Laser-Accelerated Proton Therapy Units And Superconducting Electromagnet Systems For Same

• US 20090050819A1
• Filed: 12/21/2005
• Published: 02/26/2009
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: The Institute for Cancer Research (Fox Chase Cancer Center)
• Original Assignee: Fox Chase Cancer Center
• Inventors: Fourkal, Eugene S., Luo, Wei, Ma, Chang Ming, Li, Jinsheng
• Granted Patent: US 7,755,068 B2
• Time in Patent Office: Days
• US Class Current: 250/396.ML
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1088 generated by laser radiation
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: G21K 1/093 by magnetic means
• CPC Class Codes: G21K 5/04 with beam-forming means
• CPC Class Codes: H05H 15/00 Methods or devices for acceleration of charged particles not otherwise provided for , e.g. wakefield accelerators

Abstract

Compact particle selection and collimation devices are disclosed for delivering beams of protons with desired energy spectra. These devices are useful with laser-accelerated proton therapy systems, in which the initial protons have broad energy and angular distributions. Superconducting magnet systems produce a desired magnetic field configuration to spread the protons with different energies and emitting angles for particle selection. The simulation of proton transport in the presence of the magnetic field shows that the selected protons are successfully refocused on the beam axis after passing through the magnetic field with the optimal magnet system. Dose distributions are also provided using Monte Carlo simulations of the laser-accelerated proton beams for radiation therapy applications.

Claims

1. An ion selection system, comprising:

a collimation device capable of collimating a laser-accelerated high energy polyenergetic ion beam, comprising a plurality of high energy polyenergetic positive ions;

a first magnetic field source capable of spatially separating said high energy polyenergetic positive ions according to their energy levels;

an aperture capable of modulating the spatially separated high energy polyenergetic positive ions; and

a second magnetic field source capable of recombining the modulated high energy polyenergetic positive ions;

wherein the first and second magnetic field sources are superconducting electromagnets capable of providing a magnetic field between about 0.1 and about 30 Tesla.

2. The ion selection system of claim 1, wherein the magnetic field is between about 0.2 and about 20 Tesla.

3. The ion selection system of claim 1, wherein the magnetic field is between about 0.5 and about 10 Tesla.

4. The ion selection system of claim 1, wherein the magnetic field is between about 0.8 and about 5 Tesla.

5. The ion selection system of claim 1, wherein the modulated high energy polyenergetic positive ions have energy levels in the range of from about 50 MeV to about 250 MeV.

6. The ion selection system of claim 1, wherein the high energy polyenergetic positive ions include light ions including protons, lithium, boron, beryllium, or carbon, or any combination thereof.

7. The ion selection system of claim 1, wherein said first magnetic field source is capable of bending the trajectories of the high energy polyenergetic positive ions away from a beam axis of said laser-accelerated polyenergetic ion beam.

8. The ion selection system of claim 7, further comprising a third magnetic field source, said third magnetic field source capable of bending the trajectories of the spatially separated high energy polyenergetic positive ions towards the aperture.

9. The ion selection system of claim 8, wherein the aperture is placed outside of the magnetic field of said third magnetic field.

10. The ion selection system of claim 8, wherein the magnetic field of said third magnetic field source is capable of bending the trajectories of the modulated high energy polyenergetic positive ions towards the second magnetic field source.

11. The ion selection system of claim 10, wherein the second magnetic field source is capable of bending the trajectories of the modulated high energy polyenergetic positive ions towards a direction parallel to the direction of the laser-accelerated high energy polyenergetic ion beam.

12. The ion selection system of claim 1, further comprising a secondary collimation device capable of fluidically communicating a portion of the recombined high energy polyenergetic positive ions therethrough.

13. The ion selection system of claim 12, wherein said secondary collimation device is capable of modulating the beam shape of the recombined high energy polyenergetic positive ions.

14. The ion selection system of claim 1, wherein said aperture comprises a plurality of openings, each of the openings capable of fluidically communicating high energy polyenergetic positive ions therethrough.

15. The ion selection system of claim 14, wherein the aperture is a multileaf collimator.

16. A method of forming a high energy polyenergetic positive ion beam, comprising:

forming a laser-accelerated high energy polyenergetic ion beam comprising a plurality of high energy polyenergetic positive ions characterized as having a distribution of energy levels;

collimating said laser-accelerated ion beam using a collimation device;

spatially separating said high energy positive ions according to their energy levels using a first magnetic field provided by a first superconducting electromagnet having a magnetic field of between about 0.1 and about 30 Tesla;

modulating the spatially separated high energy polyenergetic positive ions using an aperture; and

recombining the modulated high energy polyenergetic positive ions using a second magnetic field provided by a second superconducting electromagnet having a magnetic field of between about 0.1 and about 30 Tesla.

17. The method of forming a high energy polyenergetic positive ion beam of claim 16, wherein the first magnetic field or the second magnetic field, or both, is between about 0.2 and about 20 Tesla.

18. The method of forming a high energy polyenergetic positive ion beam of claim 16, wherein the first magnetic field or the second magnetic field, or both, is between about 0.5 and about 10 Tesla.

19. The method of forming a high energy polyenergetic positive ion beam of claim 16, wherein the first magnetic field or the second magnetic field, or both, is between about 0.8 and about 5 Tesla.

20. The method according to claim 16, wherein the step of modulating the spatially separated high energy polyenergetic positive ions gives rise to a portion of the positive ions being transmitted through the aperture, said portion of the positive ions having energy levels in the range of from about 50 MeV to about 250 MeV.

21. The method according to claim 16, wherein said trajectories of the high energy polyenergetic positive ions are bent away from a beam axis of said laser-accelerated high energy polyenergetic ion beam using said first magnetic field.

22. The method according to claim 21, wherein the trajectories of the spatially separated high energy polyenergetic positive ions are further bent towards the aperture using a third magnetic field.

23. The method according to claim 22, wherein the spatially separated high energy positive ions are modulated by energy level using a plurality of controllable openings in said aperture.

24. The method according to claim 22, wherein the third magnetic field further bends said trajectories towards the second magnetic field.

25. The method according to claim 24, wherein the second magnetic field bends said trajectories towards a direction parallel to the direction of a laser-accelerated high energy polyenergetic ion beam.

26. The method according to claim 16, wherein a portion of the recombined high energy polyenergetic positive ions is fluidically communicated through a secondary collimation device.

27. The method according to claim 16, wherein a plurality of high energy polyenergetic positive ion beamlets are fluidically communicated through a plurality of controllable openings in said aperture to modulate the spatially separated high energy positive ions.

28. The method according to claim 16, wherein the high energy polyenergetic positive ions are spatially separated over distances up to about 50 cm according to an energy distribution of the high energy polyenergetic positive ions, said distances being measured perpendicularly to a beam axis of said laser-accelerated ion beam entering the first magnetic field.

29. The method of claim 16, further comprising irradiating a radioisotope precursor with the recombined spatially separated high energy polyenergetic positive ions.

30. A laser-accelerated high energy polyenergetic positive ion therapy system, comprising:

a laser-targeting system, comprising a laser and a targeting system capable of producing a high energy polyenergetic ion beam, comprising high energy polyenergetic positive ions having energy levels of at least about 50 MeV, the high energy polyenergetic positive ions being spatially separated based on energy level;

an ion selection system capable of producing a therapeutically suitable high energy polyenergetic positive ion beam from a portion of said high energy polyenergetic positive ions, said ion selection system comprising at least two superconducting electromagnets each capable of providing a magnetic field of between about 0.1 and about 30 Tesla; and

an ion beam monitoring and control system.

31. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 30, wherein the magnetic field is between about 0.2 and about 20 Tesla.

32. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 30, wherein the magnetic field is between about 0.5 and about 10 Tesla,

33. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 30, wherein the magnetic field is between about 0.8 and about 5 Tesla.

34. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 30, wherein the high energy polyenergetic positive ions include light ions including protons, lithium, boron, beryllium, or carbon, or any combination thereof.

35. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 30, wherein the ion selection system comprises:

a collimation device capable of collimating said laser-accelerated high energy polyenergetic ion beam;

a first magnetic field source capable of spatially separating said high energy polyenergetic positive ions according to their energy levels, wherein the first magnetic field source includes one of the superconducting electromagnets;

an aperture capable of modulating the spatially separated high energy polyenergetic positive ions; and

a second magnetic field source capable of recombining the modulated high energy polyenergetic positive ions, wherein the second magnetic field source includes one of the superconducting electromagnets different than the one used in the first magnetic field source.

36. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 35, wherein the modulated high energy polyenergetic positive ions are characterized as having energy levels in the range of from about 50 MeV to about 250 MeV.

37. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 35, wherein said first magnetic field source provides a first magnetic field, capable of bending the trajectories of the high energy polyenergetic positive ions, said bending being in a direction away from a beam axis of said laser-accelerated high energy polyenergetic ion beam.

38. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 37, wherein the ion selection system further comprises a third magnetic field source, capable of bending the trajectories of the spatially separated high energy polyenergetic positive ions towards the aperture.

39. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 38, wherein the aperture is placed outside of the magnetic field of said third magnetic field.

40. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 38, wherein the magnetic field of said third magnetic field source is capable of bending the trajectories of said portion of the spatially separated high energy polyenergetic positive ions towards the second magnetic field source.

41. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 40, wherein the second magnetic field source is capable of bending the trajectories of said portion of the spatially separated high energy polyenergetic positive ions towards a direction parallel to a beam axis of the laser-accelerated high energy polyenergetic ion beam.

42. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 35, further comprising a secondary collimation device capable of fluidically communicating a portion of the recombined high energy polyenergetic positive ions therethrough.

43. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 42, wherein the secondary collimation device is capable of modulating a beam shape of the recombined high energy polyenergetic positive ions.

44. The laser-accelerated high energy polyenergetic positive ion therapy system of claim 35, wherein said aperture comprises a plurality of openings, each of the openings capable of fluidically communicating ion beamlets therethrough.

45. A method of treating a patient with a laser-accelerated high energy polyenergetic positive ion therapy system, comprising:

identifying the position of a targeted region in a patient;

determining the treatment strategy of the targeted region, said treatment strategy comprising determining the dose distributions of a plurality of therapeutically suitable high energy polyenergetic positive ion beams for irradiating the targeted region;

forming said plurality of therapeutically suitable high energy polyenergetic positive ion beams from a plurality of high energy polyenergetic positive ions, that are spatially separated based on energy level using one or more superconducting electromagnets each capable of providing a magnetic field of between about 0.1 and about 30 Tesla; and

delivering the plurality of therapeutically suitable polyenergetic positive ion beams to the targeted region according to the treatment strategy.

46. The method of treating a patient with a laser-accelerated high energy polyenergetic positive ion therapy system of claim 45, wherein the magnetic field is between about 0.2 and about 20 Tesla.

47. The method of treating a patient with a laser-accelerated high energy polyenergetic positive ion therapy system of claim 45, wherein the magnetic field is between about 0.5 and about 10 Tesla.

48. The method of treating a patient with a laser-accelerated high energy polyenergetic positive ion therapy system of claim 45, wherein the magnetic field is between about 0.8 and about 5 Tesla.

49. The method of treating a patient according to claim 45, wherein determining the dose distributions comprises determining the energy distribution, intensity and direction of a plurality of therapeutically suitable high energy polyenergetic positive ion beams.

50. The method of treating a patient according to claim 45, wherein said therapeutically suitable polyenergetic positive ion beams are prepared by:

forming a laser-accelerated high energy polyenergetic ion beam comprising high energy polyenergetic positive ions;

collimating said laser-accelerated high energy polyenergetic ion beam using at least one collimation device;

spatially separating said high energy polyenergetic positive ions according to their energy levels using a first magnetic field provided by one of the superconducting electromagnets;

modulating the spatially separated high energy polyenergetic positive ions using an aperture; and

recombining the modulated high energy polyenergetic positive ions using a second magnetic field provided by a superconducting electromagnet different than the one used for providing the first magnetic field.

51. The method of treating a patient according to claim 50, wherein the modulated high energy polyenergetic positive ions have energy levels in the range of from about 50 MeV to about 250 MeV.

52. The method of treating a patient according to claim 50, wherein the high energy polyenergetic positive ions include light ions including protons, lithium, boron, beryllium, or carbon, or any combination thereof.

53. The method of treating a patient according to claim 50, wherein the trajectories of the high energy polyenergetic positive ions are bent away from a beam axis of said laser-accelerated high energy polyenergetic ion beam using said first magnetic field.

54. The method of treating a patient according to claim 53, wherein the trajectories of the spatially separated high energy polyenergetic positive ions are bent towards the aperture using a third magnetic field.

55. The method of treating a patient according to claim 54, wherein the spatially separated high energy polyenergetic positive ions are modulated by energy level using a plurality of controllable openings in said aperture.

56. The method of treating a patient according to claim 55, wherein the trajectories of the modulated high energy polyenergetic positive ions are further bent towards the second magnetic field using said third magnetic field.

57. The method of treating a patient according to claim 56, wherein the trajectories of the modulated high energy polyenergetic positive ions are bent towards a direction parallel to the direction of a beam axis of the laser-accelerated high energy polyenergetic ion beam using said second magnetic field.

58. The method of treating a patient according to claim 50, wherein a portion of the recombined high energy polyenergetic positive ions are fluidically communicated through a secondary collimation device.

59. The method of treating a patient according to claim 58, wherein the beam shape of the recombined high energy polyenergetic positive ions is modulated by the secondary collimation device.

60. A laser-accelerated high energy polyenergetic positive ion beam treatment center, comprising:

a location for securing a patient; and

a laser-accelerated high energy polyenergetic positive ion therapy system capable of delivering a therapeutically suitable high energy polyenergetic positive ion beam to a patient at said location, the ion therapy system comprising;

a laser-targeting system, said laser-targeting system comprising a laser and a target assembly capable of producing a high energy polyenergetic ion beam, comprising high energy polyenergetic positive ions having energy levels of at least about 50 MeV;

an ion selection system capable of producing a therapeutically suitable high energy polyenergetic positive ion beam using said high energy polyenergetic positive ions, the high energy polyenergetic positive ions being spatially separated based on energy level using superconducting electromagnets each capable of providing a magnetic field of between about 0.1 and about 30 Tesla; and

a monitoring and control system for said therapeutically suitable high energy polyenergetic positive ion beam.

61. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the magnetic field is between about 0.2 and about 20 Tesla.

62. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the magnetic field is between about 0.5 and about 10 Tesla.

63. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the magnetic field is between about 0.8 and about 5 Tesla.

64. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the ion selection system comprises:

a collimation device capable of collimating said high energy polyenergetic ion beam;

a first magnetic field source capable of spatially separating said high energy polyenergetic positive ions according to their energy levels, said first magnetic field source provided by one of the superconducting electromagnets;

an aperture capable of modulating the spatially separated high energy polyenergetic positive ions; and

a second magnetic field source capable of recombining the modulated high energy polyenergetic positive ions into said therapeutically suitable high energy polyenergetic positive ion beam, the second magnetic field provided by a superconducting electromagnet different than the one that provides the first magnetic field.

65. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 64, wherein the modulated high energy polyenergetic positive ions are characterized as having energy levels in the range of from about 50 MeV to about 250 MeV.

66. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 64, wherein the high energy polyenergetic positive ions include light ions including protons, lithium, boron, beryllium, or carbon, or any combination thereof.

67. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 64, wherein said first magnetic field source is capable of bending the trajectories of the high energy polyenergetic positive ions away from a beam axis of said laser-accelerated polyenergetic ion beam entering the first magnetic field.

68. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 67, wherein the ion selection system further comprises a third magnetic field source capable of bending the trajectories of the spatially separated high energy polyenergetic positive ions towards the aperture.

69. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 68, wherein the aperture is placed outside of the magnetic field of said third magnetic field.

70. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 68, wherein the magnetic field of said third magnetic field source is capable of bending the trajectories of the modulated high energy positive ions towards the second magnetic field source.

71. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 70, wherein the second magnetic field source is capable of bending the trajectories of the modulated high energy polyenergetic positive ions towards a direction parallel to a beam axis of the laser-accelerated high energy polyenergetic ion beam.

72. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 67, further comprising a secondary collimation device capable of fluidically communicating a portion of the recombined high energy polyenergetic positive ions therethrough.

73. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 64, wherein said aperture comprises a plurality of openings, each of the openings capable of fluidically communicating ion beamlets therethrough.

74. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the target assembly and the ion selection system are placed on a rotating gantry.

75. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein a laser beam of said laser is reflectively transported to the target assembly using a plurality of mirrors.

76. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 75, wherein the ion selection system is robotically mounted to give permit scanning of the therapeutically suitable high energy polyenergetic positive ion beam.

77. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 75, further comprising at least one beam splitter to split the laser beam to each of at least two target assemblies.

78. The laser-accelerated high energy polyenergetic positive ion beam treatment center of claim 60, wherein the laser-targeting system comprises a plurality of target assemblies, each of said target assemblies capable of producing a high energy polyenergetic positive ion beam, said high energy polyenergetic positive ion beam comprising high energy polyenergetic positive ions comprising energy levels of at least about 50 MeV;

a plurality of ion selection systems each capable of individually producing a therapeutically suitable high energy polyenergetic positive ion beam from each of said individual high energy polyenergetic positive ion beams; and

an individual polyenergetic ion beam monitoring and control system for each of said therapeutically suitable high energy polyenergetic positive ion beams.

79. A compact superconducting electromagnet system for magnetically separating a polyenergetic positive ion beam, comprising:

a series of two or more superconducting coils in fluidic communication, wherein each of the superconducting coils is individually capable of providing a magnetic field of between about 0.1 and about 30 Tesla, wherein at least two of the magnetic fields are provided in opposite directions to each other.

80. The compact superconducting electromagnet system for magnetically separating a polyenergetic positive ion beam of claim 79, wherein the magnetic field is between about 0.2 and about 20 Tesla.

81. The compact superconducting electromagnet system for magnetically separating a polyenergetic positive ion beam of claim 79, wherein the magnetic field is between about 0.5 and about 10 Tesla.

82. The compact superconducting electromagnet system for magnetically separating a polyenergetic positive ion beam of claim 79, wherein the magnetic field is between about 0.8 and about 5 Tesla.

83. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils have dimensions in the range of from about 5 cm to about 100 cm.

84. The compact superconducting electromagnet system of claim 79, wherein the maximum magnetic field of each of the electromagnets is less than about 5 Tesla.

85. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils each comprise between about 1,000 and about 100,000 turns of one or more superconducting wires.

86. The compact superconducting electromagnet system of claim 85, wherein the superconducting coils comprise between about 5,000 and about 20,000 turns of superconducting wire.

87. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils each comprise one or more NbTi superconducting wires.

88. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils each comprise one or more Nb₃Sn superconducting wires.

89. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils each comprise one or more high temperature superconducting wires.

90. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils are each capable of carrying an electric current in the range of from about 60 A to about 600 A.

91. The compact superconducting electromagnet system of claim 79, comprising:

two outer electromagnets each capable of providing a magnetic field in the same direction, and

two inner electromagnets each capable of providing a magnetic field in the same direction to each other and opposite the direction of the magnetic field of the outer electromagnets.

92. The compact superconducting electromagnet system of claim 91, wherein the magnetic fields of the two inner electromagnets have about the same strength.

93. The compact superconducting electromagnet system of claim 92, wherein the two inner electromagnets are separated by a gap in the range of from about 0.2 cm to about 5 cm.

94. The compact superconducting electromagnet system of claim 79, further comprising a series of collimators each having an aperture size in the range of from about 0.02 cm to about 2 cm.

95. The compact superconducting electromagnet system of claim 79, wherein the superconducting coils have a rectangular shape.