What is Gamma Knife Radiosurgery? Gamma Knife radiosurgery is a highly precise, non-invasive form of radiation therapy designed to treat tumours, lesions, and abnormalities in the brain and upper spine without a surgical incision. Despite its name, Gamma Knife involves no cutting, instead, it uses 192 focused beams of cobalt-60 gamma rays to deliver a high dose of radiation directly to the target area. Each beam is weak and passes harmlessly through healthy tissue. But where all beams converge, at the tumour or lesion, it creates a powerful therapeutic effect. This precise targeting allows physicians to treat difficult-to-reach brain conditions with minimal impact on surrounding tissue.