The Design and Construction of Compensators and Wedges for Cobalt-60 Beams Using Two Basic Factors

抄録

Methods have been proposed to construct compensators and wedges for Co-60beams. Each of them is a set of a main compensator or wedge and its supplementary filter. Two basic factors of F(d) and F2(d) have been deduced by an extension of van de Geijn's idea with respect to the triangular shaped compensator and wedge design. The main compensator and main wedge are constructed using F1(d) and F2(d)respectively, and their supplementary filters using F2(d). Both factors depend on the source-to-surface distance (SSD), the depth dose (D), the derivative of D with depth, and the linear attenuation coefficient of beam modifying filter material (A). It has been experimentally confirmed for Co-60 photon beams that such compensated and wedged dose distributions' as are desired can be generated by the new compensator and wedge techniques, respectively.