Under computer guidance and using stereotactic principles, any part of the head can be touched by a probe and the position displayed on the CT or MRI brain scan.
What are the benefits ?
Before the skin is cut, the tumour can be located on the surface of the brain so that the skin incision and bone flap are cut in the best position. During the operation, the tumour can be accurately located, as well as important surrounding brain structures. And after the tumour has been removed, the margins can be inspected to see if any residual tumour has been left behind. The end result is safer neurosurgery.
What is the limitation ?
The information in the computer is based on the brain scan that was done before the operation. As tumour is removed and there is less pressure on the brain, the brain moves so that the localisation may not be so accurate. The neurosurgeon will always be aware of this.