are directed to the treatment area in the brain, optimised to hit only the target without damaging surrounding healthy tissue. It offers a safe and effective treatment for more than 77,000 patients worldwide every year. The treatment procedure is simple, painless and straightforward.
There are 192 sources of cobalt-60 loaded within the treatment unit. Thousands of radiation beams can be generated from these sources with a level of accuracy better than 0.5mm, about the thickness of a strand of hair. Individually, each radiation beam is too weak to damage the normal tissues it crosses on the way to the target. But when focused precisely on that target, the beams intersect and the combined radiation is sufficient to treat the targeted area.
The radiation damages the DNA in the cells of the tumour or other abnormality being treated, such that the cells that make up the abnormal tissue targeted can no longer reproduce. Eventually, when these cells come to the end of their natural life span, they find that they are unable to reproduce and replace themselves because the DNA essential to this process is no longer functioning properly. Because Gamma Knife radiosurgery is so accurate, the full dose of radiation can be delivered during a single session, compared with multiple visits for conventional radiotherapy treatments.