# US 11,896,851 B2 · Radiation therapy system using a digital tomosynthesis process for near real-time localization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,851 B2 - Document ID: US11896851B2 - Status: Granted - Kind: B2 - Application number: 17/467,270 - Filed: 2021-09-05 - Published: 2021-12-23 - Granted: 2024-02-13 - Earliest claimed: 2018-07-28 - Assignees: Varian Medical Systems, Inc. - Applicants: Varian Medical Systems, Inc. - Inventors: John Van Heteren; Liangjia Zhu; Daniel Morf - Web page: https://patentgrep.com/patent/US11896851B2 ## CPC - A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries} - A61N 5/1067: {in real time, i.e. during treatment} - A61B 6/032: {Transmission computed tomography [CT]} - A61B 6/541: {involving acquisition triggered by a physiological signal} - A61N 5/1031: {using a specific method of dose optimization} - A61N 5/1038: {taking into account previously administered plans applied to the same patient, i.e. adaptive radiotherapy} - A61N 5/1039: {using functional images, e.g. PET or MRI} - A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam} - A61N 5/107: {in real time, i.e. during treatment} - A61N 5/1071: {for verifying the dose delivered by the treatment plan} - A61N 2005/1054: {using a portal imaging system} - A61N 2005/1061: {using an x-ray imaging system having a separate imaging source} - A61N 2005/1074: {Details of the control system, e.g. user interfaces} - G06T 7/0012: {Biomedical image inspection} - G06T 12/30: Image post-processing, e.g. metal artefact correction - G06T 2207/10081: Computed x-ray tomography [CT] - G06T 2207/20081: Training; Learning - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A method of radiation therapy comprises, while a gantry of a radiation therapy system rotates continuously in a first direction through a treatment arc from a first treatment delivery position to a second treatment delivery position, causing an imaging X-ray source mounted on the gantry to direct X-rays through a target volume and receiving a set of X-ray projection images from an X-ray imager mounted on the gantry; determining a current location of the target volume based on the set of X-ray projection images; and while the gantry to continues to rotate to the second treatment delivery position, initiating delivery of a treatment beam of a treatment-delivering X-ray source mounted on the gantry to the target volume, and continuing to cause the gantry to rotate in the first direction from the second treatment delivery position to a third treatment delivery position. ## Claims ### Claim 1 A radiation treatment system comprising: a gantry that is rotatably coupled to a drive stand and is configured to rotate about a bore of the radiation treatment system; a treatment-delivering X-ray source mounted on the gantry and configured to direct treatment X-rays to a target volume of a patient disposed in the bore; an imaging X-ray source mounted on the gantry; an X-ray imager mounted on the gantry; and a processor configured to: cause the gantry to rotate continuously in a first direction from a first treatment delivery position to a second treatment delivery position; while causing the gantry to rotate in the first direction from the first treatment delivery position to the second treatment delivery position, cause the imaging X-ray source to direct X-rays through the target volume and toward the X-ray imager; receive a first set of X-ray projection images from the X-ray imager in response to the X-rays being directed toward the X-ray imager; based on the first set of X-ray projection images, monitor the patient for a loss of breath hold; and in response to a determination that the patient has not lost breath hold: cause the gantry to continue to rotate to the second treatment delivery position; and while causing the gantry to continue to rotate to the second treatment delivery position, initiate delivery of a treatment beam of the treatment-delivering X-ray source to the target volume. ### Claim 2 (depends on 1) The radiation treatment system of claim 1, wherein the processor is further configured to, while causing the gantry to continuously rotate in the first direction from a first imaging position to a second imaging: cause the imaging X-ray source to direct initial X-rays through the target volume; receive an initial set of X-ray projection images from the X-ray imager, wherein the initial set of X-ray projection images are based on the initial imaging X-rays; and determine an initial location of the target volume based on the initial set of X-ray projection images. ### Claim 3 (depends on 2) The radiation treatment system of claim 2, wherein the initial set of X-ray projection images are generated via a cone-beam computed tomography process. ### Claim 4 (depends on 2) The radiation treatment system of claim 2, wherein, when the processor causes the gantry to rotate continuously in the first direction from the first treatment delivery position to the second treatment delivery position, the processor to causes the gantry to rotate continuously in the first direction through the first imaging position, the second imaging position, the first treatment delivery position, and the second treatment delivery position in a single rotation. ### Claim 5 (depends on 2) The radiation treatment system of claim 2, wherein when rotating in the first direction, the gantry passes through the second imaging position prior to passing through the first treatment delivery position. ### Claim 6 (depends on 2) The radiation treatment system of claim 2, wherein the processor is further configured to: based on the initial location of the target volume, determine that the initial location of the target volume is less than a threshold distance from the planned treatment location; and initiate delivery of the treatment beam of the treatment-delivering X-ray source to the target volume based in part of the determination that the initial location of the target volume is less than the threshold distance from the planned treatment location. ### Claim 7 (depends on 1) The radiation treatment system of claim 1, wherein the processor is configured to monitor the patient for the loss of breath hold by determining a current location of the target volume based on the first set of X-ray projection images. ### Claim 8 (depends on 7) The radiation treatment system of claim 7, wherein determining the current location of the target volume based on the set of X-ray projection images comprises: based on an initial set of X-ray projection images, generating image data for a digital volume that includes the target volume, wherein the initial set of X-ray projection images are received while the processor causes the gantry to rotate continuously in the first direction from a first imaging position to a second imaging position; updating the image data for the digital volume based on the first set of X-ray projection images; and after updating the image data for the digital volume, determining the current location of the target volume based on the image data for the digital volume. ### Claim 9 (depends on 1) The radiation treatment system of claim 1, wherein the imaging X-ray source and the X-ray imager are operable to be positioned on the gantry in a half-fan configuration. ### Claim 10 (depends on 1) The radiation treatment system of claim 1, wherein the imaging X-ray source and the X-ray imager are operable to be positioned on the gantry in a full-fan configuration. ### Claim 11 (depends on 10) The radiation treatment system of claim 10, wherein the imaging X-ray source and the X-ray imager are configured to be adjustable from the full-fan configuration to a half-fan configuration. ### Claim 12 (depends on 10) The radiation treatment system of claim 10, wherein the X-ray imager is movably mounted on the gantry and is operable to be moved from a full-fan position to a half-fan position. ### Claim 13 (depends on 10) The radiation treatment system of claim 10, wherein the imaging X-ray source is movably mounted on the gantry and is operable to be moved from a full-fan position to a half-fan position. ### Claim 14 (depends on 10) The radiation treatment system of claim 10, wherein the second imaging X-ray source includes a collimator configured to change between a half-fan position and a full-fan position. ### Claim 15 A radiation treatment system comprising: a gantry that is rotatably coupled to a drive stand and is configured to rotate about a bore of the radiation treatment system; a treatment-delivering X-ray source mounted on the gantry and configured to direct treatment X-rays to a target volume of a patient disposed in the bore; an imaging X-ray source mounted on the gantry; an X-ray imager mounted on the gantry; and a processor configured to: cause the gantry to rotate continuously in a first direction through a first treatment arc that includes a first treatment delivery position and a second treatment delivery position; while causing the gantry to rotate through the first treatment arc in the first direction from the first treatment delivery position to the second treatment delivery position, cause the imaging X-ray source to direct X-rays through the target volume and toward the X-ray imager; receive a set of X-ray projection images from the X-ray imager in response to the X-rays being directed toward the X-ray imager; based on the set of X-ray projection images, monitor the patient for a loss of breath hold; and in response to a determination that the patient has lost breath hold: store a gantry angle at which the patient has lost breath hold; and end the first treatment arc. ### Claim 16 (depends on 15) The radiation treatment system of claim 15, wherein the processor is further configured to, in response to determining that the patient has lost breath hold, prevent delivery of the treatment beam to the target volume while causing the gantry to continue to rotate to the second treatment delivery position. ### Claim 17 (depends on 15) The radiation treatment system of claim 15, wherein the processor is further configured to, in response to determining that the patient has lost breath hold, perform a second treatment arc that begins at the gantry angle and completes the first treatment arc. ### Claim 18 (depends on 17) The radiation treatment system of claim 17, wherein the processor is further configured to perform the second treatment arc by: causing the gantry to rotate in the first direction to the gantry angle; and while causing the gantry to rotate in the first direction to the gantry angle, preventing delivery of the treatment beam. ### Claim 19 (depends on 18) The radiation treatment system of claim 18, wherein the processor is further configured to perform the second treatment arc by: determining that the current location of the target volume is less than a threshold distance from a planned treatment location; and in response, while causing the gantry to rotate in the first direction from the gantry angle, initiating delivery of the treatment beam to the target volume while causing the gantry to continue to rotate in the first direction. ### Claim 20 (depends on 15) The radiation treatment system of claim 15, wherein the processor is further configured to end the first treatment arc by preventing delivery of the treatment mean to the target volume while causing the gantry to continue to rotate in the first direction from the gantry angle.