MULTI-FIELD CHARGED PARTICLE CANCER THERAPY METHOD AND APPARATUS

• US 20100090122A1
• Filed: 12/13/2009
• Published: 04/15/2010
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: Andrey Vladimirovich Balakin, Pavel Vladimirovich Balakin
• Original Assignee: Vladimir
• Inventors: Balakin, Vladimir
• Granted Patent: US 8,436,327 B2
• Time in Patent Office: Days
• US Class Current: 250/396.0ML
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1097 Means for immobilizing the patient
• 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 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: H05H 13/04 Synchrotrons
• CPC Class Codes: H05H 7/10 Arrangements for ejecting particles from orbits

Abstract

The invention relates to treatment of solid cancers. More particularly, the invention relates to a combined rotation/raster method, referred to as multi-field charged particle cancer therapy. The system uses a fixed orientation proton source relative to a rotating patient to yield tumor irradiation from multiple directions. The system combines layer-wise tumor irradiation from many directions with controlled energy proton irradiation to deliver peak proton beam energy within a selected tumor volume or irradiated slice. Optionally, the selected tumor volume for irradiation from a given angle is a distal portion of the tumor. In this manner ingress Bragg peak energy is circumferentially spread about the tumor minimizing damage to healthy tissue and peak proton energy is efficiently, accurately, and precisely delivered to the tumor.

Claims

1. An apparatus using charged particles for irradiation of a tumor of a patient, comprising:

a synchrotron comprising multi-axis control, said multi-axis control comprising control of;

an energy; and

an intensity,

wherein said control of said energy and said control of said intensity occurs during extraction.

2. The apparatus of claim 1, further comprising separate control of said energy and said intensity during an extraction phase of said synchrotron, wherein said energy comprises a speed of the charged particles, wherein said intensity comprises a number of the charged particles per second, wherein said multi-axis control independently changes both said energy and said intensity over a time period of less than one second.

3. The apparatus of claim 1, further comprising:

a rotatable platform,

wherein said rotatable platform rotates through about three hundred sixty degrees during an irradiation period,

wherein said multi-axis control operates during at least ten rotation positions of said rotatable platform.

4. The apparatus of claim 1, further comprising:

a respiration sensor generating a respiration signal, said respiration signal corresponding to a respiration cycle of the patient, wherein a timing controller uses said respiration signal to time delivery of the charged particles to a set point in said respiration cycle,

wherein said multi-axis control further comprises independent control of all of;

a horizontal position of the charged particles;

a vertical position of the charged particles;

said energy; and

said intensity, wherein said multi-axis control comprises delivery of the charged particles at said set point in the respiration cycle and in coordination with rotation of the patient on said rotatable platform during said at least ten rotation positions of said rotatable platform.

5. The apparatus of claim 1, said synchrotron further comprising:

an acceleration period accelerating the charged particles; and

an extraction foil, wherein timing of the charged particles striking said extraction foil in said acceleration period results in extraction at said energy.

6. The apparatus of claim 5, further comprising:

a current resulting from the charged particles striking said extraction foil, said current used as a feedback control to a radio-frequency cavity system, wherein an applied radio frequency, using said feedback control, in said radio-frequency cavity system results in said control of said intensity.

7. The apparatus of claim 1, wherein said synchrotron further comprises:

a beam extraction path, said path sequentially comprising;

a radio-frequency cavity system comprising a first pair of blades;

a foil, said foil comprising a thickness of about thirty to one-hundred microns, said foil consisting essentially of atoms having six or fewer protons;

a second pair of blades; and

an extraction magnet,

wherein a radio-frequency applied across said first pair of blades alters trajectory of the charged particles through said foil yielding reduced energy charged particles, wherein the reduced energy charged particles pass through said second pair of blades, wherein a direct current voltage of at least five hundred volts applied across said second pair of blades and said extraction magnet combine to extract the reduced energy charged particles out of said synchrotron,

wherein said control of said intensity further comprises a feedback control, said feedback control using a current generated by the charged particles transmitting through said foil as an indicator of charged particle intensity.

8. The apparatus of claim 1, further comprising:

a rotatable platform,

wherein said rotatable platform rotates through at least one hundred eighty degrees during a single irradiation period of the patient,

wherein timing of said multi-axis control of said energy and said intensity occurs in greater than four rotation positions of said rotatable platform during the irradiation period.

9. The apparatus of claim 1, further comprising:

a respiration sensor generating a respiration signal, said respiration signal corresponding to a respiration cycle of the patient,

wherein timing of said multi-axis control of said energy and said intensity correlates with said respiration signal,

wherein delivery of the charged particles occurs in greater than four rotation positions of said rotatable platform,

wherein said multi-axis control further comprises control of timing of charged particle delivery, said control of timing correlated with patient respiration,

wherein said control of timing further comprises control of;

injection of hydrogen gas into an ion beam generation system, wherein a magnetic field barrier in said ion beam generation system exists between a high temperature plasma region and a low temperature plasma zone, said ion beam generation system generating the charged particles,

wherein said ion beam generation system further comprises a first vacuum chamber on a first side of a converting foil and a second vacuum chamber on a second side of said converting foil, said first vacuum operating at a separate pressure from said second vacuum chamber.

10. The apparatus of claim 1, wherein said control of said energy further comprises:

use of readings from a magnetic sensor, said magnetic sensor proximate a bending magnet in said synchrotron; and

a feedback system, wherein said feedback system stabilizes a magnetic field in said bending magnet using input from said magnetic sensor to control a correction coil operating at less than ten percent the power of a winding coil, both said correction coil and said winding coil wound around said bending magnet.

11. The apparatus of claim 1, wherein said multi-axis control further comprises:

monitoring both a horizontal position of the charged particles and a vertical position of the charged particles in a beam transport path using a coating on a foil, said foil comprising a vacuum barrier between said synchrotron and atmosphere, said coating comprising a layer yielding a luminescent, fluorescent, or phosphorescent signal when struck by the charged particles.

12. The apparatus of claim 1, wherein said multi-axis control increases said intensity when targeting a distal portion of the tumor, wherein said distal portion of said tumor changes with rotation of the patient on a platform rotating to as least ten distinct rotational positions in a period of less than one minute during irradiation of the tumor by the charged particles.

13. The apparatus of claim 1, wherein said multi-axis control further comprises:

horizontal position control of the charged particles;

vertical position control of the charged particles; and

an X-ray input signal, wherein said X-ray input signal comprises a signal generated by an X-ray source less than about five centimeters from the charged particle beam, wherein the X-ray source comprises a static position during both use of said X-ray source and use of said synchrotron,

wherein said X-ray input signal is used in;

setting position of said horizontal position and setting position of said vertical position.

14. A method for controlling charged particles, the charged particles used to irradiate a tumor of a patient, comprising the steps of:

extracting the charged particles from a synchrotron; and

controlling the charged particles along multi-axis, said multi-axis comprising;

an energy; and

an intensity,

wherein said step of controlling said energy and said step of controlling said intensity both occur prior to the charged particles passing through a Lamberson extraction magnet in said synchrotron during said step of extracting.

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

rotating a rotatable platform through about three hundred sixty degrees during an irradiation period,

wherein a step of controlling said energy and a step of extracting both operate during at least ten rotation positions of said rotatable platform,

wherein said step of controlling energy changes an energy level of the charged particles at each of said ten irradiation positions.

16. The method of claim 15, further comprising the steps of:

holding the patient with said rotatable platform;

delivering the charged particles to the tumor of the patient from said synchrotron during said step of rotating the patient on said rotatable platform; and

distributing ingress energy of the charged particles to at least ten areas about the tumor.

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

independently controlling said multi-axis, wherein said multi-axis further comprises;

a horizontal position of the charged particles; and

a vertical position of the charged particles, and

delivering the charged particles at a set point in a respiration cycle and in coordination with said step of rotating during at least ten rotation positions of said rotatable platform;

accelerating the charged particles during an acceleration period of said synchrotron; and

timing extraction of the charged particles striking an extraction foil to yield said energy;

striking said extraction foil with the charged particles to yield a current;

using said current as a feedback control to a radio-frequency cavity system; and

controlling said intensity by applying a radio frequency in said feedback control to said radio-frequency cavity system.

18. The method of claim 14, wherein said synchrotron further comprises:

a beam extraction path, said beam extraction path sequentially comprising;

a radio-frequency cavity system comprising a first pair of blades;

a foil, said foil comprising a thickness of about thirty to one-hundred microns, said foil consisting essentially of atoms having six or fewer protons;

a second pair of blades; and

an extraction magnet,

wherein said method further comprises the steps of;

applying a radio-frequency across said first pair of blades to yield altered trajectory charged particles;

passing the altered trajectory charged particles through said foil yielding reduced energy charged particles;

transmitting the reduced energy charged particles pass through said second pair of blades;

applying a direct current voltage of at least five hundred volts across said second pair of blades; and

extracting the reduced energy charged particles out of said synchrotron using an extraction magnet.

19. The method of claim 18, further comprising the steps of:

feedback controlling said intensity of the charged particles using a feedback control, said feedback control using a current generated by the charged particles transmitting through said foil as an indicator of charged particle intensity;

rotating a rotatable platform through at least one hundred eighty degrees during an irradiation period of the patient; and

timing said step of controlling the charged particles along said multi-axes of said energy and said intensity in greater than four rotation positions of said rotatable platform

generating a respiration signal with a respiration sensor, said respiration signal corresponding to a respiration cycle of the patient;

rotating a rotatable platform, said platform configured to hold the patient during use, through at least one hundred eighty degrees during an irradiation period of the patient,

timing said step of controlling the charged particles along multi-axis to correlate with said respiration signal, and

delivering the charged particles in greater than four rotation positions of said rotatable platform.

20. The method of claim 14, wherein said multi-axis control of said intensity further comprises the step of:

increasing said intensity when targeting a distal portion of the tumor, wherein said distal portion of said tumor changes with rotation of the patient on a platform rotating to as least ten distinct rotational positions in a period of less than one minute during irradiation of the tumor by the charged particles.

21. The method of claim 14, wherein said multi-axis control further comprises the steps of:

horizontally controlling the charged particles;

vertically controlling the charged particles; and

providing an X-ray input signal, wherein said X-ray input signal comprises a signal generated by an X-ray source less than about two centimeters from the charged particle beam;

wherein both said step of horizontally controlling and said step of vertically controlling use said X-ray input signal.