Gamma Knife or Gamma unit definition
Gamma Knife or Gamma unit means a specialized type of equipment used to perform stereotactic radiosurgery on small brain tumors and vascular malformations using multiple Cobalt- 60 gamma radiation sources focused through a collimator helmet and arrayed in a semicircular arc so that they may be very precisely focused and the radiation dose may be very precisely distributed, permitting treatment in neurosurgical cases where the site is inaccessible or otherwise unsuitable for other invasive methods.