Isokinetic gantry arrangement for the isocentric guidance of a particle beam and a method for constructing same

• US 6,897,451 B2
• Filed: 09/05/2003
• Issued: 05/24/2005
• Est. Priority Date: 09/05/2002
• Status: Expired due to Fees

• Current Assignee: Gessellschaft Fur Schwerionenforschung MbH, Mania Technologie AG
• Original Assignee: Gessellschaft Fur Schwerionenforschung MbH, Mania Technologie AG
• Inventors: Linn, Stefan, Koch, Dietmar, Fuchs, Ralf, Bourgeois, Walter, Zimmerer, Thomas, Kaercher, Hans, Spiller, Peter
• Primary Examiner(s): Lee, John R.
• Assistant Examiner(s): Souw, Bernard E.
• Application Number:
  US10/655,616
• Publication Number:
  US 20040159795A1
• Time in Patent Office: 627 Days
• Field of Search: 250/396.R, 250/492.3, 248/121, 248/122.1, 248/123.11, 248/127, 248/218.4, 248/219.2, 248/575, 248/612, 248/637, 248/638, 248/672, 248/674, 248/676, 378/4, 378/15, 378/68, 378/208, 378/210, 378/65, 378/143, 378/144, 378195-198
• US Class Current: 250/396.00R
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: A61N 5/1081 Rotating beam systems with a specific mechanical construction, e.g. gantries

Abstract

The invention relates to an isokinetic gantry arrangement for the isocentric guidance of a particle beam (12), that can be rotated about a horizontal longitudinal axis (16) and has a beam optical system, symbolized by magnets (36, 38, 40), that deflects the particle beam (12) axially infected by a particle beam accelerator, radially and vertically relative to the horizontal longitudinal axis (16), with a largely rotationally-symmetrical primary structure (18) and a secondary structure (30) that holds the magnets (36, 38, 40) and is supported by the primary structure (18), with the secondary structure (30) having a rigidity that is designed so that the vertical displacements of the magnets (36, 38, 40) due to their weight are essentially of equal magnitude (isokinetic) in all the angle of rotation positions of the gantry arrangement (10), and a method for its design.

Claims

1. Gantry arrangement for the isocentric guidance of a particle beam (12) that can be rotated about a horizontal longitudinal axis (16) and has a beam optical system symbolized by magnets (36, 38, 40) that radially and vertically relative to the horizontal longitudinal axis (16) deflect a particle beam (12) that has been axially injected by a particle beam accelerator, with an extensive rotationally-symmetrical primary structure (18) and a secondary structure (30) supported by the primary structure (18) and holding the magnets (36, 38, 40), with the secondary structure (30) having a rigidity that is designed such that vertical displacements of the magnets (36, 38, 40) due to their weight are essentially of the same magnitude (isokinetic) in all the angle of rotation positions of the gantry arrangement (10).

2. Gantry arrangement in accordance with claim 1, characterized in that, the secondary structure (30) has a rigidity that is designed such that vertical displacements of the magnets (36, 38, 40) due to their weight are of equal magnitude in all angle of rotation positions of the gantry arrangement (10).

3. Gantry arrangement in accordance with claim 1, characterized in that, the magnets (36, 38, 40) can move on circular tracks about an axis of rotation (52) that is displaced in the unloaded state relative to the horizontal longitudinal axis (16) of the gantry arrangement (10).

4. Gantry arrangement in accordance with claim 3, characterized in that, as a radiation point of aim, the intersection point between the particle beam and the load-displaced axis of rotation (52) is used, that with respect to the horizontal longitudinal axis (16) of the gantry arrangement (10) in the unloaded state can be determined from the load displacements of the magnets (36, 38, 40) using the method of the smallest error squares.

5. Gantry arrangement in accordance with claim 1, characterized in that, the primary structure (18) is designed as a three-dimensional framework consisting essentially of horizontal and vertical members (20, 20′

) and diagonal members (20″

).

6. Gantry arrangement in accordance with claim 5, characterized in that, some of the diagonal members (20″

) stiffen the rectangular frame of the primary structure (18) and intersect in the centre points (22, 22′

) of the surface.

7. Gantry arrangement in accordance with claim 1, characterized in that, the primary structure (18) has at its ends (24, 24′

) two, particularly box-shaped, member support rings (26, 26′

) that interact with fixed bearing pedestals (28, 28′

).

8. Gantry arrangement in accordance with claim 7, characterized in that, one (28) of the two fixed bearing pedestals (28, 28′

) is designed as a floating bearing and the other (28′

) of the two fixed bearing pedestals (28, 28′

) is designed as a fixed bearing.

9. Gantry arrangement in accordance with claim 1, characterized in that, the secondary structure (30) holding the magnets (36, 38, 40) and supported by the primary structure (18) is of a less-rigid design than the primary structure (18).

10. Gantry arrangement in accordance with claim 1, characterized in that, the secondary structure (30) holding the magnets (36, 38, 40) and supported by the primary structure (18) is attached to the primary structure (18) so as to be torsionally stiff with respect to tilting movements of the magnets (36, 38, 40) in azimuth.

11. Gantry arrangement in accordance with claim 1, characterized in that, the secondary structure (30) supported by the primary structure (18) has at least one, in particular three, magnet(s) (36, 38, 40).

12. Gantry arrangement in accordance with claim 11, characterized in that, a first magnet (36) is essentially arranged on the horizontal longitudinal axis (16) facing towards the particle accelerator, to take the axially injected particle beam (12) and to deflect it from the horizontal longitudinal axis (16).

13. Gantry arrangement in accordance with claim 12, characterized in that, the first magnet (36) deflects the axially injected particle beam (12) from the horizontal longitudinal axis (16) by an angle approximately between 30°

to 60°

, in particular of approximately 45°

.

14. Gantry arrangement in accordance with claim 12, characterized in that, the first magnet (36) is cantilever mounted on the primary structure (18) on the horizontal longitudinal axis (16) above long members (32′

).

15. Gantry arrangement in accordance with claim 11, characterized in that, a second magnet (38) is provided to take the particle beam (12) coming from the first magnet (36), and deflect it parallel to the horizontal longitudinal axis (16), and is coupled to the first magnet by struts (50).

16. Gantry arrangement in accordance with claim 15, characterized in that, the second magnet (38) deflects the particle beam (13), deflected by the first magnet (36), back parallel to the horizontal longitudinal axis (16) by an angle of approximately between 30°

to 60°

, in particular by approximately 45°

.

17. Gantry arrangement in accordance with claim 11, characterized in that, a third magnet (40) is provided to take the particle beam (12) coming from the second magnet (38), that deflects it radially and vertically relative to the horizontal longitudinal axis (16) and is coupled to the second magnet by struts (50).

18. Gantry arrangement in accordance with claim 17, characterized in that, the third magnet (40) deflects the particle beam (12) coming from the second magnet (38), radially and essential vertical to the horizontal longitudinal axis (16) by an angle of approximately between 60°

to 120°

, in particular by approximately 90°

.

19. Gantry arrangement in accordance with claim 1, characterized in that, the magnets (36, 38, 40) are designed to take and deflect a particle beam (12) of protons.

20. Gantry arrangement in accordance with claim 1, characterized in that, the magnets (36, 38, 40) are designed to take and deflect a particle beam (12) of ions.

21. Gantry arrangement in accordance with claim 1, characterized in that, particle beam guidance elements are arranged between the magnets (36, 38, 40).

22. Gantry arrangement in accordance with claim 1, characterized in that, the second and third magnets form an integrated unit.

23. Method for design of a gantry arrangement (10) for the isocentric guidance of a particle beam (12) in accordance with one of the preceding claims, by means of which the rigidity of a primary structure (18) that is essentially rotationally-symmetrical is designed in such a way that the vertical displacements of the magnets (36, 38, 40) due to their weight are essentially of equal magnitude, preferably of exactly equal magnitude, in all the angle of rotation positions of the gantry arrangement (10), with the magnets (36, 38, 40) moving on circular tracks about an axis of rotation (52) that is displaced with respect to the horizontal longitudinal axis (16) of the gantry arrangement (10) in the unloaded state.

24. Method in accordance with claim 23, characterized in that, the theoretical axis of rotation (52) lowered due to loads is determined with respect to the horizontal longitudinal axis (16) of the gantry arrangement (10) in the unloaded state by means of the method of smallest error squares and the “

intersection point”

between the particle beam and the load-displaced theoretical axis of rotation (52) is defined as the radiation point of aim.