PARTICLE BEAM IRRADIATION SYSTEM

• US 20120223247A1
• Filed: 03/02/2011
• Published: 09/06/2012
• Est. Priority Date: 03/02/2011
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Honda, Taizo, Ikeda, Masahiro
• Granted Patent: US 9,265,970 B2
• Time in Patent Office: Days
• US Class Current: 250/396.R
• CPC Class Codes: A61N 2005/1059 using cameras imaging the patient
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: A61N 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment
• CPC Class Codes: A61N 5/1068 Gating the beam as a function of a physiological signal

Abstract

A particle beam irradiation system comprises deflection electromagnets which scan by deflecting the particle beam in two dimensions in the lateral direction which is perpendicular to an irradiation direction of the particle beam, and an energy width expanding device through which the particle beam passes so as to expand an energy width of the particle beam and form a SOBP in a depth direction of the irradiation target, that is, in an irradiation direction of the particle beam, wherein the energy width expanding device is configured to form the SOBP in the depth direction along whole irradiation area in the depth direction of the irradiation target, and the deflection electromagnets are controlled so as for an irradiation spot which is formed in the irradiation target by the particle beam to move stepwise along whole irradiation area in the lateral direction of the irradiation target.

Claims

1. A particle beam irradiation system comprising a particle beam generation part at which an accelerator is provided;

an irradiation nozzle which irradiates a particle beam which is generated in the particle beam generation part to an irradiation target; and

an irradiation control part which controls the irradiating particle beam, wherein the irradiation nozzle comprises deflection electromagnets for scanning which scan by deflecting the particle beam in two dimensions in the lateral direction which is perpendicular to an irradiation direction of the particle beam, and an energy width expanding device through which the particle beam passes so as to expand an energy width of the particle beam and form a SOBP in a depth direction of the irradiation target, that is, in an irradiation direction of the particle beam,

the energy width expanding device is configured to form the SOBP in the depth direction along whole irradiation area in the depth direction of the irradiation target, and the irradiation control part controls the deflection electromagnets for scanning so as for an irradiation spot which is formed in the irradiation target by the particle beam to move stepwise along whole irradiation area in the lateral direction of the irradiation target.

2. The particle beam irradiation system as claimed in claim 1 further comprising a displacement phase detecting part which detects a phase of a displacement of the irradiation target, wherein the displacement phase detecting part outputs a gate signal which permits to irradiate the particle beam onto the irradiation target while the displacement of the irradiation target is in a predetermined phase, and the irradiation control part controls the deflection electromagnets for scanning so as for the irradiation spot to move stepwise along whole irradiation area in the lateral direction of the irradiation target while one gate signal among the gate signals is outputted.

3. The particle beam irradiation system as claimed in claim 2 comprising a treatment planning part and an irradiation control calculation part which computes an irradiation parameter of each irradiation spot of the irradiation spots which move stepwise by using data which is received from the treatment planning part,

wherein the irradiation control calculation part evaluates a phase of moving period of the irradiation target by using data which is received from the displacement phase detecting part, and computes the irradiation parameter for irradiating whole irradiation area in a lateral direction of the irradiation target while the one gate signal so as to transmit data for irradiating by the irradiation parameter which is computed.

4. The particle beam irradiation system as claimed in claim 2, wherein the timing to start of extraction of a particle beam from the accelerator is synchronized with a result whether residual time capable for extracting from the accelerator is longer than the planned irradiation time within the gate or not.

5. The particle beam irradiation system as claimed in claim 1, wherein the energy width expanding device is an element which expands an energy width so as for an energy width to have different distributions in the lateral direction.

6. (canceled)