DEVICE AND METHOD FOR PARTICLE BEAM DELIVERY

• US 20110297850A1
• Filed: 06/03/2011
• Published: 12/08/2011
• Est. Priority Date: 06/07/2010
• Status: Active Grant

• Current Assignee: Ion Beam Applications s.a.
• Original Assignee: Ion Beam Applications s.a.
• Inventors: Claereboudt, Yves, Closset, Michel
• Granted Patent: US 8,916,838 B2
• Time in Patent Office: Days
• US Class Current: 250/492.1
• 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 5/103 Treatment planning systems
• CPC Class Codes: A61N 5/1044 with multiple repetitions of the scanning pattern

Abstract

The present invention relates to a particle therapy system that comprises a spot scanning system to irradiate with a particle beam a plurality of spots in a layer of a target with prescribed spot doses for each spot of the layer. The therapy system is further adapted to perform multiple paintings of the layer and to deliver partial spot doses to selected spots of the layer during each painting time so that each spot of the layer will have received its prescribed dose after completion of the multiple paintings. The therapy system further comprises means for setting the partial spot doses and the number of times that a spot will be selected for irradiation in the course of the multiple paintings to such values that any spot of the layer will never have to be irradiated with a partial dose which would fall below a minimum dose deliverable by the system, and this whatever the number chosen for the number of layer paintings.

The invention also relates to a corresponding irradiation method.

Claims

1. A particle therapy system (10) for irradiating with a particle beam (50) a plurality of spots (70) in a layer (65) of a target (60), said system (10) comprising means (30) for scanning the particle beam over said layer a prescribed number of layer scanning times (Nlayer_painting), means for irradiating selected spots of said layer with partial spot doses (Dspot_partial) in the course of each said layer scanning time so that each spot respectively receives a prescribed total spot dose (Dspot) after completion of the prescribed number of layer scanning times, said system (10) being only able to irradiate a spot with a spot dose which is larger than or equal to a minimum spot dose (Dmin), characterized in that the system further comprises means (45) for determining, for each spot (70) of said layer, the partial spot doses (Dspot_partial) and a number of times that said spot is to be selected for irradiation (Nspot_painting), according to both the following rules a) and b):

a) each of the partial spot doses (Dspot_partial) is larger or equal to Dmin,

b) if (Dspot/Nlayer_painting>

=Dmin), then (Nspot_painting=Nlayer_painting), else (Nspot_painting<

Nlayer_painting).

2. A particle therapy system according to claim 1, characterized in that Nspot_painting is determined according to the following rule b):

b) if (Dspot/Nlayer_painting>

=Dmin), then (Nspot_painting=Nlayer_painting), else (Nspot_painting=Floor (Dspot/Dmin)).

3. A particle therapy system according to any of claim 1 or 2, characterized in that, for each spot of said layer, each of the partial spot doses (Dspot_partial) is determined according to the following rule a):

a) Dspot_partial=Dspot/Nspot_painting.

4. A particle therapy system according to any of claim 1 or 2, further comprising means for determining which spots of the layer are to be selected for irradiation with their respective partial spot doses in the course of each scanning time of said layer according to the following sequence:

5. A method for irradiating with a particle beam (50) a plurality of spots in a layer (65) of a target (60), said method comprising the steps of:

providing a particle therapy system (10) for irradiating the plurality of spots with the particle beam, said system being only able to irradiate a spot with a spot dose which is larger than or equal to a minimum spot dose (Dmin),

scanning the particle beam over the layer a prescribed number of layer scanning times (Nlayer_painting),

irradiating selected spots of said layer in the course of each said layer scanning time with partial spot doses (Dspot_partial) so that each spot receives a prescribed total spot dose (Dspot) after completion of the prescribed number of layer scanning times, characterized in that, for each spot of the layer (65), the partial spot doses (Dspot_partial) and a number of times that said spot is to be selected for irradiation (Nspot_painting), are set according to both the following rules a) and b);

a) each of the partial spot doses (Dspot_partial) is larger or equal to Dmin

b) if (Dspot/Nlayer_painting>

=Dmin), then (Nspot_painting=Nlayer_painting), else (Nspot_painting<

Nlayer_painting).

6. A method according to claim 5, characterized in that Nspot_painting is set according to the following rule b):

b) if (Dspot/Nlayer_painting>

=Dmin), then (Nspot_painting=Nlayer_painting), else (Nspot_painting=Floor (Dspot/Dmin)).

7. A method according to any of claim 5 or 6, characterized in that, for each spot of said layer, each of the partial spot doses (Dspot_partial) is set according to the following rule a):

a) Dspot_partial=Dspot/Nspot_painting.

8. A method according to any of claim 5 or 6, characterized in that, for each scanning time of the layer, the following spots of said layer are selected for irradiation with their respective partial spot doses: