Krembil Neuroscience Program

Gamma Knife Radiosurgery

What is Gamma Knife Radiosurgery?
Gamma Knife Radiosurgery, a form of stereotactic radiosurgery, is a sophisticated radiation tool known worldwide for its precise treatment to targeted areas of the brain. The "Tools" of the Gamma Knife are the beams of gamma radiation that deliver single doses of radiation therapy with precision of less than 1 mm. The Gamma Knife Centre is located in a new wing at UHN’s Toronto Western Hospital and operates as a unique collaboration between the Neuroscience, Medical Imaging, and the Radiation Medicine Programs. Each of these programs are world leaders in their own right and, combined, promise to offer state-of-the-art care for Ontarians.

Role in Treating Neurological Disease
The beams of gamma radiation are specifically programmed to target areas of the brain where surgical access is challenging or too dangerous or are not optimally suited for other medical treatments. In a single treatment session, 201 beams of gamma radiation focus precisely on the target. The exposure is brief and only the tissue being treated receives a significant radiation dose, while the surrounding tissue remains unharmed.

Who is Eligible for Gamma Knife Surgery?
Patients may be referred to the Gamma Knife Centre for consideration of radiosurgery for the following standard clinical indications:

  • Patients with typical Trigeminal Neuralgia who have failed an adequate trial of medications, and may have also failed prior surgical intervention.
  • Patients with brain or dural vascular malformations (AVM) suitable for radiosurgery.
  • Patients with Brain Tumours may be referred for gamma knife radiosurgery when considered technically advantageous over alternate radiosurgical approaches, or stereotactic radiotherapy. Evaluation by a radiation oncologist is strongly recommended prior to referral to the Gamma Knife Centre.

Patients may be referred to the Gamma Knife Centre for consideration of radiosurgery under a research protocol for non-standard indications. This may include the following:

  • Movement Disorders and Intractable (unstoppable) Pain
  • Patients with medial temporal lobe epilepsy.


  • Since Gamma Knife radiosurgery is performed without incisions or general anesthesia, the usual risks associated with conventional neurosurgery, such as neurological deficit, infection and bleeding, are virtually eliminated.
  • Patients are discharged from the Gamma Knife Centre on the day of treatment and are usually able to return to their normal activities within 24 hours.
  • Associated with lower treatment costs.
  • Gamma Knife technology is a recognized safe treatment. It has been in use for more than 15 years and over 300,000 patients worldwide have benefited from this treatment.
  • Patients will benefit from the advanced imaging resources at the state-of-the-art TWH imaging centre as well as on-going innovations in imaging. Better determination of the location and extent of the target is key to fully exploiting this new technology for the benefit of the patient.
  • Gamma Knife delivers single doses of radiation therapy to targeted areas of the brain with a precision of less than 1 mm. The beam is so precise that the surrounding normal tissue receives minimum radiation.


  • Only patient referrals that meet the indications for Gamma Knife radiosurgery will be accepted.
  • Patients are referred by a specialist to the Gamma Knife Referral Centre for consideration of stereotactic radiosurgery. Patient self-referrals will not be accepted.
  • Referrals must include sufficient clinical documentation and diagnostic imaging in order to determine the appropriateness of stereotactic radiotherapy.
  • The Gamma Knife Centre accepts referrals for Ontario residents and out-of-province Canadian residents. Referrals for non-residents or uninsured patients are not accepted at this time.
  • Referrals and supporting documentation are faxed or mailed to the Gamma Knife Centre:

Phone: (416) 603-5445
Fax: (416) 603-5155

Patient Referrals - Gamma Knife Centre
Toronto Western Hospital
Room MC 3-449
399 Bathurst St.
Toronto, ON M5T 2S8

[Back to top]

Terms & Conditions | Privacy Policy | Copyright © 2008
University Health Network 190 Elizabeth Street, Toronto ON M5G 2C4