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

• US 7,049,613 B2
• Filed: 12/08/2004
• Issued: 05/23/2006
• 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): Wells, Nikita
• Assistant Examiner(s): Vanore, David A.
• Application Number:
  US11/006,605
• Publication Number:
  US 20050127306A1
• Time in Patent Office: 531 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 particle beam irradiation system comprising a charged particle beam generator and an irradiation field forming apparatus for irradiating a charged particle beam extracted from said charged particle beam generator to an irradiation target,

said irradiation field forming apparatus comprising a Bragg peak spreading-out device for spreading out a Bragg peak of the charged particle beam, 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,

said Bragg peak spreading-out device and said scattering compensator being mounted in said irradiation field forming apparatus movably in a direction of advance of the charged particle beam.

2. A particle beam irradiation system according to claim 1, further comprising a control unit for positioning said Bragg peak spreading-out device and said scattering compensator to a setting position in the direction of advance of the charged particle beam, the setting position being determined based on treatment plan information.

3. A particle beam irradiation system according to claim 1, further comprising a driving unit for moving said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam, and a motion control system for controlling said driving unit and controlling an amount by which said Bragg peak spreading-out device and sad scattering compensator is moved.

4. A particle beam irradiation system according to claim 1, wherein said Bragg peak spreading-out device and said scattering compensator are joined to each other, and said irradiation system further comprises a driving unit for moving a joined unit of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam, and a motion control system for controlling said driving unit and controlling an amount by which the joined unit of said Bragg peak spreading-out device and sad scattering compensator is moved.

5. A particle beam irradiation system according to claim 4, wherein the joined unit of said Bragg peak spreading-out device and sad scattering compensator is arranged upstream of said scatterer device and said range adjusting device in the direction of advance of the charged particle beam.

6. A particle beam irradiation system according to claim 1, wherein said Bragg peak spreading-out device is a range modulation wheel rotatably supported in a path along which the charged particle beam advances and having blade portions of which thicknesses in the direction of advance of the charged particle beam differ from each other in a stepwise way.

7. A particle beam irradiation system comprising a charged particle beam generator and an irradiation field forming apparatus for irradiating a charged particle beam extracted from said charged particle beam generator to an irradiation target,

said irradiation field forming apparatus comprising a Bragg peak spreading-out device for spreading out a Bragg peak of the charged particle beam, 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,

at least one of said Bragg peak spreading-out device and said scattering compensator being mounted in said irradiation field forming apparatus movably in a direction of advance of the charged particle beam.

8. A particle beam irradiation system according to claim 7, further comprising a driving unit for moving said scatterer device in the direction of advance of the charged particle beam, and a motion control system for controlling said driving unit and controlling an amount by which said scatterer device is moved.

9. A particle beam irradiation system according to claim 7, further comprising a driving unit for moving said range adjusting device in the direction of advance of the charged particle beam, and a motion control system for controlling said driving unit and controlling an amount by which said range adjusting device is moved.

10. A particle beam irradiation system according to claim 7, further comprising a driving unit for 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, and a motion control system for controlling said driving unit and controlling an amount by which at least one of said Bragg peak spreading-out device and sad scattering compensator is moved.

11. A particle beam irradiation system according to claim 7, wherein said Bragg peak spreading-out device and said scattering compensator are joined to each other, and said irradiation system further comprises a driving unit for moving a joined unit of said Bragg peak spreading-out device and said scattering compensator in the direction of advance of the charged particle beam, and a motion control system for controlling said driving unit and controlling an amount by which the joined unit of said Bragg peak spreading-out device and sad scattering compensator is moved.

12. A particle beam irradiation system according to claim 7, wherein said Bragg peak spreading-out device is a range modulation wheel rotatably supported in a path along which the charged particle beam advances and having blade portions of which thicknesses in the direction of advance of the charged particle beam differ from each other in a stepwise way.

13. An irradiation field forming apparatus for irradiating a charged particle beam extracted from a charged particle beam generator to an irradiation target,

wherein said irradiation field forming apparatus comprises a Bragg peak spreading-out device for spreading out a Bragg peak of the charged particle beam, 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,

said Bragg peak spreading-out device and said scattering compensator being mounted movably in a direction of advance of the charged particle beam.