Particle beam therapeutic apparatus

• US 7,378,672 B2
• Filed: 10/04/2005
• Issued: 05/27/2008
• Est. Priority Date: 04/13/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Harada, Hisashi
• Primary Examiner(s): Berman; Jack I.
• Assistant Examiner(s): Sahu; Meenakshi S
• Application Number:
  US11/242,086
• Publication Number:
  US 20060231775A1
• Time in Patent Office: 966 Days
• Field of Search: 250/493.1, 250/492.3, 250/505.1, 250/515.1, 250/503.1, 250/359.1, 378/65, 378/147, 378/152, 313/359.1
• US Class Current: 250/492.3
• CPC Class Codes: A61N 2005/1074 Details of the control system, e.g. user interfaces
• 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 5/1037 taking into account the movement of the target, e.g. 4D-image based planning
• CPC Class Codes: A61N 5/1044 with multiple repetitions of the scanning pattern

Abstract

A particle beam therapeutic apparatus can ensure the uniformity of dose distribution by overlapping the desired loci of the irradiation of a particle beam a reduced number of times. A flow of a particle beam transported so as to be irradiated to a diseased part is caused to deflect in two mutually orthogonal directions perpendicular to the direction of travel of the particle beam. The irradiation position of the particle beam is scanned, upon each period, in a manner to return to a position of irradiation located at the start of the period, whereby a plurality of loci drawn within one period are overlapped with one another thereby to irradiate a desired planned dose to the diseased part. The particle beam can be interrupted only at the end of the period.

Claims

1. A particle beam therapeutic apparatus in which a flow of a particle beam transported so as to be irradiated to a diseased part is caused to deflect in two mutually orthogonal directions perpendicular to the direction of travel of said particle beam, and the irradiation position of said particle beam is scanned, upon each period, in a manner to return to a position of irradiation located at the start of said period, whereby a plurality of loci drawn within one period are overlapped with one another thereby to irradiate a desired planned dose to said diseased part,

wherein said particle beam can be interrupted only at the end of said period.

2. The particle beam therapeutic apparatus as set forth in claim 1, wherein when the irradiation position of said particle beam is scanned in such a manner that said transported particle beam rotates at a predetermined angular velocity about a center at which said particle beam passes through a plane perpendicular to the direction of travel of said particle beam with a distance to said particle beam from said center being increased and decreased, the initial phase of the rotation of said particle beam at the start time point of said period can be made variable.

3. The particle beam therapeutic apparatus as set forth in claim 2, further comprising;

a storage section having a plurality of areas to which addresses are assigned, and in which amplitude data which is increased and decreased in said period when read out from said areas while said address is forwarded and designated progressively, and sine wave function data which oscillates at the said angular velocity in a sinusoidal manner when read out from said areas are stored in said plurality of areas;

a command value transmission part that sends a command in the form of the product of said amplitude data and said sine wave function data, which are read out from said areas at an address designated progressively each time a clock signal is input, to an X-axis electromagnet power supply as an X-axis exciting current command value, and also sends a command in the form of the product of said amplitude data and sine wave function data, which advances 90 degrees in phase from said sine wave function data, to a Y-axis electromagnet power supply as a Y-axis exciting current command value;

said X-axis electromagnet power supply that controls an X-axis exciting current supplied to an X-axis electromagnet based on said X-axis exciting current command value;

said Y-axis electromagnet power supply that controls a Y-axis exciting current supplied to a Y-axis electromagnet based on said Y-axis exciting current command value;

said X-axis electromagnet that deflects the flow of said transported particle beam toward an X-axis direction perpendicular to the direction of travel of said particle beam by said X-axis exciting current being supplied thereto; and

said Y-axis electromagnet that deflects the flow of said transported particle beam toward a Y-axis direction perpendicular to the direction of travel of said particle beam by said Y-axis exciting current being supplied thereto.

4. The particle beam therapeutic apparatus as set forth in claim 2, wherein

a storage section having a plurality of areas to which addresses are assigned, and in which sine wave function data from whose amplitude is repeatedly increased and decreased in said period and oscillates at said angular velocity when read out from said areas while said address is designated progressively, and cosine wave function data whose amplitude is repeatedly increased and decreased in said period with its phase advancing 90 degrees from said sine wave function data when read out from said areas are stored;

a command value transmission part that sends a command in the form of said sine wave function data, which are read out from said areas at an address designated progressively each time a clock signal is input, to an X-axis electromagnet power supply as an X-axis exciting current command value, and also sends a command in the form of said cosine wave function data to a Y-axis electromagnet power supply as a Y-axis exciting current command value;

said X-axis electromagnet power supply that controls an X-axis exciting current supplied to an X-axis electromagnet based on said X-axis exciting current command value;

said Y-axis electromagnet power supply that controls a Y-axis exciting current supplied to a Y-axis electromagnet based on said Y-axis exciting current command value;

said X-axis electromagnet that deflects the flow of said transported particle beam toward an X-axis direction perpendicular to the direction of travel of said particle beam by said X-axis exciting current being supplied thereto; and

said Y-axis electromagnet that deflects the flow of said transported particle beam toward a Y-axis direction perpendicular to the direction of travel of said particle beam by said Y-axis exciting current being supplied thereto.

5. The particle beam therapeutic apparatus as set forth in claim 2, further comprising:

a storage section having a plurality of areas to which addresses are assigned, and in which amplitude data which is increased and decreased in said period when read out from said areas while said address is designated progressively, and periodical function data are stored in said plurality of areas;

a command value transmission part that sends a command in the form of the product of said amplitude data and said function data, which are read out from said areas at an address designated progressively each time a clock signal is input, to an X-axis electromagnet power supply as an X-axis exciting current command value, and also sends a command in the form of the product of said amplitude data and function data, which advances a predetermined phase from said function data, to a Y-axis electromagnet power supply as a Y-axis exciting current command value;

said X-axis electromagnet power supply that controls an X-axis exciting current supplied to an X-axis electromagnet based on said X-axis exciting current command value;

said Y-axis electromagnet power supply that controls a Y-axis exciting current supplied to a Y-axis electromagnet based on said Y-axis exciting current command value;

said X-axis electromagnet that deflects the flow of said transported particle beam toward an X-axis direction perpendicular to the direction of travel of said particle beam by said X-axis exciting current being supplied thereto; and

said Y-axis electromagnet that deflects the flow of said transported particle beam toward a Y-axis direction perpendicular to the direction of travel of said particle beam by said Y-axis exciting current being supplied thereto.

6. The particle beam therapeutic apparatus as set forth in claim 1, further comprising:

a patient monitor device that monitors the state of a patient; and

a beam turn on and off device that turns on and off said particle beam based on the state of said patient;

wherein by maintaining, upon turning off of said particle beam, an X-axis exciting current and a Y-axis exciting current flowing through said X-axis electromagnet and said Y-axis electromagnet at constant values, respectively, the scanning of said particle beam is resumed, upon turning on of said particle beam, from that position of said diseased part which was irradiated by said particle beam when said particle beam was turned off.

7. The particle beam therapeutic apparatus as set forth in claim 3, further comprising:

a dose monitor that measures a dose irradiated to said diseased part;

a beam detection device that sends a clock signal each time a predetermined dose has been irradiated; and

a storage device whose address is advanced progressively by said clock.

8. The particle beam therapeutic apparatus as set forth in claim 3, further comprising:

a dose recording device that records an X-axis excitation current value, a Y-axis excitation current value, and a dose in a time series manner when said particle beam is turned on; and

a dose calculation device that calculates an irradiation position from said X-axis excitation current value and said Y-axis excitation current value, and compares a dose at said irradiation position with a prescribed value.

9. The particle beam therapeutic apparatus as set forth in claim 8, wherein

said dose calculation device compares a dose at each irradiation position with a described value, and warns an abnormal state when it makes a determination of abnormality based on a prescribed abnormality determination criterion.