"The SMD-XGD/AR Galaxy Rotating Gamma System is a teletherapy device which contains 30 cobalt - 60 sources distributed on a hemispheric source carrier, which is inside a hemispheric shield. Inside the source unit is the ""built-in"" secondary collimator, which has 4 sizes of collimators and 1 block position. When not treating a patient, all sources are aligned with the block position of the secondary collimator, which in this case acts as a radiation shutter Treatment starts by aligning the sources to the desired collimator size, then both the source unit and the secondary collimator rotates as one unit. By rotating the cobalt -60 y-ray beams during treatment, 30 non-overlapping full 360° arcs are formed, resulting in high focal dose uniformity and small focal spot penumbra. The entire system consists of a) The y-ray treatment unit, and b) the stereotactic 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.
ourunited.com