# US 2013/0253252 A1 · Particle beam irradiation apparatus and particle beam therapy system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0253252 A1 - Document ID: US20130253252A1 - Status: Published application - Kind: A1 - Application number: 13/894,731 - Filed: 2013-05-15 - Published: 2013-09-26 - Earliest claimed: 2009-11-03 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Takaaki IWATA - Web page: https://patentgrep.com/patent/US20130253252A1 ## CPC - A61N 5/1048: {Monitoring, verifying, controlling systems and methods} - A61N 5/10: X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy (A61N5/01 takes precedence) - G21K 1/093: by magnetic means - G21K 1/10: Scattering devices; Absorbing devices; Ionising radiation filters - G21K 5/04: with beam-forming means - A61N 2005/1087: {Ions; Protons} - A61N 2005/1095: {Elements inserted into the radiation path within the system, e.g. filters or wedges} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES ## Abstract The objective of the present invention is to eliminate noise caused by driving a ridge filter and to achieve a uniform dose distribution without making a patient sense discomfort or anxiety. There are provided a ridge filter having a thickness distribution in which the energy that a charged particle beam loses differs depending on the position thereon through which the charged particle beam passes, a deflector that deflects the charged particle beam, and a controller that controls the deflector in such a way that the charged particle beam passes through the thickness distribution of the ridge filter. ## Claims ### Claim 1 A particle beam irradiation apparatus that irradiates a charged particle beam accelerated by an accelerator onto an irradiation subject, the particle beam irradiation apparatus comprising: a ridge filter having a thickness distribution in which energy that the charged particle beam loses differs depending on the position thereon through which the charged particle beam passes; a deflector that deflects the charged particle beam; and a controller that controls the deflector in such a way that the charged particle beam with a wobbling motion passes through the thickness distribution of the ridge filter. ### Claim 2 (depends on 1) The particle beam irradiation apparatus according to claim 1, wherein the deflector comprises an upstream deflector that is disposed at an upstream side of the ridge filter and includes a first upstream deflector that deflects the charged particle beam in a direction that departs from a beam axis along which the charged particle beam enters and a second upstream deflector that is disposed at a downstream side of the first upstream deflector and deflects the charged particle beam in direction parallel to the beam axis. ### Claim 3 (depends on 1) The particle beam irradiation apparatus according to claim 1, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters. ### Claim 4 (depends on 3) The particle beam irradiation apparatus according to claim 3, wherein the beam scanning unit includes an X-direction scanning electromagnet that scans the charged particle beam in the X direction and a Y-direction scanning electromagnet that scans the charged particle beam in the Y direction. ### Claim 5 (depends on 3) The particle beam irradiation apparatus according to claim 3, wherein the beam scanning unit includes an X-direction wobbler electromagnet and a Y-direction wobbler electromagnet that make the charged particle beam rotate around the beam axis. ### Claim 6 (depends on 1) The particle beam irradiation apparatus according to claim 1, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters, wherein the beam scanning unit includes (i) an X-direction beam scanning unit that is disposed in the vicinity of the ridge filter and scans the charged particle beam in the X direction and (ii) a Y-direction scanning electromagnet that scans the charged particle beam in the Y direction, and the X-direction beam scanning unit includes (i) an X-direction scanning electromagnet that scans the charged particle beam in the X direction and (ii) an X-direction downstream deflector that is disposed at the upstream side of the X-direction scanning electromagnet and deflects the charged particle beam in such a way as to lead the charged particle beam that has passed through the ridge filter to the X-direction scanning electromagnet. ### Claim 7 (depends on 1) The particle beam irradiation apparatus according to claim 1, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters, wherein the beam scanning unit includes an X-direction wobbler electromagnet and a Y-direction wobbler electromagnet that make the charged particle beam rotate around the beam axis, the X-direction wobbler electromagnet is disposed in the vicinity of the ridge filter, and the beam scanning unit has an X-direction downstream deflector that is disposed at the upstream side of the X-direction wobbler electromagnet and deflects the charged particle beam in such a way as to lead the charged particle beam that has passed through the ridge filter to the X-direction wobbler electromagnet. ### Claim 8 (depends on 1) The particle beam irradiation apparatus according to claim 1, wherein the ridge filter has a plurality of ridges in the thickness distribution. ### Claim 9 (depends on 1) A particle beam therapy system comprising: an ion beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator until the charged particle beam acquires predetermined energy; an ion beam transport system that transports the charged particle beam accelerated by the ion beam generation apparatus; and a particle beam irradiation apparatus that irradiates the charged particle beam transported by the ion beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is a particle beam irradiation apparatus according to claim 1. ### Claim 10 (depends on 2) The particle beam irradiation apparatus according to claim 2, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters. ### Claim 11 (depends on 2) The particle beam irradiation apparatus according to claim 2, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters, wherein the beam scanning unit includes (i) an X-direction beam scanning unit that is disposed in the vicinity of the ridge filter and scans the charged particle beam in the X direction and (ii) a Y-direction scanning electromagnet that scans the charged particle beam in the Y direction, and the X-direction beam scanning unit includes (i) an X-direction scanning electromagnet that scans the charged particle beam in the X direction and (ii) an X-direction downstream deflector that is disposed at the upstream side of the X-direction scanning electromagnet and deflects the charged particle beam in such a way as to lead the charged particle beam that has passed through the ridge filter to the X-direction scanning electromagnet. ### Claim 12 (depends on 2) The particle beam irradiation apparatus according to claim 2, further including a beam scanning unit, disposed at the downstream side of the ridge filter, that scans the charged particle beam in the XY plane that intersects the beam axis along which the charged particle beam enters, wherein the beam scanning unit includes an X-direction wobbler electromagnet and a Y-direction wobbler electromagnet that make the charged particle beam rotate around the beam axis, the X-direction wobbler electromagnet is disposed in the vicinity of the ridge filter, and the beam scanning unit has an X-direction downstream deflector that is disposed at the upstream side of the X-direction wobbler electromagnet and deflects the charged particle beam in such a way as to lead the charged particle beam that has passed through the ridge filter to the X-direction wobbler electromagnet. ### Claim 13 (depends on 2) The particle beam irradiation apparatus according to claim 2, wherein the ridge filter has a plurality of ridges in the thickness distribution. ### Claim 14 (depends on 2) A particle beam therapy system comprising: an ion beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator until the charged particle beam acquires predetermined energy; an ion beam transport system that transports the charged particle beam accelerated by the ion beam generation apparatus; and a particle beam irradiation apparatus that irradiates the charged particle beam transported by the ion beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is a particle beam irradiation apparatus according to claim 2.