Online angle selection in rotational imaging and tracking systems

1. A method of operating a radiation apparatus, the method comprising:

selecting at least a first angle and a second angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold;

generating, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and

generating, using the imaging device, a second tracking image of the target from the second angle during the first rotation of the gantry.

2. The method of claim 1 , wherein the tracking quality metric value of the first angle is higher than a second tracking quality metric value of the second angle, and wherein the second angle has a separation from the first angle of at least an angle separation threshold.

3. The method of claim 1 , further comprising:

determining, based on the second tracking image, that target tracking has failed during delivery of a radiation treatment beam;

determining a time window within which a next tracking image must be taken;

determining that no angle from the set of angles will be available within the time window; and

interrupting delivery of the radiation treatment beam.

4. The method of claim 1 , further comprising:

generating a plurality of x-ray images of the target from two or more angles from the set of angles; and

generating a motion model of the target from the plurality of x-ray images.

5. The method of claim 1 , wherein the method is performed during an alignment phase of operation of the radiation apparatus.

6. The method of claim 1 , wherein the method is performed during a treatment stage of operation of the radiation apparatus.

7. A computer-readable medium comprising instructions that when executed by a process device, cause the processing device to:

select at least a first angle and a second angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold;

generate, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and

generate, using the imaging device, a second tracking image of the target from the second angle during the first rotation of the gantry.

8. The computer-readable medium of claim 7 , wherein the tracking quality metric value of the first angle is higher than a second tracking quality metric value of the second angle, and wherein the second angle has a separation from the first angle of at least an angle separation threshold.

9. The computer-readable medium of claim 7 , wherein the instructions further cause the processing device to:

determine, based on the second tracking image, that target tracking has failed during delivery of a radiation treatment beam;

determine a time window within which a next tracking image must be taken;

determine that no angle from the set of angles will be available within the time window; and

interrupt delivery of the radiation treatment beam.

10. The computer-readable medium of claim 7 , wherein the instructions further cause the processing device to:

generate a plurality of x-ray images of the target from two or more angles from the set of angles; and

generate a motion model of the target from the plurality of x-ray images.

11. The computer-readable medium of claim 7 , wherein the instructions are executed by the processing device during an alignment phase of operation of the radiation apparatus.

12. The computer-readable medium of claim 7 , wherein the instructions are executed by the processing device during a treatment stage of operation of the radiation apparatus.

13. A method of operating a radiation apparatus, the method comprising:

selecting at least a first angle from a set of angles for a first rotation of a gantry of a radiation apparatus, wherein the first angle is selected from the set of angles based on having a tracking quality metric value satisfying a tracking quality metric criterion, wherein the tracking quality metric value includes a numerical value representing a confidence that a target is trackable based on images generated at the first angle, and wherein the tracking quality metric criterion includes a numerical threshold;

generating, using an imaging device mounted to the gantry, a first tracking image of the target from the first angle during the first rotation of the gantry; and

performing target tracking based on the first tracking image.

14. The method of claim 13 , further comprising:

generating a plurality of x-ray images of the target from two or more angles from the set of angles; and

generating a motion model of the target from the plurality of x-ray images.

15. The method of claim 13 , wherein the method is performed during a treatment stage of operation of the radiation apparatus.