PROBLEM TO BE SOLVED: To provide a particle beam therapy system easily improving an accuracy in therapy by spot scanning irradiation.SOLUTION: The particle beam therapy system 100 includes a synchrotron 200, a beam transport system 300, and an irradiation device 500. In the particle beam therapy system, a controller 600 turns on a high frequency power applied on a beam emission device 26 when a charged particle beam is supplied to the irradiation device 500. When the supply of the charged particle beam is cut off, the controller turns off the high frequency power applied on the beam emission device 26 and then changes an amount of excitation of an electromagnet disposed in the synchrotron 200 to extend stability limit and stop the emission of the charged particle beam. Before restarting the supply of the charged particle beam, the controller controls to emit a part of the charged particle beam by narrowing the stability limit and cuts off the charged particle beam by an electromagnet disposed in the beam transport system 300.COPYRIGHT: (C)2011,JPO&INPIT【課題】スポットスキャニング照射で治療精度を容易に向上できる粒子線治療システムを提供する。【解決手段】粒子線治療システム100は、シンクロトロン200とビーム輸送系300と照射装置500から構成される。制御装置600は、照射装置500に荷電粒子ビームを供給する際には出射装置26に印加する高周波電力をONし、荷電粒子ビームの供給を遮断する際には出射装置26に印加する高周波電力をOFFした後に、シンクロトロン200に設置した電磁石の励磁量を変化させて安定限界を広げ荷電粒子ビームの出射を停止し、次に荷電粒子ビームの供給を再開する前に安定限界を狭め荷電粒子ビームの一部を出射し、該荷電粒子ビームをビーム輸送系300に設置した電磁石で遮断する。【選択図】図1
