JP4834315B2 - Radiation diaphragm device and radiotherapy apparatus having the diaphragm device - Google Patents

Description

  The present invention relates to a radiation diaphragm device capable of arbitrarily changing a radiation diaphragm range by a diaphragm body, and a technique for supporting return to origin of the diaphragm body in the radiation diaphragm range in a radiation therapy apparatus having the radiation diaphragm apparatus.

  A radiotherapy device is a device that enables noninvasive treatment by irradiating a predetermined region including a treatment target with ionizing radiation to kill the affected tissue. With recent advances in computer technology and medical technology, it is possible to irradiate a large amount of radiation to the treatment target, and to irradiate the surrounding normal tissue with as little radiation as possible, with less side effects and non-invasive treatment. Is attracting attention.

  In such a radiotherapy apparatus, a measure for reducing radiation exposure to the subject is taken due to the property of irradiating the affected area with radiation. As one of them, a multi-division diaphragm device is provided for limiting the irradiation field so as to irradiate the affected area (treatment site) with limited radiation (see, for example, Patent Document 1 and Patent Document 2). .

  FIG. 10 is a diagram for explaining an example of a conventional multi-division diaphragm. As shown in the figure, in the conventional multi-segment diaphragm apparatus, a plurality of pairs of diaphragm bodies 100A and 100B sandwiching the radiation source S are provided along one direction (X-axis direction in the figure). Each of the apertures 100A and 100B is movable along the Y-axis direction substantially perpendicular to the X-axis direction (that is, can be moved toward and away from each other), and can be moved to a predetermined position so as to have an arbitrary shape. Can be formed.

  By the way, the position of each aperture of the aperture device is obtained by calculation. In order to perform this calculation, it is necessary to position the origin position of each aperture (that is, register the reference position such as the origin). Conventionally, for example, an origin positioning light is irradiated from the radiation source side, and a serviceman determines the origin while visually observing the shape, or the diaphragm is applied to a mechanical limit related to the moving direction, and the position is set. The origin of each diaphragm is positioned by the method of setting the origin.

  However, the positioning of the origin of the diaphragm in the conventional radiotherapy apparatus has the following problems, for example.

  In other words, since an artificial method requires a great amount of time, the work load is great and the apparatus cannot be moved during that time. In addition, since special techniques and experience are required, only a serviceman can perform origin positioning, and even if an origin position deviation is found, the origin position cannot be quickly restored.

  Further, in the method using the mechanical limit, wear or the like occurs because the mechanisms are brought into contact with each other, and the required accuracy cannot be secured over time.

  In addition to the positioning of the origin of the diaphragm, inconveniences that occur in the radiotherapy apparatus are still often handled only by specialists such as service personnel, and there is a need for a system that can be quickly and easily handled by the user. is there.

In addition, as a well-known document relevant to this application, there exist the following, for example.
JP 2001-66397 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a radiation diaphragm device that allows a user himself / herself to quickly and easily deal with a malfunction occurring in the apparatus without relying on a specialist such as a serviceman, and the diaphragm device. It aims at providing the radiotherapy apparatus which comprises.

  In order to achieve the above object, the present invention takes the following measures.

The invention according to claim 1 is a radiation aperture device that is arranged between a radiation source and a subject, and that forms a radiation field that is a region where radiation from the radiation source is irradiated onto the subject. there are, are arranged closely adjacent to each other in the first direction, the plurality of throttle bodies movable along a second direction different from the first direction, the second of the throttle body A contact portion for determining one end of a moving range relating to a direction; and a detection means for detecting contact between the contact portion and the diaphragm by an electrical or optical means, and the contact portion Is a radiation diaphragm device characterized in that when it comes into contact with the diaphragm, it can be agitated along the second direction .
The invention according to claim 4 is disposed between a radiation source for irradiating the subject with radiation, and between the radiation source and the subject, and the subject is irradiated with radiation from the radiation source. A means for forming a radiation field that is a region, a plurality of which are arranged closely adjacent to each other along a first direction and are movable along a second direction different from the first direction A diaphragm, a contact part for determining one end of a movement range of the diaphragm in the second direction, and contact between the contact part and the diaphragm is detected by electrical or optical means. And a radiation aperture means having a detection means , wherein the abutment portion can be instigated along the second direction when abutting against the aperture body. Radiotherapy device.

  As described above, according to the present invention, a radiation diaphragm apparatus that allows a user himself / herself to quickly and easily deal with a malfunction occurring in the apparatus without inducing mechanical wear and without relying on a specialist such as a serviceman, and the diaphragm. A radiotherapy apparatus including the apparatus can be realized.

  Hereinafter, a first embodiment and a third embodiment of the present invention will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 1 shows a block diagram of a radiotherapy apparatus 1 according to this embodiment. As shown in the figure, the radiation therapy apparatus 1 includes a radiation irradiation apparatus 10 that irradiates a subject with radiation from a radiation source, and a treatment table 20 that places the subject P and positions a radiation irradiation site. And a control system (not shown in FIG. 1) for organically controlling each device constituting the radiation treatment apparatus including the radiation irradiation apparatus 10 and the treatment table 20.

  The radiation irradiation apparatus 10 includes a fixed base 11, a rotary base 12, an irradiation head 13, and a diaphragm unit 14. The fixed mount 11 is installed on the floor, and the rotary mount 12 is rotatably supported by the fixed mount 11. The irradiation head 13 includes a diaphragm device 14 that is provided at a distal end portion that extends in the lateral direction from one end of the rotary mount 12 and that shapes the shape of the irradiated radiation and determines the radiation irradiation field. The configuration of the aperture device 14 will be described in detail later.

  Further, the rotary mount 12 can be rotated about 360 degrees around the horizontal rotation center axis H of the fixed mount 11, and the diaphragm device 14 is also around the irradiation axis I of the radiation irradiated from the irradiation head 13. It can be rotated. The intersection of the rotation center axis H of the rotating gantry 12 and the radiation irradiation axis I is referred to as an isocenter IC. The rotating base 12 is configured to be able to rotate in accordance with various irradiation modes other than the fixed irradiation of radiation, for example, rotation irradiation, pendulum irradiation, intermittent irradiation, and the like.

  The treatment table 20 has an upper mechanism 21, a top plate 22, an elevating mechanism 23, and a lower mechanism 24. The treatment table 20 is rotatable on a floor in a direction of an arrow G in a predetermined angle range along an arc centered on an isocenter IC. is set up. The top plate 22 is a bed plate on which the subject P is placed, and is supported by the upper mechanism 21. The upper mechanism 21 includes a mechanism for moving the top plate 22 in the front-rear direction indicated by arrow e and in the left-right direction indicated by arrow f. The upper mechanism 21 is supported by the lifting mechanism 23. The elevating mechanism 23 is constituted by, for example, a link mechanism, and elevates the upper mechanism 21 and the top plate 22 by a predetermined range by itself elevating in the vertical direction indicated by the arrow d. Further, the elevating mechanism 23 is supported by the lower mechanism 24. The lower mechanism 24 includes a mechanism that rotates the elevating mechanism 23 in the direction indicated by the arrow F around a position that is a distance L from the isocenter IC. Therefore, together with the lifting mechanism 23, the upper mechanism 21 and the top plate 22 can rotate by a predetermined angle in the direction of arrow F.

  It should be noted that the positioning of the subject P and the setting of the radiation field by the diaphragm device 14 are performed by the medical staff D such as a doctor during the treatment.

(Aperture device)
Next, the configuration of the diaphragm device 14 will be described in detail. When performing radiation therapy, it is important to concentrate radiation only on a treatment site such as a malignant tumor so as not to damage normal tissue. This diaphragm device 14 is for restricting (restricting) the radiation field so that the normal tissue is not irradiated with radiation as much as possible, and is incorporated in the irradiation head 13 so as to be rotatable around the radiation irradiation axis I. Yes.

  In the present embodiment, a multi-segment diaphragm device having a plurality of arc-shaped diaphragms is taken as an example. However, the technical idea of the present invention is not limited to this, and can be applied to a multi-division diaphragm apparatus having a plurality of diaphragm bodies, for example, a multi-division diaphragm apparatus having a plurality of rectangular diaphragm bodies. Hereinafter, the configuration of the diaphragm device 14 will be described in detail with reference to FIGS. 2 to 5.

FIG. 2 is a view as seen from one side of the diaphragm device 14, and FIG. 3 is a view as seen from another side located in a direction substantially perpendicular to FIG. 2. In the actual radiotherapy apparatus 1, the diaphragm device 14 has a predetermined housing, but is not shown in FIGS. 2 and 3 for convenience of explanation.

  The aperture device 14 includes first aperture bodies 140A and 140B, second aperture bodies 141Ak and 141Bk (where k is a natural number satisfying 1 ≦ k ≦ n), first drive devices 142A and 142B, and second drive. The devices 143Ak and 143Bk1 (where k is a natural number satisfying 1 ≦ k ≦ n) are included.

  The first diaphragms 140A and 140B are provided on the side closer to the radiation source S than the second diaphragms 141Ak and 141Bk, respectively, and are single bodies made of a heavy metal such as tungsten. The first diaphragm 140A and the first diaphragm 140B are arranged to face each other so that the end surfaces thereof face each other along the first direction (Y direction in FIG. 3) with the radiation irradiation axis I in between. It moves by the 1st drive device 142A, 142B so that it moves to the direction of the arrow X along the circular-arc-shaped track surface on the concentric circle centering on the source | sauce S, and approaches and leaves | separates mutually. Yes.

  The second diaphragms 141Ak and 141Bk are provided on the side farther from the radiation source S than the first diaphragms 140A and 140B, and include a plurality of diaphragms made of heavy metal such as tungsten (multi-segment diaphragms). Body). The second diaphragm body 141Ak and the second diaphragm body 141Bk are arranged such that their end surfaces are in the second direction (X direction in FIG. 2) substantially orthogonal to the first direction and the radiation irradiation axis I is between them. The second drive unit 143A is arranged so as to face each other and moves in a direction indicated by an arrow Y along a circular arc-shaped track surface on a concentric circle including the radiation source S as a center so as to approach and separate from each other. , 143B. Further, the n second diaphragms 141A1 to An (and the n second diaphragms 141B1 to Bn) are arranged along the X direction so as to be closely adjacent to each other so as not to cause radiation leakage. .

  FIG. 4 is a view of the second diaphragms 141Ak and 141Bk and the second driving devices 143Ak and 143Bk as viewed from the radiation source S side. As shown in the figure, each of the leaves 141A1 to 141An and 141B1 to 141B of the second diaphragms 141A and 141B is provided with driving devices 143A1 to 143An and 143B1 to 143Bn, respectively, and the driving devices 143A1 to 143A1 are provided. The leaves 141A1 to 141An and 141B1 to 141Bn are driven by 143An and 143B1 to 143Bn so as to approach and separate in the arrow Y direction along arcuate orbital surfaces along concentric circles each including the radiation source S. It has become.

  Accordingly, the first diaphragms 140A and 140B are moved so as to approach and separate from each other in the X direction, and the second diaphragms 141Ak and 141Bk are individually moved so as to approach and separate from each other in the Y direction. By combining them, it is possible to form an irregularly shaped radiation field U that approximates an arbitrary shape of the treatment site.

  The diaphragm device 14 also detects whether or not one end of each second diaphragm body is disposed at a reference position for determining the effective movable range of each second diaphragm body (reference position detection). Device). Here, the effective movable range of the second diaphragm is an effective range for shaping the actual radiation within the movable range of the second diaphragm. In the effective movable range, the position calculation of the second diaphragm is always executed. The following reference position detection device will be described.

  FIGS. 5A and 5B are diagrams illustrating an example of the reference position detection devices 30A and 30B included in the diaphragm device 14. As shown in FIG. 4, the reference position detection device 30A (reference position detection device 30B) has a radiation irradiation axis outside the second diaphragm 141Ak (141Bk), that is, sandwiching the second diaphragm 141Ak (141Bk). It is arranged on the opposite side to I. FIG. 5A is a diagram illustrating a side surface of the reference position detection device 30A (reference position detection device 30B) on the second aperture body 141Ak (141Bk) side, and FIG. 5B is a diagram illustrating FIG. It is the figure which showed the side surface of 30 A of reference position detection apparatuses (reference position detection apparatus 30B) on the opposite side.

  As shown in each figure, the reference position detection device 30A (reference position detection device 30B) includes an abutting portion 31A (31B), a blocking bar 32A (32B), an optical sensor 33A (33B), and a light source 34A (34B). is doing.

  When the abutting portion 31A (31B) receives a mechanical action due to the abutting surface T coming into contact with the outer end surface of the second aperture body 141Ak (141Bk), the abutting portion 31A (31B) is agitated about the axis. The position of the abutting portion 31A (31B) is used as a reference position when determining the effective movable range of the second aperture body 141Ak (141Bk). This will be described in detail later.

  The light source 34A (34B) constantly emits a beam toward the optical sensor 33A (33B) while the radiotherapy apparatus 1 is in operation.

  The blocking bar 32A (32B) is disposed between the light source 34A (34B) and the optical sensor 33A (33B) so as to block the beam emitted from the light source 34A (34B). Further, the blocking bar 32A (32B) moves up and down in conjunction with this movement when the abutting portion 31A (31B) is mechanically actuated and instigated. Accordingly, only when the abutting portion 31A (31B) is agitated by the mechanical action from the second aperture body 141Ak (141Bk), the blocking of the beam is interrupted by the vertical movement of the blocking bar 32A (32B), and the optical sensor 33A. (33B) detects the beam emitted from the light source 34A (34B).

(Control system)
Next, the configuration of the control system of the radiation therapy apparatus 1 will be described.

  FIG. 6 is a block diagram showing the configuration of the control system of the radiation therapy apparatus 1. As shown in the figure, the radiation therapy apparatus 1 includes a diaphragm position calculation unit 39, a control unit 40, a storage unit 42, an operation unit 44, a transmission / reception unit 46, and a display unit 48 as a control system.

  The aperture position calculation unit 39 calculates the respective positions of the first aperture and the second aperture based on a pre-registered reference position (for example, the origin) and information from the potentiometer and encoder included in the aperture device 14. Calculate

  The control unit 40 reads out the program stored in the storage unit 42 and develops it on the memory. According to these, the unit 40 and the entire system are controlled statically or dynamically, and the operation of the radiotherapy apparatus 1 is integrated. To control. In particular, the control unit 40 performs control related to return to origin described later.

  The storage unit 42 includes a patient information storage unit 42a, an irradiation condition storage unit 42b, and an effective movable range storage unit 42c. The patient information storage unit 42a stores the patient information received by the transmission / reception unit 46 via the network and the patient information input from the operation unit 44. The irradiation condition storage unit 42b stores irradiation conditions (for example, irradiation intensity, irradiation time, etc.) of radiation irradiated to each patient in association with patient information. The effective movable range storage unit 42c stores, for each second diaphragm, an effective movable range based on the position of the abutting unit 31A (31B) that is used in the origin return support described later.

  The operation unit 44 includes an input device such as a keyboard, a trackball, a mouse, and a dedicated interface for executing return to origin described later.

  The transmission / reception unit 46 transmits / receives data such as patient information to / from other devices via a network.

  The display unit 48 converts image data received from the CT image generation unit 14 into a video signal, and displays patient information, irradiation conditions, medical images, and the like used for treatment based on the video signal.

(Home return support function)
Next, the origin return support function of the radiation therapy apparatus 1 will be described. This origin return support function uses a reference position detection device, and when an error occurs in the registered origin position for calculating the position of the diaphragm, the user himself / herself can quickly and easily find the origin of each diaphragm. Return (correction of registered origin position) is enabled.

  FIG. 7 shows a case where an error has occurred in the origin position registered for the position calculation of the second diaphragm in the radiotherapy apparatus 1 (that is, an error has occurred in the position calculation of the second diaphragm). 5 is a flowchart showing a flow of a procedure of origin return processing executed in step S2.

  In the figure, first, when the radiotherapy apparatus 1 is installed, a serviceman or the like previously registers the origin position of each second diaphragm and stores the effective movable range in the effective movable range storage unit 42c. (Step S1). This process is executed, for example, as follows by an artificial operation by a service person and the control and calculation process of the control unit 40. That is, first, using the light source for origin position alignment, the origin position (that is, the position where the displacement in the X direction is 0) of each second diaphragm is opposed to the origin position along the X direction from the origin position. The position X1 (for example, the position moved 10 cm from the origin) moved by a predetermined amount toward the aperture 2 side is stored as a lower limit of the effective movable range (step S1a). Next, the second diaphragms are moved away from the second diaphragms facing each other along the X direction, and each second diaphragm and the reference position detection device 30A (reference position detection device 30B). The position X2 at which the optical sensor 33A (33B) detects contact with the butting portion 31A (31B) is primarily stored as the upper limit of the effective movable range (step S1b). Next, as shown in FIG. 8, the effective movable range storage unit uses the difference X = X2−X1 between the position X2 and the position X1 registered for each second diaphragm as the effective movable range of each second diaphragm. 42c (step S1c).

  After the origin registration and the storage of the effective movable range, a treatment process using the radiation treatment apparatus 1 is performed on a daily basis. In this daily operation, it is assumed that a position calculation error of any second diaphragm is detected (either automatic detection by the device or artificial detection may be used). This error can be resolved by correcting the registered origin to the correct origin again. Therefore, for example, a doctor, an engineer, or the like executes the origin return process of the second diaphragm that is the error target using the effective operating range stored in the effective movable range storage unit 42c (step S2). This process is executed, for example, as follows by an artificial operation by a doctor or the like and a control and calculation process of the control unit 40. That is, first, the second diaphragm body that is an error target is moved away from the second diaphragm body that is opposed in the X direction, and each second sensor body at the position where the optical sensor 33A (33B) has reacted. Is stopped (step S2a). Next, the position of −10.00 cm is reversely calculated from the effective movable range of the second diaphragm stored in the effective movable range storage unit 42c (step S2b), and the origin of the second diaphragm subjected to the error is calculated. The position is corrected (step S2b).

  By such a series of processes, when a position calculation error of the second diaphragm occurs, the origin position registered by the origin return support function using the reference position detection device is corrected, whereby each second position is corrected. The diaphragm can be returned to the correct origin position.

  According to the configuration described above, the following effects can be obtained.

  According to the radiation squeezing device and the radiotherapy device, even when an origin error occurs, from the effective movable range stored in the effective movable range storage unit 42c and the position of the abutment portion of the reference position detection device, It is possible to automatically return the origin position of the second aperture body to the normal position. Therefore, it is possible to perform recovery procedures on the user's side without calling a specialist such as a service person. As a result, it is possible to reduce the burden of man-made work as compared with the prior art, and to treat until the malfunction on the system is resolved. The interruption period can be shortened.

  In the radiation diaphragm device and the radiation therapy apparatus, a reference position detection device that optically or electrically detects the reference position arrangement of the diaphragm body end face is used in the return processing of the origin position of the diaphragm body. Therefore, it is possible to prevent the occurrence of play due to mechanical contact using a mechanical limit or the like, and it is possible to realize a highly reliable radiation aperture process.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In a normal radiotherapy apparatus, calibration is performed at four points on the radiation irradiation field S, and the degree of opening of each diaphragm is calculated from the data to determine whether or not it is in a normal state. This calibration data is appropriately stored in the battery backup RAM of the control system PC board and used at a necessary timing. Therefore, when the calibration data stored in the battery backup RAM is lost or changed due to some cause (for example, loss due to battery exhaustion or deterioration in reliability due to generation of damage noise), the opening degree data becomes abnormal. The degree of opening of each throttle body cannot be properly determined.

  In such a case, conventionally, a service man re-executes calibration and restores opening degree data. Accordingly, the work burden on the service person becomes large, and the treatment by the radiotherapy apparatus is forced to be interrupted until the opening degree data is restored by the service person.

  The radiotherapy apparatus according to the present embodiment has a function of supporting such automatic restoration of calibration data.

  FIG. 9 is a conceptual diagram for explaining an automatic restoration function of calibration data of the radiation therapy apparatus 1 according to the second embodiment. As shown in the figure, the radiotherapy apparatus 1 includes three battery backup RAMs 400a, 401a, and 402a that store the same calibration data in the control unit 40, for example. The battery backup RAMs 400a, 401a, and 402a are provided on different PC boards 400, 401, and 402, respectively. In this embodiment, the case where three battery backup RAMs 400a, 401a, and 402a are used is taken as an example, but the present invention is not limited to this, and at least three or more battery backup RAMs (each provided on a different PC board). Any configuration may be used as long as the configuration is used.

  The controller 40 compares the calibration data stored in the three battery backup RAMs 400a, 401a, and 402a, for example, at the timing of power-on, for example, and uses them as they are if they are all the same. On the other hand, when the calibration data of only one battery backup RAM is different from the other two, the calibration data stored in the same two battery backup RAMs are used and the remaining one is stored. The data is restored by overwriting and saving the calibration data stored in the same two battery backup RAMs.

  When the calibration data stored by the three battery backup RAMs 400a, 401a, and 402a are all different, the control unit 40 does not use any calibration data and outputs an error message. In addition, the probability that such a case will occur is low.

  According to the configuration described above, calibration is automatically performed using data in the battery backup RAM provided on each of at least three PC boards even when the calibration data is lost or damaged. Recovery data can be restored to normal. Accordingly, the user can perform a recovery procedure without calling a specialist such as a service person. As a result, it is possible to reduce the burden of man-made work and shorten the treatment interruption period until the problem on the system is resolved, as compared with the conventional case.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  In general, there is a technique for automatically acquiring the origin position of a diaphragm in a multi-division diaphragm (not limited to the technique described in the first embodiment). In such a multi-segment diaphragm device, there is no switch (for instructing automatic acquisition of the origin position) accessible by the user. Therefore, for example, it has a function of counting the number of times the power of the radiotherapy apparatus is turned ON / OFF and automatically acquiring the origin position when the value reaches the set value.

  However, when using this function, it is necessary to repeat ON / OFF of the power supply to the set value in order to realize automatic acquisition of the origin position of the aperture, and it is determined that the operation time is required and necessary for that. Execution at an arbitrary timing is impossible.

  Therefore, the radiotherapy apparatus 1 according to the present embodiment uses a predetermined switch on the operation unit 44 that can be accessed by a service person, and the switch is operated a predetermined number of times (for example, twice) within a predetermined time. Suppose that the control unit 40 automatically acquires the origin position of the aperture. On the other hand, if the predetermined switch is not operated a predetermined number of times within a fixed time, the origin position of the aperture is not automatically acquired.

  According to such a configuration, it is possible to automatically acquire the origin position of the diaphragm in a short time and at an arbitrary timing by a simple operation by the user himself / herself.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Specific examples of modifications are as follows.

  In the first embodiment, the effective movable range is stored for each first diaphragm, and the origin return support is performed using this. On the other hand, the effective movable range common to the n second diaphragms 141Ak and the effective movable range common to the n second diaphragms 141Bk are stored, and the second diaphragm is stored using these. The configuration may be such that origin return support is provided to the body 141Ak and the second aperture body 141Bk.

  In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  As described above, according to the present invention, it is possible to realize a radiation squeezing device that allows a user himself / herself to quickly and easily deal with a malfunction occurring in the device without relying on a specialist such as a serviceman, and a radiotherapy device including the squeezing device. can do.

FIG. 1 shows a block configuration diagram of a radiation therapy apparatus 1 according to an embodiment of the present invention. FIG. 2 is a view showing one side of the diaphragm device 14 included in the radiation therapy apparatus 1 according to the present embodiment. FIG. 3 is a view seen from another side located in a direction substantially perpendicular to FIG. FIG. 3 is a view showing another side surface of the diaphragm device 14 according to the present embodiment. FIG. 4 is a view of the second diaphragms 141Ak and 141Bk and the second driving devices 143A and 143B as viewed from the radiation source S side. FIGS. 5A and 5B are diagrams illustrating an example of the reference position detection devices 30A and 30B included in the diaphragm device 14. FIG. 6 is a block diagram showing the configuration of the control system of the radiation therapy apparatus 1. FIG. 7 is a flowchart showing the flow of the procedure of origin return processing that is executed when an error occurs at the origin position registered for the position calculation of the second aperture. FIG. 8 is a conceptual diagram for explaining the effective movable range. FIG. 9 is a conceptual diagram for explaining an automatic restoration function of calibration data of the radiation therapy apparatus 1 according to the second embodiment. FIG. 10 is a diagram for explaining the configuration of a conventional diaphragm device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Radiation therapy apparatus, 10 ... Radiation irradiation apparatus, 20 ... Treatment stand, 11 ... Fixed mount, 12 ... Rotation mount, 13 ... Irradiation head, 14 ... Diaphragm device, 21 ... Upper mechanism, 22 ... Top plate, 23 ... Lifting Mechanism, 24 ... Lower mechanism, 39 ... Diaphragm position calculation unit, 40 ... Control unit, 42 ... Storage unit, 44 ... Operation unit, 46 ... Transmission / reception unit, 48 ... Display unit, 140A, 140B ... First diaphragm, 141Ak, 141Bk ... 2 apertures, 142A, 142B ... first drive device, 143Ak, 143Bk ... second drive device, P ... subject

Claims (7)

A radiation aperture device for forming a radiation field that is disposed between a radiation source and a subject and is a region irradiated with radiation from the radiation source.
Are arranged closely adjacent to each other in the first direction, and a plurality of throttle bodies movable along a second direction different from the previous SL first direction,
A contact portion for determining one end of a movement range of the diaphragm body in the second direction, and a detection means for detecting contact between the contact portion and the diaphragm body by an electrical or optical means;
Comprising
The abutment portion can be instigated along the second direction when abutting against the aperture body;
Radiation diaphragm device according to claim. The second direction, the radiation diaphragm device according to claim 1, characterized in that the circumferential direction of a circle about the radiation source. The second direction, the radiation diaphragm according to claim 1, wherein it is a direction perpendicular to the irradiation axis of the radiation from the radiation source. A radiation source for irradiating the subject with radiation;
A means for forming a radiation field, which is disposed between a radiation source and a subject and is irradiated with radiation from the radiation source, is densely aligned along a first direction. A plurality of diaphragms arranged adjacent to each other and movable along a second direction different from the first direction, and one end of a movement range of the diaphragm body in the second direction A radiation stop means having a contact portion, and a detection means for detecting contact between the contact portion and the stop body by an electrical or optical means;
Comprising
The abutment portion can be instigated along the second direction when abutting against the aperture body;
The radiotherapy apparatus according to claim.   5. The radiotherapy apparatus according to claim 4, further comprising registration means for registering a reference position of a moving range of the diaphragm based on detection by the detection means. The second direction is a circumferential direction of a circle centered on the radiation source,
The plurality of diaphragms have a shape corresponding to a circular arc centered on the radiation source ;
The radiotherapy apparatus according to claim 4 or 5 . The second direction is a direction perpendicular to an irradiation axis of radiation from the radiation source,
The plurality of diaphragms are polyhedrons having a plane perpendicular to the irradiation axis ;
The radiotherapy apparatus according to any one of claims 4 to 6.

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