Gamma Knife® radiosurgery (stereotactic radiosurgery) delivers a single, large dose of radiation to a specific target in the brain with surgical precision. The radiation reacts on a molecular level with the cancer cells and stops their reproduction, killing the cancer.

Sometimes referred to as “surgery without the knife,” Gamma Knife® radiosurgery minimizes the damage to surrounding healthy tissue. With Gamma Knife® radiosurgery patients experience little discomfort, and the absence of an incision eliminates the risk of bleeding and infection. With reduced side effects, patients can return more quickly to their daily activities.

Gamma Knife® radiosurgery provides innovative care for the following conditions:

• Acoustic neuroma/schwannoma
• Epilepsy
• Glial tumors
• Meningioma
• Metastatic brain tumors
• Movement disorders, including Parkinson's disease
• Oligodendroglioma
• Pituitary tumors
• Primary brain tumors
• Trigeminal neuralgia
• Vascular disorders, including arteriovenous malformations (AVMs)

How does Gamma Knife® radiosurgery work?

The Gamma Knife® isn't actually a knife, but an instrument that allows the physician to focus 192 beams of radiation just on the area being treated. Alone, each beam is too weak to cause any damage to the normal brain tissue. The Gamma Knife® is extremely precise, using 3-D planning to shape the radiation dose to the size and shape of the affected area.

Most often, only one Gamma Knife® treatment session is needed. The treatment begins early in the morning and lasts most of the day. The process involves four phases:

1. Head frame placement: A 3-D reference frame with special markers is placed on your head until after your surgery.
2. Imaging: An MRI or CT scan is completed, followed by an angiogram.
3. Planning: The team uses computer software to plan your specific treatment.
4. Treatment: The team makes you as comfortable as possible before leaving the room. You will be able to talk to the team and listen to music during treatment.

The reduction of excess radiation is important to everyone, but particularly if you are receiving other radiotherapy treatments. Treatment of a metastatic brain tumor – a cancer that has spread from the original site – might have to be delayed by up to six weeks if certain less precise treatments are used.

The full effects of Gamma Knife® radiosurgery don't happen right away, which makes follow-up care, including office visits and imaging studies very important. Call your neuro-oncologist's office to make your follow-up appointments as instructed.