PROBLEM TO BE SOLVED: To provide a stacked conformation radiotherapy system capable of homogenizing a radiation dose distribution better than conventional ones in stacked conformation irradiation.SOLUTION: The stacked conformation radiotherapy system includes an irradiation head 4 which projects a particle beam accelerated by an accelerator 2a toward an object to-be-irradiated and includes wobbler electromagnets 42a, 42b for deflecting and scanning the particle beam. In carrying out stacked conformation radiotherapy by deflecting and scanning the particle beam, the irradiation control means 5 subjects the wobbler electromagnets 42a, 42b to magnetization controls so that the particle beam may depict a one-stroke revolving orbit which begins with a start point and returns to the start point, and it performs a control so that the irradiation period Tb of the particle beam to be outputted from the irradiation head 4 may become integral times a wobbler cycle Tw which is required for the particle beam to make one revolution of the revolving orbit.COPYRIGHT: (C)2009,JPO&INPIT【課題】積層原体照射において、照射線量分布を従来よりも均一化することが可能な積層原体照射システムを提供する。【解決手段】加速器2aで加速された粒子線を被照射体に向けて照射する照射ヘッド4を備え、照射ヘッド4は、粒子線の偏向走査用のワブラ電磁石42a,42bを有し、照射制御手段5は、ワブラ電磁石42a,42bを励磁制御して粒子線を偏向走査して積層原体照射を行う際に、粒子線が始点から開始して始点に戻るような一筆書の周回軌道を描くようにワブラ電磁石42a,42bを励磁制御するとともに、照射ヘッド4から出力される粒子線の照射期間Tbが、粒子線が周回軌道を一周するのに要するワブラ周期Twの整数倍になるように制御する。【選択図】図2
