Radiotherapy Conformal Wedge Computational Simulations,Optimization Algorithms, and Exact Limit Angle Approach

Radiotherapy wedges constitute an important group within the generic classification of so-called Beam Modification Devices (BMD). Wedges are subdivided into Static, Dynamic, and Omni Wedges sug-groups. The standard static wedge attenuates the beam progressively, in such a way that the dose delivery is higher at the thin side, and lower at the broader side. The slope of the inferior surface has the geometry of the hypotenuse of a triangle, formed by the lateral wall of the wedge. Conformal/Standard radiotherapy wedges [refs 3-7,Casesnoves 2005] present several bioengineering-industrial design difficulties to obtain an optimal beam/beamlets-IMRT upper-surface radiation distribution,avoiding that them could emerge undesirably from lateral walls instead the lower wedge plane.We calculated the improved exact beamlet limit-angle mathematical method for a standard/conformal wedge filter design.It was developed with basic mathematical algorithms,geometrical design,and Numerical Simulations linked to this mathematical formulation.All that was done using the AAA algorithm integral attenuation exponential factor [AEF],which modulates the convolution kernel of the integral dose delivery.Results comprise the geometrical design of the conformal wedge,showed in several sketches,and simulations with appropriate software. In addition,a series of geometrical formulas/tables for the beamlets limits,trigonometric AEF background,and mathematical formulation with the simulations of the AEF for a 2-steps conformal wedge are obtained.