Gamma Knife Module

Background Information

The Leksell Gamma Knife® is used to treat disorders of the brain (such as tumors and malformed blood vessels) when conventional surgery would be too risky or too difficult. Treatment with the Gamma Knife requires no surgical incision because gamma rays are used to destroy the target. Gamma rays, which are high-energy electromagnetic waves, are produced by certain radioactive elements. The Gamma Knife apparatus uses a radioactive form of cobalt as its source of gamma rays.

Gamma Knife radiosurgery can precisely concentrate 201 gamma rays at a specific target in the patient's head without damaging the surrounding tissues. In order to protect specific healthy structures (such as the optic nerve), the patient's head is held stationary by a stereotactic frame. A targeting helmet is then fixed to this stereotactic frame. The Gamma Knife helmet contains 201 holes that can be closed to prevent specific gamma rays from reaching healthy structures. Before treating a patient with the Gamma Knife, medical professionals and physicists plan the procedure to decide which holes in the helmet should be left open and which holes should be closed.

Activities in the Gamma Knife Module introduce the electromagnetic spectrum and focus on the use of gamma rays in Gamma Knife radiosurgery. Applications of other electromagnetic waves in surgery are presented in the Laser Module (visible, ultraviolet, and infrared light) and the Endoscope Module (visible light).