Multi-field charged particle cancer therapy method and apparatus

• US 8,766,217 B2
• Filed: 05/21/2009
• Issued: 07/01/2014
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Balakin, Vladimir Yegorovich
• Primary Examiner(s): Berman, Jack
• Assistant Examiner(s): STOFFA, WYATT A
• Application Number:
  US12/994,130
• Publication Number:
  US 20110233423A1
• Time in Patent Office: 1,867 Days
• Field of Search: 250/492.1, 250/503.1, 250/492.3
• US Class Current: 250/492.3
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: G21K 1/087 by electrical means
• CPC Class Codes: G21K 1/093 by magnetic means
• CPC Class Codes: G21K 1/14 using charge exchange devices, e.g. for neutralising or changing the sign of the electrical charges of beams producing or accelerating neutral particle beams H05H3/00
• CPC Class Codes: H05H 13/04 Synchrotrons
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof
• CPC Class Codes: H05H 7/08 Arrangements for injecting particles into orbits
• CPC Class Codes: H05H 7/10 Arrangements for ejecting particles from orbits

Abstract

The invention comprises a multi-field charged particle irradiation method and apparatus. Radiation is delivered through an entry point into the tumor and Bragg peak energy is targeted to a distal or far side of the tumor from an ingress point. Delivering Bragg peak energy to the distal side of the tumor from the ingress point is repeated from multiple rotational directions. Preferably, beam intensity is proportional to radiation dose delivery efficiency. Preferably, the charged particle therapy is timed to patient respiration via control of charged particle beam injection, acceleration, extraction, and/or targeting methods and apparatus. Optionally, multi-axis control of the charged particle beam is used simultaneously with the multi-field irradiation. Combined, the system allows multi-field and multi-axis charged particle irradiation of tumors yielding precise and accurate irradiation dosages to a tumor with distribution of harmful irradiation energy about the tumor.

Claims

1. A method for irradiating a tumor of a patient with charged particles, comprising the steps of:

delivering the charged particles with a charged particle therapy system, comprising;

a synchrotron;

an extraction foil;

a charged particle beam path; and

a rotatable platform, wherein said charged particle beam path runs through said synchrotron and above said rotatable platform;

controlling intensity of the charged particles using a current originating at said extraction foil, said extraction foil positioned in the charged particle beam path after entry into said synchrotron and prior to a Lambertson extraction magnet, wherein electrons of said current originate in atoms of said extraction foil;

actively scanning the charged particles along at least three axes, wherein said at least three axes comprise;

a horizontal axis, a vertical axis, and an applied energy axis;

during an irradiation period, rotating said rotatable platform to at least five irradiation positions covering at least ninety degrees of rotation of said rotatable platform;

timing delivery of the charged to the tumor using a respiration signal, wherein a respiration command is sent to the patient using a display monitor, said display monitor configured to co-rotate with said rotatable platform, said respiration signal monitor respiration of the patient; and

irradiating the tumor with the charged particles during each of said at least five irradiation positions.

2. The method of claim 1, further comprising the steps of:

holding the patient with said rotatable platform during said irradiation period; and

delivering the charged particles through said charged particle beam path, wherein said charged particle beam path circumferentially surrounds the charged particles at least in said synchrotron.

3. The method of claim 1, further comprising the step of:

rotating said rotatable platform through about three hundred sixty degrees during said irradiation period.

4. The method of claim 3, said charged particle therapy system further comprising an irradiation control module, wherein the tumor comprises a distal region, wherein said irradiation control module further comprises the step of:

terminating said charged particle beam path in said distal region of the tumor, using control of energy of the charged particles, in each of said at least five irradiation positions.

5. The method of claim 4, further comprising the step of:

said irradiation control module controlling both rotation of said rotatable platform and said energy of the charged particles to irradiate, with Bragg peak energy of the charged particles, a changing distal position of the tumor as a function of position of said rotatable platform.

6. The method of claim 1, said charged particle therapy system further comprising the step of:

distributing delivered distal energy of the charged particles about an outer perimeter of the tumor, wherein ingress energy of the charged particles comprises three hundred sixty degrees of circumferential distribution about a plane of the tumor.

7. The method of claim 1, further comprising the steps of:

controlling energy of the charged particles during an extraction phase of the charged particles from said synchrotron using said extraction foil; and

controlling said intensity of the charged particles during said extraction phase of the charged particles from said synchrotron using the electrons originating in the atoms of the extraction foil.

8. The method of claim 1, wherein said step of rotating said rotatable platform comprises rotation of said rotatable platform through about three hundred sixty degrees during said irradiation period, and

wherein said step of irradiating the tumor occurs with the charged particles in at least thirty rotation positions of said rotatable platform during said irradiation period.

9. The method of claim 1, wherein said step of actively scanning occurs at each of said of said at least five irradiation positions.

10. The method of claim 9, wherein said active scanning system further comprises the step of:

controlling said intensity of the charged particles.

11. The method of claim 1, further comprising the steps of:

focusing ions using electric field lines terminating at metal conducting paths within the charged particle beam path, said metal conducting paths comprising a conductive mesh; and

injecting the ions as the charged particles into said synchrotron.

12. The method of claim 1, further comprising the step of:

turning the charged particles in said synchrotron about ninety degrees using a set of four turning magnets, said set of turning magnets wound by a coil, wherein said coil does not occupy space directly between any of said four magnets.

13. The method of claim 1, further comprising the step of:

accelerating the charged particles in an accelerator system in said synchrotron, said accelerator system comprising;

a set of at least ten coils;

a set of at least ten wire loops;

a set of at least ten microcircuits, each of said microcircuits integrated to one of said loops, wherein each of said loops completes at least one turn about at least one of said coils; and

timing said accelerator system with a radio-frequency synthesizer sending a low voltage signal to each of said microcircuits, each of said microcircuits amplifying said low voltage signal yielding an acceleration voltage.

14. The method of claim 1, further comprising the step of:

applying a radio-frequency field to the charged particles in said synchrotron to yield oscillating charged particles, wherein the current is used in control of the radio-frequency field;

extracting the oscillating charged particles from said synchrotron by slowing the oscillating charged particles with said extraction foil.

15. The method of claim 1, further comprising the step of:

monitoring both a horizontal position of the charged particles and a vertical position of the charged particles in a beam transport path using photons emitted from a coating on an output foil, said photons emitted from said coating when struck by the charged particles.

16. The method of claim 1, further comprising the steps of:

generating an image of the tumor using an X-ray system; and

said charged particle therapy system targeting the tumor using said image, wherein said X-ray system comprises a cathode comprising a first diameter and an electron beam path comprising a second diameter, said first diameter at least twice said second diameter, wherein electrons emitted at said cathode traverse said electron beam path before striking an X-ray generation source.

17. The method of claim 1, further comprising the steps of;

monitoring respiration of the patient using a respiration sensor; and

controlling said respiration, said step of controlling using a signal generated by said respiration sensor and feedback respiration instructions provided to the patient provided on a monitor.

18. The method of claim 1, further comprising the step of;

dynamically adjusting timing of said step of delivering the charged particles to occur in synchronization with a changing respiration rate of the patient.

19. A method for irradiating a tumor of a patient with charged particles, comprising the steps of:

delivering the charged particles with a charged particle therapy system, comprising;

a synchrotron;

an extraction foil;

a charged particle beam path; and

a rotatable platform, wherein said charged particle beam path runs through said synchrotron and above said rotatable platform;

maintaining a first vacuum in an on beam focusing system in the charged particle beam path prior to said synchrotron;

maintaining a second vacuum in said synchrotron, said first vacuum in said ion beam focusing system and said second vacuum in said synchrotron separated by a converting foil, said converting foil converting negative ions into positive ions, pressure of said first vacuum not equal to pressure of said second vacuum;

controlling intensity of the charged particles using a current originating at said extraction foil, said extraction foil positioned in the charged particle beam path after entry into said synchrotron and prior to a Lambertson extraction magnet, wherein electrons of said current originate in atoms of said extraction foil;

during an irradiation period, rotating said rotatable platform to at least five irradiation positions covering at least ninety degrees of rotation of said rotatable platform; and

irradiating the tumor with the charged particles during each of said at least five irradiation positions.