[Choice of the geometric parameters in optimizing the irradiation of patients with malignant neoplasms]

The authors have devised an algorithm and made a program of 2-stage optimization of irradiation conditions. At the 1st stage geometric parameters of irradiation are selected (field sizes, their number, a tangential shift of the field axis) proceeding from the peculiarities of the position of tumors, vital organs and tissues in space in respect to a source for each irradiation direction. Dose optimization is done at the 2nd stage. Doses are calculated on the basis of empirical expressions for the distribution of a dose of single gamma- and inhibition radiation beams up to 42 MEV Tissue inhomogeneity and surface curvature are taken into consideration by means of corrections.