Q&A: Gamma Knife®
Radiosurgery for Brain Tumors

Gamma Knife® is a major advance in the field of stereotactic radiosurgery for certain

brain cancer patients. It offers a non-invasive procedure that can be performed in one

session and with extreme precision.

What is a Gamma Knife?
The Gamma Knife is a 30-ton machine that contains a cylindrical cone made of the world's largest piece of tungsten with lead shielding.
The machine has 192 Cobalt-60 radiation sources that are shaped by eight sectors that surround the patient's head.

What is Gamma Knife radiosurgery? Gamma Knife surgery is actually a form of radiation therapy invented in 1967 by Lars Leksell, a Swedish neurosurgeon. The latest model, Perfexion, has been redesigned and reengineered, and it is the first fully automated Gamma Knife at M. D.
Anderson

For the one-day procedure, the patient first has a brain MRI with a head frame placed by a neurosurgeon.
Then the Gamma Knife team creates a customized treatment plan, which is delivered to the patient who lies on a sophisticated and highly accurate patient positioning system (PPS).
The patient's head is inserted into the cone-shaped tungsten cylinder that delivers highly focused gamma rays around the head

While the contribution of each ray is relatively small -- allowing for less damage to surrounding healthy cells -- when the multiple rays converge on the tumor, they have great intensity.
The Gamma Knife unit also has an audio/visual connection so the patient can be seen and also communicate with the treatment team While the contribution of each ray is relatively small -- allowing for less damage
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