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Leksell Gamma Knife® Perfexion™

What is Perfexion™?

Perfexion™ is the most advanced unit in the GammaKnife® family of stereotactic radiosurgergy devices. Each GammaKnife contains about 200 Co-60 radioactive sources that are used to non-invasively deliver a high dose of radiation to treat brain disorders.

How is treatment delivered?

To ensure accuracy, patients receiving treatments on Gamma Knife® have a frame affixed directly onto their head with four pins. Patient images are then acquired on a MRI or CT scanner and the site of the lesion can be located relative to the frame. Using these images, the treatment plan is developed. The head frame, with the patient, is then fastened to the treatment couch. Treatment is delivered by exposing the sources from their shielded positions in a configuration that was developed during treatment planning. This is an outpatient procedure that is completed in one day.
If you would like to learn more about the Perfexion™ treatment unit, please refer to: https://www.elekta.com/radiosurgery/leksell-gamma-knife-perfexion.html

How is Leksell Gamma Knife® Perfexion™ different?

Leksell Gamma Knife® Perfexion™ is a project that is funded in part by Elekta, the manufacturer of Prefexion™. It consists of a Perfexion™ device with a cone-beam CT (CBCT) imager mounted to the front of the treatment unit. The hardware for the imager was designed and built in-house at the Princess Margaret Hospital. A patient can now be positioned on the treatment couch and then imaged without moving from one device to another. On line CBCT imaging will reveal any discrepancy in patient positioning, providing guidance to correct any errors and ensure the treatment accuracy without using the invasive head frame.

Fractionated radiation treatment, where a patient receives multiple radiation treatments but at lower doses thus giving healthy irradiated tissue time to heal between treatments, is a common technique that is used for other radiation therapy devices. However this technique has not been fully employed on Perfection™/GammaKnife® units due to the use of the head frame. IGP will open up the possibility of fractionated Perfexion™ procedures for the treatment of brain cancers; adding another weapon in the fight against cancer.

Progress

Leksell Gamma Knife® Perfexion™ gets a new arm
(first published by Tracey Lui, M.Sc February 6th, 2012)

The Leksell Gamma Knife® Perfexion™ radiation therapy unit is one step closer to reaching its goal to eliminate the use of the head frame required for treating patients. A new smaller and lighter imaging arm has been installed which has the ability to rotate over 210 degrees. The result is improved image quality for better image guidance. The next step of this project is to commission the unit followed by the imaging of patients.