Single-pass imaging and radiation treatment delivery via an extended rotation gantry
A radiation therapy system delivers radiation treatment over a 360-degree arc and performs a prepended imaging process, in a single pass, via an extended rotation gantry. While rotating the gantry in one direction about a bore of the radiation system, the radiation system generates multiple images of a target volume disposed in the bore using an imaging X-ray source mounted on the gantry. Then, while continuing to rotate the gantry in the same direction, the radiation system delivers a treatment beam to the target volume using a treatment-delivering X-ray source mounted on the gantry, where the treatment beam is delivered from some or all of a 360-degree arc about the bore. Thus, the prepended imaging process and the delivery of radiation are performed in a single pass of the gantry about a target volume, eliminating the need for a return stroke of the gantry for completion.
1. A computer-implemented method of radiation therapy in a radiation therapy system that includes a gantry with a treatment-delivering X-ray source and an imaging X-ray source mounted thereon, the method comprising:
in response to a start of a patient breath hold, rotating the gantry in a first direction at a first rotational velocity about an open bore and concurrently rotating an annular support structure at a second rotational velocity about the open bore, wherein the second rotational velocity is less than the first rotational velocity;
while continuing to rotate the gantry in the first direction about the open bore from a first position to a treatment position, generating multiple images of a target volume disposed in the open bore using the imaging X-ray source; and
upon rotating the gantry to the treatment position:
initiating delivery of a treatment beam to the target volume with the treatment-delivering X-ray source; and
continuing to rotate the gantry a complete revolution in the first direction from the treatment position back to the treatment position during the patient breath hold.
2. The computer-implemented method of claim 1 , wherein the treatment position is separated from the first position in the first direction by at least about one quarter rotation of the gantry.
3. The computer-implemented method of claim 1 , further comprising, prior to rotating the gantry in the first direction from the first position to the treatment position and while rotating the gantry in the first direction from a start position to the first position, rotationally accelerating the gantry from no rotational velocity to a target rotational velocity.
4. The computer-implemented method of claim 1 , further comprising, after continuing to rotate the gantry the complete revolution in the first direction from the treatment position to the treatment position and while rotating the gantry in the first direction from the treatment position to the stopping position, rotationally decelerating the gantry from a target rotational velocity to no rotational velocity.
5. The computer-implemented method of claim 4 , further comprising, after rotationally decelerating the gantry from the target rotational velocity to no rotational velocity, rotating the gantry in a second direction to the start position.
6. The computer-implemented method of claim 5 , wherein the first direction is opposite to the second direction.
7. The computer-implemented method of claim 1 , wherein generating multiple images of the target volume comprises rotating the gantry through at least about one quarter of a revolution.
8. The computer-implemented method of claim 1 , further comprising:
based on at least a portion of the multiple images of the target volume, determining a modified delivery of the treatment beam to the target volume; and
while continuing to rotate the gantry the complete revolution in the first direction from the treatment position back to the treatment position, implementing the modified delivery of the treatment beam to the target volume.
9. The computer-implemented method of claim 8 , wherein the multiple images of the target volume comprise X-ray projection images, and wherein determining the modified delivery of the treatment beam to the target volume comprises performing digital tomosynthesis on the projection images to generate a cross-sectional image of the target volume.
10. The computer-implemented method of claim 1 , further comprising, while continuing to rotate the gantry the complete revolution, interleaving an imaging process with the delivery of the treatment beam.
11. A radiation treatment system comprising:
a drive stand;
a gantry with a treatment-delivering X-ray source and an imaging X-ray source mounted thereon, wherein the gantry is rotatably coupled to the drive stand and is configured to rotate in a first direction about a bore of the radiation treatment system at a first rotational velocity;
an annular support structure that is rotatably coupled to the drive stand and is configured to rotate in the first direction about the bore of the radiation treatment system at a second rotational velocity when the gantry rotates about the bore at the first rotational velocity, wherein the second rotational velocity is less than the first rotational velocity; and
a processor configured to:
while rotating the gantry in a first direction about the bore from a first position to a treatment position, generate multiple images of a target volume disposed in the bore using the imaging X-ray source; and
upon rotating the gantry to the treatment position:
initiate delivery of a treatment beam to the target volume with the treatment-delivering X-ray source; and
continue to rotate the gantry a complete revolution in the first direction from the treatment position to the treatment position.
12. The radiation treatment system of claim 11 , further comprising:
a guide wheel rotatably coupled to the annular support structure; and
a flexible utility conduit with a first end that is coupled to a fixed connection on the drive stand, a second end that is coupled to a fixed connection on the gantry, and is routed from the fixed connection on the drive stand, around the guide wheel for one-half turn, to the fixed connection on the gantry.
13. The radiation treatment system of claim 12 , wherein the flexible utility conduit is further routed along a conduit management surface on the gantry.
14. The radiation treatment system of claim 12 , further comprising at least one cable separator that is rotatably coupled to the annular support structure and configured to separate a first portion of the flexible utility conduit from a second portion of the flexible utility conduit during rotation of the gantry.
15. The radiation treatment system of claim 12 , further comprising at least one electromagnet that is coupled to the drive stand and is configured to, when energized, attract a ferromagnetic plate to separate a first portion of the flexible utility conduit from a second portion of the flexible utility conduit during rotation of the gantry, wherein the ferromagnetic plate is coupled to the flexible utility conduit.
16. The radiation treatment system of claim 11 , wherein the imaging x-ray source is stationary with respect to the treatment delivering x-ray source during generation of the multiple images.
17. The radiation treatment system of claim 11 , wherein an axis of rotation of the gantry is parallel to an axis of the bore.
18. The radiation treatment system of claim 11 , wherein an axis of rotation of the annular support structure is coincident with an axis of rotation of the gantry.
19. The radiation treatment system of claim 11 , wherein the processor is further configured to:
based on at least a portion of the multiple images of the target volume, determine a modified delivery of the treatment beam to the target volume; and
while continuing to rotate the gantry the complete revolution in the first direction from the treatment position to the treatment position, implement the modified delivery of the treatment beam to the target volume.
20. A computer-implemented method of radiation therapy in a radiation therapy system that includes a gantry with a treatment-delivering X-ray source and an imaging X-ray source mounted thereon, the method comprising:
while rotating the gantry in a first direction about an open bore from a first position to a treatment position, generating multiple images of a target volume disposed in the open bore using the imaging X-ray source; and
upon rotating the gantry to the treatment position:
initiating delivery of a treatment beam to the target volume with the treatment-delivering X-ray source; and
continuing to rotate the gantry a complete revolution in the first direction from the treatment position back to the treatment position while a first end of a flexible utility conduit is coupled to the treatment-delivering X-ray source, a second end of the flexible utility conduit is coupled to a fixed support structure of the radiation therapy system that is rotatably coupled to the gantry, and no more than a single turn of the flexible utility conduit is collected onto a conduit management surface of the gantry.