Radiation measurement device and radiation measurement method

Abstract

To make it possible to easily switch between measurements in both an orthogonal direction and a parallel direction with respect to a beam when taking the measurements.SOLUTION: A radiation measurement device 20 comprises: a dark box 23; a first phosphor 21 attached to the dark box 23, and for emitting light in response to radiation; a second phosphor 22 attached to the dark box 23, and for emitting light in response to the radiation; and a detector 26 provided inside the dark box 23, and for detecting light emission L1 generated from the first phosphor 21 when a beam B caused by the radiation is applied to the first phosphor 21, and detecting light emission L2 generated from the second phosphor 22 when the beam B is applied to the second phosphor 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to radiation measurement techniques. [Background technology]

[0002] Radiation therapy is a treatment in which high-energy radiation (hereinafter referred to as beam) is irradiated to cancer cells in the human body, and beam adjustment before the start of treatment and periodic quality assessment are extremely important to ensure appropriate irradiation. Measurements in the beam adjustment and quality assessment are performed in directions perpendicular to and parallel to the beam. Here, measurements perpendicular to the beam consider the beam size, beam spread, irradiation position accuracy, and dose distribution, while measurements parallel to the beam consider the beam range and beam incidence angle, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-151158 [Patent Document 2] Patent Publication No. 2021-137106 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional radiation measurement devices can only measure in either a direction perpendicular to the beam or a direction parallel to the beam. Therefore, when changing the measurement item, the entire radiation measurement device must be replaced, which is time-consuming.

[0005] The embodiments of the present invention have been made in consideration of the above circumstances, and have an object to easily switch between measurements when measurements are performed in both directions perpendicular to and parallel to the beam. [Means for solving the problem]

[0006] A radiation measurement device according to an embodiment of the present invention includes a dark box, a first phosphor attached to the dark box and emitting light in response to radiation, a second phosphor attached to the dark box and emitting light in response to the radiation, and a detector provided inside the dark box, which detects light emission generated from the first phosphor when the first phosphor is irradiated with a beam of radiation, and detects light emission generated from the second phosphor when the beam is irradiated with the second phosphor. a reflector provided inside the dark box and configured to reflect light emitted from at least one of the first phosphor and the second phosphor toward the detector; Equipped with. [Effects of the Invention]

[0007] Embodiments of the present invention allow for easy switching between measurements in both directions perpendicular to and parallel to the beam. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a particle beam therapy system according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a radiation measurement device according to a first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the radiation measurement device during measurement using the first phosphor of the first embodiment. [Figure 4] FIG. 3 is a cross-sectional view showing the radiation measurement device during measurement using the second phosphor of the first embodiment. [Figure 5] FIG. 2 is an explanatory diagram showing the arrangement of the radiation measurement device according to the first embodiment. [Figure 6] FIG. 10 is an explanatory diagram showing an arrangement of a radiation measurement device according to a second embodiment. [Figure 7] FIG. 10 is an explanatory diagram showing an arrangement of a radiation measurement device according to a third embodiment. [Figure 8] FIG. 10 is a perspective view showing a radiation measurement device including a gantry according to a third embodiment. [Figure 9] FIG. 11 is a side view showing the radiation measurement device during measurement using the first phosphor of the third embodiment. [Figure 10] FIG. 11 is a side view showing the radiation measurement device during measurement using the second phosphor of the third embodiment. [Figure 11]FIG. 10 is an explanatory diagram showing a particle beam therapy system according to a fourth embodiment. [Figure 12] FIG. 10 is a cross-sectional view showing a radiation measurement device according to a fourth embodiment. [Figure 13] FIG. 10 is an explanatory diagram showing an arrangement of a radiation measurement device according to a fourth embodiment. [Figure 14] FIG. 11 is a cross-sectional view showing the radiation measurement device during measurement using the first phosphor of the fifth embodiment. [Figure 15] FIG. 11 is a cross-sectional view showing the radiation measurement device during measurement using a second phosphor according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) Hereinafter, with reference to the drawings, embodiments of a radiation measurement device and a radiation measurement method will be described in detail, taking particle beam therapy as an example. Note that the present embodiment may be applied to radiation therapy other than particle beam therapy. First, a first embodiment will be described with reference to FIGS. 1 to 5.

[0010] Reference numeral 1 in Fig. 1 denotes a particle beam therapy system according to a first embodiment. This particle beam therapy system 1 is a so-called particle beam cancer therapy device that performs treatment by irradiating a particle beam B, which is therapeutic radiation, onto lesion tissue (cancer) of a patient P. For the beam B, a heavy particle beam using, for example, carbon ions is used. Note that the beam B may also be an X-ray, a gamma ray, a proton beam, or the like.

[0011] The particle beam therapy system 1 includes a treatment room 2, a particle beam generator 3, a transport path 4, two particle beam irradiation devices 5 and 6, an irradiation control device 7, a treatment table 8, a table control device 9, and a table operation terminal 10. Fig. 1 illustrates a partial configuration of the particle beam therapy system 1, and the particle beam therapy system 1 may include other configurations.

[0012] A patient P is placed in the treatment room 2 when particle beam therapy is performed. The particle beam generator 3 is a device that generates a particle beam B. For example, the particle beam generator 3 includes an ion source, a linear accelerator, a circular accelerator, etc. The particle beam generator 3 generates the beam B with a ray type, energy, and dose according to the doctor's request.

[0013] The transport path 4 is a path for transporting the beam B generated by the particle beam generator 3. For example, the transport path 4 includes a vacuum duct, a bending electromagnet, a focusing electromagnet, etc. The transport path 4 accelerates and focuses the beam B generated by the particle beam generator 3 and transports it to the particle beam irradiation devices 5 and 6. For example, the transport path 4 extends from the particle beam generator 3, branches midway, and guides the beam B to each of the particle beam irradiation devices 5 and 6.

[0014] Of the two particle beam irradiation devices 5, 6, the particle beam irradiation device 5 is a device that irradiates the transported beam B horizontally onto the patient P. The other particle beam irradiation device 6 is a device that irradiates the transported beam B vertically onto the patient P. These particle beam irradiation devices 5, 6 are fixed to the walls and ceiling of the treatment room 2. The treatment room 2 to which the particle beam irradiation devices 5, 6 are fixed in this manner is called a fixed room. Each particle beam irradiation device 5, 6 is equipped with irradiation ports 11, 12 that face the direction of the patient P and from which the beam B is emitted toward the patient P. These irradiation ports 11, 12 are provided inside the treatment room 2.

[0015] The irradiation controller 7 is a computer that controls each of the particle beam irradiation devices 5 and 6. For example, the irradiation controller 7 controls the irradiation position and irradiation timing of beam B. The particle beam irradiation devices 5 and 6 change the direction of beam B according to instructions from the irradiation controller 7, and beam B is irradiated from irradiation ports 11 and 12 to patient P. In other words, beam B is radiation whose irradiation direction and irradiation range are controlled for use in treatment.

[0016] The particle beam irradiation devices 5 and 6 and the irradiation ports 11 and 12 are either those that irradiate the beam B in the horizontal direction or those that irradiate the beam B in the vertical direction, but either one of them may be used.

[0017] The treatment couch 8 is a table on which a patient P, who is the target of irradiation with the beam B, is placed. The table control device 9 is a computer that controls the treatment couch 8. The table operation terminal 10 is a terminal that allows a user such as a doctor, radiologist, or maintenance worker to operate the treatment couch 8.

[0018] The treatment table 8 is supported by a moving arm (not shown) fixed to the floor surface 13 of the treatment room 2, and moves with the patient P placed on it to position the affected area of ​​the patient P at the isocenter, which is the irradiation position of the beam B. By moving the treatment table 8, the patient P can be moved to the irradiation position of the beam B and aligned. The treatment table 8 and the table operation terminal 10 are provided inside the treatment room 2.

[0019] The treatment couch 8, with the patient P resting on it, moves and rotates within the treatment room 2 in accordance with instructions from the couch control device 9. By moving the treatment couch 8 in this way, the patient P can be moved to the irradiation position of the beam B. For example, when a user inputs the position of the treatment couch 8 into the couch operation terminal 10, the couch control device 9 outputs instructions to the treatment couch 8 to move and rotate. The treatment couch 8 can also be moved to a position that has been registered in advance in the couch control device 9.

[0020] Next, the radiation measurement device 20 of the first embodiment will be described with reference to Figures 2 to 4. The radiation measurement device 20 is used to carry out a radiation measurement method.

[0021] In the particle beam therapy system 1 (FIG. 1), radiation measurements such as the irradiation field, energy, beam size, accuracy of the irradiation position, dose distribution, range, and incident angle of beam B are performed to adjust beam B and check the quality before starting treatment. For example, a radiation measurement device 20 is placed at the irradiation position of beam B, and a maintenance worker (user) checks that beam B is being irradiated to the position as instructed by the irradiation control device 7. The radiation measurement device 20 is used to perform such radiation measurements.

[0022] The radiation measurement device 20 includes a first phosphor 21, a second phosphor 22, and a dark box 23. In the example of FIG. 2, the upper side of the paper will be described as the upper side of the dark box 23. The first phosphor 21 is attached to the top surface (first position) of the dark box 23. The second phosphor 22 is attached to a side surface (second position) different from the top surface of the dark box 23. In this way, the first phosphor 21 and the second phosphor 22 are attached to different positions on the dark box 23, so that the first phosphor 21 and the second phosphor 22 can be attached to one dark box 23 at the same time.

[0023] 3 and 4 will be described as side views of the radiation measurement device 20, corresponding to FIG. 2. However, the radiation measurement device 20 may be used with the dark box 23 lying on its side. For example, the first phosphor 21 may face to the side instead of facing upward. In that case, FIGS. 3 and 4 will be plan views of the radiation measurement device 20.

[0024] 3 and 4, the dark box 23 is a box that is L-shaped (inverted T-shaped) in side view. For example, the portion of the dark box 23 where the first phosphor 21 is attached is a convex portion that protrudes upward.

[0025] The first phosphor 21 and the second phosphor 22 emit light in response to radiation. For example, the first phosphor 21 is made of a rectangular sheet-shaped phosphor film. The first phosphor 21 spreads in a direction perpendicular to the irradiation direction of the beam B (white arrow in FIG. 3 ) and measures at least the irradiation field of the beam B.

[0026] The second phosphor 22 is made of a disk-shaped scintillator. This second phosphor 22 spreads in a direction perpendicular to the irradiation direction of the beam B (black arrow in FIG. 4) and measures at least the range of the beam B. The second phosphor 22 also has a predetermined thickness (width) that allows the beam B to be incident thereon.

[0027] The first phosphor 21 is attached to a first attachment / detachment mechanism 24. Furthermore, the second phosphor 22 is attached to a second attachment / detachment mechanism 25. The first attachment / detachment mechanism 24 and the second attachment / detachment mechanism 25 are jigs that can be detachably attached to the first position and the second position of the dark box 23, respectively. In this way, the first phosphor 21 and the second phosphor 22 can be attached to the first position and the second position of the dark box 23 in a state where they can be interchanged.

[0028] For example, the first and second attachment / detachment mechanisms 24 and 25 are fixed to the dark box 23 with a predetermined attachment. The first and second attachment / detachment mechanisms 24 and 25 may also be fixed to the dark box 23 with screws (not shown). When the first phosphor 21 or the second phosphor 22 deteriorates, only the deteriorated first phosphor 21 or second phosphor 22 can be removed from the dark box 23 and replaced with a new one.

[0029] When the first phosphor 21 and the second phosphor 22 are attached, the inside of the dark box 23 is completely shielded from light so that no external light other than the light emitted by the first phosphor 21 or the second phosphor 22 enters.

[0030] In this embodiment, the irradiation field and range of beam B can be measured using one radiation measurement device 20. For example, beam B (white arrow in FIG. 3) is irradiated onto first phosphor 21, thereby measuring the irradiation field, energy, beam size, accuracy of irradiation position, dose distribution, etc. of beam B. Furthermore, beam B (black arrow in FIG. 4) is irradiated onto second phosphor 22, thereby measuring the range, incident angle, etc. of beam B.

[0031] The radiation measurement device 20 includes a detector 26, a reflector 27, and an angle changing mechanism 28, which are provided inside a dark box 23.

[0032] Detector 26 is a device that detects the light emissions L1 and L2. For example, detector 26 detects light emission L1 generated from first phosphor 21 when beam B is irradiated onto first phosphor 21 (FIG. 3). Furthermore, detector 26 detects light emission L2 generated from second phosphor 22 when beam B is irradiated onto second phosphor 22 (FIG. 4).

[0033] The reflector 27 reflects the luminescence L1 generated from the first phosphor 21 toward the detector 26 (FIG. 3). This reflector 27 is composed of, for example, a mirror. The detector 26 will malfunction if it is on the trajectory of the beam B. For this reason, the detector 26 is fixed in a position outside the trajectory of the beam B inside the dark box 23 to prevent the beam B from directly irradiating the detector 26. The luminescence L1 of the first phosphor 21 is reflected by the reflector 27 and guided to the detector 26.

[0034] In the example of Fig. 3, beam B is reflected in a direction at 90 degrees to the irradiation direction of beam B, and detector 26 is provided at the end of the reflected beam. Detector 26 may be provided at any position other than on the trajectory of beam B. However, the focal lengths from first phosphor 21 and second phosphor 22 to detector 26 are the same. For example, detector 26 may include a lens or the like that adjusts the focal length, and detector 26 may adjust the focal length in response to detection of light emissions L1, L2 from first phosphor 21 or second phosphor 22.

[0035] Since the light emission L1 from the first phosphor 21 occurs in the same direction as the irradiation direction of the beam B, the light emission L1 is reflected by the reflector 27 and changes its trajectory toward the detector 26, so that the detector 26 can detect the light emission L1.

[0036] Furthermore, the angle of the reflector 27 is changeable. For example, the angle of the reflector 27 can be switched between a first angle (FIG. 3) at which the light emission L1 generated from the first phosphor 21 is reflected toward the detector 26, and a second angle (FIG. 4) at which the light emission L2 generated from the second phosphor 22 passes toward the detector 26. In this way, the light emissions L1 and L2 of both the first phosphor 21 and the second phosphor 22 can be detected by a single detector 26.

[0037] The angle change mechanism 28 is a mechanism for changing the angle of the reflector 27. For example, the angle change mechanism 28 includes a drive motor (not shown) for swinging the reflector 27 and an angle sensor (not shown) for detecting the angle of the reflector 27. In this way, the angle of the surface of the reflector 27 that reflects the light emission L1 is changed, and therefore the light emissions L1 and L2 guided toward the detector 26 can be switched.

[0038] The angle of reflector 27 may be automatically switched by angle changing mechanism 28, or may be manually switched by the user. For example, as shown in FIG. 2, dark box 23 includes an opening 29 through which the user can change the angle of reflector 27, and a light-shielding door 30 that closes opening 29. The user opens light-shielding door 30 and manually moves reflector 27. In this way, the user can appropriately switch between detecting light emissions L1, L2 of either first phosphor 21 or second phosphor 22 with detector 26.

[0039] As shown in FIG. 4 , when measurement is performed using the second phosphor 22, light emission L2 is generated in a direction perpendicular to the traveling direction of the beam B, and the reflector 27 is retracted to a position where it does not interfere with this light emission L2. For example, the user opens the light-shielding door 30 of the dark box 23, stores the reflector 27 on the bottom surface of the dark box 23, and closes the light-shielding door 30 of the dark box 23. At this time, the reflector 27 may be removed from the dark box 23. Then, measurement is performed using the second phosphor 22. Furthermore, when measurement of the first phosphor 21 is performed after measurement using the second phosphor 22, the user opens the light-shielding door 30 of the dark box 23 again, returns the position of the reflector 27 to its original state, and closes the light-shielding door 30 of the dark box 23.

[0040] The reflector 27 may be stored in any position in the dark box 23, such as on the side or top surface of the dark box 23, as long as it does not block the fluorescence from the first phosphor 21 and the second phosphor 22.

[0041] The radiation measurement device 20 includes a measurement computer (not shown). The measurement computer has hardware resources such as a CPU (Central Processing Unit), GPU (Graphics Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), and SSD (Solid State Drive), and the CPU executes various programs to realize software-based information processing using the hardware resources. Furthermore, at least a part of the radiation measurement method of this embodiment is realized by causing the measurement computer to execute various programs.

[0042] The measurement computer (not shown) and detector 26 are connected by a predetermined cable (not shown) for transmitting signals. Detector 26 sends the detection results of the light emissions L1 and L2 to the measurement computer, along with information indicating the angle of reflector 27 detected by an angle sensor (not shown) of angle change mechanism 28. When outputting the detection results as an image or numerical values, the measurement computer switches the output format depending on the angle of reflector 27. In other words, the detection results of light emission L1 from first phosphor 21 and the detection results of light emission L2 from second phosphor 22 are output in a manner that allows the user to distinguish between them. This makes it easier for the user to know whether the detection results of first phosphor 21 or second phosphor 22 are being output by the measurement computer.

[0043] For example, when detector 26 detects the light emission L1 or L2 generated by first phosphor 21 or second phosphor 22, it sends the measurement data, which is the detection result, to a measurement computer (not shown). The measurement computer processes the measurement data using image processing software or the like and displays it on a display as numerical values ​​and an image. The image processing software outputs appropriate analysis results for measurements in the perpendicular direction and the parallel direction to beam B. The format of the analysis results is automatically determined by the angle of reflector 27. For example, when the angle of reflector 27 is the first angle (Figure 3), the irradiation field, energy, beam size, irradiation position accuracy, dose distribution, etc. of beam B are displayed on the display. When the angle of reflector 27 is the second angle (Figure 4), the range, incident angle, etc. of beam B are displayed on the display.

[0044] The analysis results include the environment in which the measurement was performed, such as the measurement date and time, measurement location, and measurement conditions. The image processing software for the two types of measurements corresponding to the first phosphor 21 and the second phosphor 22 may be separate, or one image processing software may be used to output analysis results that can be switched. The analysis results are displayed on a screen in real time and then stored in the measurement computer. These stored analysis results can be redisplayed using the image processing software even after measurement, and multiple analysis results can be displayed superimposed.

[0045] Fig. 5 shows an example of an arrangement of the radiation measurement device 20. In the example of Fig. 5, the radiation measurement device 20 measures the beam B irradiated in the horizontal direction from the particle beam irradiation device 5. Note that in this arrangement, the radiation measurement device 20 may also measure the beam B irradiated in the vertical direction from the particle beam irradiation device 6.

[0046] The radiation measurement device 20 of the first embodiment includes a gantry 31 for mounting the dark box 23 on the treatment table 8. In this way, when performing maintenance on the particle beam therapy system 1, the dark box 23 can be installed on the treatment table 8 and various measurements of the beam B can be performed. In addition, the gantry 31 includes a position changing mechanism 32 for changing the position of the dark box 23 while being fixed to the treatment table 8.

[0047] When the dark box 23 is fixed to the stand 31, the user can fine-tune the position of the dark box 23 using the position change mechanism 32. The position change mechanism 32 moves the dark box 23 in the horizontal direction. For example, the user can use the position change mechanism 32 to change the position of the dark box 23 between when measuring beam B with the first phosphor 21 and when measuring beam B with the second phosphor 22.

[0048] The position change mechanism 32 may be equipped with an operating handle (not shown) or the like, which allows the user to manually adjust the position of the dark box 23, or may be equipped with a drive motor (not shown) or the like, which automatically adjusts the position of the dark box 23.

[0049] When measuring radiation, the user first fixes the gantry 31 on the treatment couch 8. Next, the user places the dark box 23 on the gantry 31. Here, the user adjusts the orientation of the dark box 23 and the angle of the reflector 27 to match the direction of the beam B to be measured and the measurement item. For example, when measuring the beam B irradiated horizontally, the user sets the reflector 27 to a first angle (FIG. 3) and places the dark box 23 so that the first phosphor 21 faces the irradiation port 11 to be measured. Next, the user operates the tabletop operation terminal 10 to move the treatment couch 8 so that the dark box 23 is positioned at the measurement position. The user also fine-tunes the position of the dark box 23 using the position change mechanism 32, turns on the detector 26, and retreats from the treatment room 2. Then, the beam B is irradiated and measurement is performed.

[0050] It is also possible to place the dark box 23 directly on the treatment table 8 without disposing the stand 31 for adjusting the position of the dark box 23 on the treatment table 8.

[0051] The radiation measurement device 20 of the first embodiment can attach multiple or multiple types of phosphors to one dark box 23. Therefore, one radiation measurement device 20 can perform measurements in both directions perpendicular to and parallel to the beam B, which are necessary for adjusting and evaluating the quality of the beam B. This reduces the time required to replace the radiation measurement device 20 and the pedestal 31, and reduces the manufacturing costs of multiple types of radiation measurement devices 20 and pedestals 31.

[0052] Furthermore, by making it possible to adjust the internal structure of the radiation measurement device 20 and the position of the radiation measurement device 20, radiation measurement can be performed in a short time without changing the radiation measurement device 20 and the pedestal 31.

[0053] (Second embodiment) Next, a second embodiment will be described with reference to Fig. 6. Note that the same components as those shown in the above-described embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0054] 6 shows an example in which the radiation measurement device 20 measures the beam B irradiated in the horizontal direction from the particle beam irradiation device 5. In this arrangement, the radiation measurement device 20 may also measure the beam B irradiated in the vertical direction from the particle beam irradiation device 6.

[0055] The radiation measurement device 20 of the second embodiment includes a gantry 31A placed on the floor 13 of the treatment room 2. The gantry 31A includes a base 33 on which the dark box 23 is placed, a support 34 that supports the gantry 33, an elevator 35 that raises and lowers the support 34, and a position changing mechanism 32. The base 33 and the support 34 may be integrated.

[0056] When the dark box 23 is fixed to the stand 31A, the user can fine-tune the height of the dark box 23 with the lifting device 35. Furthermore, the position changing mechanism 32 moves the support 34 in the horizontal direction. For example, the user can use the position changing mechanism 32 and the lifting device 35 to change the position and height of the dark box 23 when measuring the beam B with the first phosphor 21 and when measuring the beam B with the second phosphor 22.

[0057] When measuring radiation, the user first fixes the gantry 31A to the floor surface 13 of the treatment table 8. Next, the user places the dark box 23 on the gantry 31A. Here, the user aligns the orientation of the dark box 23 and the angle of the reflector 27 (Fig. 2) with the direction of the beam B to be measured and the measurement item. Then, the user adjusts the position of the dark box 23 using the position changing mechanism 32 to match a mark such as a scribe or laser pointer on the gantry 31A, turns on the detector 26, and retreats from the treatment room 2. Then, the beam B is irradiated and measurement is performed.

[0058] (Third embodiment) Next, a third embodiment will be described with reference to Figures 7 to 10. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0059] In the example of FIG. 7, a mode is shown in which the radiation measurement device 20 measures the beam B irradiated in the vertical direction from the particle beam irradiation device 6.

[0060] The gantry 31B of the third embodiment is attached to the irradiation port 12 of the particle beam irradiation device 6. The gantry 31B allows the dark box 23 to be attached to the irradiation port 12. In this way, when performing maintenance on the particle beam therapy system 1, the dark box 23 can be provided at the irradiation port 12 and various measurements of the beam B can be performed.

[0061] 8, the mount 31B includes a frame 36, horizontal rails 37, vertical rails 38, and a position change mechanism 32A. The frame 36 is a member assembled into a rectangular shape. A predetermined detachable metal fitting 39 that can be detachably attached to the irradiation port 12 is provided on the upper end of the frame 36.

[0062] For example, two horizontal rails 37 are fixed to the frame 36. A vertical rail 38 is connected to each of these horizontal rails 37. These vertical rails 38 are capable of moving horizontally along the horizontal rails 37. Furthermore, the dark box 23 is connected to the vertical rails 38. The dark box 23 is capable of moving vertically along the vertical rails 38.

[0063] Furthermore, the position change mechanism 32A of the stand 31B changes the position of the dark box 23 while it is fixed to the irradiation port 12. This position change mechanism 32A moves the dark box 23 in the horizontal and vertical directions. In this way, it is possible to fine-tune the position of the dark box 23. For example, the user can use the position change mechanism 32 to change the position of the dark box 23 when measuring beam B with the first phosphor 21 (FIG. 9) and when measuring beam B with the second phosphor 22 (FIG. 10).

[0064] The position change mechanism 32A may be equipped with an operating handle (not shown) or the like, which allows the user to manually adjust the position of the dark box 23, or may be equipped with a drive motor (not shown) or the like, which automatically adjusts the position of the dark box 23.

[0065] Each component of the mount 31B is structured so as not to interfere with the trajectory of the beam B. Furthermore, the mount 31B can be arranged with the dark box 23 facing in a different direction. For example, the first phosphor 21 may be arranged not only so that it faces upward, but also so that it faces sideways.

[0066] The user moves the dark box 23 to an appropriate position using the position changing mechanism 32A. For example, when performing measurement using the first phosphor 21, the user moves the dark box 23 so that the first phosphor 21 is positioned on the trajectory of the beam B (white arrow in FIG. 9). When performing measurement using the second phosphor 22, the user moves the dark box 23 so that the second phosphor 22 is positioned on the trajectory of the beam B (black arrow in FIG. 10).

[0067] When measuring radiation, the user first attaches the dark box 23 to the gantry 31B. Next, the user attaches the gantry 31B to the irradiation port 12. Here, the user adjusts the orientation of the dark box 23 and the angle of the reflector 27 (Fig. 2) to match the direction of the beam B to be measured and the measurement item. The user also adjusts the position of the dark box 23 using the position change mechanism 32A (Fig. 8), turns on the power of the detector 26, and retreats from the treatment room 2. Then, the beam B is irradiated and measurement is performed.

[0068] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figures 11 to 13. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0069] 11, a particle therapy system 1A of the fourth embodiment includes a rotating gantry 40, a gantry control device 41, and a gantry operation terminal 42. A patient P is placed at the center of rotation of the rotating gantry 40. The interior of the rotating gantry 40 is called a gantry room where treatment is performed.

[0070] The rotating gantry 40 is a cylindrical device. The rotating gantry 40 is installed with its cylindrical axis facing horizontally and can rotate to any angle around this horizontal axis. The rotating gantry 40 rotatably supports the vacuum duct, bending electromagnets, and focusing electromagnets that constitute part of the transport path 4.

[0071] For example, the vacuum duct is led from the end of the rotating gantry 40 along its horizontal axis. Then, after the vacuum duct leaves the horizontal axis of the rotating gantry 40, it is directed in a direction perpendicular to the horizontal axis. The tip of this vacuum duct is connected to the particle beam irradiation device 43.

[0072] Gantry control device 41 is a computer that controls the rotation of rotating gantry 40. Gantry operation terminal 42 is a terminal that allows users such as doctors, radiologists, or maintenance workers to operate rotating gantry 40. Although gantry operation terminal 42 is provided inside rotating gantry 40 in the example of FIG. 11 , it may be provided outside rotating gantry 40.

[0073] The particle beam irradiation device 43 is supported by the rotating gantry 40. The particle beam irradiation device 43 is equipped with an irradiation port 44. The irradiation port 44 is fixed to the inner peripheral surface of the rotating gantry 40. The irradiation port 44 faces the center of rotation of the rotating gantry 40. Beam B is irradiated from the rotating gantry 40 toward patient P, who is located at the center of the rotating gantry 40. By changing the irradiation direction of beam B by the rotating gantry 40, beam B can be irradiated to an appropriate area, such as the diseased tissue of patient P.

[0074] 13, the radiation measurement device 20A of the fourth embodiment includes a gantry 31B. The gantry 31B allows the dark box 23 to be attached to the irradiation port 44 of the particle beam irradiation device 43. The gantry 31B (FIG. 8) is the same as that of the third embodiment.

[0075] 12, the radiation measurement device 20A includes a rotation mechanism 45 that rotates the detector 26, in addition to the components including the first phosphor 21, the second phosphor 22, the dark box 23, the detector 26, the reflector 27, and the angle changing mechanism 28. The rotation mechanism 45 rotates the detector 26 around an axis 47 that is perpendicular to the light receiving surface 46 of the detector 26. This makes it easy to measure the beam B emitted from the irradiation port 44 that rotates using a rotating gantry 40 or the like.

[0076] The detector 26 is fixed to the dark box 23 via a rotation mechanism 45. The rotation mechanism 45 rotates the detector 26 in accordance with the angle of the rotating gantry 40. The detector 26 is rotated in the opposite direction to the rotation of the rotating gantry 40, and this rotation positions the detector 26 so that it is always horizontal. For example, when the rotating gantry 40 rotates 30 degrees counterclockwise (FIG. 13), the detector 26 rotates 30 degrees clockwise.

[0077] The rotation mechanism 45 may be equipped with an operating handle (not shown) or the like, which allows the user to rotate the detector 26 manually, or may be equipped with a drive motor (not shown) or the like, which allows the detector 26 to be rotated automatically.

[0078] 13, when the irradiation port 44 is rotated by the rotating gantry 40, the dark box 23 rotates together with the gantry 31A. When performing measurement using the first phosphor 21, the dark box 23 rotates in accordance with the angle of the irradiation port 44, so that the first phosphor 21 always faces the emission direction of the beam B, making it possible to perform measurement in a direction perpendicular to the beam B regardless of the angle of the irradiation port 44. Note that when measurement is performed using the first phosphor 21, the detector 26 is not rotated by the rotation mechanism 45.

[0079] When measurement is performed using the second phosphor 22, the dark box 23 also rotates to match the angle of the irradiation port 44. When measurement is performed using the second phosphor 22, the detector 26 is rotated by the rotation mechanism 45 to measure the beam B.

[0080] When measuring radiation, the user first attaches the gantry 31B to the irradiation port 44. Next, the user attaches the dark box 23 to the gantry 31B. Here, the user aligns the orientation of the dark box 23 and the angle of the reflector 27 (FIG. 12) with the direction of the beam B to be measured and the measurement item. The user also adjusts the position of the dark box 23 using the position change mechanism 32A (FIG. 8) and adjusts the angle of the rotating gantry 40 using the gantry operation terminal 42. The user then rotates the detector 26 using the rotation mechanism 45 to match the angle of the rotating gantry 40. The user also turns on the power of the detector 26 and retreats from the gantry room. Then, irradiation with the beam B is performed, and measurement is performed.

[0081] (Fifth embodiment) Next, a fifth embodiment will be described with reference to Figures 14 and 15. Note that the same components as those shown in the above-described embodiments will be assigned the same reference numerals and redundant description will be omitted.

[0082] 14, the dark box 23 of the radiation measurement device 20B of the fifth embodiment is a box that is L-shaped in side view. For example, the first phosphor 21 is detachably attached to the upper end of the dark box 23 via a first attachment / detachment mechanism 24A. Note that the angle of the reflector 27 of the fifth embodiment cannot be changed and is provided fixedly.

[0083] As shown in FIG. 15, by removing the first phosphor 21 from the dark box 23, the second phosphor 22 can be detachably attached to the upper end of the dark box 23 via the second attachment / detachment mechanism 25A.

[0084] In the fifth embodiment, the first phosphor 21 and the second phosphor 22 can be attached at the same position on the dark box 23 in a state where they can be interchanged.

[0085] The reflector 27 in the fifth embodiment may be an angle-changeable reflector 27, as in the first embodiment. The radiation measurement device 20B in the fifth embodiment may include a rotation mechanism 45 that rotates the detector 26, as in the fourth embodiment. The dark box 23 in the fifth embodiment is attached to the same stands 31, 31A, and 31B as in the first to fourth embodiments, and measurements are performed. However, the first phosphor 21 and the second phosphor 22 are replaced depending on the measurement item of the beam B. The orientation of the dark box 23 is also changed depending on the first phosphor 21 or the second phosphor 22.

[0086] The present invention has been described above based on the first to fifth embodiments, but the configuration applied in any of the embodiments may be applied to other embodiments, and the configurations applied in each embodiment may be combined.

[0087] The measurement computer of the above-described embodiment includes a control device with a highly integrated processor such as a CPU, GPU, FPGA (Field Programmable Gate Array), or dedicated chip; a storage device such as ROM and RAM; an external storage device such as an HDD or SSD; a display device such as a monitor; an input device such as a mouse and keyboard; and a communication interface. This measurement computer can be realized with a hardware configuration using a conventional computer. This measurement computer can also be configured by combining separate modules that independently perform the functions of the components and are interconnected via a network or dedicated lines.

[0088] The program executed by the measurement computer in the above-described embodiment is provided by being pre-installed in a ROM or the like. Additionally or alternatively, the program is provided by being stored as an installable or executable file on a non-transitory storage medium readable by a typical computer. This storage medium includes a CD-ROM, a CD-R, a memory card, a DVD, a flexible disk (FD), and the like.

[0089] This program may also be stored in a predetermined computer connected to a network such as the Internet and provided by being downloaded via the network.

[0090] Although the above-described embodiment illustrates a human patient P as an irradiation target to be irradiated with the beam B, other embodiments are also possible. For example, animals such as dogs and cats may be irradiated. The particle beam therapy system 1 may be used to administer radiation therapy to these animals.

[0091] In the above-described embodiment, only the light emission L1 generated from the first phosphor 21 is reflected by the reflector 27 toward the detector 26, but other configurations are also possible. For example, the light emissions L1 and L2 of both the first phosphor 21 and the second phosphor 22 may be reflected by the reflector 27, and the light emissions L1 and L2 guided to the detector 26 may be switched depending on the angle of the reflector 27.

[0092] In the above-described embodiment, the light emissions L1, L2 guided to the detector 26 are switched by the reflector 27, but other aspects are also possible. For example, the light emissions L1, L2 guided to the detector 26 may be switched by changing the position or orientation of the detector 26 without providing the reflector 27.

[0093] In the above-described embodiment, the reflector 27 is configured as a mirror, but other configurations are also possible. For example, the reflector 27 may be a half mirror or a prism. Furthermore, the function of refraction of light may be used in addition to or instead of the function of reflection of light.

[0094] The types, shapes, and arrangements of the first phosphor 21 and the second phosphor 22 are not limited to those in the above-described embodiment, and may be other forms. For example, three or more phosphors may be provided in one dark box 23.

[0095] According to at least one of the embodiments described above, by providing a detector 26 that detects the luminescence L1 generated from the first phosphor 21 when the beam B is irradiated onto the first phosphor 21, and that detects the luminescence L2 generated from the second phosphor 22 when the beam B is irradiated onto the second phosphor 22, it is possible to easily switch between measurements when performing measurements in both directions perpendicular to and parallel to the beam B.

[0096] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and modifications thereof are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0097] DESCRIPTION OF SYMBOLS 1, 1A... particle beam therapy system, 2... treatment room, 3... particle beam generator, 4... transport path, 5, 6... particle beam irradiation device, 7... irradiation control device, 8... treatment table, 9... table control device, 10... table operation terminal, 11, 12... irradiation port, 13... floor, 20, 20A, 20B... radiation measurement device, 21... first phosphor, 22... second phosphor, 23... dark box, 24, 24A... first attachment / detachment mechanism, 25, 25A... second attachment / detachment mechanism, 26... detector, 27... reflector, 28... angle change mechanism , 29...opening, 30...light-shielding door, 31, 31A, 31B...mounting stand, 32, 32A...position change mechanism, 33...base, 34...support, 35...lifting device, 36...frame, 37...horizontal rail, 38...vertical rail, 39...detachable fittings, 40...rotating gantry, 41...gantry control device, 42...gantry operation terminal, 43...particle beam irradiation device, 44...irradiation port, 45...rotation mechanism, 46...light-receiving surface, 47...axis, B...beam, L1, L2...emission, P...patient.

Claims

1. A dark box and a first phosphor attached to the dark box and emitting light in response to radiation; a second phosphor attached to the dark box and emitting light in response to the radiation; a detector provided inside the dark box, the detector detecting luminescence generated from the first phosphor when the first phosphor is irradiated with the radiation beam, and detecting luminescence generated from the second phosphor when the second phosphor is irradiated with the radiation beam; a reflector provided inside the dark box and configured to reflect light emitted from at least one of the first phosphor and the second phosphor toward the detector; Equipped with Radiation measurement device.

2. the first phosphor measures at least the irradiation field of the beam; The second phosphor measures at least the range of the beam. The radiation measurement device according to claim 1 .

3. the first phosphor is attached to a first position of the dark box; the second phosphor is attached to a second position of the dark box that is different from the first position; The radiation measurement device according to claim 1 or 2.

4. The dark box has an opening for a user to change the angle of the reflector. The radiation measurement device according to claim 1 .

5. An angle changing mechanism is provided for changing the angle of the reflector. The radiation measurement device according to claim 1 .

6. the detector sends the detection result together with information indicating the angle of the reflector to a computer; When outputting the detection result as an image or a numerical value, the computer switches the output format depending on the angle of the reflector. The radiation measurement device according to claim 1 .

7. a rotation mechanism that rotates the detector around an axis perpendicular to the light receiving surface of the detector, The radiation measurement device according to claim 1 or 2.

8. a stand for mounting the dark box on a treatment table of a particle beam therapy system; The radiation measurement device according to claim 1 or 2.

9. The stand includes a position change mechanism that changes the position of the dark box while being fixed to the treatment table. The radiation measurement device according to claim 8.

10. a stand for attaching the dark box to an irradiation port of a particle beam therapy system; The radiation measurement device according to claim 1 or 2.

11. the stand includes a position change mechanism that changes the position of the dark box while being fixed to the irradiation port; The radiation measurement device according to claim 10.

12. a first attachment / detachment mechanism that detachably attaches the first phosphor to the dark box; a second attachment / detachment mechanism that detachably attaches the second phosphor to the dark box; Equipped with The radiation measurement device according to claim 1 or 2.

13. the first attachment / detachment mechanism and the second attachment / detachment mechanism are respectively provided at a first position of the dark box and a second position of the dark box different from the first position; The radiation measurement device according to claim 12.

14. A dark box and a first phosphor attached to the dark box and emitting light in response to radiation; a second phosphor attached to the dark box and emitting light in response to the radiation; a detector provided inside the dark box for detecting luminescence; a reflector provided inside the dark box and reflecting emitted light; This is a method using the detector detects luminescence produced by the first phosphor when the beam of radiation is irradiated onto the first phosphor; the detector detects luminescence produced by the second phosphor when the beam is irradiated onto the second phosphor; the detector reflects the emitted light from at least one of the first phosphor or the second phosphor toward the detector; Radiation measurement methods.

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