Cobalt treatment still has a useful role to play in certain applications ( for example the Gamma Knife ) .
Is still in widespread use worldwide , since the machinery is relatively reliable and simple to maintain compared to the modern linear accelerator .
Cobalt treatment still has a useful role to play in certain applications ( for example the Gamma Knife ) and is still in widespread use worldwide , since the machinery is relatively reliable and simple to maintain compared to the modern linear accelerator .