JP4326567B2 - Radiotherapy apparatus control apparatus and radiation irradiation method - Google Patents

Description

  The present invention relates to a radiation therapy apparatus control apparatus and a radiation irradiation method, and more particularly to a radiation therapy apparatus control apparatus and a radiation irradiation method used when treating a patient by irradiating an affected area with radiation.

  Radiotherapy is known in which a patient is treated by irradiating the affected part (tumor) with therapeutic radiation. As radiation therapy applied when the affected area moves, it is known to irradiate a wider range than the affected area in consideration of gated irradiation, moving body tracking irradiation, and movement of the affected area. The gated irradiation is a method of irradiating therapeutic radiation or stopping irradiation based on observed patient movement. Such gated irradiation has the disadvantage that, for example, when it is irradiated only when there is a respiratory phase, the treatment time becomes longer, which puts a burden on the patient and improves the medical efficiency. Is required. The moving body tracking irradiation is a method of observing the position of an affected part and irradiating the position with therapeutic radiation.

  In radiation therapy in which a range wider than the size of the affected part is taken into consideration in consideration of the movement, a site to be irradiated, that is, a target volume (target) is first determined. In determining the target volume, it is most important to understand the extent of lesion development. In addition to visual inspection and palpation, various image diagnoses such as CT, MRI, and gastrointestinal angiography, and endoscopic findings are also referred to. The

FIG. 11 shows that the target volumes are a gross tumor volume (GTV), a clinical target volume (CTV), an internal target volume (ITV), and a planned target volume (PTV). planning target volume). The macroscopic tumor volume 101 indicates a region where it is determined that a tumor is present by image diagnosis, palpation, and visual inspection. Examples of the tumor include a primary lesion, lymph node metastasis, or distant metastasis. The clinical target volume 102 represents a region that includes a gross tumor volume 101 and a small portion. The minute portion indicates a microscopic progress range around the macroscopic tumor volume 101 or an area including a lymph node to which the tumor belongs. The internal target volume 103 indicates a region including a clinical target volume 102 and an internal margin (IM). The internal margin indicates a region around the clinical target volume 102 and indicates a region in which the clinical target volume 102 moves due to movements of internal organs such as breathing, swallowing, heartbeat, and peristalsis. The planned target volume 104 indicates an area including the internal target volume 103 and a set-up margin (SM). The setting error indicates a region around the internal target volume 103 and indicates a region in each irradiation. At this time, the volume GTV of the gross tumor volume 101, the volume CTV of the clinical target volume 102, the volume ITV of the internal target volume 103, and the volume PTV of the planned target volume 104 are radical irradiation, and the following inequality:
GTV ≦ CTV ≦ ITV <PTV
Is always true.

  In radiotherapy planning, it is necessary to calculate the internal margin and setting error for risk organs (OR; organ at risk) in the same way as for the affected organs, and plan risks with these margins added to the risk organs. An organ volume (PRV) is calculated. In an actual treatment plan, the planned target volume 104 and the planned risk organ volume may overlap, and at this time, it is indispensable that the dose of radiation applied to the normal organ is less than the tolerated dose.

  In radiotherapy, it is desired that the dose of therapeutic radiation irradiated to normal organs (risk organs) be smaller than the dose of therapeutic radiation irradiated to cells in the affected area.

  Japanese Patent Laid-Open No. 2002-186678 discloses a radiotherapy plan that accurately reflects the position and shape of a lesioned part even when the position or size of the lesioned part is changed by respiratory movement. Therefore, a radiation therapy system that can perform more accurate radiation therapy is disclosed. The radiation treatment planning system includes at least an X-ray simulator, a radiation treatment plan formulation device capable of formulating a radiation treatment plan based on an X-ray fluoroscopic image acquired by the X-ray simulator, and a radiation treatment device. A storage unit that stores a plurality of fluoroscopic images acquired during a predetermined time interval by the X-ray simulator, an image display unit that displays the plurality of fluoroscopic images in a superimposed manner, and the superposition And an input means for setting and inputting a target shape that defines a radiation irradiation region by the radiotherapy apparatus with respect to a target region on a display.

  Japanese Patent Application Laid-Open No. 08-511542 discloses a radiotherapy apparatus having a degree of freedom with a constrained angle for generating a beam only in a gantry plane. The radiotherapy device is a radiotherapy device that treats a patient with high-energy radiation: a gantry that rotates in a gantry plane; and is positioned along a translational axis that is positioned within the rotation of the gantry, A table for moving the patient along the axis of translation and a radiation source disposed in the gantry to produce a radiation beam in a fan beam plane that is substantially parallel to the gantry plane; A radiation source in which the beam includes a plurality of rays extending in a beam plane around a central ray, the central ray being directed at the patient from various gantry angles along the gantry plane; and a radiation source and a patient And attenuating means for independently controlling the intensity of each beam as a function of the gantry angle.

  Japanese Patent Laid-Open No. 2001-327514 can perform settings that accurately reflect the position and shape of a lesion that changes according to the breathing, heartbeat, and the like of a subject, thereby enabling more precise and accurate radiation therapy. A radiation therapy planning device that can be implemented is disclosed. The radiotherapy planning apparatus includes a plurality of radiotherapy planning apparatuses that formulate a radiotherapy plan based on an image acquired by exposing an X-ray to the subject according to a difference in phase data regarding the subject. Image generating means for generating an image of the image, input means for setting and inputting a target shape for a target portion existing on the image, a plurality of images according to the difference in the phase data, and the target shape And image display means for superimposing and displaying.

  Japanese Patent Application Laid-Open No. 08-089589 discloses a display method used for a radiation treatment plan capable of making a treatment plan in consideration of a plurality of states of a moving subject in a radiation irradiation region. The display method used for the radiation treatment plan reads a series of CT images obtained in each of a plurality of different states, sets a radiation irradiation region, a radiation non-irradiation region, and a radiation treatment parameter. And projecting onto the irradiation field surface using the same geometric conditions as radiation irradiation, generating projection shapes in a plurality of different states, and projecting projection shapes for radiation irradiation regions generated in a plurality of different states A radiation field shape for each irradiation angle is generated based on the radiation irradiation region superimposed for each irradiation angle and the radiation treatment region set for each irradiation angle and the set radiation treatment parameter, and the radiation irradiation region generated and the overlapped radiation irradiation region are generated. It is characterized in that the field shape is superimposed and displayed for each irradiation angle.

  Japanese Patent Application Laid-Open No. 10-146395 discloses a radiation irradiation system in which a margin such as a tissue region can be easily determined. The radiation irradiation system is formulated by the irradiation planning device that calculates the dose distribution based on the set irradiation conditions and tissue region for the input image data, and formulates the irradiation plan. In the radiation irradiation system having a radiation irradiation device for irradiating radiation based on the irradiation plan, the irradiation planning device includes an input unit for resetting the tissue region, and a tissue region input from the input unit. Based on the calculation processing means for calculating the dose distribution and the tissue area set before resetting the tissue area, the dose distribution calculated by the calculation processing means and after resetting the tissue area It is characterized by comprising display means for displaying in parallel the dose distribution calculated by the arithmetic processing means for the tissue region.

  US Pat. No. 3,810,431 discloses stereotactic radiosurgery (or radiation) on a specific target area of a patient, in particular on an irregularly shaped target area as opposed to a typically spherically shaped target area. An apparatus for performing a treatment is disclosed. The apparatus performs stereotactic radiosurgery on a specific target area, the target area including a target, and a position with respect to a peripheral area including a reference point in the vicinity is indicated. ) A radiation beam generator with a transport mechanism; (b) means for generating a target positioning beam; (c) intermittently directing a radiation beam for radiosurgery into the target region along the beam path (D) intermittently directing a plurality of target positioning radiation beams to the peripheral region including the target region and the reference point, whereby the target positioning beam is directed to the peripheral region Second means for obtaining positioning data indicating the position of the reference point in the peripheral area after passing through (e) i) obtaining positioning data from the target positioning beam; (ii) intermittently comparing the positioning data obtained in this way with previously obtained reference data; and (iii) from each of the intermittent comparisons As a result of each such comparison, third means responsive to the intermittently directed target positioning beam to determine the position of the target region relative to the reference point; and (f) (i) intermittent Directing the radiosurgical beam to the target area during a typical treatment period, directing the target positioning beam through the peripheral area during intermittent target positioning periods, and (ii) during each target positioning period, the positioning The latest positioning data obtained from the beam is used during the period, and the positioning data is compared with the reference data. A fourth means for operating the first means, the second means and the third means in cooperation with each other so as to determine the position of the target relative to the position of the reference point; g) operable within the target positioning period, and in response to the position of the target area determined by the third means within the period, the radiosurgical beam is accurately directed to the target area And means for moving the radiosurgery beam along a predetermined path that traverses the beam path, while simultaneously directing the radiosurgery beam to the target. Means for directing the region, whereby the radiosurgical beam is moved through different portions of healthy tissue as a result of movement of the radiosurgical beam along the predetermined path. Means for passing and further providing the predetermined path which is non-annular and non-linear, whereby movement of the radiosurgery beam along a non-circular and non-linear path constitutes a non-spherical target region, The means for moving the radiosurgery beam along an annular, non-linear transverse path comprises a robot arm that supports a transport mechanism of the radiation beam generator, when the radiosurgery beam is deflected from the transverse path Separate from the first means for stopping all movement of the radiosurgical beam and turning off the radiosurgical beam, the emergency stop means being independent of the first means, The fixed attachment signal transmitting / receiving means attached to a fixed surface other than the robot arm for transmitting and receiving signals, and the robot having different positions at different times A movable signal transmission / reception means attached to and movable in conjunction with the fixed attachment signal transmission / reception means; and the robot arm at a predetermined time in cooperation with the fixed attachment transmission / reception means; and Means for continuously monitoring the position of the transport mechanism of the radiation beam generator, wherein the fixed mounting signal transmitting / receiving means comprises a plurality of first devices, each of the first devices being a code Means for transmitting a coded infrared signal and means for receiving a coded ultrasound signal, wherein the movable signal transmitting / receiving means comprises a plurality of second devices, each of the second devices being coded. It is characterized by comprising means for transmitting an ultrasonic signal and means for receiving a coded infrared signal.

JP 2002-186678 A JP-T-08-511542 JP 2001-327514 A Japanese Patent Application Laid-Open No. 08-089589 JP-A-10-146395 Japanese Patent No. 3810431

An object of the present invention is to increase the dose of therapeutic radiation applied to a portion of a subject excluding the predetermined site when the therapeutic radiation fixed to the subject is irradiated to the predetermined site by a predetermined dose. An object of the present invention is to provide a radiation therapy apparatus control apparatus and a radiation irradiation method that reduce the radiation therapy apparatus.
Another object of the present invention is to provide a dose of therapeutic radiation to be irradiated on a portion of the subject excluding the predetermined portion when the predetermined portion of the therapeutic radiation fixed to the subject is irradiated. An object of the present invention is to provide a radiotherapy apparatus control apparatus and a radiation irradiation method that more easily calculate an irradiation field that reduces the radiation field.

  In the following, means for solving the problems will be described using the reference numerals used in the best modes and embodiments for carrying out the invention in parentheses. This reference numeral is added to clarify the correspondence between the description of the claims and the description of the best mode for carrying out the invention / example, and is described in the claims. It should not be used to interpret the technical scope of the invention.

  The radiotherapy apparatus control apparatus (2) according to the present invention includes an imaging unit (73) that captures a transmission image with radiation (35, 36) that passes through the subject (43), and the subject (43) using the transmission image. An irradiation range calculation unit (74) for calculating a region where the presence probability of the predetermined region is greater than the predetermined probability, and therapeutic radiation fixed to the subject (43) so that the predetermined dose is irradiated to the predetermined region And an irradiation unit (75) for irradiating the region with (23). At this time, the period during which the subject (43) is irradiated with the therapeutic radiation (23) is a period during which a part of the predetermined part is irradiated with the therapeutic radiation (23) and a part is a therapeutic radiation (23). The period during which the light is not irradiated is included. In other words, the region includes a period during which the subject (43) is irradiated with the therapeutic radiation (23), a period during which a part of the predetermined region is irradiated with the therapeutic radiation (23), and a part of the region for therapeutic use. It is calculated so as to include a period in which the radiation (23) is not irradiated. The predetermined part (affected part) generally moves and deforms with the movement of the subject (43). At this time, the radiation therapy apparatus control device (2) irradiates a portion of the subject (43) excluding the predetermined site by irradiating the therapeutic radiation (23) to the entire region where the predetermined site can be arranged. The dose of therapeutic radiation (23) to be applied can be further reduced.

  The transmission image is exposed and photographed for a time longer than the motion cycle in which the subject (43) moves. The region is calculated based on a portion of the transmission image where the affected part is projected within a predetermined luminance range. In the transmission image captured by the long exposure, the luminance of the portion where the affected part is projected corresponds to the existence probability. At this time, the radiotherapy apparatus control apparatus (2) can more easily calculate the region where the existence probability of the predetermined part is larger than the predetermined probability.

  The radiotherapy apparatus control apparatus (2) according to the present invention includes an imaging unit (73) that captures a transmission image with radiation (35, 36) that passes through the subject (43), and the subject (43) using the transmission image. Irradiation for calculating a first region having a first region having a probability greater than the first probability, and calculating a second region having a second region having a second region having a probability of being greater than the second probability using a transmission image. Excluding the second region of the first region from the range calculation unit (74) and the therapeutic radiation (23) fixed to the subject (43) so that a predetermined dose is irradiated to the first part And an irradiation unit (75) for irradiating the region. The period during which the subject (43) is irradiated with the therapeutic radiation (23) is a period during which a part of the first part is irradiated with the therapeutic radiation (23) and a part is irradiated with the therapeutic radiation (23). Period not included. At this time, the radiation therapy apparatus control device (2) irradiates the therapeutic radiation (23) to the entire region where the first part can be arranged, thereby removing the first part of the subject (43). It is possible to further reduce the dose of the therapeutic radiation (23) irradiated to the second region, and to reduce the dose of the therapeutic radiation (23) irradiated to the second portion to a predetermined dose or less.

  In the radiation irradiation method according to the present invention, a step of taking a transmission image with radiation (35, 36) transmitted through the subject (43), and the existence probability of a predetermined part of the subject (43) using the transmission image are a predetermined probability. A step of calculating a larger region, and a step of irradiating the region with therapeutic radiation (23) fixed to the subject (43) so that a predetermined dose is irradiated to a predetermined region. At this time, a period during which the subject (43) is irradiated with the therapeutic radiation (23) includes a period during which a part of the predetermined region is irradiated with the therapeutic radiation (23) and a part of the predetermined region is irradiated with the therapeutic radiation (23). The period during which the light is not irradiated is included. In other words, the region includes a period during which the subject (43) is irradiated with the therapeutic radiation (23), a period during which a part of the predetermined region is irradiated with the therapeutic radiation (23), and a part of the region for therapeutic use. It is calculated so as to include a period in which the radiation (23) is not irradiated. The predetermined part (affected part) generally moves and deforms with the movement of the subject (43). According to such a radiation irradiation method, the therapeutic radiation (23) is irradiated to the entire region where the predetermined part can be arranged, so that the treatment excluding the predetermined part of the subject (43) is irradiated. The radiation dose (23) can be further reduced.

  The transmission image is exposed and photographed for a time longer than the motion cycle in which the subject (43) moves. The region is calculated based on a portion of the transmission image where the affected part is projected within a predetermined luminance range. In the transmission image captured by the long exposure, the luminance of the portion where the affected part is projected corresponds to the existence probability. For this reason, according to such a radiation irradiation method, the area | region where the presence probability of a predetermined part is larger than a predetermined probability can be calculated more easily.

  In the radiation irradiation method according to the present invention, the step of capturing a transmission image with radiation (35, 36) that passes through the subject (43), and the existence probability of the first part of the subject (43) using the transmission image are first. A step of calculating a first region greater than one probability, a step of calculating a second region where the existence probability of the second region of the subject (43) is greater than the second probability using a transmission image, and a predetermined value for the first region Irradiating therapeutic radiation (23) fixed to the subject (43) to a region other than the second region of the first region so that a dose is irradiated. At this time, a period during which the subject (43) is irradiated with the therapeutic radiation (23) includes a period during which a part of the first part is irradiated with the therapeutic radiation (23) and a part of the first part (23). ) Is not irradiated. According to such a radiation irradiation method, by irradiating the therapeutic radiation (23) to the entire region where the first part can be disposed, the part (43) other than the first part is irradiated. The dose of the therapeutic radiation (23) can be further reduced, and the dose of the therapeutic radiation (23) applied to the second part can be made to be a predetermined dose or less.

  The radiotherapy apparatus control apparatus and the radiation irradiation method according to the present invention irradiate a portion of a subject excluding the predetermined site when the therapeutic radiation fixed to the subject is irradiated to the predetermined site by a predetermined dose. The dose of therapeutic radiation can be further reduced.

  An embodiment of a radiation therapy system according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the radiotherapy system 1 includes a radiotherapy apparatus control apparatus 2, a radiotherapy apparatus 3, a respirometer 4, and a computed tomography apparatus (CT) 5. The radiation therapy apparatus control apparatus 2 is a computer exemplified by a personal computer. The radiotherapy device controller 2 is connected to the radiotherapy device 3 so as to be able to transmit information in both directions, and the respirometer 4 and the computed tomography device 5 so as to be able to transmit information in both directions. It is connected to the.

  The respirometer 4 measures the respiration rate of the patient and outputs the respiration rate to the radiotherapy device control device 2. The respiration rate indicates the amount that changes as the patient breathes, for example, the amount of air stored in the patient's lungs.

  The computed tomography apparatus 5 captures a plurality of transmission images by transmitting X-rays from each direction to the human body, performs image processing on the plurality of transmission images with a computer, and generates an image of the cross section of the human body. The transmitted image is processed by a computer to generate three-dimensional data indicating the internal state of the human body. The computer tomography apparatus 5 can be replaced with another apparatus that measures the three-dimensional state inside the human body, and can be replaced with, for example, an MRI apparatus. The MRI apparatus detects the magnetism of a human cell using nuclear magnetic resonance, images the magnetism with a computer, and generates three-dimensional data indicating the internal state of the human body.

  FIG. 2 shows the radiation therapy apparatus 3. The radiotherapy device 3 includes a turning drive device 11, an O-ring 12, a traveling gantry 14, a swing mechanism 15, and a therapeutic radiation irradiation device 16. The turning drive device 11 supports the O-ring 12 on the base so as to be rotatable about the rotation shaft 17, and is rotated by the radiotherapy device control device 2 to rotate the O-ring 12 about the rotation shaft 17. The rotating shaft 17 is parallel to the vertical direction. The O-ring 12 is formed in a ring shape with the rotation shaft 18 as a center, and supports the traveling gantry 14 so as to be rotatable about the rotation shaft 18. The rotating shaft 18 is perpendicular to the vertical direction and passes through an isocenter 19 included in the rotating shaft 17. The rotating shaft 18 is further fixed to the O-ring 12, that is, rotates around the rotating shaft 17 together with the O-ring 12. The traveling gantry 14 is formed in a ring shape centered on the rotation shaft 18, and is disposed so as to be concentric with the ring of the O-ring 12. The radiation therapy apparatus 3 further includes a travel drive device (not shown). The travel drive device is controlled by the radiotherapy device control device 2 to rotate the travel gantry 14 around the rotation shaft 18.

  The swing mechanism 15 is fixed to the inside of the ring of the traveling gantry 14 and supports the therapeutic radiation irradiation device 16 on the traveling gantry 14 so that the therapeutic radiation irradiation device 16 is disposed inside the traveling gantry 14. Yes. The head swing mechanism 15 has a pan axis 21 and a tilt axis 22. The tilt shaft 22 is fixed to the traveling gantry 14 and is parallel to the rotation axis 18 without intersecting the rotation axis 18. The pan axis 21 is orthogonal to the tilt axis 22. The head swing mechanism 15 is controlled by the radiation therapy apparatus control apparatus 2 to rotate the treatment radiation irradiation apparatus 16 about the pan axis 21 and rotate the treatment radiation irradiation apparatus 16 about the tilt axis 22.

  The therapeutic radiation irradiation device 16 is controlled by the radiotherapy device control device 2 to emit therapeutic radiation 23. The therapeutic radiation 23 is radiated substantially along a straight line passing through an intersection where the pan axis 21 and the tilt axis 22 intersect. The therapeutic radiation 23 is formed to have a uniform intensity distribution. The therapeutic radiation 23 is further partially shielded, and the shape of the irradiation field when the therapeutic radiation 23 is irradiated to the patient is controlled.

  The therapeutic radiation 23 is once adjusted so that the therapeutic radiation irradiation device 16 is directed to the isocenter 19 by the swing mechanism 15 by the therapeutic radiation irradiation device 16 being supported by the traveling gantry 14 in this manner. Even if the O-ring 12 is rotated by the turning drive device 11 or the traveling gantry 14 is rotated by the traveling drive device, the O-ring 12 always passes through the isocenter 19 at all times. In other words, the therapeutic radiation 23 can be irradiated from any direction toward the isocenter 19 by running and turning.

  The radiotherapy apparatus 3 further includes a plurality of imager systems. That is, the radiotherapy apparatus 3 includes diagnostic X-ray sources 24 and 25 and sensor arrays 32 and 33. The diagnostic X-ray source 24 is supported by the traveling gantry 14. The diagnostic X-ray source 24 is disposed inside the ring of the traveling gantry 14, and an angle formed by a line segment connecting the diagnostic X-ray source 24 from the isocenter 19 and a line segment connecting the therapeutic radiation irradiation device 16 from the isocenter 19. Is arranged at a position that makes an acute angle. The diagnostic X-ray source 24 is controlled by the radiotherapy apparatus controller 2 and emits diagnostic X-rays 35 toward the isocenter 19. The diagnostic X-ray 35 is a conical cone beam which is emitted from one point of the diagnostic X-ray source 24 and has the one point as a vertex. The diagnostic X-ray source 25 is supported by the traveling gantry 14. The diagnostic X-ray source 25 is disposed inside the ring of the traveling gantry 14, and an angle formed by a line segment connecting the diagnostic X-ray source 25 from the isocenter 19 and a line segment connecting the therapeutic radiation irradiation device 16 from the isocenter 19. Is arranged at a position that makes an acute angle. The diagnostic X-ray source 25 is controlled by the radiotherapy apparatus controller 2 and emits diagnostic X-rays 36 toward the isocenter 19. The diagnostic X-ray 36 is a cone-shaped cone beam emitted from one point of the diagnostic X-ray source 25 and having the one point as a vertex.

  The sensor array 32 is supported by the traveling gantry 14. The sensor array 32 receives the diagnostic X-ray 35 emitted from the diagnostic X-ray source 24 and transmitted through the subject around the isocenter 19 and generates a transmission image of the subject. The sensor array 33 is supported by the traveling gantry 14. The sensor array 33 receives the diagnostic X-ray 36 emitted from the diagnostic X-ray source 25 and transmitted through the subject around the isocenter 19 and generates a transmission image of the subject. Examples of the sensor arrays 32 and 33 include FPD (Flat Panel Detector) and X-ray II (Image Intensifier).

  According to such an imager system, a transmission image centered on the isocenter 19 can be generated based on the image signals obtained by the sensor arrays 32 and 33.

  The radiation therapy apparatus 3 further includes a sensor array 31. The sensor array 31 is arranged so that a line segment connecting the sensor array 31 and the therapeutic radiation irradiation device 16 passes through the isocenter 19 and is fixed inside the ring of the traveling gantry 14. The sensor array 31 receives the therapeutic radiation 23 emitted from the therapeutic radiation irradiation device 16 and transmitted through the subject around the isocenter 19, and generates a transmission image of the subject. Examples of the sensor array 31 include FPD (Flat Panel Detector) and X-ray II (Image Intensifier).

  The radiation therapy apparatus 3 further includes a couch 41 and a couch driving device 42. The couch 41 is used when a patient 43 to be treated by the radiation therapy system 1 lies down. The couch 41 includes a fixture not shown. The fixture secures the patient to the couch 41 so that the patient does not move. The couch driving device 42 supports the couch 41 on the base and moves the couch 41 under the control of the radiation therapy device control device 2.

  FIG. 3 shows the therapeutic radiation irradiation device 16. The therapeutic radiation irradiation device 16 includes an electron beam accelerator 51, an X-ray target 52, a primary collimator 53, a flattening filter 54, a dosimeter 61, a secondary collimator 55, and a multi-leaf collimator 56. The electron beam accelerator 51 irradiates the X-ray target 52 with an electron beam 57 generated by accelerating electrons. The X-ray target 52 is formed of a high atomic number material (tungsten, tungsten alloy, etc.), and emits radiation 59 generated by bremsstrahlung when the electron beam 57 is irradiated. The radiation 59 is radiated substantially along a straight line passing through a virtual point source 58, which is a point inside the X-ray target 52. The primary collimator 53 is made of a high atomic number material (lead, tungsten, etc.), and shields the radiation 59 so that the radiation 59 is not irradiated to other than the desired part. The flattening filter 54 is formed of aluminum or the like, and is formed on a plate on which a generally conical protrusion is formed. The flattening filter 54 is disposed so that its protrusion faces the X-ray target side. The flattening filter shape is formed so that the dose in a predetermined region on a plane perpendicular to the radiation direction is distributed substantially uniformly after passing through the flattening filter. The secondary collimator 55 is formed from a high atomic number material (lead, tungsten, etc.), and shields the radiation 60 so that the radiation 60 is not irradiated to other than a desired part. The radiation 60 having a uniform intensity distribution formed in this way is partially shielded by the multi-leaf collimator 56 controlled by the radiation therapy apparatus control apparatus 2 and has a property based on a separately constructed treatment plan. A certain therapeutic radiation 23 is generated. That is, the multi-leaf collimator 56 is controlled by the radiation therapy apparatus control apparatus 2 to control a shape of an irradiation field when the patient is irradiated with the therapeutic radiation 23 by shielding a part of the radiation 60.

  The dosimeter 61 is a transmission ionization chamber that measures the intensity of transmitted radiation, and is disposed between the primary collimator 53 and the secondary collimator 55 so that the radiation 60 is transmitted. The dosimeter 61 measures the dose of the transmitted radiation 60 and outputs the dose to the radiation therapy apparatus control device 2. Such a dosimeter 61 is preferable in that non-destructive verification is possible. The X-ray intensity detector other than the transmission ionization chamber can be applied to the dosimeter 61. Examples of the X-ray intensity detector include a semiconductor detector and a scintillation detector. The semiconductor detector or the scintillation detector is preferably disposed outside the orbit because it is difficult to substitute the radiation detector on the radiation orbit like a transmission ionization chamber. For example, the therapeutic radiation is separated from the isocenter 19. The traveling gantry 14 is fixed so as to be disposed at a position facing the irradiation device 16. An ionization chamber generally has a time constant of about several seconds and has poor responsiveness. The semiconductor detector or the scintillation detector has a disadvantage that the signal intensity is lower than that of the ionization chamber when placed outside the orbit, but it is preferable because it has better response than the ionization chamber.

  The electron beam accelerator 51 includes an electron beam generator 63 and an acceleration tube 64. The electron beam generator 63 includes a cathode 66 and a grid 67. The acceleration tube 64 is formed in a cylindrical shape, and includes a plurality of electrodes 68 arranged at appropriate intervals inside the cylinder.

  The radiotherapy apparatus 3 further includes a cathode power source, a grid power source, and a klystron which are not shown. The cathode power supply is controlled by the radiotherapy device controller 2 so that the cathode 66 is heated and a predetermined amount of electrons are emitted from the cathode 66 (that is, the cathode 66 is maintained at a predetermined temperature). ), Power is supplied to the cathode 66. The grid power supply is controlled by the radiation therapy apparatus control device 2 to apply a predetermined voltage between the grid 67 and the cathode 66 so that only a predetermined amount of electrons are emitted from the electron beam generator 63. . The klystron is connected to the acceleration tube 64 via a waveguide. The klystron is controlled by the radiotherapy apparatus control device 2 so that the accelerator tube 64 accelerates electrons emitted from the electron beam generator 63 until it has a predetermined energy, and the accelerator tube is passed through the waveguide. A microwave is incident on 64.

  FIG. 4 shows the radiotherapy apparatus control apparatus 2. The radiotherapy device control device 2 is a computer, and includes a CPU, a storage device, an input device, an output device, and an interface (not shown). The CPU executes a computer program installed in the radiation therapy apparatus control apparatus 2 and controls the storage apparatus, the input apparatus, the output apparatus, and the interface. The storage device records the computer program, records information used by the CPU, and records information generated by the CPU. The input device outputs information generated by being operated by the user to the CPU. Examples of the input device include a keyboard and a mouse. The output device outputs the information generated by the CPU so that the user can recognize it. Examples of the output device include a display that displays a screen generated by the CPU. The interface outputs information generated by an external device connected to the radiotherapy device control apparatus 2 to the CPU, and outputs information generated by the CPU to the external device. The external equipment includes a radiotherapy apparatus 3, a respirometer 4, and a computed tomography apparatus 5.

  The radiotherapy apparatus control apparatus 2 includes a treatment planning unit 71, an irradiation position control unit 72, an imaging unit 73, an irradiation range calculation unit 74, and an irradiation unit 75, which are computer programs.

  The treatment planning unit 71 displays the three-dimensional data indicating the positional relationship between the affected part of the patient 43 generated by the computed tomography apparatus 5 and the surrounding organs (including the dangerous part) on the output device so that the user can view it. To do. The treatment planning unit 71 further creates a treatment plan based on the three-dimensional data and information input using the input device. The treatment plan shows three-dimensional data of the affected area of the patient 43 and shows a combination of an irradiation angle and a dose. The irradiation angle indicates the direction in which the therapeutic radiation 23 is irradiated to the affected part of the patient 43 (that is, the relative position between the patient 43 and the virtual point source 58 of the therapeutic radiation irradiation device 16), and the traveling angle and the turning angle Is shown. The traveling angle indicates the direction of the traveling gantry 14 when the traveling gantry 14 is rotated by the traveling drive device. The turning angle indicates the direction of the O-ring 12 when the O-ring 12 is rotated by the turning drive device 11. The dose indicates the dose of the therapeutic radiation 23 irradiated to the affected area from each irradiation angle.

  The irradiation position control unit 72 is configured so that the relative position between the patient 43 and the virtual point source 58 of the therapeutic radiation irradiation device 16 corresponds to the irradiation angle indicated by the treatment plan created by the treatment plan unit 71. The couch 41 is moved using 42, and the therapeutic radiation irradiation device 16 is moved using the turning drive device 11 or the traveling drive device.

  The imaging unit 73 collects the respiration rate from the respirometer 4 and calculates a respiration cycle in which the patient 43 breathes based on the respiration rate. The imaging unit 73 captures a transmission image around the affected area of the patient 43 using the imager system of the radiation therapy apparatus 3. The transmission image includes a plurality of transmission images taken from a plurality of different positions with respect to the patient 43, and the diagnostic X-ray sources 24 and 25 transmitted through the patient 43 are exposed with an exposure time equal to the respiratory cycle. Imaged. The exposure time can be a time different from the breathing cycle. Examples of the exposure time include a time that is a natural number times the respiratory cycle and a time sufficiently longer than the respiratory cycle.

  The irradiation range calculation unit 74 calculates the irradiation range based on the transmission image captured by the imaging unit 73. The irradiation range includes the position of the irradiation field of the therapeutic radiation 23 and the shape of the irradiation field when the patient 43 is irradiated with the therapeutic radiation 23 from the irradiation angle indicated by the treatment plan created by the treatment planning unit 71. Show.

  The irradiation unit 75 moves the therapeutic radiation irradiation device 16 using the swing mechanism 15 so that the therapeutic radiation 23 passes through the irradiation range calculated by the irradiation range calculation unit 74. The irradiation unit 75 further controls the multi-leaf collimator 56 so that the cross-sectional shape of the therapeutic radiation 23 matches the shape of the irradiation field indicated by the irradiation range calculated by the irradiation range calculation unit 74. The irradiation unit 75 further irradiates the patient 43 with the therapeutic radiation 23 using the therapeutic radiation irradiation device 16 by the dose indicated by the treatment plan created by the treatment planning unit 71.

  FIG. 5 shows changes in the respiration rate measured by the respirometer 4. The change 77 indicates that the respiration rate changes periodically every respiration cycle 78. In other words, the imaging unit 73 calculates the change 77 based on the respiration rate collected from the respirometer 4 every time sufficiently shorter than the respiration cycle, and calculates the respiration cycle 78 based on the change 77.

  The transmission image picked up by the imager system of the radiation therapy apparatus 3 is formed from a plurality of pixels that are sufficiently smaller than the size of the transmission image. The pixels are arranged in a matrix on the transmission image, and each indicates a luminance corresponding to the density of the captured transmission image. FIG. 6 shows a luminance distribution of luminance indicated by a transmission image of an affected area of lung cancer that is captured with a sufficiently short exposure time as compared with the respiratory cycle 78. The luminance distribution 81 indicates the luminance indicated by the pixels arranged on a straight line that crosses the region where the affected part is projected in the transmission image. The luminance distribution 81 has a so-called top flat shape, and indicates that the luminance of the region in which the affected part of the transmission image is projected is large and the luminance of the region other than the region of the transmission image is small.

  FIG. 7 shows the luminance distribution of the luminance indicated by the transmitted image of the affected area of lung cancer imaged with an exposure time of respiratory cycle 78 or more. The luminance distribution 82 indicates the luminance indicated by the pixels arranged on a straight line that crosses the region where the affected part is projected in the transmission image. The luminance distribution 82 has a so-called top flat shape, and indicates that the luminance of the region where the presence probability of the affected part in the transmission image is large is large and the luminance of the region other than the region of the transmission image is small. The existence probability of the affected area in a certain micro area indicates the ratio of the time during which the affected area exists in the micro area with respect to the respiratory cycle 78. The luminance distribution 82 further indicates that the sharpness of the luminance is duller than that of the luminance distribution 81, and the transmission imaged by the long-time exposure compared to the contour of the affected area displayed on the transmission image captured by the short-time exposure. This shows that the outline of the affected area shown in the image is blurred. This indicates that the affected area does not exist in the vicinity of the contour during one respiratory cycle 78, and the higher the luminance, the higher the existence probability of the affected area.

  FIG. 8 shows the luminance distribution of the brightness indicated by the transmission image of the affected part of the cancer of the general organ, which is imaged with a sufficiently short exposure time as compared with the respiratory cycle 78. The luminance distribution 85 indicates the luminance indicated by the pixels arranged on a straight line that crosses the region where the affected part is projected in the transmission image. Examples of the general organ include liver, gallbladder, and pancreas. The luminance distribution 85 indicates that the luminance of the region where the affected part of the transmission image is projected is large and the luminance of the region other than the region of the transmission image is small. The luminance change with respect to the position is gentler than the luminance distribution 81. It shows that there is.

  FIG. 9 shows the luminance distribution of the luminance indicated by the transmission image of the affected part of the cancer of the general organ, which was imaged with an exposure time of respiratory cycle 78 or more. The luminance distribution 86 indicates the luminance indicated by pixels arranged on a straight line that crosses the region in which the affected part is projected in the transmission image. The luminance distribution 86 indicates that the luminance of the region where the presence probability of the affected part in the transmission image is large is large and the luminance of the region other than the region of the transmission image is small. The luminance distribution 86 further indicates that the sharpness of the luminance is duller than that of the luminance distribution 85, and the transmission imaged by the long-time exposure compared to the contour of the affected area displayed on the transmission image captured by the short-time exposure. This shows that the outline of the affected area shown in the image is blurred. This indicates that the affected area does not exist in the vicinity of the contour during one respiratory cycle 78, and the higher the luminance, the higher the existence probability of the affected area.

  Here, the irradiation range calculation unit 74 displays the transmission image captured by the imaging unit 73 on the display, and sets a threshold value based on information input when the input device is operated by the user. The irradiation range calculation unit 74 calculates a region in the transmission image where the luminance is greater than the threshold value. The region corresponds to a range 84 in which the luminance is larger than the threshold 83 in the definition region of the luminance distribution 82, and corresponds to a range 88 in which the luminance is larger than the threshold 87 in the definition region of the luminance distribution 86. The irradiation range calculation unit 74 uses the imager system of the radiotherapy apparatus 3 to determine the affected area based on the position and shape of the region displayed on a plurality of transmission images captured from a plurality of different positions with respect to the patient 43. A three-dimensional region in which the existence probability is greater than a predetermined probability (for example, 0.9) is calculated. The irradiation range calculation unit 74 calculates an irradiation field based on the three-dimensional region, that is, calculates the position and shape of the irradiation field.

  The irradiation range calculation unit 74 can also calculate the area from the transmission image in a luminance range different from the luminance range larger than the threshold. In general, the density of a transparent image is reversed depending on whether positive or negative is used. For example, the irradiation range calculation unit 74 has a luminance that is higher than the threshold value input by the user when the luminance of the region where the affected part of the transmission image is projected is small and the luminance of the region other than the region of the transmission image is high. A small area is calculated from the transmission image, and the position and shape of the irradiation field are calculated. At this time, the irradiation range calculation unit 74 can calculate the position and shape of the irradiation field in the same manner as when a luminance range larger than the threshold is used. That is, the luminance range can be set as appropriate according to the representation of the transmission image.

  Further, when there is a risk organ that should not be irradiated with the therapeutic radiation 23 in the vicinity of the affected part, the irradiation range calculating unit 74 has a probability that the risk organ is greater than a predetermined probability in the same manner as the affected part. A three-dimensional risk region is calculated, and the irradiation field is calculated so that the therapeutic radiation 23 is not irradiated on the three-dimensional risk region.

  FIG. 10 shows the relationship between a known target volume and the three-dimensional region calculated by the irradiation range calculation unit 74. A region 91 in FIG. 10 corresponds to a known ITV or PTV. That is, the region 91 corresponds to a region where the affected area and its peripheral region move due to respiration (or movement of internal organs such as swallowing, heartbeat, and peristalsis), that is, a transmission image captured by long exposure. Corresponds to the area where the affected area is projected. Region 92 corresponds to GTV or CTV. That is, the region 92 corresponds to the affected part or the affected part and its peripheral region, that is, a region where the affected part appears in a transmission image captured by short-time exposure. That is, FIG. 10 shows that the region 92 is included in the region 91.

  The region 93 corresponds to a three-dimensional region in which the presence probability of the affected area is larger than a predetermined probability, that is, a region in which the luminance of the transmitted image captured by long exposure is larger than a predetermined threshold. The region 94 corresponds to a three-dimensional region in which the risk organ existence probability is larger than a predetermined probability. A region 95 corresponds to the irradiation field calculated by the irradiation range calculation unit 74. FIG. 10 shows that the irradiation field is smaller than the area 91, the irradiation field does not overlap the area 94, and the irradiation field includes more areas 93. It is calculated.

  The embodiment of the radiation irradiation method according to the present invention is executed using the radiation therapy system 1 and includes an operation of creating a treatment plan, an operation of identifying an irradiation field, and an operation of performing radiation therapy.

  In the operation of creating the treatment plan, first, the user uses the computed tomography apparatus 5 to collect three-dimensional data of the affected part of the patient 43 and the site around the affected part. Based on the three-dimensional data generated by the computed tomography apparatus 5, the radiation therapy apparatus control apparatus 2 generates an image indicating the affected area of the patient 43 and organs around the affected area. The user browses the image using the radiotherapy apparatus control apparatus 2 and specifies the position of the affected part. The user further creates a treatment plan using the treatment plan unit 71 based on the image, and inputs the treatment plan to the radiotherapy device control apparatus 2. The treatment plan shows an irradiation angle at which the affected part of the patient 43 is irradiated with the therapeutic radiation 23 and a dose and a property of the therapeutic radiation 23 irradiated from each irradiation angle. The treatment plan further indicates an imaging angle at which the diagnostic X-rays 35 and 36 are irradiated when the therapeutic radiation 23 is irradiated from each irradiation angle.

  The operation for identifying the irradiation field is executed immediately before the operation for radiation therapy. The user first fixes the patient 43 to the couch 41 of the radiotherapy apparatus 3 in the same posture as when the three-dimensional data is collected by the computed tomography apparatus 5. The radiotherapy device controller 2 uses the turning drive device 11, the travel drive device, and the couch drive device 42 so that the treatment radiation 23 is irradiated to the patient 43 at the irradiation angle indicated by the treatment plan. The radiation irradiating apparatus 16 and the patient 43 are aligned.

The radiotherapy device controller 2 collects the respiration rate from the respirometer 4 and calculates the respiration cycle in which the patient 43 breathes based on the respiration rate. The radiotherapy apparatus control apparatus 2 irradiates the patient 43 with diagnostic X-rays 35 using the diagnostic X-ray source 24, and takes a transmission image of the affected area of the patient 43 using the sensor array 32. The radiotherapy apparatus control apparatus 2 further emits diagnostic X-rays 36 using the diagnostic X-ray source 25 and captures a transmission image of the affected area of the patient 43 using the sensor array 33. The transmission images are taken by exposing the diagnostic X-ray sources 24 and 25 that have passed through the patient 43 for a predetermined exposure time.
The exposure time is equal to the natural number of times of the respiratory cycle, or is sufficiently long compared to the respiratory cycle. The radiotherapy apparatus control apparatus 2 can also capture the transmission image while collecting the respiration rate from the respirometer 4. At this time, the radiotherapy device control device 2 starts exposure when the respiration rate collected from the respirometer 4 shows a predetermined probability, and a predetermined number of times (for example, once) based on the change in the respiration rate. When it is determined that the respiration cycle has been repeated, exposure is terminated and a transmission image is taken.

  The radiotherapy apparatus control apparatus 2 displays the transmitted image on the display. The user browses the transparent image displayed on the display and inputs a threshold value of luminance using the input device. The radiation therapy apparatus control apparatus 2 calculates a region in the transmission image where the luminance is greater than the threshold value. Based on the position and shape of the region displayed in the plurality of transmission images, the radiotherapy device control apparatus 2 determines the position and shape of the three-dimensional region inside the patient 43 displayed in the region of the transmission image. And calculate. Since the luminance displayed at a certain position of the transmission image corresponds to the existence probability of the affected area in the area corresponding to the position of the patient 43, the existence probability of the affected area is larger than a predetermined probability in the three-dimensional area. Corresponds to the area. That is, the radiotherapy apparatus control apparatus 2 can calculate a region where the presence probability of the affected area is larger than a predetermined probability by appropriately setting the threshold value by the user.

  The radiotherapy device controller 2 calculates an irradiation field based on the three-dimensional region, that is, calculates the position and shape of the irradiation field. Furthermore, when there is a risk organ that should not be irradiated with the therapeutic radiation 23 in the vicinity of the affected area, the radiotherapy apparatus control apparatus 2 has a risk organ existence probability greater than a predetermined probability in the same manner as the affected area. A three-dimensional risk region is calculated, and the irradiation field is calculated so that the therapeutic radiation 23 is not irradiated on the three-dimensional risk region.

  In the radiation treatment operation, the radiation therapy apparatus control apparatus 2 moves the therapeutic radiation irradiation apparatus 16 using the swing mechanism 15 so that the therapeutic radiation 23 is irradiated to the calculated irradiation field. The radiotherapy device controller 2 further controls the multi-leaf collimator 56 so that the cross-sectional shape of the therapeutic radiation 23 matches the calculated shape of the irradiation field. The radiation therapy apparatus control apparatus 2 further irradiates the patient 43 with the therapeutic radiation 23 by using the therapeutic radiation irradiation apparatus 16 by the dose indicated by the treatment plan created by the treatment planning unit 71.

  According to such a radiation irradiation method, the period during which the patient 43 is irradiated with the therapeutic radiation 23 includes the period during which a part of the affected area is irradiated with the therapeutic radiation 23 and the part thereof is irradiated with the therapeutic radiation 23. Period not included. That is, according to such a radiation irradiation method, the radiation treatment system 1 irradiates the patient 43 with the therapeutic radiation 23 that does not move with respect to the patient 43 when the affected part moves due to the movement (breathing) of the patient 43. In this case, it is possible to irradiate the affected part with a predetermined dose of the therapeutic radiation 23 without irradiating a part of the affected part with the therapeutic radiation 23 for a minute period. For this reason, according to such a radiation irradiation method, the radiation treatment system 1 irradiates the planning target volume with the therapeutic radiation 23 as in the prior art, so that the dose of the therapeutic radiation 23 to the organ other than the affected part is irradiated. Can be reduced. Furthermore, when applied to such a radiation irradiation method, the radiation therapy system 1 does not need to be equipped with a device necessary for gated irradiation or moving body tracking irradiation, and can be produced at low cost.

  The respirometer 4 can be replaced with another device that detects the movement of the human body without using the radiation that passes through the human body. Examples of the apparatus include an electrocardiograph, a pulse meter, a sphygmomanometer, and a camera. The electrocardiograph is a device for creating an electrocardiogram of a patient, and measures the amount of activity of the patient's heart. The pulse meter measures the patient's pulse. The sphygmomanometer measures the patient's blood pressure. The camera images the patient on video. At this time, the radiotherapy system 1 performs radiotherapy on the affected area in the same manner as in the above-described embodiment with respect to the affected area that moves in conjunction with a motion other than the breathing of the patient 43 (for example, heartbeat, swallowing, etc.). When doing so, the dose of the therapeutic radiation 23 to the organ other than the affected part can be reduced.

FIG. 1 is a block diagram showing an embodiment of a radiation therapy system according to the present invention. FIG. 2 is a perspective view showing the radiation therapy apparatus. FIG. 3 is a cross-sectional view showing a therapeutic radiation irradiation apparatus. FIG. 4 is a block diagram showing the radiotherapy apparatus control apparatus. FIG. 5 is a graph showing changes in the respiration rate measured by the respirometer. FIG. 6 is a graph showing the luminance distribution of a transmission image of an affected area of lung cancer imaged by short-time exposure. FIG. 7 is a graph showing the luminance distribution of a transmission image of an affected area of lung cancer imaged by long exposure. FIG. 8 is a graph showing the luminance distribution of a transmission image of a cancerous part of a general organ imaged by short-time exposure. FIG. 9 is a graph showing the luminance distribution of a transmission image of a cancerous part of a general organ imaged by long exposure. FIG. 10 is a plan view showing a transmission image captured by long exposure. FIG. 11 is a diagram showing the relationship between the gross tumor volume, the clinical target volume, the internal target volume, and the planned target volume.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Radiation therapy system 2: Radiation therapy apparatus control apparatus 3: Radiation therapy apparatus 4: Respirometer 5: Computer tomography apparatus 11: Turning drive apparatus 12: O-ring 14: Running gantry 15: Swing mechanism 16: Radiation for treatment Irradiation device 17: rotation axis 18: rotation axis 19: isocenter 21: pan axis 22: tilt axis 23: therapeutic radiation 24: diagnostic X-ray source 25: diagnostic X-ray source 31: sensor array 32: sensor array 33: Sensor array 35: X-ray for diagnosis 36: X-ray for diagnosis 41: Couch 42: Couch driving device 43: Patient 51: Electron beam accelerator 52: X-ray target 53: Primary collimator 54: Flattening filter 55: Secondary Collimator 56: Multi-leaf collimator 57: Electron beam 58: Virtual point source 59: Radiation 60: Release Ray 61: Dosimeter 63: Electron beam generation unit 64: Acceleration tube 66: Cathode 67: Grid 68: Multiple electrodes 71: Treatment planning unit 72: Irradiation position control unit 73: Imaging unit 74: Irradiation range calculation unit 75: Irradiation Part

Claims (6)

An imaging unit that captures a transmission image with radiation transmitted through the subject;
An irradiation range calculation unit for calculating a region using the transmission image;
An irradiation unit that irradiates the region with therapeutic radiation so that a predetermined dose is irradiated to a predetermined part of the subject ;
The region indicates a region where a ratio of time during which the predetermined part of the subject is arranged when the subject moves is greater than a predetermined probability,
The period during which the subject is irradiated with the therapeutic radiation is:
A period during which a portion of the predetermined site is irradiated with the therapeutic radiation;
A radiotherapy apparatus control apparatus including a period in which the part is not irradiated with the therapeutic radiation. In claim 1,
The transmission image is exposed and photographed for a time equal to or longer than a motion cycle in which the subject moves,
The region is calculated based on a portion of the transmission image where an affected part is projected within a predetermined luminance range. An imaging unit that captures a transmission image with radiation transmitted through the subject;
An irradiation range calculation unit that calculates a first region using the transmission image and calculates a second region using the transmission image;
An irradiation unit that irradiates therapeutic radiation to a region other than the second region of the first region so that a predetermined dose is irradiated to the first part of the subject ;
The first region indicates a region in which a ratio of time during which the first part of the subject is arranged when the subject exercises is greater than a first probability,
The second region indicates a region in which a ratio of time during which the second part of the subject is arranged when the subject exercises is greater than a second probability,
The period during which the subject is irradiated with the therapeutic radiation is:
A period during which a portion of the first site is irradiated with the therapeutic radiation;
A radiotherapy apparatus control apparatus including a period in which the part is not irradiated with the therapeutic radiation. A step in which a radiation therapy apparatus control device calculates a region using a transmission image captured by radiation transmitted through a subject; and
The radiation treatment apparatus control device fixing a treatment radiation irradiation apparatus for emitting treatment radiation based on the region,
The region is said when the subject moves, the percentage of time that a predetermined portion of the subject is arranged to indicate an area greater than a predetermined probability,
The period during which the subject is irradiated with the therapeutic radiation is:
A period during which a portion of the predetermined site is irradiated with the therapeutic radiation;
A method of operating a radiation irradiation apparatus including a period during which the part is not irradiated with the therapeutic radiation . In claim 4 ,
The transmission image, the is intended the subject has been captured is exposed at a time or more motion period of movement,
The area, by the radiotherapy device control apparatus, a method of operating a radiation device affected area of the transparent image is calculated based on the portion to be displayed in a predetermined brightness range. A step in which the radiation therapy apparatus control device calculates a first region using a transmission image captured by radiation transmitted through the subject;
Calculating the second region using the transmission image by the radiation therapy apparatus control device ;
A therapeutic radiation irradiating device for emitting therapeutic radiation, the radiotherapy device controller fixing the therapeutic radiation irradiating device based on a region of the first region excluding the second region;
The first region indicates a region in which a ratio of time during which the first part of the subject is arranged when the subject exercises is greater than a first probability,
Said second region, said when the subject moves, the percentage of time that the second portion of the subject is arranged to indicate an area greater than the second probability,
The period during which the subject is irradiated with the therapeutic radiation is:
A period during which a portion of the first site is irradiated with the therapeutic radiation;
A method of operating a radiation irradiation apparatus including a period during which the part is not irradiated with the therapeutic radiation .

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