[A way to spatial irradiation planning. III. Further information on the procedure for obtaining dose homogeneity in noncoplanar ray beams and its experimental verification].

The method is based on the following principle: Single, initally unsettled parameters of irradiation are determined by explicit calculation in such a way that the dose gradient resulting from the dose gradients of the single ray beams in the point of intersection of their axes becomes zero. The separation or addition of components of the gradients is performed by use of co-ordinates for the ray beam as well as for the body. The following parameters can be determined explicitly: First, the weights of the partial doses which are to form the total dose in the point of intersection and/or second, the angles of the wedges and/or third, the rotational angles of the wedge filters, i. e. the angles of rotation of the wedge filters about an axis corresponding to the central ray. In the course of the following experimental verification of the method, maximally possible dose homogeneity results within the area of the crossing ray beams. Moreover, the advantages of field arrangements with different planes of incidence are coming into view.