JP4486610B2 - Radiation irradiation equipment - Google Patents

Description

  The present invention relates to a radiation irradiation apparatus, and more particularly to a radiation irradiation apparatus used for radiation therapy.

  In the radiation irradiation apparatus, an electron beam is accelerated by an electron accelerator, and the accelerated electron beam is placed on an X-ray target (a high atomic number material such as W or Ta or W−) disposed at an exit end of the electron accelerator. X-rays generated by the bremsstrahlung phenomenon are used for treatment or the like. The X-ray is emitted from the X-ray target with an intensity distribution determined by electron beam conditions (acceleration energy, current amount, incident angle) and material properties (atomic number, shape) of the X-ray target. Usually, the energy of the electron beam used in the radiation irradiation apparatus is about 6 to 20 MeV, and when the electron beam having the energy is incident on the X-ray target perpendicularly, the intensity distribution is relative to the incident direction of the electron beam. The symmetric system has the maximum intensity. That is, the electron beam axis and the X-ray axis are the same.

  In order to perform an appropriate amount of irradiation to the affected area and reduce the amount of irradiation to the surrounding healthy tissue, the X-ray irradiated from the therapeutic X-ray generation source of the radiation irradiation apparatus has an irradiation region set in accordance with the affected area properties. Once done, it is necessary to irradiate the affected area. In general, a multi-leaf collimator (MLC) is used as a means for setting an irradiation area according to the affected part property. The multi-leaf collimator is installed between the therapeutic X-ray generation source of the radiation irradiation apparatus and the patient, and has a plurality of leaves that can move independently. In the multi-leaf collimator, a plurality of pairs of leaves facing each other across the boundary line are arranged adjacent to each other along the boundary line. Then, by opening and removing each of the leaves facing each other with the boundary line in between, an opening serving as an irradiation space corresponding to the affected part property between the therapeutic X-ray generation source and the patient is formed. Form. Each leaf included in the multi-leaf collimator is sufficient to attenuate the intensity of X-rays emitted from the therapeutic X-ray generation source to below the required limit (specifically, 1/1000 or less of the irradiation X-rays). Has an effective thickness.

  The position of each leaf is determined by, for example, using the center of gravity of the opening when the leaf position is fully open as the origin, and a basic axis (in the plane parallel to and perpendicular to the movement of each leaf in a plane parallel to the movement direction of the leaf). This is done by specifying the coordinates when setting (X / Y axis). In a treatment plan that is separately prepared in advance prior to a treatment action, the arrangement coordinate position of each leaf is determined for each irradiation angle of the X-rays irradiated from the therapeutic X-ray generation source. Then, at the time of treatment, the final leaf placement position is determined based on the result of re-evaluation of the affected area.

  Here, it is necessary to optimize the relative position between the absolute position of the affected part, which is the X-ray irradiation target site, and the opening formed by each leaf of the multi-leaf collimator. In the prior art, the couch position is adjusted so that the center of the gantry and the center of the affected area substantially coincide. That is, the coincidence is achieved by constructing an absolute coordinate system based on the gantry center. At that time, the X-ray irradiation axis and the central axis of the multi-leaf collimator (the axis passing through the origin (center of gravity) of the leaf movement plane (XY plane) and perpendicular to the leaf movement plane) coincide with each other. A multi-leaf collimator is mechanically connected to the therapeutic X-ray source. As a result, an X-ray intensity distribution symmetric with respect to the central axis of the multi-leaf collimator can be obtained, and the treatment plan can be simplified. This is true regardless of the use of a flattening filter for making the X-ray intensity distribution top flat, for example.

  However, there is a problem that the irradiation axis of the electron beam in the therapeutic X-ray generation source and the central axis of the electron beam acceleration device do not necessarily coincide with each other because of the distortion in each electrode arrangement and the acceleration tube body. Therefore, the relative arrangement of the multi-leaf collimator with respect to the X-ray irradiation axis may deviate from a desired relationship.

  In the above-described prior art, even if the X-ray irradiation axis and the central axis of the multi-leaf collimator are adjusted to coincide with each other at the initial stage, the mechanical structure shape and the combination arrangement due to its own weight change over time. As a result, the equivalence cannot always be maintained over a long period of time. That is, the correlation between the X-ray irradiation axis and the central axis of the multi-leaf collimator cannot be clearly obtained only by mechanically fitting both the electron beam accelerator and the multi-leaf collimator. This means, for example, that the radiation intensity distribution of the therapeutic X-ray is asymmetric with respect to the central axis of the multi-leaf collimator. As described above, only by mechanical alignment between the X-ray irradiation axis and the central axis of the multi-leaf collimator, which has been performed in the prior art, even if the irradiation condition is set according to the treatment plan, an appropriate therapeutic effect on the affected area is achieved. As well as the possibility of adverse effects on surrounding healthy organizations.

  In relation to the above-described technology, the following proposals have been made.

  In the “radiation irradiation apparatus” disclosed in Japanese Patent Application Laid-Open No. 2004-97646, a radiation irradiation head that irradiates therapeutic radiation to a treatment field of a subject, and an X that radiates diagnostic X-rays to the treatment field of the subject. A radiation irradiation apparatus comprising: a radiation source; and a sensor array that detects transmission X-rays of diagnostic X-rays that have passed through the subject and outputs them as diagnostic image data, the sensor array moving in conjunction with movement of the radiation irradiation head Has been proposed.

JP 2004-97646 A

  An object of the present invention is to irradiate an irradiation target site with an appropriate amount of radiation and to reduce the irradiation dose to a region outside the irradiation target site, in accordance with the shape of the irradiation target site. It is an object of the present invention to provide a radiation irradiation apparatus that can irradiate radiation after setting a radiation irradiation region.

  Hereinafter, means for solving the problems will be described using the numbers and symbols used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers and symbols are added to clarify the correspondence between the description of [Claims] and the description of [Best Mode for Carrying Out the Invention]. It should not be used to interpret the technical scope of the invention described in “

  The radiation irradiation apparatus (100) according to the present invention is arranged on the X-ray emission direction side with respect to the radiation generation apparatus (2) that emits X-rays and adjusts the irradiation field of the emitted X-rays A multi-leaf collimator (8), an arrangement adjusting unit (11, 13) for adjusting the relative arrangement of the radiation generating apparatus with respect to the multi-leaf collimator, and a control unit (300) for controlling the operation of the position adjusting unit. It has.

  In the radiation irradiation apparatus (100), the arrangement adjusting unit adjusts the relative position of the radiation generating apparatus with respect to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening surface of the multi-leaf collimator. Part (11).

  In said radiation irradiation apparatus (100), an arrangement | positioning adjustment part has an angle adjustment part (13) which adjusts the relative angle of a radiation generator with respect to the opening surface of a multi-leaf collimator.

  In the radiation irradiation apparatus (100), the angle adjustment unit rotates the radiation generation apparatus around the first rotation axis and the second rotation axis that is perpendicular to the first rotation axis direction. A freely rotating mechanism (13) is provided.

  In said radiation irradiation apparatus (100), a position adjustment part moves a radiation irradiation apparatus to the direction parallel to the opening surface of the said multileaf collimator.

  The radiation irradiation apparatus (100) further includes a detector (6) that detects X-rays irradiated by the radiation irradiation apparatus. The control unit compares the symmetry of the intensity distribution of the X-rays detected by the detector with a predetermined symmetry allowable range. When the symmetry of the detected X-ray intensity distribution is not within the allowable range, the control unit drives the angle adjustment unit to adjust the angle between the radiation generation apparatus and the multi-leaf collimator. When the symmetry of the detected X-ray intensity distribution is within an allowable range, the control unit drives the position adjustment unit to adjust the relative position between the radiation generation apparatus and the multi-leaf collimator.

  In the radiation irradiation apparatus (100), when the symmetry of the detected X-ray intensity distribution is within an allowable range, the control unit determines that the intensity center of the X-ray intensity distribution is relative to the multi-leaf collimator. The position of the radiation generator is adjusted so as to be positioned on the central axis (8e) of the multi-leaf collimator which is the reference axis for alignment set in the above.

  In the radiation irradiation apparatus (100), the radiation generation apparatus is arranged in the traveling direction of the electron gun (2e) that generates the electron beam and the electron beam (2b) generated by the electron gun, and responds to the collision of the electron beam. And an X-ray target (2c) for generating X-rays. The arrangement adjusting unit includes an electron beam trajectory adjusting unit (200a, 200b) for adjusting the trajectory of the electron beam. The position and angle when the electron beam is incident on the X-ray target are adjusted by the electron beam trajectory adjusting unit.

In the radiation irradiation apparatus (100), the electron beam trajectory adjusting unit is a steering coil (200a, 200b).

  In the radiation irradiation apparatus (100), a gantry (1) to which the radiation generation apparatus is attached, and a gantry angle adjustment unit (16) for adjusting the angle between the gantry, the X-ray irradiation axis, and the multi-leaf collimator, It is preferable to comprise.

  The radiation irradiation apparatus (100) further includes a slit (15) having a rotationally symmetric opening and disposed concentrically with the central axis of the multi-leaf collimator. The detection unit detects X-rays that have passed through the slit.

  In the radiation irradiation apparatus (100), the slit is detachable. When the control unit compares the symmetry of the intensity distribution of X-rays with an allowable range with a predetermined symmetry, a single slit is attached. On the other hand, when the control unit drives the position adjusting unit to adjust the relative position between the radiation generating apparatus and the multi-leaf collimator, the plurality of slits (15A, 1B) are attached.

  A method for controlling a radiation irradiation apparatus according to the present invention includes: a radiation generation apparatus that emits X-rays; and an X-ray emission direction side of the radiation generation apparatus that is arranged and cuts and emits a part of the emitted X-rays A control method of a radiation irradiation apparatus comprising a multi-leaf collimator for adjusting a field. A positioning step (step S70) for adjusting the ground where the radiation generating apparatus is not relative to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening of the multi-leaf collimator.

  The above-described method for controlling the radiation irradiation apparatus further includes an angle adjustment step (step S70) for adjusting an angle formed by the radiation generation apparatus relative to the opening surface of the multi-leaf collimator.

  The radiation irradiation apparatus control method further includes a detection step (step S30) for detecting X-rays irradiated by the radiation irradiation apparatus, symmetry of the intensity distribution of the X-rays detected in the detection step, and a predetermined determination. A comparison step (step S40) for comparing the determined tolerance of symmetry. In the comparison step, when the symmetry of the detected X-ray intensity distribution is not within the allowable range, the angle adjustment step is performed. In the comparison step, when the symmetry of the detected X-ray intensity distribution is within an allowable range, the positioning step is performed.

  In the method of controlling the radiation irradiation apparatus, the radiation irradiation apparatus further includes a slit having a rotationally symmetric opening and arranged concentrically with the center of the opening of the multi-leaf collimator central axis. In the detection step, X-rays that have passed through the slit are detected.

  In the method of controlling the radiation irradiation apparatus, the slit is detachable. In the comparison step, a single slit is attached. In the positioning step, a plurality of the slits are attached.

  In the method of controlling a radiation irradiation apparatus, the radiation generation apparatus is further arranged in an advancing direction of an electron gun that generates an electron beam and an electron beam generated by the electron gun, and emits X-rays according to the collision of the electron beam. And an X-ray target to be generated. In the angle adjustment step, the position and angle when the electron beam is incident on the X-ray target are adjusted by adjusting the trajectory of the electron beam.

  The radiation irradiation apparatus control program according to the present invention is a computer-readable radiation irradiation apparatus control program for realizing the radiation irradiation apparatus control method.

  A radiation irradiation apparatus (100) according to the present invention includes a gantry (1), a mounting base disposed in the gantry, a radiation generating apparatus that is supported by the mounting base and emits X-rays toward the inside of the gantry. A multi-leaf collimator that is arranged on the X-ray emission direction side with respect to the radiation generator, cuts a part of the emitted X-rays to adjust the irradiation field, and is fixed to the radiation generator; A gantry, and a gantry angle adjustment unit (16) for adjusting an angle between the X-ray emission direction and the multi-leaf collimator.

  According to the present invention, it is possible to provide a radiation irradiation apparatus that can irradiate an irradiation target site with an appropriate amount of radiation and reduce the irradiation dose to a region outside the irradiation target site.

  The best mode for carrying out the radiation irradiation apparatus according to the present invention will be described below with reference to the accompanying drawings. In the following description, a case will be described as an example of a treatment apparatus that performs treatment by irradiating an affected area of a patient with X-rays as a radiation irradiation apparatus.

  The radiation irradiation apparatus according to the present invention realizes radiation irradiation to the affected area with the properties as previously determined by optimizing the correlation between the reference axis for setting the radiation irradiation region and the radiation irradiation axis.

(First embodiment)
FIG. 1 shows a schematic configuration of the radiation irradiation apparatus according to the first embodiment of the present invention, and FIG. 2 shows a sectional structure thereof. The radiation irradiation apparatus 100 of this embodiment includes a gantry 1, a therapeutic X-ray generation source 2 that is attached to the gantry 1 and emits therapeutic radiation, and a therapeutic X-ray generation source 2 of the gantry 1. A detector (FPD, CCD, MWPC, X-ray film, etc.) 6 for detecting X-rays emitted from the therapeutic X-ray generation source 2 attached to the opposite position, and attached to the gantry 1 for the patient's The diagnostic X-ray generation source 5 for acquiring a fluoroscopic image for confirming the position of an affected part (cancer lesion) in the body and the diagnostic X-ray generation source (X-ray tube) 5 of the gantry 1 are opposed to each other. A detector 4 that detects X-rays attached to the position and emitted from the diagnostic X-ray generation source 5 and a couch 7 that lays the patient down are provided. The gantry 1 has a circular frame shape. The couch 7 is arranged so that the patient P lies at a position passing through the center of the circular frame of the gantry 1. The gantry 1 is formed so as to rotate with a straight line passing through the therapeutic X-ray generation source, the center of the circle, and the detector as a rotation axis. A therapeutic X-ray generation source 2 that is attached to the gantry 1 and emits therapeutic radiation can rotate its X-ray irradiation axis about two axes as necessary to control the directivity angle. It has structure 3. The therapeutic X-ray generation source 2 is provided so as to be able to run on a circular frame of the gantry 1. Further, the radiation irradiation apparatus 100 according to the present embodiment has a computer (not shown) provided with a CPU and a storage unit, and the storage unit operates the radiation irradiation apparatus of the present embodiment. The radiation irradiation apparatus control program is stored in advance. Thereby, the radiation irradiation apparatus 100 according to the present embodiment performs the direction control of the X-ray irradiation axis emitted from the therapeutic X-ray generation source 2 and the position control of the couch 7 on which the patient is placed.

  In the radiation irradiation apparatus 100 according to the present embodiment, a system coordinate system with the isocenter as the origin is set. The isocenter described above is set at the intersection of an axis that passes through the center of the circle of the gantry 7 and is orthogonal to the plane of the circle and the pivot axis of the gantry 7, and the radiation axis of the therapeutic X-ray source 2 is used for diagnosis. The radiation axes from the X-ray generation source (X-ray tube) 5 are all set to intersect at one point at this isocenter. Prior to irradiation, the position of the couch 7 is adjusted so that the center of the affected area of the patient P is at the isocenter. The X-ray irradiation axis irradiated from the therapeutic X-ray generation source 2 is adjusted so as to pass through the isocenter.

  Further, in the present embodiment, in order to set a radiation irradiation region according to the affected part property and to reduce the radiation irradiation amount to the healthy tissue around the affected part, between the therapeutic X-ray generation source 2 and the affected part. A multi-leaf collimator (MLC) 8 is provided. A schematic configuration of the therapeutic X-ray generation source 2 and the multi-leaf collimator (MLC) 8 in the present embodiment is shown in FIG. In the therapeutic X-ray generation source 2, the electron beam 2 b emitted from the electron gun is accelerated while obtaining energy while passing through the electron beam accelerator 2 a, and is mechanically applied to the end of the electron beam accelerator 2 a. It collides with the connected X-ray target 2c. From the X-ray target 2c, X-rays 9 having the same irradiation axis as the electron beam are generated by bremsstrahlung, for example, based on the relationship between the electron beam incident direction and the X-ray emission angle distribution as shown in FIG. To do. As shown in FIG. 3, the X-ray 9 generated by the X-ray target 2 c is changed according to the affected part property by a multi-leaf collimator (MLC) 8 disposed between the therapeutic X-ray generation source 2 and the affected part. The irradiation area is limited. A flattening filter (not shown) may be provided between the multi-leaf collimator 8 and the X-ray target 2c. As shown in FIG. 4, when viewed from the irradiation axis direction, the multi-leaf collimator (MLC) 8 is opposed across a boundary line (line parallel to the Y axis 8c) passing through the center of gravity of the multi-leaf collimator (MLC) 8. In addition, a plurality of leaves 8a that can move independently are provided along the boundary line. Then, by moving each leaf 8a facing the boundary line, an opening 8b, which is an irradiation space having a shape corresponding to the affected part property, is formed between the therapeutic X-ray generation source 2 and the affected part. .

  Here, as shown in FIG. 6, when a deviation (θ) occurs in the installation angle of the electron gun in the therapeutic X-ray generation source 2, the electron beam 2 b strikes the X-ray target 2 c obliquely. The central axis of the X-ray generated by the bremsstrahlung from the X-ray target 2 c is inclined with respect to the X-ray detector 6. As a result, the X-ray intensity distribution on the X-ray detector 6 is not symmetric with respect to the irradiation axis. Therefore, the X-ray state that is actually irradiated to the affected area deviates from the desired state. In order to match the relative arrangement, an axis for axis alignment is virtually set in the multi-leaf collimator 8. In the following description, an axis that passes through the origin of the leaf movement plane (XY plane) (the center of gravity when the multi-leaf collimator opening is fully open) and is perpendicular to the leaf movement plane is used as the axis for alignment. (Hereinafter, referred to as the central axis of the multi-leaf collimator) will be described.

  In the radiation irradiation apparatus 100 according to the present embodiment, as shown in FIG. 7, the therapeutic X-ray generation source 2 and the multi-leaf collimator 8 are respectively attached to the circumferential position of the gantry 1 on the gantry. Can be moved at an arbitrary angle and can be fixed at an arbitrary position. In the radiation irradiation apparatus 100 according to the present embodiment, in particular, the therapeutic X-ray generation source 2 is fixed to the support base 12 via a rotation mechanism 13 having two rotation axes orthogonal to each other. Thereby, the directivity angle of the radiation emitted from the therapeutic X-ray generation source 2 can be controlled to an arbitrary angle with respect to the support base. Further, the therapeutic X-ray generation source 2 can be horizontally moved in two axial directions with respect to the support base 12 via the positioning mechanism 11 independently of the treatment X-ray generation source 2. The multi-leaf collimator 8 is fixed to the inside of the gantry 1 via a support base 12.

  In the radiation irradiation apparatus 100 according to the present embodiment, therapeutic X-ray generation is performed by adjusting the mounting angle and relative position of the therapeutic X-ray generation source 2 with respect to the support 12 by the rotation mechanism 13 and the positioning mechanism 11. It is possible to control the irradiation axis of the X-rays emitted from the source 2 and the central axis of the multi-leaf collimator 8 fixed to the support base 12 so that each axis is directed to the isocenter. As a result, when the X-ray irradiation axis and the central axis of the multi-leaf collimator, which are the problems of the prior art, are matched, the central axis of the electron beam accelerator 2a and the irradiation axis of the electron beam are used as therapeutic X-rays. An accurate X-ray irradiation axis cannot always be found due to the arrangement of each electrode and the like in the source 2 and distortion in the accelerating tube body. Therefore, the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 are made to coincide with each other with high accuracy. Can solve problems that can not be. Further, in the present embodiment, even if the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 are adjusted to coincide with each other at the initial stage, the mechanical structure shape and the combination arrangement due to its own weight are changed over time. Therefore, the conventional problem that cannot be ensured for a long period of time is defined as the X-ray irradiation axis of the therapeutic X-ray source 2 attached to the support 12 as the central axis of the multi-leaf collimator 8. The problem can be solved by adjusting them so that they coincide with each other and controlling each axis at an arbitrary time interval so that each axis is directed to the isocenter.

  As described above, in the present embodiment, in order to irradiate the affected part with an appropriate amount of radiation and to reduce the radiation dose to the healthy tissue around the affected part, a radiation irradiation region corresponding to the affected part property is set. In addition, a radiation irradiation apparatus that can irradiate the affected area with radiation can be provided.

(Operation principle of Embodiment 1)
Hereinafter, the operation flow of the present embodiment will be described with reference to FIG. When the radiation irradiation apparatus according to the present embodiment is activated, the CPU of the computer provided in the radiation irradiation apparatus 100 according to the present embodiment reads and executes a radiation irradiation apparatus control program stored in advance in the storage unit. When the radiation irradiation apparatus control program is executed, the CPU irradiates the affected area with an appropriate amount of radiation, sets a radiation irradiation area according to the affected area properties, and applies the radiation dose to the surrounding healthy tissue. In order to reduce this, the X-ray irradiation axis and the central axis of the multi-leaf collimator are adjusted to be the same by the following method.

  First, the leaves facing each other across the boundary line of the multi-leaf collimator (MLC) 8 fixed to the support base 12 are moved so that the opening is fully opened (step S10). Next, X-rays for adjusting the X-ray irradiation axis and the central axis of the multi-leaf collimator to be the same are emitted (step S20). Then, the X-ray intensity distribution is measured by the detector 6 (step S30). Based on the evaluation result of step S30, it is determined whether or not the X-ray intensity distribution has acceptable symmetry (step S40). In step S40, when it is determined that the direction of the current X-ray irradiation axis is not within the allowable range, the driving unit provided in the rotation mechanism 13 is driven to generate the therapeutic X-ray generation source for the support 12 2 is adjusted, and the direction of the X-ray irradiation axis of the therapeutic X-ray generation source 2 is reset so as to be within an allowable range (step S60). On the other hand, when it is determined that the direction of the current X-ray irradiation axis is within the allowable range, the X-ray irradiation axis of the therapeutic X-ray generation source 2 attached to the support 12 and the central axis of the multileaf collimator 8 are used. It is determined whether or not the deviation of the relative position of the axis directed to the isocenter is within a predetermined allowable range (step S50). If it is determined in step S50 that the relative positional deviation between the X-ray irradiation axis of the current therapeutic X-ray generation source 2 and the central axis of the multi-leaf collimator 8 is not within the allowable range, the X-ray irradiation axis is fixed to the support base 12. The therapeutic X-ray generation source 2 is adjusted in the biaxial direction with respect to the support base by driving a driving unit provided in the positioning mechanism 11, whereby the X-ray irradiation axis and the center of the multi-leaf collimator 8 are adjusted. The deviation of the relative position with respect to the shaft is reset so as to be within the allowable range (step S70). On the other hand, if it is determined that the relative positional deviation between the X-ray irradiation axis of the current therapeutic X-ray generation source 2 and the central axis of the multi-leaf collimator 8 is within an allowable range, the therapeutic X-ray generation source 2 A series of operations for directing to the isocenter between the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 ends. After this operation is completed, by moving each leaf 8a facing the boundary line, an opening which is an irradiation space having a shape corresponding to the affected part property between the therapeutic X-ray generation source and the patient 8b is formed, and radiotherapy based on the treatment plan is started. When moving each leaf 8a, the center of gravity of the leaf movement plane (XY plane) may be used as the origin, and the amount of movement of the leaf 8a may be determined using this origin as a reference, or the leaf movement plane (XY plane). The movement amount of the leaf 8a may be determined using a point other than the center of gravity of the origin as the origin.

  In this way, the X-ray irradiation axis and the central axis of the multi-leaf collimator can be accurately matched by the radiation irradiation apparatus 100 according to the present embodiment. Even if the X-ray irradiation axis and the central axis of the multi-leaf collimator are adjusted so as to coincide with each other at the initial stage, the mechanical structure shape and combination arrangement due to its own weight change over time. Although the equivalence could not be maintained, according to this embodiment, it is possible to always keep both axes accurately aligned by appropriately controlling the directions of both axes based on the calibration results performed at arbitrary time intervals. . Thereby, irradiation conditions can be set based on a treatment plan, and an appropriate treatment effect can always be obtained for the affected area.

  In the present embodiment, the case where the axis is aligned by shifting the therapeutic X-ray generation source by the positioning mechanism 11 after adjusting the angle by the rotation mechanism 13 has been described. The position of the opening of the multi-leaf collimator may be adjusted by correcting the movement amount of each 8a. Even in this case, the relative arrangement of the X-ray irradiation axis and the opening of the multi-leaf collimator can be in a desired relationship. In this case, since the positioning mechanism 11 is not required, the size and weight are reduced, and further cost reduction is achieved.

  In addition, when a flattening filter is used between the multi-leaf collimator 8 and the X-ray target 2c, the intensity distribution of the X-ray 9 does not have a steep peak like a Gaussian distribution. It has a gradient that can be evaluated.

(Embodiment 2)
FIG. 9 shows a schematic configuration of the radiation irradiation apparatus according to the second embodiment of the present invention. The basic configuration of radiation therapy according to the present embodiment is the same as that of the first embodiment. However, the radiation irradiating apparatus according to the present embodiment further includes a slit 15 between the multi-leaf collimator 8 and the affected part to be irradiated with the patient. The slit 15 provided in the present embodiment has a rotationally symmetric shape by physically shielding the irradiation region of the radiation beam, and the irradiation line whose irradiation region is narrowed by the multi-leaf collimator 8 is provided. Cut stray light components.

  In the present embodiment, the slit 15 is not configured as a single sheet, but may be configured as a plurality of structures such as a two-sheet structure as shown in FIG. For example, when the slit has two slits of slit 1 (15A) and slit 2 (15B), the X-ray intensity distribution can be corrected even when it is shifted from symmetry (see FIG. 11). Weight can be reduced.

  As described above, according to the present embodiment, in addition to the operational effects shown in the first embodiment, the affected area is irradiated with an appropriate amount of radiation controlled with higher accuracy and the radiation to the healthy tissue around the affected area. The irradiation dose can be reduced.

(Operation Principle of Embodiment 2)
Based on the operation flow shown in FIG. 12, the operation principle of the radiation irradiation apparatus according to the present embodiment will be described. The basic principle of the operation according to the present embodiment is the same as that in the first embodiment. However, in this Embodiment, the process of attaching the slit 15 further between the multileaf collimator 8 and the affected part of the patient used as irradiation object is added.

  When the radiation irradiation apparatus according to the present embodiment is activated, the CPU of the computer provided in the radiation irradiation apparatus according to the present embodiment reads and executes the radiation irradiation apparatus control program stored in advance in the storage unit. When the radiation irradiation apparatus control program is executed, the CPU irradiates the affected area with an appropriate amount of radiation, sets a radiation irradiation area according to the affected area properties, and applies the radiation dose to the surrounding healthy tissue. In order to reduce this, the X-ray irradiation axis and the central axis of the multi-leaf collimator are adjusted to be the same by the following method.

  First, the slit 15 is automatically or manually attached between the multi-leaf collimator and the affected part of the patient to be irradiated. And the leaf which opposes on both sides of the boundary line of a multileaf collimator is moved, respectively, and an opening part is made into a fully open form (step S100). Next, X-rays for causing the X-ray irradiation axis to coincide with the central axis of the multi-leaf collimator are emitted from the therapeutic X-ray generation source 2 (step S20). Then, the X-ray intensity distribution is measured by the detector 6 (step S30). Based on the evaluation result of step S30, it is determined whether or not the X-ray intensity distribution has acceptable symmetry (step S40). In step S40, when it is determined that the direction of the current X-ray irradiation axis is not within the allowable range, the driving unit provided in the rotation mechanism 13 is driven and the support base 12 is treated with the therapeutic X-ray. The attachment angle of the generation source 2 is adjusted, and the direction of the X-ray irradiation axis of the therapeutic X-ray generation source 2 is reset (step S60). On the other hand, when it is determined that the direction of the current X-ray irradiation axis is within the allowable range, the X-ray irradiation axis of the therapeutic X-ray generation source 2 attached to the support 12 and the central axis of the multileaf collimator 8 are used. It is determined whether or not the deviation of the relative position of the axis directed to the isocenter is within a predetermined allowable range (step S50). If it is determined in step S50 that the relative positional deviation between the X-ray irradiation axis of the current therapeutic X-ray generation source 2 and the central axis of the multi-leaf collimator 8 is not within the allowable range, the X-ray irradiation axis is fixed to the support base 12. The therapeutic X-ray generation source 2 is adjusted in the biaxial direction with respect to the support base by driving a driving unit provided in the positioning mechanism 11, whereby the X-ray irradiation axis and the center of the multi-leaf collimator 8 are adjusted. The deviation of the relative position with respect to the shaft is reset so as to be within the allowable range (step S70). On the other hand, if it is determined that the relative positional deviation between the X-ray irradiation axis of the current therapeutic X-ray generation source 2 and the central axis of the multi-leaf collimator 8 is within an allowable range, the therapeutic X-ray generation source 2 A series of operations for directing to the isocenter between the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 ends. After this operation is finished, each of the leaves 8a facing the boundary line is one-dimensionally taken in and out, so that an irradiation space having a shape corresponding to the affected part property between the therapeutic X-ray generation source and the patient. Is formed, and radiation therapy based on the treatment plan is started.

  Thus, in addition to the effects shown in the first embodiment, the radiation irradiation apparatus according to the present embodiment irradiates the affected area with an appropriate amount of radiation controlled with higher accuracy, and the affected area is healthy. It is possible to reduce the radiation dose to the tissue. This is because there is a limit due to mechanical accuracy (eg, gear pitch) in positioning of the irradiation region of the irradiation beam by the multi-leaf collimator, and it is not possible to obtain alignment accuracy of a certain degree (several hundreds μm order) or more. However, by installing a rotationally symmetric aperture (slit in the present embodiment) corresponding to the opening of the multi-leaf collimator separately, the same correspondence can be achieved with machining accuracy (on the order of several μm).

(Embodiment 3)
The schematic configuration of the radiation irradiation apparatus according to the present embodiment is the same as that in the second embodiment. However, in the present embodiment, when adjusting the mounting angle of the therapeutic X-ray generation source 2 supported by the support base 12 with respect to the support base 12, a single slit 15 is provided. When the horizontal position with respect to 12 is adjusted, two slits 15A and 15B are provided.

(Operational principle of Embodiment 3)
The operation principle of the radiation irradiation apparatus according to this embodiment will be described based on the operation flow shown in FIG. When the radiation irradiation apparatus according to the present embodiment is activated, the CPU of the computer reads and executes the radiation irradiation apparatus control program stored in advance in the storage unit, as in the first and second embodiments. When the radiation irradiation apparatus control program is executed, the CPU irradiates the affected area with an appropriate amount of radiation, sets a radiation irradiation area according to the affected area properties, and applies the radiation dose to the surrounding healthy tissue. In order to reduce this, the X-ray irradiation axis and the central axis of the multi-leaf collimator are adjusted to be the same by the following method.

  First, each opposing leaf is moved across the boundary line of the multi-leaf collimator so that the opening is fully opened (step S200), or between the multi-leaf collimator and the affected area of the patient to be irradiated, One of the steps is selected, in which one slit 15 is attached automatically or manually, and then the opening of the multi-leaf collimator is fully opened (step S210). Next, X-rays for adjusting the X-ray irradiation axis and the central axis of the multi-leaf collimator to be the same are emitted (step S220). Then, the X-ray intensity distribution is measured by the detector 6 (step S230). Based on the evaluation result of step S230, it is determined whether or not the X-ray intensity distribution has acceptable symmetry (step S240). In step S240, when it is determined that the direction of the current X-ray irradiation axis is not within the allowable range, the driving unit provided in the rotation mechanism 13 is driven to generate the therapeutic X-ray generation source for the support base 12. 2 is adjusted, and the direction of the X-ray irradiation axis of the therapeutic X-ray generation source 2 is set again within an allowable range (step S300). On the other hand, when it is determined that the direction of the current X-ray irradiation axis is within the allowable range, the X-ray irradiation is stopped (step S250). Then, the single-slit slit 15 attached between the multi-leaf collimator and the affected part of the patient to be irradiated is removed, and a multi-stage slit (here, the two-slit slit 1 (in this case, the two-slit slit ( 15A) and slit 2 (15B)) are attached (step S260). When the attachment of the multi-stage slit is completed, X-rays are emitted again from the therapeutic X-ray generation source 2 (step S270). Then, the detector 6 detects the X-ray intensity distribution (step S280). Based on the intensity distribution data of the X-ray detected by the detector 6, it is evaluated whether or not the intensity distribution has the maximum intensity (step S290). In step S290, the current X-ray generation source for treatment is used. 2, when it is determined that the intensity distribution of the X-rays emitted from 2 is not the maximum, the therapeutic X-ray generation source 2 fixed to the support 12 is driven by the drive unit provided in the positioning mechanism 11. The position is adjusted in two axial directions that are horizontal with respect to the support base, and thus the intensity distribution of the X-rays emitted from the therapeutic X-ray generation source 2 is reset so as to be maximized on the detection surface of the detector 6. (Step S310). On the other hand, when it is determined that the intensity distribution of the X-rays emitted from the current therapeutic X-ray generation source 2 is the maximum, the X-ray irradiation axis of the therapeutic X-ray generation source 2 and the center of the multi-leaf collimator 8 A series of operations for matching the axis ends. After this operation is finished, each of the leaves 8a facing the boundary line is one-dimensionally taken in and out, so that an irradiation space having a shape corresponding to the affected part property between the therapeutic X-ray generation source and the patient. Is formed, and radiation therapy based on the treatment plan is started.

  In the present embodiment, when the X-ray intensity in the detector 6 is evaluated, the two small-diameter slits 15A and 15B are installed so as to be perpendicular to the concentric axes. The thickness and material of each of the slits shall reduce X-rays by a significant amount or more compared to the inside of the slit opening. In the present embodiment, the intensity of X-rays emitted through two slits that are emitted from X-rays and parallel with a concentric axis (which is already parallel to the X-ray axis and coincides with the central axis of the multi-leaf collimator). By adjusting the position of the X-ray generator so that the value becomes the largest, the X-ray axis and the central axis of the multi-leaf collimator are matched. In particular, the second embodiment is based on the premise that absolute coordinates are obtained for the X-rays detected by the X-ray detector 6. However, in reality, it may not always be easy to obtain an accuracy of about several hundred μm. On the other hand, in the present embodiment, by using the above simple method of installing two slits, it is possible to carry out the adjustment for matching both axes with high accuracy.

(Embodiment 4)
FIG. 14 shows a schematic configuration of the therapeutic X-ray generator 2 and the multileaf collimator 8 of the radiation irradiation apparatus according to the fourth embodiment of the present invention. The basic configuration of the radiation irradiation apparatus according to this embodiment is the same as that shown in the first to third embodiments. However, in this embodiment, the rotation mechanism 13 and the positioning mechanism 11 provided in the first to third embodiments are not provided, but instead, a magnetic field is generated to generate electrons in the therapeutic X-ray generation source 2. Two sets of steering coils 200a and 200b capable of controlling the traveling direction of the beam are provided. In the present embodiment, the relative position of the multi-leaf collimator is fixed with respect to the therapeutic X-ray generator 2.

  In the present embodiment, as shown in FIG. 14, the two sets of steering coils 200a and 200b are arranged so as to generate magnetic fields perpendicular to the traveling direction of the electron beams. The By passing a direct current through the two sets of steering coils 200a and 200b, the two sets of steering coils 200a and 200b are approximately perpendicular to the traveling direction of the electron beam and in two orthogonal directions (Bx and Bx in FIG. 15). A magnetic field is generated in each (By direction). And the intensity | strength and direction of a magnetic field of Bx and By direction are changed by adjusting the electric current amount and electric current direction which flow through each coil. Thereby, by applying a deflection based on the Lorentz force to the trajectory of the electron beam, the incident angle and relative position of the electron beam to the X-ray target are controlled.

  In the present embodiment, adjustment of the relative position between the electron beam and the X-ray target is not mechanically performed, but a magnetic field that can be controlled in two orthogonal directions perpendicular to the traveling direction of the electron beam is used. By doing so, the angle of the X-ray irradiation axis bremsstrahlung from the X-ray target and the relative position between the X-ray irradiation axis and the central axis of the multi-leaf collimator are optimized. This eliminates the need for the rotation mechanism 13 and the positioning mechanism 11 that are provided for adjusting the swing angle of the therapeutic X-ray generation source 2 and the horizontal relative position with respect to the support base 12.

  In the present embodiment, an explanation has been given of controlling the incident angle and relative position of the electron beam to the X-ray target based on the two sets of steering coils 200a and 200b. You may control finely with the above. Moreover, you may arrange | position facing the side surface of any position in the advancing path | route of an electron beam. Furthermore, the steering coil is not limited to a single-stage type, but may be a multi-stage type along the traveling path of the electron beam. Further, although the steering coil is exemplified for deflecting the electron beam, the arrangement is not limited to the steering coil as long as it has a function capable of generating a similar magnetic field. Further, the rotation mechanism 13 and the positioning mechanism 11 provided for adjusting the swing angle of the therapeutic X-ray generation source 2 and the horizontal relative position with respect to the support base 12 may be used together.

  The present embodiment is applicable to all of the first to third embodiments. According to the present embodiment, as described above, the rotation mechanism 13 and the positioning mechanism 11 are not required, and in addition to the functions and effects described in the first to third embodiments, the components are simplified, that is, the product is lightweight. And reduction of manufacturing cost.

(Embodiment 5)
FIG. 16 shows a schematic configuration of the therapeutic X-ray generator 2 and the multi-leaf collimator 8 of the radiation irradiation apparatus according to the fifth embodiment of the present invention. The basic configuration of the radiation irradiation apparatus according to this embodiment is the same as that shown in the first embodiment. However, in the present embodiment, the arrangement of the multi-leaf collimator 8 and the therapeutic X-ray generator 2 is relatively fixed by the fixing member 16. The relative arrangement of the fixed body (multi-leaf collimator 8 and therapeutic X-ray generator 2) and the gantry 1 is adjusted by the rotation mechanism 16. That is, the rotation mechanism 16 does not adjust the angle between the multi-leaf collimator 8 and the therapeutic X-ray generator, but adjusts the angle of the fixed body with respect to the gantry 1. Further, similarly to the fourth embodiment, steering coils 200a and 200b are added. The relative arrangement (angle and position) between the X-ray irradiation axis and the multi-leaf collimator 8 is adjusted by the steering coils 200a and 200b.

(Operational principle of Embodiment 5)
The operation principle of the radiation irradiation apparatus according to the present embodiment will be described based on the operation flow shown in FIG. The basic principle of the operation related to the present embodiment is the same as that in the first embodiment. However, in the present embodiment, a step of evaluating the setting of the steering coil (step S01) and a step of determining whether or not the adjustment is possible by adjusting the mounting angle (step S45) are added.

  First, before the steering coils 200a and 200b are attached to the gantry 1, the steering coils 200a and 200b are evaluated. In this evaluation, when the incident angle and position of the electron beam have already shifted when no current is flowing through the steering coil, it is necessary to obtain the amount of current necessary to correct this shift. Done. A steering coil correction value is calculated based on the evaluation result. Then, the steering coils 200a and 200b are mounted on the gantry 1 based on the steering coil correction value. The steering coil may be evaluated after being mounted on the gantry.

  Subsequently, as in the first embodiment, the multi-leaf collimator 8 is fully opened (step S10). Further, X-rays are emitted (step S20). The emitted X-ray is detected, and the intensity distribution of the X-ray is measured (step S30). Based on the evaluation result of step S30, the symmetry of the X-ray intensity distribution is evaluated (step S40).

  In step S40, if the symmetry is out of the allowable range, it is determined whether or not the adjustment is possible by adjusting the angle (step S45). If it is determined that the adjustment is not possible by adjusting the angle, the process returns to step S01 again, and the setting evaluation of the steering coil is performed. On the other hand, if it is determined that adjustment is possible by adjusting the angle, the incident angle of the electron beam to the X-ray target is adjusted by the steering coil (step S60). Then, the evaluation of the intensity distribution in step S30 is performed again.

  If the symmetry is within the allowable range in step S40, it is determined whether the deviation between the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 is within the allowable range (step S50). If it is determined in step S50 that it is outside the allowable range, the incident position of the electron beam on the X-ray target is adjusted by the steering coil, and the relative position shift between the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 is adjusted. Is reset within the allowable range (step S70). After the resetting, the process returns to step S30 again, and the X-ray intensity distribution is evaluated. On the other hand, if it is determined in step S50 that it is within the allowable range, a series of operations relating to the axis alignment between the X-ray irradiation axis and the central axis of the multi-leaf collimator 8 is completed.

  As described above, according to the present embodiment, the rotation mechanism 16 adjusts the relative arrangement of the fixed object of the multi-leaf collimator 8 and the therapeutic X-ray generator 2 with respect to the gantry 1. Therefore, even if the gantry 1 itself is deformed by the weight of the device, the X-ray irradiation axis can be directed to the isocenter. The relative arrangement relationship (angle and position) between the central axis of the multi-leaf collimator 8 and the X-ray irradiation axis is adjusted by the steering coils 200a and 200b. Therefore, after adjusting the relative arrangement of the fixed body (multi-leaf collimator and therapeutic X-ray generator) with respect to the gantry 1, the relative arrangement between the multi-leaf collimator 8 and the therapeutic X-ray generator 2 is further adjusted. Can do.

  In adjusting the relative arrangement (angle and position) between the multi-leaf collimator 8 and the X-ray irradiation axis, the rotation mechanism 13 and the positioning mechanism 11 may be used instead of the steering coils 200a and 200b. If the relative arrangement (angle and position) of the therapeutic X-ray generator with respect to the multi-leaf collimator 8 is adjusted by another rotating mechanism 13 and positioning mechanism 11, the same effects as when the steering coil is used can be obtained. It is obvious to those skilled in the art.

  Further, instead of the steering coils 200a and 200b, the relative arrangement of the X-ray target and the electron beam accelerator may be variable. Such a configuration can be performed, for example, by connecting the X-ray target and the electron beam accelerator with a flexible material. By adjusting the relative arrangement of the X-ray target and the electron beam accelerator, the X-ray irradiation axis is the same as when the above-described steering coil 200a is used or when another rotating mechanism 13 and positioning mechanism 11 are provided. Can coincide with the central axis of the multi-leaf collimator.

(Embodiment 6)
FIG. 18 shows a schematic configuration of the therapeutic X-ray generator 2 and the multileaf collimator 8 of the radiation irradiation apparatus according to the sixth embodiment of the present invention. The basic configuration of the radiation irradiation apparatus according to this embodiment is the same as that shown in the first to third embodiments. However, in the present embodiment, the multi-leaf collimator 8 is relatively fixed to the therapeutic X-ray generator 2 by the fixing member 16.

  Since the multi-leaf collimator 8 is fixed to the therapeutic X-ray generator 2, when the rotation mechanism 16 is driven, the angle between the fixed body (the therapeutic X-ray generator 2 and the multi-leaf collimator 8) and the gantry 1 is changed. Adjusted.

  Since a large number of devices are fixed to the gantry 1, a burden due to the weight of the devices is applied. According to the present embodiment, since the angle of the fixed body with respect to the gantry-1 is adjusted, even if the gantry 1 itself is deformed due to the weight of the device, the X-ray irradiation axis can be directed to the isocenter.

It is a figure which shows schematic structure of the radiation irradiation apparatus concerning embodiment of this invention. It is a figure which shows the cross section of the radiation irradiation apparatus concerning embodiment of this invention. It is a figure which shows schematic structure of the X-ray generation source for treatment and the multileaf collimator of the radiation irradiation apparatus concerning embodiment of this invention. It is a figure which shows an example of the opening form of the multileaf collimator of the radiation irradiation apparatus concerning embodiment of this invention. It is a figure which shows the relationship between the electron beam incident direction and X-ray emission angle distribution in the therapeutic X-ray generation source of the radiation irradiation apparatus concerning embodiment of this invention. It is a figure which shows the relationship between the deviation | shift amount of the electron beam incident angle in the therapeutic X-ray generation source of the radiation irradiation apparatus concerning embodiment of this invention, and the X-ray intensity distribution on the X-ray detector in connection with it. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 1, and a multileaf collimator. FIG. 3 is a diagram illustrating an operation flow of the radiation irradiation apparatus according to the first embodiment. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 2, and a multileaf collimator. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 2, and a multileaf collimator. It is a figure which shows the relationship between the electron beam irradiation position shift | offset | difference in the therapeutic X-ray generation source of the radiation irradiation apparatus concerning Embodiment 2, and the X-ray intensity distribution on the X-ray detector in connection with it. FIG. 10 is a diagram illustrating an operation flow of the radiation irradiation apparatus according to the second embodiment. FIG. 10 is a diagram illustrating an operation flow of the radiation irradiation apparatus according to the third embodiment. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 4, and a multileaf collimator. It is the figure which looked at an example of the arrangement | positioning form of the coil in FIG. 14 from the emission direction of the electron beam. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 5, and a multileaf collimator. FIG. 10 is a diagram illustrating an operation flow of the radiation irradiation apparatus according to the fifth embodiment. It is a figure which shows schematic structure of the X-ray generation source for treatment of the radiation irradiation apparatus concerning Embodiment 6, and a multileaf collimator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gantry 2 ... Treatment X-ray generation source 2a ... Electron beam accelerator 2b ... Electron beam 2c ... X-ray target 2d ... X-ray center axis 2e ... Electron gun 3 ... Gimbal structure 4 ... Detector 5 ... Diagnostic X-ray Source 6 ... X-ray detector 7 ... Couch 8 ... Multi-leaf collimator (MLC)
8a ... Leaf 8b ... Opening 8c ... Y-axis (boundary line)
8d ... X-axis 8e ... Multi-leaf collimator central axis 9 ... X-ray 10 ... Utilizing line cone 11 ... Positioning mechanism 12 ... Support base 13 ... Rotating mechanism 14 ... Collimator 15 ... Slit 15A ... Slit 1
15B ... Slit 2
16 ... Rotating mechanism 100 ... Radiation irradiation apparatus 200a ... Coil A
200b ... Coil B
300 ... Computer

Claims (19)

A radiation generator for emitting X-rays;
A multi-leaf collimator which is arranged on the X-ray emission direction side with respect to the radiation generating device and adjusts an irradiation field by cutting a part of the emitted X-ray;
An arrangement adjusting unit for adjusting the relative arrangement of the radiation generating apparatus with respect to the multi-leaf collimator;
A control unit for controlling the operation of the arrangement adjusting unit;
Equipped with,
The arrangement adjusting unit has an angle adjusting unit that adjusts a relative angle of the radiation generating device with respect to an opening surface of the multi-leaf collimator,
The angle adjustment unit includes a rotation mechanism that allows the radiation generator to rotate around a first rotation axis and a second rotation axis that is perpendicular to the first rotation axis direction. and has <br/> irradiation apparatus. The radiation irradiation apparatus according to claim 1,
The arrangement adjusting unit is
A position adjusting unit that adjusts the relative position of the radiation generating device with respect to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening surface of the multi-leaf collimator;
Irradiation apparatus having a. The radiation irradiation apparatus according to claim 1 or 2 ,
The said position adjustment part is a radiation irradiation apparatus which moves the said radiation irradiation apparatus to the direction parallel to the opening surface of the said multileaf collimator. The radiation irradiation apparatus according to any one of claims 1 to 3 ,
Furthermore,
Comprising a detector for detecting X-rays irradiated by the radiation generator ;
The controller is
Comparing the symmetry of the intensity distribution of the X-rays detected by the detector with a predetermined tolerance of symmetry,
If the symmetry of the detected X-ray intensity distribution is not within an allowable range, the angle adjustment unit is driven to adjust the angle between the radiation generator and the multi-leaf collimator,
A radiation irradiation apparatus that drives the position adjustment unit to adjust the relative position between the radiation generation apparatus and the multi-leaf collimator when the symmetry of the detected X-ray intensity distribution is within an allowable range. . The radiation irradiation apparatus according to claim 4 ,
The controller is
When the symmetry of the detected X-ray intensity distribution is within an allowable range, the intensity center of the X-ray intensity distribution is a multi-axis alignment reference axis set for the multi-leaf collimator. A radiation irradiation apparatus for adjusting a position of the radiation generation apparatus so as to be positioned on a central axis of a leaf collimator. The radiation irradiation apparatus according to claim 1,
The radiation generator is
An electron gun that generates an electron beam;
An X-ray target arranged in the traveling direction of the electron beam generated by the electron gun and generating X-rays in response to the collision of the electron beam;
Have
The arrangement adjusting unit is
An electron beam trajectory adjusting unit for adjusting the trajectory of the electron beam;
Have
A radiation irradiation apparatus in which a position and an angle when the electron beam is incident on the X-ray target are adjusted by the electron beam trajectory adjusting unit. The radiation irradiation apparatus according to claim 6 ,
The electron beam trajectory adjustment unit is a radiation irradiation device that is a steering coil. The radiation irradiation apparatus according to any one of claims 1 to 7 ,
Furthermore,
A gantry to which the radiation generator is attached;
A radiation irradiation apparatus comprising a gantry angle adjusting unit that adjusts an angle between the gantry and the X-ray emission direction and the multi-leaf collimator. The radiation irradiation apparatus according to any one of claims 1 to 8 ,
Furthermore,
A slit having a rotationally symmetric opening and arranged concentrically with the central axis of the multi-leaf collimator;
The said detection part is a radiation irradiation apparatus which detects the X-ray which passed the said slit. The radiation irradiation apparatus according to claim 9 ,
The slit is detachable,
When the control unit compares the symmetry of the intensity distribution of the X-rays with a predetermined allowable range of symmetry, a single slit is attached,
A radiation irradiation apparatus to which a plurality of slits are attached when the control unit drives the position adjustment unit to adjust the relative position between the radiation generation device and the multi-leaf collimator.   A radiation generator for emitting X-rays;
  A multi-leaf collimator which is arranged on the X-ray emission direction side with respect to the radiation generating device and adjusts an irradiation field by cutting a part of the emitted X-ray;
  An arrangement adjusting unit for adjusting the relative arrangement of the radiation generating apparatus with respect to the multi-leaf collimator;
  A control unit for controlling the operation of the arrangement adjusting unit;
  A detector for detecting X-rays irradiated by the radiation generator;
Comprising
  The arrangement adjusting unit has an angle adjusting unit that adjusts a relative angle of the radiation generating device with respect to an opening surface of the multi-leaf collimator,
  The controller is
    Comparing the symmetry of the intensity distribution of the X-rays detected by the detector with a predetermined tolerance of symmetry,
    If the symmetry of the detected X-ray intensity distribution is not within an allowable range, the angle adjustment unit is driven to adjust the angle between the radiation generator and the multi-leaf collimator,
    When the symmetry of the detected X-ray intensity distribution is within an allowable range, the relative position between the radiation generator and the multi-leaf collimator is adjusted by driving the position adjusting unit.
Radiation irradiation device.   A radiation generator for emitting X-rays;
  A multi-leaf collimator which is arranged on the X-ray emission direction side with respect to the radiation generating device and adjusts an irradiation field by cutting a part of the emitted X-ray;
  An arrangement adjusting unit for adjusting the relative arrangement of the radiation generating apparatus with respect to the multi-leaf collimator;
  A control unit for controlling the operation of the arrangement adjusting unit;
  A slit having a rotationally symmetric opening and arranged concentrically with the central axis of the multi-leaf collimator;
  A detector for detecting X-rays irradiated by the radiation irradiation device and passed through the slit;
  The arrangement adjustment unit has a position adjustment unit that adjusts the relative position of the radiation generating device with respect to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening surface of the multi-leaf collimator,
  The slit is detachable,
  When the control unit compares the symmetry of the intensity distribution of the X-rays with a predetermined allowable range of symmetry, a single slit is attached,
  A radiation irradiation apparatus to which a plurality of slits are attached when the control unit drives the position adjustment unit to adjust the relative position between the radiation generation device and the multi-leaf collimator. A radiation irradiation apparatus control method comprising: a radiation generator that emits X-rays; and a multi-leaf collimator that adjusts an irradiation field of X-rays emitted from the radiation generator;
An angle adjustment step of adjusting an angle formed by the radiation generator relative to the opening surface of the multi-leaf collimator relative to the first rotation axis;
An angle adjusting step of adjusting an angle of the radiation generating device relative to a second rotation axis which is a direction perpendicular to the first rotation axis with respect to an opening surface of the multi-leaf collimator.
Method for controlling radiation irradiation apparatus
The control program of the radiation irradiation apparatus which can be read by the computer for implement | achieving. A control program of the irradiation apparatus according to claim 1 3,
The method for controlling the radiation irradiation apparatus further includes:
A detection step of detecting X-rays irradiated by the radiation irradiation device;
A comparison step of comparing the symmetry of the intensity distribution of the X-rays detected in the detection step with a predetermined symmetry tolerance;
Comprising
In the comparison step, when the symmetry of the detected X-ray intensity distribution is not within an allowable range, the angle adjustment step is performed.
In the comparison step, when the symmetry of the detected X-ray intensity distribution is within an allowable range, a control program for a radiation irradiation apparatus that performs the positioning step. A control program of the irradiation device according to any one of claims 13 to 1 4,
The radiation irradiation apparatus further includes a slit having a rotationally symmetric opening and arranged concentrically with the opening center of the multi-leaf collimator central axis ,
A control program for a radiation irradiation apparatus in which X-rays that have passed through the slit are detected in the detection step. A control program for a radiation irradiation apparatus according to claim 15 ,
The slit is detachable,
In the comparison step, a single slit is attached,
In the positioning step, a control program for a radiation irradiation apparatus to which a plurality of the slits are attached.   A radiation irradiation apparatus control method comprising: a radiation generator that emits X-rays; and a multi-leaf collimator that adjusts an irradiation field of X-rays emitted from the radiation generator;
  A positioning step of adjusting the relative position of the radiation generating device with respect to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening surface of the multi-leaf collimator;
  A detection step of detecting X-rays irradiated by the radiation irradiation device;
  A comparison step of comparing the symmetry of the intensity distribution of the X-rays detected in the detection step with a predetermined tolerance of symmetry,
  In the comparison step, when the symmetry of the detected X-ray intensity distribution is not within an allowable range, the angle adjustment step is performed.
  In the comparison step, when the symmetry of the detected X-ray intensity distribution is within an allowable range, the positioning step is performed.
Method for controlling radiation irradiation apparatus
  The control program of the radiation irradiation apparatus which can be read by the computer for implement | achieving.   A radiation generator for emitting X-rays;
  A multi-leaf collimator for adjusting the irradiation field of the X-rays emitted from the radiation generator;
  A slit having a rotationally symmetric opening and arranged concentrically with the opening center of the central axis of the multi-leaf collimator;
  A method for controlling a radiation irradiation apparatus comprising:
  A positioning step of adjusting the relative position of the radiation generating device with respect to the opening of the multi-leaf collimator by shifting in a direction parallel to the opening surface of the multi-leaf collimator;
  A detection step of detecting X-rays irradiated by the radiation irradiation device;
  A comparison step of comparing the symmetry of the intensity distribution of the X-rays detected in the detection step with a predetermined tolerance of symmetry,
  In the detection step, X-rays passing through the slit are detected,
  The slit is detachable,
  In the comparison step, a single slit is attached,
  In the positioning step, a plurality of the slits are attached.
Method for controlling radiation irradiation apparatus
  The control program of the radiation irradiation apparatus which can be read by the computer for implement | achieving. A control program for a radiation irradiation apparatus according to any one of claims 13 to 18 ,
The radiation generator further includes an electron gun that generates an electron beam, and an X-ray target that is disposed in a traveling direction of the electron beam generated by the electron gun and generates an X-ray in response to the collision of the electron beam. Have
In the angle adjustment step,
A control program for a radiation irradiation apparatus, wherein a position and an angle when the electron beam is incident on the X-ray target are adjusted by adjusting a trajectory of the electron beam .

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