Patent Number: 
Section: abstract

Aspects of a multiple layer multileaf collimator capable of improving resolution for coverage of a target during radiation therapy are described. A multiple layer multileaf collimator includes a first layer of multiple elongated radiation blocking leaves supported by a first frame for individual leaf positioning in a first direction. The multiple layer multileaf collimator further includes a to second layer of multiple elongated radiation blocking leaves supported by a second frame for individual leaf positioning in a second direction, the second direction offset at a desired angle relative to the first direction, wherein the individual leaves of the first and second layers conform more closely with a target shape to improve resolution. Further, the second layer is positioned above the first layer and provides leakage coverage for the multiple elongated radiation blocking leaves of the first layer. The multiple layer multileaf collimator is not limited to a single type of multileaf collimator and thus is suitable for use in a variety of multileaf collimator designs, including single focus and double focus multileaf collimators.