Ion beam therapy system and a method for operating the system

• US 6,683,318 B1
• Filed: 07/10/2001
• Issued: 01/27/2004
• Est. Priority Date: 09/11/1998
• Status: Expired due to Term

• Current Assignee: Gessellschaft Fur Schwerionenforschung MbH
• Original Assignee: Gessellschaft Fur Schwerionenforschung MbH
• Inventors: Kraemer, Michael, Scholz, Michael, Dolinski, Aleksiy, Krause, Udo, Eickhoff, Hartmut, Schardt, Dieter, Dahl, Ludwig, Pawelke, Joerg, Pavlovic, Marius, Klabunde, Juergen, Hinz, Rainer, Kraft, Gerhard, Franczak, Bernhard, Weber, Ulrich, Kraft-Weyrather, Wilma, Enghardt, Wolfgang, Haberer, Thomas, Ratzinger, Ulrich, Schlitt, Bernhard
• Primary Examiner(s): Nguyen, Judy
• Assistant Examiner(s): MOUTTET, BLAISE L
• Application Number:
  US09/786,698
• Time in Patent Office: 931 Days
• Field of Search: A61/N.501, 250/492.1, 250/492.3, 378/65
• US Class Current: 250/492.3
• CPC Class Codes: A61N 2005/1052 using positron emission tomography [PET] single photon emission computer tomography [SPECT] imaging
• 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 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• 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 ion beam therapy system and method for operating the system includes a source of ions (300), an accelerator system (400) and an ion beam transport system (60) for directing an ion beam to a plurality of treatment stations (100) to treat patients. The ion beam transport system (60) includes a gantry (8) carrying a vertical deflection system (45) and horizontal deflection system (55) positioned upstream from a last bending magnet (65) so as to provide a parallel scanning mode by an edge focusing effect.

Claims

1. An ion beam therapy system comprising:

a source of ions (300);

an accelerator system (400) for accelerating ions as a beam (50);

an ion beam transport system (60) for directing an ion beam from the accelerator to treatment stations (100) to treat patients supported in fixed orientation by patient support (200),

wherein said ion beam transport system (60) comprises;

at least a horizontal beam delivery system and at least a gantry (8) rotatable about an axis of rotation,

said gantry carries optics for receiving the ion beam on its axis of rotation (80), transporting said ion beam away from the axis of rotation and returning the ion beam on a path intersecting the axis at a target isocentre (90) within the patient, delivering said ion beam (50) by rotation of the gantry to said target isocentre (90) from different angles between 0 and 360 degrees;

said gantry (8) and said horizontal beam delivery system carries means (45, 55) for raster scanning said ion beam (50), enclosing vertical deflection means (45) and horizontal deflection means (55), positioned upstream of a last bending magnet (65), directing said ion beam (50) towards the patient and downstream the last quadrupole lens (75) of said gantry (8),

characterized in that the system comprises

the plurality of separate patient treatment stations (100) each having the patient support (200) for orienting a patient in a fixed position; and

wherein said vertical deflection means (45) and said horizontal deflection means (55) for said raster scanning each comprises one scanning magnet and deflects said ion beam (50) perpendicular to its beam axis, so that the beam (50) can be scanned by two scanning magnets over a predetermined controlled area around said target isocentre (90) after passing said last bending magnet (65), which provides a parallel scanning mode by an edge focusing effect at its entrance and exit edges and which comprises a normal conducting last dipole magnet.

2. The ion beam therapy system according to claim 1, characterized in that the ions of said ion beam (50) are one out of the group helium, carbon or oxygen ions.

3. The ion beam therapy system according to claim 1, characterized in that the system further comprises a position emission tomography camera oriented towards an inbeam position.

4. The ion beam therapy system according to claim 1, characterized in that the accelerator system (400) comprises a linear accelerator (22) and a Synchrotron (23) accelerator.

5. The ion beam therapy system according to claim 4, wherein the rigidity of an injected ion beam injected into said Synchrotron (23) accelerator is in the range of 0.38 to 0.76 Tm.

6. The ion beam therapy system according to claim 1, characterized in that said system comprises means for monitoring the raster scanned beam after passing the last bending magnet (65).

7. The ion beam therapy system according to claim 6, characterized in that said means for monitoring are mounted in-beam to a common support upstream of the patient support (200) and downstream the last bending magnet (65) coupled to the gantry (8) or upstream of the patient on a movable support for said monitoring means.

8. The ion beam therapy system according to claim 6, characterized in that said monitoring means comprise parallel-plate-ionisation chambers and multi-wire proportional chambers.

9. The ion beam therapy system according to claim 1, characterized in that the last bending magnet (65) has a bending angle of more than 60°

.

10. The ion beam therapy system according to claim 1, wherein an extraction mode of the extraction procedure is providing a variable extraction time between 1 and 10 seconds adapted to a tumor painting time for completion of a tumor slice and a beam monitoring time.

11. The ion beam therapy system according to claim 1, wherein values of emittances of extracted beams depend upon beam properties at injection includes the extraction beam energy, the extraction procedure and the Synchrotron (23) settings before the extraction starts.

12. The ion beam therapy system according to claim 1, wherein an extraction system (SM) provides a switching off and on within the same Synchrotron (23) cycle having the same beam energy.

13. The ion beam therapy system according to claim 1, wherein the optical properties at the gantry (8) are an achromatic beam transport from the Synchrotron (23) to a coupling point of the gantry (8), beam waists in both planes and an equal beam size in horizontal and vertical planes.

14. The ion beam therapy system according to claim 1, wherein an energy beam transport system (60) comprises quadrupole lenses (Q, 75), bending magnets (BM, 65) and beam diagnostic devices.

15. The ion beam therapy system according to claim 1, wherein an abort chopper for emergency switch off is installed subsequent to an extraction magnet.

22. A method for operating the system according to claim 1 comprising the steps of:

generating selected ions selected out of the group Helium, carbon or oxygen ions of a specific isotope;

forming an ion beam of said ions and selecting said isotope by mass spectrometric means;

accelerating said ion beam by linear accelerating means (22) and Synchrotron (23) means;

transferring said ion beam (50) along to said axis of rotation of a rotatable gantry (8);

bending said ion beam away from said axis around the perifering of said gantry (8);

characterized by

scanning said ion beam by deflecting said ion beam (50) in a vertical and horizontal direction in respect to the axis of said ion beam before said ion beam is bent by a last bending magnet (65) which provides a parallel scanning mode by an edge focusing effect towards the isocentre of said gantry (8).

23. The method for operating the system according to claim 22, wherein the rigidity of the injected ion beam injected into said Synchrotron (23) accelerator chain is maintained in the range of 0.38 to 0.76 Tm.

24. The method for operating the system according to claim 22, wherein the extraction mode of the extraction process provides a variable extraction time between 1 and 10 seconds adapted to a tumor painting time for completion of a tumor slice and a beam monitoring time.

25. The method for operating the system according to claim 22, wherein the values of emittances of the extracted beams depend upon beam properties at injection, extraction beam energy, the extraction process and the Synchrotron (23) settings before the extraction starts.

26. The method for operating the system according to claim 22, wherein the extraction process provides a switching off and on within the same Synchrotron (23) cycle having the same beam energy.

27. The method for operating the system according to claim 22, wherein a pulse-to-pulse variation of beam energy and intensity is performed by an accelerator chain (23) in parameter intervals, of 50-430 MeV/n for extraction beam energy and of 1:

1000 ratio between a minimum and a maximum bean intensity.

28. The method for operating the system according to claim 22, wherein a variation of the spill-duration and a switching off and on the extraction process at the same flat-top level is performed by an extraction system.

29. The method for operating the system according to claim 22, wherein a switching between different ion species is performed by an injection chain within less than 30 minutes.

30. The method for operating the system according to claim 22, wherein in the case of components failures or incorrect beam properties a control and safety system avoids a patient irradiation.

16. An ion beam therapy system comprising:

a source of ions (300);

an accelerator system (400) for accelerating ions as a beam (50);

an ion beam transport system (60) for directing an ion beam from the accelerator to the treatment stations (100) to treat patients supported in fixed orientation by the patient support (200),

wherein said ion beam transport system (60) comprises;

at least a horizontal beam delivery system and at least a gantry (8) rotatable about an axis of rotation, a plurality of separate patient treatment stations (100) each having a patient support (200) for orienting a patient in a fixed position;

characterized in that

the therapy system provides a multifield intensity-controlled raster scan treatment facility, comprising;

a Synchrotron (23) accelerator chain providing a pulse-to-pulse variation of beam energy and intensity in parameter intervals of 50-430 MeV/n for the extraction beam energy and of 1;

1000 ratio between a minimum and a maximum beam intensity,

an extraction system (SM) providing a variation of the spill-duration and a switching off and on the extraction process within the same Synchrotron (23) cycle having the same beam energy at the same flat-top level

an injection chain providing a switching between different ion species within less that 30 minutes,

a control and safety system having an abort chopper emergency switch off, installed subsequent to an extraction magnet, avoiding a patient irradiation in case of components failures or incorrect beam properties

a gantry beam delivery system (8) providing a 4π

tumor targeting equipped with an intensity controlled raster scanning system having two scanning magnets (45, 55) upstream of a last bending magnet (65), which provides a parallel scanning mode by an edge focusing effect at its entrance and exit edges and which comprises a normal conducting last dipole magnet.

17. The ion beam therapy system according to claim 16, wherein the rigidity of an injected ion beam injected into said Synchrotron (23) accelerator chain is in the range of 0.38 to 0.76 Tm.

18. The ion beam therapy system according to claim 17, wherein an extraction mode of the extraction procedure is providing a variable extraction time between 1 and 10 seconds adapted to a tumor painting time for completion of a tumor slice and a beam monitoring time.

19. The ion beam therapy system according to claim 18, wherein values of emittances of extracted beams depend upon beam properties at injection the extraction beam energy, the extraction procedure and the Synchrotron (23) settings before the extraction starts.

20. The ion beam therapy system according to claim 16, wherein the optical properties at the gantry (8) are an achromatic beam transport from the Synchrotron (23) to a coupling point of the gantry (8), beam waists in both planes and an equal beam size in horizontal and vertical planes.

21. The ion beam therapy system according to claim 16, wherein an energy beam transport system (60) comprises quadrupole lenses (Q, 75), bending magnets (BM, 65) and beam diagnostic devices.