Compensating filter design using radiographic stereo shift information

This paper describes a method of designing 3 dimensional compensating filters for radiation therapy using photon beams. A radiopaque grid is placed on the patient surface and stereo shift radiographs are taken of the treatment area. With the aid of a computer, tissue deficit information is calculated. Isothickness lines are plotted for the different missing tissue thicknesses and lead sheets with proper magnification are cut from these plots and assembled into the final tissue compensator.