title: A 3-D beam subtraction method for inhomogeneity correction in high energy X-ray radiotherapy.
abstract: Most methods of inhomogeneity correction in high energy X-ray beams, assume an infinite lateral extent of the heterogeneous volumes ("slab models") or require sophisticated time-consuming computer algorithms. We present here a method, developed for parallelepiped inhomogeneities based on a beam subtraction concept combined with a conventional "slab model". Provided that the conventional model is appropriately chosen, this method gives agreement with experimental results better than 1% in most cases. It accounts properly for the scatter modification according to the size and position of the inhomogeneous volume. One example of a computer application is also presented.
mesh_terms: D003201:Computers; D006801:Humans; D008961:Models, Structural; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000379:methods*; D012542:Scattering, Radiation; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed