Multileaf collimator shape matrix decomposition

摘要: An important method in cancer treatment is the use of high energetic radiation. In order to kill tumor cells patient exposed radiation that delivered by a linear accelerator whose beam head can be rotated about couch. Inevitably healthy tissue surrounding also some So problem arises arrange way such receives sufficiently uniform dose while damage normal as small possible. The standard approach this follows. First body discretized into so called voxels. set voxels then partitioned three sets: clinical target volume, critical structures and remaining tissue. There are certain constraints for each these parts. Basically volume has sufficient cancerous must not destroy functionality corresponding organs. determination combination fields usually done inverse methods based on physical models how passes through body. early 1990’s intensity modulated therapy (IMRT) was developed obtain additional flexibility. Using multileaf collimator (MLC) it possible form homogeneous different shapes. By superimposing an field delivered. MLC consists two banks metal leaves which block shifted irregularly shaped beams (Fig. 1). most common planning divide optimization phases. At first, angles fluence matrices determined. second step sequence leaf positions determined yields desired distribution. Very recently there have been attempts combine both steps one routine [22, 9].