# US 12,440,702 B2 · Radiation treatment system comprising a CT apparatus, a treatment planning apparatus, and a radiation control apparatus, radiation control method, and storage medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,440,702 B2 - Document ID: US12440702B2 - Status: Granted - Kind: B2 - Application number: 18/135,924 - Filed: 2023-04-18 - Published: 2023-10-26 - Granted: 2025-10-14 - Earliest claimed: 2022-04-26 - Assignees: Anzal Medical Co., Ltd. - Applicants: Anzai Medical Co., Ltd. - Inventors: Hirofumi Arai; Takeshi Sasaki - Web page: https://patentgrep.com/patent/US12440702B2 ## CPC - A61N 5/1068: {Gating the beam as a function of a physiological signal} - A61N 5/103: {Treatment planning systems} - A61N 5/1037: {taking into account the movement of the target, e.g. 4D-image based planning} - A61N 5/1045: {using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT} - A61N 5/1047: {with movement of the radiation head during application of radiation, e.g. for intensity modulated arc therapy or IMAT} - A61N 5/1048: {Monitoring, verifying, controlling systems and methods} - A61N 5/1049: {for verifying the position of the patient with respect to the radiation beam} - A61N 5/1081: {Rotating beam systems with a specific mechanical construction, e.g. gantries} - A61N 2005/1061: {using an x-ray imaging system having a separate imaging source} - A61N 2005/1062: {using virtual X-ray images, e.g. digitally reconstructed radiographs [DRR]} - A61N 2005/1074: {Details of the control system, e.g. user interfaces} - 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) ## Abstract A plurality of shift images are generated by shifting a fluoroscopic image by a prescribed increment within a prescribed range in a craniocaudal direction. Then, a normalized correlation coefficient between a DRR image and each of the plurality of shift images is calculated. Next, a shift amount of the shift image corresponding to the largest normalized correlation coefficient among the plurality of normalized correlation coefficients is determined to be the positional deviation. ## Claims ### Claim 1 A radiation control apparatus that controls radiation of a radiation beam from a radiation beam source toward a subject, based on a treatment plan for the subject and a fluoroscopic image of the subject, wherein: the treatment plan includes a computed tomography image at a specific respiratory phase of the subject and isocenter coordinates for specifying an irradiation position of the radiation beam at the specific respiratory phase of the subject; the radiation beam source is mounted on a gantry, and is configured to irradiate the subject with the radiation beam when the subject is positioned along a rotational axis of the gantry; the fluoroscopic image of the subject is generated by a fluoroscopic image generation apparatus arranged approximately coaxially with the rotational axis of the gantry; and the radiation control apparatus comprises one or more processors and a memory storing computer-executable instructions configured to cause the one or more processors to function as: a treatment plan acquiring section that acquires the treatment plan; a digitally reconstructed radiograph image generating section that generates a digitally reconstructed radiograph image of the subject for each prescribed angle of the gantry, based on the computed tomography image and the isocenter coordinates included in the acquired treatment plan; a fluoroscopic image acquiring section that acquires the fluoroscopic image of the subject and a rotational angle of the gantry at a time when the fluoroscopic image of the subject was generated; a positional deviation calculating section that calculates a positional deviation between a position of a diaphragm of the subject in the generated digitally reconstructed radiograph image of the subject and a position of the diaphragm of the subject in the acquired fluoroscopic image of the subject, for a same rotational angle; and a radiation permission determining section that permits radiation of the radiation beam from the radiation beam source toward the subject, in a case where the positional deviation is less than or equal to a prescribed value; and the positional deviation calculating section: generates a plurality of shift images by shifting the fluoroscopic image of the subject by a prescribed increment along a craniocaudal direction of the subject, within a prescribed range in the craniocaudal direction; calculates a normalized correlation coefficient between the digitally reconstructed radiograph image of the subject and each of the generated plurality of shift images; and determines a shift amount of a shift image corresponding to a largest normalized correlation coefficient among a plurality of calculated normalized correlation coefficients, relative to the digitally reconstructed radiograph image of the subject in the craniocaudal direction, to be the positional deviation. ### Claim 2 (depends on 1) The radiation control apparatus according to claim 1, wherein the positional deviation calculating section: selects a single first partial image region that includes the diaphragm, from within the digitally reconstructed radiograph image of the subject; selects a second partial image region having a same coordinate position as the single first partial image region, from within the fluoroscopic image of the subject; generates the plurality of shift images by shifting the selected second partial image region by the prescribed increment within the prescribed range; and calculates the normalized correlation coefficient between the single first partial image region and each of the generated plurality of shift images. ### Claim 3 (depends on 2) The radiation control apparatus according to claim 2, wherein: the positional deviation calculating section sets a search image region within the digitally reconstructed radiograph image of the subject, searches for an image region that includes the diaphragm within the set search image region, and selects an image region found by a search as the single first partial image region. ### Claim 4 (depends on 3) The radiation control apparatus according to claim 3, wherein: the positional deviation calculating section calculates a first normalized correlation coefficient between a prescribed reference image and each of a plurality of image regions within the search image region, and selects an image region having a largest first normalized correlation coefficient as the single first partial image region. ### Claim 5 (depends on 4) The radiation control apparatus according to claim 4, wherein: the prescribed reference image is a rectangular image region, in which pixel values of one portion in the craniocaudal direction are lower than pixel values of another portion. ### Claim 6 (depends on 1) The radiation control apparatus according to claim 1, wherein the positional deviation calculating section: generates a first shift image by, for each of the plurality of shift images, subtracting a predetermined value from a plurality of pixel values of pixels forming each shift image of the plurality of shift images, then replacing pixel values that are negative with 0 if pixels with negative pixel values are present among a plurality of pixels, and then exponentiating each of the plurality of pixel values of the pixels; calculates a first average value of the pixel values of the plurality of pixels forming the first shift image; generates a first digitally reconstructed radiograph image by exponentiating each of pixel values of a plurality of pixels forming the digitally reconstructed radiograph image; calculates a second average value of the pixel values of the plurality of pixels forming the first digitally reconstructed radiograph image; and calculates the normalized correlation coefficient for each of a plurality of first shift images, using a deviation between the first average value and each of the pixel values of the plurality of pixels forming the first shift image and a deviation between the second average value and each of a plurality of pixel values of pixels forming the first digitally reconstructed radiograph image. ### Claim 7 (depends on 6) The radiation control apparatus according to claim 6, wherein: the positional deviation calculating section applies median filter processing to the fluoroscopic image of the subject, the shift image, or the first shift image. ### Claim 8 (depends on 6) The radiation control apparatus according to claim 6, wherein the positional deviation calculating section: sets the predetermined value to be 0; selects any number from 1 to 70 as an exponent for exponentiating each of a plurality of pixel values of a plurality of pixels forming the shift image, for each of the plurality of shift images; and selects any number from 1 to 4 as an exponent for exponentiating each of a plurality of pixel values of a plurality of pixels forming the digitally reconstructed radiograph image. ### Claim 9 (depends on 6) The radiation control apparatus according to claim 6, wherein the positional deviation calculating section: selects any number from 40000 to 55000 as the predetermined value; selects any number from 1 to 30 as an exponent for exponentiating each of a plurality of pixel values of a plurality of pixels forming the shift image, for each of the plurality of shift images; and selects any number from 1 to 4 as an exponent for exponentiating each of a plurality of pixel values of a plurality of pixels forming the digitally reconstructed radiograph image. ### Claim 10 (depends on 1) The radiation control apparatus according to claim 1, wherein: the prescribed range is a range in the craniocaudal direction of ±2 mm to ±10 mm in the craniocaudal direction along an anatomical shape of the subject, for the fluoroscopic image of the subject; and the prescribed increment along a craniocaudal direction of the subject is within a range from 0.5 mm to 1.5 mm. ### Claim 11 (depends on 10) The radiation control apparatus according to claim 10, wherein: the prescribed range in the craniocaudal direction is an integer or a half-integer from ±2 mm to ±10 mm; and the prescribed increment along a craniocaudal direction of the subject is an integer or a half-integer within a range from 0.5 mm to 1.5 mm. ### Claim 12 (depends on 1) The radiation control apparatus according to claim 1, wherein: the treatment plan acquiring section acquires the computed tomography image and the isocenter coordinates before the fluoroscopic image acquiring section acquires the fluoroscopic image of the subject and the rotational angle. ### Claim 13 (depends on 1) The radiation control apparatus according to claim 1, wherein: the fluoroscopic image acquiring section acquires the fluoroscopic image of the subject and the rotational angle from the fluoroscopic image generation apparatus via a gigabit Ethernet line. ### Claim 14 (depends on 1) The radiation control apparatus according to claim 1, wherein: the treatment plan acquiring section acquires data of the computed tomography image and the isocenter coordinates in a DICOM-RT standard, from a treatment planning apparatus that creates the treatment plan. ### Claim 15 (depends on 1) The radiation control apparatus according to claim 1, wherein: the digitally reconstructed radiograph image generating section generates the digitally reconstructed radiograph image for each prescribed incremental angle that is 0.5° to 5°. ### Claim 16 A radiation treatment system comprising: a treatment planning apparatus that creates a treatment plan for a radiation treatment of a subject; a radiation treatment apparatus that includes a gantry and a radiation beam source mounted on the gantry, and is configured to irradiate the subject with a radiation beam from the radiation beam source in a case, where the subject is positioned along a rotational axis of the gantry; a fluoroscopic image generation apparatus that is arranged approximately coaxially with the rotational axis and generates a fluoroscopic image of the subject; and a radiation control apparatus that controls radiation of the radiation beam from the radiation beam source toward the subject, based on the treatment plan for the radiation treatment and the fluoroscopic image of the subject, wherein: the treatment plan includes a computed tomography image at a specific respiratory phase of the subject and isocenter coordinates for specifying an irradiation position of the radiation beam at the specific respiratory phase of the subject; the radiation control apparatus includes one or more processors and a memory storing computer-executable instructions configured to cause the one or more processor to function as: a treatment plan acquiring section that acquires the treatment plan from the treatment planning apparatus; a digitally reconstructed radiograph image generating section that generates a digitally reconstructed radiograph image of the subject for each prescribed angle of the gantry, based on the computed tomography image and the isocenter coordinates included in the acquired treatment plan; a fluoroscopic image acquiring section that acquires the fluoroscopic image of the subject and a rotational angle of the gantry at a time when the fluoroscopic image of the subject was generated, from the fluoroscopic image generation apparatus; a positional deviation calculating section that calculates a positional deviation between a position of a diaphragm of the subject in the generated digitally reconstructed radiograph image of the subject and a position of the diaphragm of the subject in the acquired fluoroscopic image of the subject, for a same rotational angle; and a radiation permission determining section that permits radiation of the radiation beam from the radiation beam source toward the subject, when the positional deviation is less than or equal to a prescribed value; and the positional deviation calculating section: generates a plurality of shift images by shifting the fluoroscopic image of the subject by a prescribed increment along a craniocaudal direction of the subject, within a prescribed range in the craniocaudal direction; calculates a normalized correlation coefficient between the digitally reconstructed radiograph image of the subject and each of the generated plurality of shift images; and determines a shift amount of a shift image corresponding to a largest normalized correlation coefficient among a plurality of calculated normalized correlation coefficients, relative to the digitally reconstructed radiograph image of the subject in the craniocaudal direction, to be the positional deviation. ### Claim 17 A radiation control method for controlling radiation of a radiation beam from a radiation beam source toward a subject, based on a treatment plan for the subject and a fluoroscopic image of the subject, wherein: the treatment plan includes a computed tomography image at a specific respiratory phase of the subject and isocenter coordinates for specifying an irradiation position of the radiation beam at the specific respiratory phase of the subject; the radiation beam source is mounted on a gantry, and is configured to irradiate the subject with the radiation beam when the subject is positioned along a rotational axis of the gantry; and the fluoroscopic image of the subject is generated by a fluoroscopic image generation apparatus arranged approximately coaxially with the rotational axis of the gantry; the radiation control method comprises: a first step of acquiring the treatment plan; a second step of generating a digitally reconstructed radiograph image of the subject for each prescribed angle of the gantry, based on the computed tomography image and the isocenter coordinates included in the acquired treatment plan; a third step of acquiring the fluoroscopic image of the subject and a rotational angle of the gantry at a time when the fluoroscopic image of the subject was generated; a fourth step of calculating a positional deviation between a position of a diaphragm of the subject in the generated digitally reconstructed radiograph image of the subject and a position of the diaphragm of the subject in the acquired fluoroscopic image of the subject, for a same rotational angle; and a fifth step of permitting radiation of the radiation beam from the radiation beam source toward the subject, in a case where the positional deviation is less than or equal to a prescribed value; and the fourth step includes: generating a plurality of shift images by shifting the fluoroscopic image of the subject by a prescribed increment along a craniocaudal direction of the subject, within a prescribed range in the craniocaudal direction; calculating a normalized correlation coefficient between the digitally reconstructed radiograph image of the subject and each of the generated plurality of shift images; and determining a shift amount of a shift image corresponding to a largest normalized correlation coefficient among a plurality of calculated normalized correlation coefficients, relative to the digitally reconstructed radiograph image of the subject in the craniocaudal direction, to be the positional deviation. ### Claim 18 (depends on 17) A non-transitory storage medium storing a program that causes a computer to execute the radiation control method according to claim 17.