Particle beam therapy system

• US 7,772,577 B2
• Filed: 08/13/2008
• Issued: 08/10/2010
• Est. Priority Date: 08/17/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sakurabata, Hiroaki, Saito, Kazuyoshi
• Primary Examiner(s): Wells; Nikita
• Application Number:
  US12/190,909
• Publication Number:
  US 20090065706A1
• Time in Patent Office: 727 Days
• Field of Search: 250/505.1, 250/396.ML, 250/492.3, 315/503, 315/500, 315/111.61, 313/363.1
• US Class Current: 250/505.1
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: H05H 13/02 Synchrocyclotrons, i.e. frequency modulated cyclotrons
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof
• CPC Class Codes: H05H 7/10 Arrangements for ejecting particles from orbits

Abstract

A particle beam therapy system using a spot scanning method includes a synchrotron, a beam transport system, an irradiation system, and a controller. A controller is configured to turn on a radio frequency electromagnetic field to be applied to an extraction system when a charged particle beam is to be supplied to the irradiation system, and turn off the radio frequency electromagnetic field to be applied to the extraction system when the supply of the charged particle beam to the irradiation system is to be blocked by means of an electromagnet provided in the beam transport system or in the synchrotron. The controller is also adapted to turn off a radio frequency acceleration voltage to be applied to an acceleration cavity in synchronization with the turning-off of the radio frequency electromagnetic field to be applied to the extraction device.

Claims

1. A particle beam therapy system comprising:

a synchrotron for accelerating a charged particle beam by means of a radio frequency acceleration voltage applied to an acceleration cavity such that the charged particle beam has a predetermined energy level, causing the charged particle beam to exceed a stability limit by means of a radio frequency electromagnetic field applied to an extraction device, and then extracting the thus-prepared charged particle beam;

a beam transport system for introducing the charged particle beam extracted from said synchrotron to a treatment room;

an irradiation system for irradiating an affected area of a patient with the charged particle beam in conformity with the shape of the affected area in the treatment room; and

a controller for turning on the radio frequency electromagnetic field to be applied to the extraction device when the charged particle beam is to be supplied to said irradiation system, turning off the radio frequency electromagnetic field to be applied to the extraction device when the supply of the charged particle beam to said irradiation system is to be blocked by means of an electromagnet provided in said beam transport system or in said synchrotron, and turning off the radio frequency acceleration voltage to be applied to the acceleration cavity in synchronization with the turning-off of the radio frequency electromagnetic field to be applied to the extraction device.

2. The particle beam therapy system according to claim 1, wherein

the electromagnet, which is provided in said beam transport system and adapted to block the supply of the charged particle beam to said irradiation system, is a bending magnet for producing a dipole magnetic field.

3. The particle beam therapy system according to claim 1, wherein

the electromagnet, which is provided in said synchrotron and adapted to block the supply of the charged particle beam to said irradiation system, is a focusing magnet for producing a quadrupole magnetic field or is a defocusing magnet for producing a quadrupole magnetic field.

4. A particle beam therapy system comprising:

a synchrotron for accelerating a charged particle beam by means of a radio frequency acceleration voltage applied to an acceleration cavity such that the charged particle beam has a predetermined energy level, causing the charged particle beam to exceed a stability limit by means of a radio frequency electromagnetic field applied to an extraction device, and then extracting the thus-prepared charged particle beam;

a beam transport system for introducing the charged particle beam extracted from said synchrotron to a treatment room;

an irradiation system for irradiating an affected area of a patient with the charged particle beam in conformity with the shape of the affected area in the treatment room; and

a controller for turning on the radio frequency electromagnetic field to be applied to the extraction device when the charged particle beam is to be supplied to said irradiation system, turning off the radio frequency electromagnetic field to be applied to the extraction device when the supply of the charged particle beam to said irradiation system is to be blocked by means of an electromagnet provided in said beam transport system or in said synchrotron, turning off the radio frequency acceleration voltage to be applied to the acceleration cavity in synchronization with the turning-off of the radio frequency electromagnetic field to be applied to the extraction device, and turning on the radio frequency acceleration voltage to be applied to the acceleration cavity at least once under the condition which the radio frequency electromagnetic field to be applied to the extraction device is turned off.