Particle beam irradiation system and method of adjusting irradiation field forming apparatus

• US 7,154,107 B2
• Filed: 03/28/2005
• Issued: 12/26/2006
• Est. Priority Date: 12/10/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Akiyama, Hiroshi, Matsuda, Koji, Yanagisawa, Masaki, Fujimaki, Hisataka
• Primary Examiner(s): Vanore, David A.
• Application Number:
  US11/090,206
• Publication Number:
  US 20050167616A1
• Time in Patent Office: 638 Days
• Field of Search: 250/492.3, 315/501, 315/505, 315/507
• US Class Current: 250/492.3
• CPC Class Codes: A61N 1/44 Applying ionised fluids ion generators H01J37/00
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters

Abstract

A particle therapy system, as one example of a particle beam irradiation system, comprises a charged particle beam generator and an irradiation field forming apparatus. An ion beam from the charged particle beam generator is irradiated to a diseased part in the body of a patient through the irradiation field forming apparatus. A scattering compensator and a range modulation wheel (RMW) are disposed on the upstream side in a direction of beam advance and are movable along a beam axis. The movement of the scattering compensator and the RMW adjusts a size of the ion beam entering a scatterer device, whereby a change in scattering intensity of the ion beam in the scatterer device is adjusted. As a result, a penumbra in dose distribution is reduced and a more uniform dose distribution in a direction perpendicular to the direction of beam advance is obtained in the diseased part.

Claims

1. A method of adjusting an irradiation field forming apparatus comprising a Bragg peak spreading-out device for spreading out a Bragg peak of a charged particle beam extracted from a charged particle beam generator, and a scattering compensator provided on said Bragg peak spreading-out device and compensating differences in scattering intensity of the charged particle beam in said Bragg peak spreading-out device, thereby irradiating the charged particle beam to an irradiation target,

wherein said method includes a step of, prior to extracting the charged particle beam, moving at least one of said Bragg peak spreading-out device and said scattering compensator in a direction of advance of the charged particle beam to a predetermined position.

2. A method of adjusting an irradiation field forming apparatus according to claim 1, wherein said method further includes a step of moving at least one of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam depending on incident energy of the charged particle beam.

3. A method of adjusting an irradiation field forming apparatus according to claim 1, wherein said method further includes a step of moving at least one of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam depending on a thickness of a portion of said range adjusting device through which the charged particle beam passes.

4. A method of adjusting an irradiation field forming apparatus comprising a Bragg peak spreading-out device for spreading out a Bragg peak of a charged particle beam extracted from a charged particle beam generator, a scattering compensator provided on said Bragg peak spreading-out device and compensating differences in scattering intensity of the charged particle beam in said Bragg peak spreading-out device, a scatterer device through which the charged particle beam passes, and a range adjusting device for changing a range of the charged particle beam, thereby irradiating the charged particle beam to an irradiation target,

wherein said method includes a step of, prior to extracting the charged particle beam, moving at least one of said Bragg peak spreading-out device and said scattering compensator in a direction of advance of the charged particle beam to a predetermined position.

5. A method of adjusting an irradiation field forming apparatus according to claim 4, wherein said method further includes a step of moving at least one of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam depending on incident energy of the charged particle beam.

6. A method of adjusting an irradiation field forming apparatus according to claim 4, wherein said method further includes a step of moving at least one of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam depending on a thickness of a portion of said range adjusting device through which the charged particle beam passes.