Patent Document ID: 5418715
Application ID: 08213405
Patent Flag: 1

Claim One:
1. A method of irradiating a patient with electron beams directed at a volume of interest in the patient having Cartesian dimensions x, y and z, with a dosage pattern described by the matrix D and electron flux within the patient defined by the matrix .PSI. at elements spatially dispersed within layers of constant z in the volume of interest and further identified to particular angular trajectories .alpha. and .beta. with respect to an axis in the z dimension, the method comprising the steps of: (a) providing to an electronic computer: (i) a matrix T describing the scattering power of the patient at the elements within the volume of interest; (ii) an incident field .PSI. having values corresponding to the electron flux of the electrons entering the region of interest; (b) instructing the electronic computer to: (i) set an initial matrix layer equal to the incident field .PSI.; (ii) generate from the initial matrix layer .PSI. through an algebraic approximation of Fermi's partial differential equation, a next matrix layer of flux values, offset by a predetermined amount in z; (iii) store the flux values of the next matrix layer determined at step (ii); (iv) set the flux values of the initial matrix layer equal to the flux values of the next matrix layer; (v) repeat steps (ii) and (iv) until flux values have been determined for the entire volume of interest; (c) using the flux values for the entire volume of interest to see if a dose is within a predetermined range; (d) control the electron beam directed at the volume of interest according to the incident field .PSI. if the dose for the volume of interest is within the range.