DOSE-OPTIMISED PATIENT POSITIONING FOR RADIOTHERAPY

• US 20140171726A1
• Filed: 08/02/2011
• Published: 06/19/2014
• Est. Priority Date: 08/02/2011
• Status: Active Grant

• Current Assignee: Brainlab AG
• Original Assignee: Brainlab AG
• Inventors: Froehlich, Stephan, Gum, Herrn Franz
• Granted Patent: US 9,403,035 B2
• Time in Patent Office: Days
• US Class Current: 600/1
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/4085 Cone-beams
• CPC Class Codes: A61N 2005/1061 using an x-ray imaging system having a separate imaging source
• CPC Class Codes: A61N 5/1031 using a specific method of dose optimization
• CPC Class Codes: A61N 5/1039 using functional images, e.g. PET or MRI
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1077 Beam delivery systems

Abstract

The present invention relates to a method for positioning an arrangement of at least one beam position relative to a patient'"'"'s body when the patient is placed for treatment by means of a treatment device which can emit treatment radiation, wherein the at least one beam position describes at least one position of at least one treatment beam, wherein the arrangement is referred to as the treatment arrangement and the treatment beam comprises the treatment radiation, wherein the method is executed by a computer and comprises the following steps:

• providing treatment beam absorption data which describe the absorption properties of the at least part of the body with respect to absorbing the treatment radiation, and the relative position between the at least part of the body and the treatment arrangement;
• providing treatment beam data which describe radiation properties of the at least one treatment beam;
• providing condition data which describe a condition for treating the at least part of the body;
• determining an optimum relative position between the treatment arrangement and the at least part of the body on the basis of the condition data, the treatment beam data and the treatment beam absorption data.

Claims

1. A method for positioning an arrangement of at least one beam position relative to a patient'"'"'s body when the patient is placed for treatment by means of a treatment device which can emit treatment radiation, wherein the at least one beam position describes at least one position of at least one treatment beam, wherein the arrangement is referred to as the treatment arrangement and the treatment beam comprises the treatment radiation, wherein the method is executed by a computer and comprises the following steps:

a) providing treatment beam absorption data which describe the absorption properties of the at least part of the body with respect to absorbing the treatment radiation, and the relative position between the at least pmi of the body and the treatment anangement;

b) providing treatment beam data which describe radiation properties of the at least one treatment beam;

c) providing condition data which describe a condition for treating the at least part of the body;

d) determining an optimum relative position between the treatment arrangement and the at least part of the body on the basis of the condition data, the treatment beam data and the treatment beam absorption data.

2. The method according to claim 1, wherein the condition data comprise planning data which describe planned relative positions between the beam positions of a planned arrangement, and wherein the optimum relative position is determined subject to the condition that the relative beam positions of the treatment arrangement correspond to the planned relative positions.

3. The method according to claim 1, wherein image data which are referred to as pre-optimisation image data are provided, which describe an image referred to as the pre-optimisation image which is generated using a medical imaging method at a preoptimisation time at which the patient is placed for treatment with the treatment beam, and wherein the treatment beam absorption data are determined on the basis of the preoptimisation image data.

4. The method according to claim 3, wherein the pre-optimisation image data describe a relative position of the treatment arrangement relative to the at least part of the body, wherein said relative position is referred to as the pre-optimisation relative position and is used to determine the optimum relative position.

5. The method according to claim 1, wherein the treatment beam absorption data describe relative positions between regions of the at least part of the body and the absorption properties of the regions.

6. The method according to claim 1, wherein the treatment beam absorption data describe the radiation properties of elements of the body and relative positions between the elements of the body, wherein one of these elements is the part of the body to be treated and is referred to as the treatment body part.

7. The method according to claim 6, wherein the relative positions of the elements of the body are determined on the basis of planning image data which describe an image of the body which shows the at least part of the body segmented into the elements, wherein the planning image is generated at a time referred to as the planning time, before the body is placed for the treatment.

8. The method according to claim 3,

wherein image data which are referred to as pre-optimisation image data are provided, which describe an image referred to as the pre-optimisation image which is generated using a medical imaging method at a preoptimisation time at which the patient is placed for treatment with the treatment beam, and wherein the treatment beam absorption data are determined on the basis of the preoptimisation image data

wherein the planning image is used to supplement the pre-optimisation image if the pre-optimisation image does not show all the parts through which the at least one treatment beam will pass, wherein the treatment beam absorption data are determined on the basis of the supplemented pre-optimisation image.

9. The method according to claim 1, comprising the step of:

determining expected dose data which describe an expected dose which is applied to the at least part of the body, wherein the expected dose is the dose which is expected if the at least part of the body is in a position relative to the treatment arrangement which is referred to as the expected relative position and is treated by the treatment beam, wherein the expected dose data are determined on the basis of the treatment beam absorption data, the expected relative position and the treatment beam data.

10. The method according to claim 9, wherein the expected relative position is varied in order to determine the expected doses for different expected positions, and wherein the optimum relative position is detenuined by comparing the different expected doses with the conditions described by the condition data.

11. The method according to claim 9, wherein the at least part of the body comprises at least one of a target region for which an expected target dose is to be determined and an off-target region for which an expected off-target dose is determined if the treatment arrangement is in the expected relative position, and wherein the condition data comprise conditions for the target region and the off-target region.

12. The method according to claim 1, wherein the treatment beam absorption data are provided on the basis of the CBCT image data which describe a CBCT image.

13. The method according to claim 12, wherein the treatment beam absorption data are provided additionally on the basis of a CT image, and wherein CT values of the CT image are used to determine absorption values for elements of the body shown in both the CT image and the CBCT image, and wherein the position and geometry of the elements is described by the CBCT image, wherein the CBCT image is generated when the patient is placed for treatment and the CT image is generated before the patient is placed for treatment.

14. A program which, when running on a computer or when loaded onto a computer, causes the computer to perform the method according to claim 1.

15. A program storage medium on which the program of claim 14 is stored.

16. A computer on which the program of claim 14 is running or into the memory of which the program of claim 14 is loaded.

17. A signal wave, in particular a digital signal wave, carrying information which represents the program of claim 14.

18. A radiotherapy system comprising the treatment device specified in claim 1 which generates the treatment beam.

19. A computer according to claim 16 for positioning the arrangement of the at least one beam position relative to the patient'"'"'s body when the patient is placed for treatment by means of the treatment device.