"The device contains 30 Cobalt-60 sources, distributed in a single, compact source carrier or source drawer, which is inside a hemispheric shield. Immediately adjacent to the source unit is the ""built-in"" primary collimator. An independently rotating secondary collimator hemisphere contains 4 sizes of collimator and a blocking position. The rotating gamma system focuses the thirty beams and combining their individual doses at the target. The design of the system automates the treatment delivery by moving the target to the focal point, while the patient’s head is immobilized in a head frame which has been fitted prior to the commencement of treatment. The entire system consists of a) the gamma ray treatment unit, and b) the stereo-tactic localization system."
A stationary assembly of computer-based devices designed to deliver a therapeutic radiation dose to an anatomical region from a single external radiation beam produced by a radionuclide source, typically to treat malignant tumours; it does not provide image-guided radiation therapy (IGRT) functionality during treatment delivery. A typical system is: 1) the treatment head (a shielded source vault containing a single radioactive source); 2) a rotating or fixed gantry with the treatment head; 3) a collimator mechanism attached to the gantry to align the treatment beam; 4) a moveable patient table; and 5) an operator's console with controls. It is commonly known as a cobalt therapy machine.
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