Geometrically reduced individual irregular compensator - for radiation therapy with high energy photons

摘要

Method is provided for mfg. a geometrically reduced individual irregular compensator to be placed at a distance from a patient in the path of radiation, for improving dose distribution in therapeutical irradiation of irregular body surfaces with high-energy photons, with scanning of the body surface and simultaneous transmission to means for shaping the compensator. To place the compensator at the radiation source, a precise negative or positive of the compensator is formed with lateral geometrical correction and radial absorption correction. A material of high at.no. and high density and with sufficient strength and high deformation capacity is then supplied for the positive, to minimise its thickness so that it can then be placed at a radiation source. Pref. the compensation is made of an alloy comprising 50%Bi, 26.7%Pb, 13.3%Sn and 10%Cd,. Pref. the Schmidt corrector is made from polystyrene and plexiglass.