Radiation therapy method with target detection

1. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy.

2. The method of claim 1 , wherein the delivery is accomplished by one or more of the following: administering the radiation therapy; refraining from administering the radiation therapy; repositioning the patient; redirecting a therapeutic radiation beam; or modifying the therapeutic radiation beam.

3. The method of claim 1 , wherein the image capture conditions are determined using a digitally reconstructed radiograph.

4. The method of claim 1 , wherein the desired image capture conditions are determined so as to maximize contrast between the radiation therapy target and its surrounding region.

5. The method of claim 1 , wherein the at least one two-dimensional radiographic image is acquired using dual energy.

6. The method of claim 1 , wherein the desired image capture conditions is calculated using light fields.

7. The method of claim 1 , wherein a radiation therapy apparatus delivers the radiation therapy, and a digital radiography unit is employed to capture the two-dimensional radiographic image, and a position and orientation of the digital radiography unit is determined automatically in a coordinate system of the radiation therapy apparatus.

8. The method of claim 1 , further comprising the step of enhancing the radiation therapy target in the at least one two-dimensional radiographic image.

9. The method of claim 1 , further comprising the step of enhancing a background anatomy in the at least one two-dimensional radiographic image.

10. The method of claim 1 , wherein the position of the radiation therapy target is detected in one of the captured two-dimensional radiographic images based on the detection of the radiation therapy target in another captured two-dimensional radiographic image.

11. The method of claim 1 , wherein a position of the radiation therapy target is detected in three-dimensional space using two or more two-dimensional radiographic images.

12. The method of claim 1 , wherein a position of the radiation therapy target is detected in three-dimensional space using a location of the radiation therapy target in one two-dimensional radiographic image and the radiation therapy target's magnification.

13. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining one or more desired digitally reconstructed radiographs using the planning image;

capturing at least one two-dimensional radiographic image corresponding to each of the one or more desired digitally reconstructed radiographs using a digital radiography unit;

detecting a position of the radiation therapy target in each of the at least one captured digital two-dimensional radiographic images;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the captured at least one two-dimensional radiographic image; and

delivering the radiation therapy.

14. The method of claim 13 , wherein a location of the radiation therapy target is detected in the least one two-dimensional radiographic image based on characteristics of the radiation therapy target in at least one of one or more desired digitally reconstructed radiographs.

15. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy, and

wherein the desired image capture conditions are determined so as to minimize an overlap of the radiation therapy target with patient anatomy.

16. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy, and

wherein the desired image capture conditions are determined such that a boundary of the radiation therapy target is distinct.

17. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy, and

wherein the desired image capture conditions are determined such that a portion of the patient's anatomy that overlaps with the radiation therapy target has a substantially uniform attenuation.

18. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy, and

wherein the desired image capture conditions are determined such that a maximum dimension of the radiation therapy target is projected.

19. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

delivering the radiation therapy, and

wherein the desired image capture conditions are determined such that a concavity of the radiation therapy target is obtained.

20. A method for delivering radiation therapy to a patient using a three-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, the method comprising the steps of:

determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image;

enhancing the radiation therapy target in the at least one two-dimensional radiographic image to generate an enhanced target image;

enhancing a background anatomy in the at least one two-dimensional radiographic image to generate an enhanced background anatomy image; and

generating a difference image using the enhanced target image and the enhanced background anatomy image.

21. An apparatus for delivering radiation therapy to a patient using a thee-dimensional planning image for radiation therapy of the patient wherein the planning image includes a radiation therapy target, comprising:

means for determining desired image capture conditions for the capture of at least one two-dimensional radiographic image of the radiation therapy target using the three-dimensional planning image;

means for using the determined image capture conditions to capture the at least one two-dimensional radiographic image;

means for detecting a position of the radiation therapy target in the captured at least one two-dimensional radiographic image;

means for determining a delivery of the radiation therapy in response to the radiation therapy target's detected position in the at least one captured two-dimensional radiographic image; and

means for delivering the radiation therapy.