Patent Number: 055639259
Section: claims

1. A method for adjusting the radiation output delivered to an object from a radiation source, comprising the following steps: generating a radiation beam having a variable radiation output and a substantially lossless beam path from a radiation source to the object;  delimiting the beam path by moving at least one beam-shielding device;  defining an irradiated field of the object;  varying the radiation output of the beam as a predetermined function of the position of the beam-shielding device, a wedge factor of the radiation output thereby varying according to a predetermined profile, in which the wedge factor is defined as the ratio between a reference radiation output along a reference axis of the beam with a predetermined physical wedge in the beam path and an actual radiation output of the beam in a substantially lossless beam path; and  varying the radiation output such that the wedge factor is constant regardless of the size of the irradiated field.  a radiation source generating a radiation beam having a variable radiation output;  an irradiated field of the object;  beam-shielding means for delimiting the output beam to at least one predetermined irradiation field of the object;  a dose controller for varying a degree of shielding of the beam and the radiation output; and  processing means for generating and applying to the dose controller set dose signals, comprising nominal dose signals and wedge correction factors, and for thereby varying the radiation output such that a wedge factor is constant regardless of the degree of shielding, where the output factor is defined as the ratio between a reference radiation output along a reference axis of the beam with a predetermined physical wedge in the beam path and an actual radiation output of the beam in a substantially lossless beam path. 2. A method as in claim 1, in which the wedge factor is equal to unity. 3. A system for adjusting the radiation output delivered to an object from a radiation source, comprising: