Method for the operation of a radiotherapy system and a radiotherapy system

Patent metadata

Field	Value
Publication number	US-9604075-B2
Application number	US-201213684463-A
Country	US
Kind code	B2
Filing date	Nov 23, 2012
Priority date	Nov 23, 2011
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A method for calculating local part radiation doses in a radiotherapy system for applying a total radiation dose in a target volume with several beams is provided. The method includes determining at least one first control plane for controlling the dosing of the beams, determining at least one second control plane for controlling the positioning of the beams, and allocating beams to the first and second control planes. The method also includes, for at least one side of a first control plane, calculating in isolation of the corresponding local part radiation doses of all the beams allocated to the first control plane.

First claim

The invention claimed is:

1. A method for calculating local part radiation doses in a radiotherapy system for the application of a total radiation dose in a target volume with beams, the method comprising:
determining, by a treatment planning system, a location of at least one first control plane for controlling the dosing of the beams, wherein each of the at least one first control plane divides the target volume into two part volumes;
allocating, by the treatment planning system, at least one of the beams for a front side and a rear side of each of the at least one first control plane, respectively;
determining, by the treatment planning system, for each of the at least one first control plane, a sub-volume total radiation dose for each of the two part volumes as a fraction of the total radiation dose;
determining, by the treatment planning system, a location of at least one second control plane for the control of the positioning of the beams, wherein each of the at least one second control plane divides the target volume into two sub-volumes;
allocating, by the treatment planning system, at least one of the beams to each of the at least one second control plane, wherein the at least one beam allocated to the second control plane is divided in two by the respective second control plane such that a local part radiation dose of two beams obtained in this way in different sub-volumes, defined by the respective second control plane, is not equal to zero;
calculating, by a processing device, for at least one side of the at least one first control plane, in isolation, the corresponding local part radiation doses of all the beams allocated to the at least one first control plane, such that the sum of the local part radiation doses of the beams that are allocated to the side of the respective first control plane that faces the respective sub-volume, provides the respective sub-volume total radiation dose, and the sum of the local part radiation doses of the beams allocated to the remainder of the at least one first control plane provides a difference between the respective sub-volume total radiation dose and the total radiation dose; and
applying, by a radiation generating device, said beams based on the local part radiation doses calculated by the processing device.

2. The method as claimed in claim 1 , wherein allocating the at least one beam for the front side and the rear side of each of the at least one first control plane comprises allocating a beam in each case to a side of the at least one first control plane.

3. The method as claimed in claim 1 , wherein the local part radiation doses of a beam allocated to a side of a first control plane of the at least one first control plane are different in the sub-volumes defined by the first control plane.

4. The method as claimed in claim 1 , wherein the at least one first control plane includes a finite thickness, and
wherein beams that exhibit different local part radiation doses on different sides of a respective first control plane of the at least one first control plane provide, by a local course of the local part radiation dose inside the respective first control plane, a gradual transition of the local part radiation dose.

5. The method as claimed in claim 1 , further comprising determining a beam weight for each of the beams,
wherein the beam weights determine relative ratios of the part radiation doses of different beams to one another.

6. The method as claimed in claim 5 , wherein also inside the target volume for a specific side of a specific first control plane of the at least one first control plane, the method further comprises:
determining first local weighting factors for each distance interval perpendicular to the specific first control plane, wherein the first local weighting factors define fractions of the sub-volume total radiation dose in the total radiation dose;
determining, for each of the beams allocated to the specific side of the specific first control plane, second local weighting factors for each distance interval perpendicular to a second control plane, to which the respective beam is allocated, wherein the second local weighting factors modify the beam weights of the beams as a function of a position in relation to the at least one second control plane; and
calculating, for each of the beams allocated to the specific side of the specific first control plane, the local part radiation dose for each sub-volume for the respective beam based on elements, the elements comprising radiation weighting factors, the first local weighting factors, the second local weighting factors, the total radiation dose, or a combination thereof.

7. The method as claimed in claim 6 , wherein, in the calculation of the local part radiation dose, the second local weighting factors modify the radiation weighting factors between 0% and 100% of the radiation weighting factors.

8. The method as claimed in claim 6 , wherein the at least one first control plane and the at least one second control plane include a thickness, the first local weighting factors and the second local weighting factors varying inside a corresponding control plane of the at least one first control plane and the at least one second control plane as a function of a position.

9. The method as claimed in claim 5 , wherein the calculation of the local part radiation dose is carried out in a spatially-resolved manner in accordance with the following formula for one side of a first control plane of the at least one control plane

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Assignees

• Scholz Christian
• Siemens Ag

Inventors

• Scholz Christian

Classifications

• A61N5/1047

  with movement of the radiation head during application of radiation, e.g. for intensity modulated arc therapy or IMAT · CPC title

• A61N5/1031 Primary

  using a specific method of dose optimization · CPC title