Particle beam irradiation apparatus

• US 5,818,058 A
• Filed: 01/17/1997
• Issued: 10/06/1998
• Est. Priority Date: 01/18/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Tsukishima, Chihiro, Matsuda, Tetsuya, Sato, Shinji, Tanaka, Hirofumi, Maruyama, Akihiko, Nakanishi, Tetsuya
• Primary Examiner(s): Berman, Jack I.
• Application Number:
  US08/785,257
• Time in Patent Office: 627 Days
• Field of Search: 250/492.3, 376/112, 315/502
• US Class Current: 250/492.3
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: A61N 5/1079 Sharing a beam by multiple treatment stations
• CPC Class Codes: A61N 5/1081 Rotating beam systems with a specific mechanical construction, e.g. gantries
• CPC Class Codes: G21K 5/10 with provision for relative movement of beam source and object to be irradiated

Abstract

An acceleration orbit face of particle beam circular acceleration unit is placed at right angles to a rotation shaft of rotation unit for rotating the particle beam circular acceleration unit, beam transport unit, and irradiation field formation unit in one piece. Shields for shielding radiations and magnetism are placed symmetrically with respect to the center axis of the particle beam circular acceleration unit. Shields are placed symmetrically with respect to the center line of the particle beam circular acceleration means, thereby lessening the amount of beams coming in collision with surrounding walls from the beam acceleration orbit, decreasing the radiation leakage amount, lightening the shields, and providing a light particle beam irradiation apparatus.

Claims

1. A particle beam irradiation apparatus comprising:

particle beam circular acceleration means having particle beam generation means for generating a particle beam, said particle beam circular acceleration means generating a magnetic field through which the generated particle beam is accelerated, circularly accelerating the particle beam, and emitting a resultant particle beam;

beam transport means for transporting the particle beam to an irradiation room in which an irradiated body is placed;

irradiation field formation means for forming the particle beam to any desired shape and irradiating the irradiated body with the particle beam; and

means for rotating said particle beam circular acceleration means, said beam transport means, and said irradiation field formation means as a unit,

wherein an acceleration orbit plane, containing the circular paths along which said particle beam is accelerated, of said particle beam circular acceleration means is disposed at right angles to a rotation axis of said rotation means, and wherein

the irradiated body to be irradiated with the particle beam is placed on the rotation axis of said rotation means.

2. The particle beam irradiation apparatus as claimed in claim 1, wherein said particle beam circular acceleration means and said rotation means are placed so that an axis of said particle beam circular acceleration means and a center line of said rotation means become coaxial.

3. The particle beam irradiation apparatus as claimed in claim 1, wherein an extension in an emission direction of said irradiation field formation means for irradiating the irradiated body with the particle beam emitted from said particle beam circular acceleration means and transported via said beam transport means is placed so as to cross an extension to the rotation shaft of said rotation means.

4. The particle beam irradiation apparatus as claimed in claim 1, wherein a rotation frame of said rotation means for rotating said particle beam circular acceleration means, said beam transport means, and said irradiation field formation means in one piece is disposed at three places of both end faces of said particle beam circular acceleration means and a portion of said irradiation field formation means.

5. The particle beam irradiation apparatus as claimed in claim 1, wherein a shield for shielding a radiation is placed between said particle beam circular acceleration means and the irradiation room in which an irradiated body is placed.

6. The particle beam irradiation apparatus as claimed in claim 5, wherein the shield placed between said particle beam circular acceleration means and the irradiation room is placed axially symmetrically with respect to the axis of said particle beam circular acceleration means.

7. The particle beam irradiation apparatus as claimed in claim 6, wherein the radiation shield placed between said particle beam circular acceleration means and the irradiation room is a composite shield comprising a nonmagnetic material and a magnetic material laminated on each other with the nonmagnetic material placed on a side of said particle beam circular acceleration means and the magnetic material on a side of the irradiation room.

8. The particle beam irradiation apparatus as claimed in claim 6, wherein the shield placed between said particle beam circular acceleration means and the irradiation room is a composite shield comprising a radiation shield and a magnetic material laminated on each other with the radiation shield placed on a side of said particle beam circular acceleration means and the magnetic material on a side of the irradiation room and wherein a portion of the radiation shield larger than an outer diameter of said particle beam circular acceleration means is thinned.

9. The particle beam irradiation apparatus as claimed in claim 1, wherein a composite shield comprising a magnetic material and a radiation shield laminated on each other is placed on both side faces of an irradiation room side of said particle beam circular acceleration means and an opposite side thereto with the magnetic material placed on a side of said particle beam circular acceleration means.

10. The particle beam irradiation apparatus as claimed in claim 1, wherein said particle beam circular acceleration means has magnetic field generation means formed of superconducting coils, said superconducting coils being cooled only by a very-low-temperature refrigerator.

11. The particle beam irradiation apparatus as claimed in claim 10, wherein a center axis of cylinders of the very-low-temperature refrigerator for cooling the superconducting coils is placed in parallel with the rotation shaft of said particle beam circular acceleration means or at least with a very-low-temperature part placed on a bottom.

12. The particle beam irradiation apparatus as claimed in claim 1, wherein the magnetic field generation means of said particle beam circular acceleration means comprises a superconducting coil for generating a main magnetic field and a shielding coil being placed on an outer periphery of said superconducting coil for canceling a magnetic field leaked on the outer periphery of said superconducting coil.

13. The particle beam irradiation apparatus as claimed in claim 1, wherein the magnetic field generation means of said particle beam circular acceleration means comprises a superconducting coil for generating a main magnetic field, a shielding coil being placed on an outer periphery of said superconducting coil for canceling a magnetic field leaked on the outer periphery of said superconducting coil, and a magnetic body placed on an outer periphery of said shielding coil.

14. The particle beam irradiation apparatus as claimed in claim 12, wherein said superconducting coil is formed of a superconducting coil.

15. The particle beam irradiation apparatus as claimed in claim 13, wherein said superconducting coil is formed of a superconducting coil.

16. The particle beam irradiation apparatus as claimed in claim 1, wherein an emission direction of a particle beam taken out from said particle beam circular acceleration means is adjusted so as to become a direction along an extension to a line connecting an emission position and a center of said particle beam circular acceleration means.

17. The particle beam irradiation apparatus as claimed in claim 1, wherein said particle beam circular acceleration means comprises:

magnetic field generation means and high-frequency voltage application means for circularly accelerating the particle beam;

an emission mechanism for outputting the accelerated particle beam;

and a dispersion function correction magnet,

wherein a dispersion function of the particle beam at an output thereof and a value resulting from differentiating the dispersion function in a beam travel direction become almost zero.

18. The particle beam irradiation apparatus as claimed in claim 1, wherein said particle beam circular acceleration means is a cyclotron or synchrocyclotron.

19. A particle beam irradiation apparatus comprising:

(1) rotary particle beam irradiation means comprising;

particle beam circular acceleration means having particle beam generation means for generating a particle beam, said particle beam circular acceleration means generating a magnetic field through which the generated particle beam is accelerated, circularly accelerating the particle beam, and emitting a resultant particle beam;

beam transport means for transporting the accelerated particle beam;

irradiation field formation means for forming the particle beam into any desired shape and irradiating a first irradiated body with the particle beam; and

means for rotating said particle beam circular acceleration means, said beam transport means, and said irradiation field formation means as a unit;

wherein said first irradiated body is placed in a rotary irradiation room accommodating said first irradiated body on the rotation axis of said rotation means; and

(2) at least one fixed irradiation room, each comprising;

fixed beam transport means that can be connected to said beam transport means of said rotary particle beam irradiation means; and

fixed irradiation field formation means for forming the particle beam into any desired shape and irradiating a second irradiated body, placed within said at least one fixed irradiation room, with the particle beam.

20. The particle beam irradiation apparatus as claimed in claim 19 wherein said particle beam circular acceleration means is a cyclotron or synchrocyclotron.

21. The particle beam irradiation apparatus as claimed in claim 19 wherein said fixed beam transport means is disposed outside a room containing said first irradiated body.

22. A particle beam irradiation apparatus comprising:

(1) rotary particle beam irradiation means comprising;

particle beam circular acceleration means having particle beam generation means for generating a particle beam, said particle beam circular acceleration means generating a magnetic field through which the generated particle beam is accelerated, circularly accelerating the particle beam, and emitting a resultant particle beam;

beam transport means for transporting the accelerated particle beam;

irradiation field formation means for forming the particle beam to any desired shape and irradiating a first irradiated body with the particle beam; and

means for rotating said particle beam circular acceleration means, said beam transport means, and said irradiation field formation means as a unit;

wherein said first irradiated body is placed in a rotary irradiation room accommodating said first irradiated body on the rotation axis of said rotation means; and

(2) at least one fixed irradiation room comprising;

fixed beam transport means that can be connected to said beam transport means of said rotary particle beam irradiation means; and

fixed irradiation field formation means for forming the particle beam into any desired shape and irradiating a second irradiated body, placed within said at least one fixed irradiation room, with the particle beam,

wherein an acceleration orbit plane, containing the circular paths along which said particle beam is accelerated, of said particle beam circular acceleration means is disposed at right angles to a rotation axis of said rotation means.

23. The particle beam irradiation apparatus as claimed in claim 22 wherein said particle beam circular acceleration means is a cyclotron or synchrocyclotron.