04868843 is referenced by 143 patents and cites 13 patents.

In a radiation therapy machine it is desirable to produce irregular radiation field shapes in order to shield critical organs not invaded by the tumor. A system is provided using a multileaf collimator formed of a multiplicity of heavy metal bar leaves driven relative to a pair of frames which are driven relative to jaws of a rectangular field collimator. A multiplicity of compensators, one attached to each leaf on one of the pair of frames is used to adjust the local intensity of the radiation within the field. The x-ray beam is limited to a fan with the jaws, the ends and selected parts of the fan are blocked by the multileaf collimator, and the intensity within various portions of the remaining beam is adjusted with compensators. The field of the fan beam is dynamically controlled by these means while the patient table is moved perpendicular to the plane of the fan beam.

Title
Multileaf collimator and compensator for radiotherapy machines
Application Number
168621
Publication Number
4868843
Application Date
July 10, 1987
Publication Date
September 19, 1989
Inventor
Craig S Nunan
Los Altos Hills
CA, US
Agent
Kenneth L Warsh
Peter J Sgarbossa
Stanley Z Cole
Assignee
Varian Associates
CA, US
IPC
G21K 1/04
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