摘要 |
A particle beam therapeutic apparatus can ensure the uniformity of dose distribution by overlapping the desired loci of the irradiation of a particle beam a reduced number of times. A flow of a particle beam transported so as to be irradiated to a diseased part is caused to deflect in two mutually orthogonal directions perpendicular to the direction of travel of the particle beam. The irradiation position of the particle beam is scanned, upon each period, in a manner to return to a position of irradiation located at the start of the period, whereby a plurality of loci drawn within one period are overlapped with one another thereby to irradiate a desired planned dose to the diseased part. The particle beam can be interrupted only at the end of the period. |