Method and device for determining an irradiation plan for a particle irradiation unit

Patent metadata

Field	Value
Publication number	US-9370671-B2
Application number	US-201314414608-A
Country	US
Kind code	B2
Filing date	Jun 11, 2013
Priority date	Jul 13, 2012
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

An irradiation plan for a particle irradiation unit is determined in a first run based on a specified target volume in a test object and a specified dose distribution to apply the particle beam in the target volume. The target volume includes a plurality of isoenergy layers. The irradiation plan may be determined in a second run with an additional condition that at least one of the isoenergy layers, determined according to one or more criteria, is not irradiated. Alternatively, the irradiation plan may be determined in a second run with an additional condition that only certain isoenergy layers, determined according to one or more criteria, are irradiated.

First claim

The invention claimed is:

1. A method for determining an irradiation plan for a particle irradiation unit, the particle irradiation unit being configured to irradiate a target volume in an examination object with a particle beam based on the irradiation plan, the method comprising:
prescribing the target volume and a predetermined dose distribution;
determining the irradiation plan in a first pass to apply the particle beam based on the predetermined dose distribution in the target volume, the target volume comprising a plurality of isoenergy layers;
determining the irradiation plan in a second pass with an additional condition that at least one isoenergy layer of the plurality of isoenergy layers is not irradiated; and
determining the at least one isoenergy layer of the plurality of isoenergy layers based on a criterion selected from the group consisting of:
(a) the at least one isoenergy layer is not irradiated if the particle beam has an energy below a minimum peak energy;
(b) the at least one isoenergy layer is not irradiated if the particle beam has an energy above a maximum peak energy;
(c) the at least one isoenergy layer is not irradiated if, according to the irradiation plan determined in the first pass, the at least one isoenergy layer has a smallest number of raster points;
(d) the at least one isoenergy layer is not irradiated if, according to the irradiation plan determined in the first pass, the at least one isoenergy layer has a smallest overall number of particles;
(e) the at least one isoenergy layer is not irradiated if, according to the irradiation plan determined in the first pass, the at least one isoenergy layer makes a smallest dose contribution to an overall dose to be applied in the target volume;
(f) the at least one isoenergy layer is not irradiated if, according to the irradiation plan determined in the first pass, the at least one isoenergy layer makes a smallest contribution to a target function, the target function being calculated for determining the irradiation plan;
(g) the at least one isoenergy layer is not irradiated if, according to the irradiation plan determined in the first pass, the at least one isoenergy layer has a smallest dose compensation error, wherein the dose compensation error defines an error resulting from non-irradiation of the at least one isoenergy layer despite corresponding compensation by irradiated isoenergy layers;
(h) the at least one isoenergy layer is not irradiated if the at least one isoenergy layer has a first target function value having a smallest change in relation to a second target function value, wherein the first target function value is determined based on an irradiation plan generated under an assumption that the at least one isoenergy layer is not irradiated, and wherein the second target function value is generated based on the irradiation plan determined in the first pass; and
(i) combinations thereof.

2. The method of claim 1 , further comprising:
forming a ratio between a number or a proportion of the at least one isoenergy layer and a sum of numbers or proportions of all isoenergy layers of the plurality of isoenergy layers;
wherein the at least one isoenergy layer is selected such that the ratio lies below a predetermined threshold but will exceed the predetermined threshold if an additional isoenergy layer of the plurality of isoenergy layers is added to the at least one isoenergy layer.

3. The method of claim 1 , further comprising:
forming a sum of a number or a proportion of the at least one isoenergy layer;
selecting the at least one isoenergy layer such that the sum lies below a predetermined maximum value but will exceed the predetermined maximum value if an additional isoenergy layer of the plurality of isoenergy layers is added to the at least one isoenergy layer.

4. The method of claim 1 , further comprising:
prescribing a condition to be complied with by the irradiation plan; and
adding additional isoenergy layers to the at least one isoenergy layer until the irradiation plan does not comply with the condition.

5. The method claim 1 , further comprising:
determining a set of isoenergy layers, wherein the set comprises each isoenergy layer of the plurality of isoenergy layers except for the at least one isoenergy layer;
re-performing the first pass for determining the irradiation plan starting from the set of isoenergy layers; and
determining the irradiation plan in the second pass with additional conditions that at least one isoenergy layer of the set of isoenergy layers is not irradiated, and that at least one isoenergy layer of the set of isoenergy layers is determined according to at least one of the criteria.

6. A method for determining an irradiation plan for a particle irradiation unit, the particle irradiation unit being configured to irradiate a target volume in an examination object with a particle beam based on the irradiation plan, the method comprising:
prescribing the target volume and a predetermined dose distribution;
determining the irradiation plan in a first pass to apply the particle beam based on the predetermined dose distribution in the target volume, the target volume comprising a plurality of isoenergy layers;
determining the irradiation plan in a second pass with an additional condition that only specific isoenergy layers of the plurality of isoenergy layers are irradiated; and
determining the specific isoenergy layers of the plurality of isoenergy layers based on a criterion selected from the group consisting of:
(a) only the specific isoenergy layers are irradiated if the particle beam has an energy above a minimum peak energy;
(b) only the specific isoenergy layers are irradiated if the particle beam has an energy below a maximum peak energy;
(c) only the specific isoenergy layers are irradiated if, according to the irradiation plan determined in the first pass, the specific isoenergy layers have a largest number of raster points;
(d) only the specific isoenergy layers are irradiated if, according to the irradiation plan determined in the first pass, the specific isoenergy layers have a largest overall number of particles;
(e) only the specific isoenergy layers are irradiated if, according to the irradiation plan determined in the first pass, the specific isoenergy layers make a largest dose contribution to an overall dose to be applied in the target volume;
(f) only the specific isoenergy layers are irradiated if, according to the irradiation plan determined in the first pass, the specific isoenergy layers make a largest contribution to a target function, the target function being calculated for determining the irradiation plan;
(g) only the specific isoenergy layers are irradiated if, according to the irradiation plan determined in the first pass, the specific isoenergy layers have a largest dose compensation error, wherein the dose compensation error defines an error resulting from non-irradiation of the specific isoenergy layers despite corresponding compensation by irradiated isoenergy layers;
(h) the specific isoenergy layers are determined from a set of isoenergy layers based on the irradiation plan determined in the first pass, wherein a first target function value is generated based on an irradiation plan generated under an assumption that only the set of isoenergy layers is irradiated, wherein in each case an isoenergy layer is added to the set of isoenergy layers that modifies a second target function value in relation to the first target function value to a greatest extent, wherein the second target function value is determined based on an irradiation plan generated under an assumption that only the added isoenergy layer and the set of isoenergy layers are irradiated, wherein an additional isoenergy layer is added to the set of i

Assignees

• Siemens Ag

Inventors

• Bohsung Jörg
• Elsässer Thilo
• Grözinger Sven Oliver
• Kim Johann
• Neuhauser Robert
• Rietzel Eike
• Schweizer Bernd
• Thilmann Oliver

Classifications

• A61N2005/1087

  Ions; Protons · CPC title

• A61N5/1031 Primary

  using a specific method of dose optimization · CPC title

• A61N5/103 Primary

  Treatment planning systems · CPC title