Gamma Knife overview 1. Gamma Knife History and Present State early in 1951 it was suggested that stereotactic method with the calibration of the location of intracranial lesions with high-energy rays irradiated from different directions, focus on the idea of lesions. In 1968, the advent of the world's first gamma knife and used in clinical, when the Gamma Knife is a spherical array of 179 radioactive sources, radiation exposure to the hot core focus. The irradiation technology can be carried out on high-dose cranial radiation lesions, necrotic lesions caused almost no damage to adjacent normal tissue, like a knife as the boundary, so called "radiosurgery." Because of the use of 60 Y-rays produced as the drill sources, so this is known as stereotactic gamma knife treatment system.
In the early stages, mainly for the treatment of benign disease, such as the destruction of brain nuclei to treat intractable pain, Parkinson's disease and mental illness. In 1974, the second generation of gamma knife come out, 60 using drill 201 sources, the formation of spherical target in the brain, according to the situation choose different types of lesions collimator helmets, the indications expanded to brain tumors and cerebrovascular disease. 80 years of the 20th century, CT, MRI and digital subtraction angiography has facilitated the development of stereotactic radiosurgery, the third generation from the collimator to the gamma knife positioning, etc. has been improved, and its higher accuracy, error only 0.1 mm with disabilities to receive gamma knife treatment of patients every year.
Gamma Knife overview 2. The basic structure of gamma knife is equipped with 60 drilling radioactive sources by the host, collimating system, the treatment bed, stereotactic head frame and computer treatment planning system and other components.
(1) the main body of gamma knife: a dome (helmet-like) of the metal shielding system, which is equipped with a 201 after the wiring harness to form a very narrow, concentrated exposure to the Globe.
(2) alignment system: the host primary collimator, secondary collimator helmet is a hemispherical, with 201 holes. There are 4 different types of helmets, the diameter of 4 mm, 8 mm, 14 mm and 18 mm holes. According to the size of lesions, the choice of different types of helmets, you can also plug the hole to change some of the target shape to be precise irradiation.
(3) the treatment couch: a helmet connected with the treatment bed is used to support a fixed collimator helmet. Automatically sent to the patient treatment couch treatment site, the end of treatment and then automatically return to the original position.
(4) stereotactic head frame: This is a three-dimensional coordinate system perpendicular to each other, which is used to determine the exact lesion location in mind, the equivalent of positioning system.
(5) a comprehensive introduction gamma knife, the computer treatment planning system: by computer software system to provide optimal treatment design.