SYSTEM FOR DETERMINING PARTICLE BEAM DIRECTION, METHOD FOR DETERMINING PARTICLE BEAM DIRECTION, AND COMPUTER PROGRAM FOR DETERMINING PARTICLE BEAM DIRECTION

摘要

A system for determining the direction of a particle beam, which determines the direction of a robust beam for a patient setup error, is provided. A beam direction image generating unit (1) generates a plurality of electron density beam direction images as viewed from a plurality of beam source positions. An average power spectrum calculation unit (2') calculates the average power spectrum of each of the plurality of electron density beam direction images. A slope calculation unit (3A) calculates the slope of the average power spectrum determined from the plurality of electron density beam direction images. A beam direction determination unit (3B) determines the direction of a particle beam on the basis of the slope.