JP7169830B2 - Neutron capture therapy system - Google Patents

Description

The present invention relates to a neutron capture therapy system.

As a neutron capture therapy system for irradiating a patient with neutron beams, the one described in Patent Document 1 is known. This neutron capture therapy system includes a mounting table on which a patient is placed, and a neutron beam irradiation section that irradiates the patient mounted on the mounting table with neutron beams. A laser sensor is used to align the patient placed on the mounting table with the neutron beam irradiation unit.

JP 2015-231497 A

In the neutron capture therapy system described above, the positioning accuracy cannot be quantified because the laser sensor is used to align the patient. Therefore, there is room for improvement in patient registration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a neutron capture therapy system capable of improving the positioning accuracy of a patient with respect to a neutron beam irradiation unit.

In order to achieve the above object, a neutron capture therapy system according to one aspect of the present invention is a neutron capture therapy system for irradiating a patient with neutron beams, comprising: a mounting table on which the patient is placed; a neutron beam irradiation unit that irradiates a neutron beam to a patient who has been placed thereon; and a position detection unit that detects the position of the patient. A first marker unit attached to a patient placed on a mounting table, reflecting a first electromagnetic wave from the emitting unit, or receiving the first electromagnetic wave and emitting a second electromagnetic wave different from the first electromagnetic wave. and a calculation unit that acquires the reflected wave from the first marker unit or the second electromagnetic wave and calculates the position of the first marker unit in three-dimensional coordinates.

The neutron capture therapy system described above comprises a position detector for detecting the position of the patient. The position detection unit includes an emitting unit that emits a first electromagnetic wave toward the mounting table, and is attached to the patient placed on the mounting table and reflects the first electromagnetic wave from the emitting unit or emits the first electromagnetic wave. A first marker unit that receives and emits a second electromagnetic wave different from the first electromagnetic wave, a reflected wave from the first marker unit, or a second electromagnetic wave is acquired, and the first marker in three-dimensional coordinates and a computing unit that computes the position of the part. For example, when trying to detect a patient placed on a table with a CT device, the CT device interferes with the neutron beam irradiator, so the measurement cannot be performed. On the other hand, since the position detection section detects the position using electromagnetic waves, it is possible to quantitatively acquire the position of the first marker section while avoiding the above-described interference between devices. Therefore, the position detection section can quantitatively acquire the patient's position in the three-dimensional coordinates based on the position of the first marker section. As a result, the position detection unit can three-dimensionally and quantitatively determine whether or not the patient is displaced from the neutron beam irradiation unit. can be obtained. As described above, it is possible to improve the positional accuracy of the patient with respect to the neutron beam irradiation unit.

The position detection unit is attached to at least one of the neutron beam irradiation unit and the mounting table, reflects the first electromagnetic wave from the emission unit, or receives the first electromagnetic wave and generates a third electromagnetic wave different from the first electromagnetic wave. The device may further include a second marker unit that emits, and the calculation unit may obtain a reflected wave or a third electromagnetic wave from the second marker unit and calculate the position of the second marker unit in three-dimensional coordinates. . In the neutron capture therapy system, the positions of the neutron beam irradiation unit and the mounting table are fixed during treatment. Therefore, the position detection section can quantitatively acquire the position of the neutron beam irradiation section in three-dimensional coordinates based on the position of the second marker section. This makes it easier for the position detection unit to determine the displacement of the patient with respect to the neutron beam irradiation unit.

The calculation unit may calculate the relative positional relationship between the patient and the neutron beam irradiation unit based on the position of the first marker unit and the position of the second marker unit. Accordingly, the position detection unit can determine the displacement of the patient with respect to the neutron beam irradiation unit based on the relative positional relationship between the patient and the neutron beam irradiation unit in three-dimensional coordinates.

The emitting portion may emit infrared radiation as the first electromagnetic wave and the first marker portion may reflect the infrared radiation. By using infrared rays as electromagnetic waves, the position of the first marker portion can be obtained accurately without affecting the device.

At least two second marker portions may be provided on the surface of the irradiation hole through which the neutron beam passes or the surface of the wall portion in which the irradiation hole is formed. In this case, the computing unit can accurately acquire the center point of the irradiation hole based on at least two second marker parts in the vicinity of the irradiation hole through which the neutron beam is emitted. By determining the displacement of the patient with respect to the center point of the irradiation aperture, the patient can be more accurately irradiated with the neutron beam.

A neutron capture therapy system according to one aspect of the present invention is a neutron capture therapy system that irradiates a patient with a neutron beam, and includes a mounting table on which the patient is placed, and a neutron beam to the patient placed on the mounting table. A neutron beam irradiation unit for irradiation and a position detection unit for detecting the position of the patient are provided, and the position detection unit is configured by a motion capture system.

The neutron capture therapy system described above comprises a position detector for detecting the position of the patient. The position detector is configured by a motion capture system. For example, when trying to detect a patient placed on a table with a CT device, the CT device interferes with the neutron beam irradiator, so the measurement cannot be performed. On the other hand, the motion capture system can quantitatively acquire the patient's position in three-dimensional coordinates while avoiding the interference between devices as described above. As a result, the position detection unit can three-dimensionally and quantitatively determine whether or not the patient is displaced from the neutron beam irradiation unit. can be obtained. As described above, it is possible to improve the positional accuracy of the patient with respect to the neutron beam irradiation unit.

ADVANTAGE OF THE INVENTION According to this invention, the neutron capture therapy system which can improve the positional accuracy of the patient with respect to a neutron beam irradiation part can be provided.

1 is a block diagram of a treatment system including a neutron capture therapy system according to an embodiment of the invention; FIG. It is a figure showing composition of a neutron capture therapy system concerning an embodiment of the present invention. It is a figure which shows the neutron beam irradiation part vicinity in the neutron capture therapy system of FIG. It is the figure which looked at the neutron beam irradiation part from the irradiation chamber side. It is an enlarged view which shows the positional relationship of a collimator and a patient. 4 is a flow chart showing processing in a computing unit; FIG. 2 illustrates a method for determining patient misalignment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

A schematic configuration of a treatment system 150 including a neutron capture therapy system 100 according to this embodiment will be described with reference to FIG. As shown in FIG. 1, treatment system 150 includes treatment planning device 130 and neutron capture therapy system 100 . The neutron capture therapy system 100 is a system for performing treatment by neutron capture therapy in which a patient S is irradiated with a neutron beam N. As shown in FIG.

The treatment planning device 130 is a device that prepares in advance a treatment plan for how to irradiate the patient S with neutron beams. The treatment planning device 130 grasps the position of the tumor of the patient S from a CT image or the like, and also determines what kind of posture the patient should take in order to irradiate the tumor with neutron beams. The treatment planning device 130 transmits the created treatment plan to the neutron capture therapy device 110 . Thereby, the neutron capture therapy apparatus 110 irradiates a neutron beam based on the treatment plan.

The neutron capture therapy system 100 includes a neutron capture therapy device 110 and a position detection system 120 (position detector). The neutron capture therapy device 110 is a device that performs treatment by neutron capture therapy based on the treatment plan set by the treatment planning device 130 . The position detection system 120 is a system that detects the patient's S position. The position detection system 120 can detect the relative positional relationship between the patient S and the neutron capture therapy device 110 during treatment.

An overview of the neutron capture therapy system 100 will be described with reference to FIGS. 2 and 3. FIG. As shown in FIGS. 2 and ³ , the neutron capture therapy apparatus for performing cancer treatment using boron neutron capture therapy has a neutron It is a system that performs cancer treatment by irradiating radiation. Treatment by the neutron capture therapy apparatus 110 is performed in an irradiation room 2 in which a patient S restrained on a mounting table 3 is irradiated with neutron beams N. As shown in FIG.

Preparatory work such as restraining the patient S to the mounting table 3 is performed in a preparation room (not shown) outside the irradiation room 2, and the mounting table 3 with the patient S restrained is moved from the preparation room to the irradiation room 2. . After that, the mounting table 3 is installed at a predetermined position in front of the exit port of the irradiation chamber 2 . In addition, the neutron capture therapy apparatus 110 includes a mounting table 3 on which the patient S is mounted, a neutron beam generation unit 10 for generating a neutron beam N for treatment, and a mounting table 3 placed in the irradiation chamber 2. and a neutron beam irradiation unit 20 for irradiating a neutron beam N to a patient S who is present. Although the irradiation chamber 2 is covered with a shielding wall W, a passageway and a door 41 are provided for the passage of patients, workers, and the like.

The neutron beam generation unit 10 includes an accelerator 11 that accelerates charged particles and emits a charged particle beam L, a beam transport path 12 that transports the charged particle beam L emitted by the accelerator 11, and a charged particle beam L that scans. A charged particle beam scanning unit 13 that controls the irradiation position of the charged particle beam L with respect to the target 8, a target 8 that causes a nuclear reaction to generate a neutron beam N by being irradiated with the charged particle beam L, and a charged particle beam. and a current monitor 16 that measures the current in L. The accelerator 11 and the beam transport path 12 are arranged in a substantially rectangular charged particle beam generation chamber 14. The charged particle beam generation chamber 14 is a space covered with a shield wall W made of concrete. . The charged particle beam generation chamber 14 is provided with a passageway and a door 42 for maintenance workers to pass through. In addition, the charged particle beam generation chamber 14 is not limited to a substantially rectangular shape, and may have another shape. For example, if the path from the accelerator to the target is L-shaped, the charged particle beam generation chamber 14 may also be L-shaped. Also, the charged particle beam scanning unit 13 controls, for example, the irradiation position of the charged particle beam L with respect to the target 8 , and the current monitor 16 measures the current of the charged particle beam L with which the target 8 is irradiated.

The accelerator 11 accelerates charged particles such as protons to generate charged particle beams L such as proton beams. A cyclotron is employed as the accelerator 11 in this embodiment. As the accelerator 11, instead of the cyclotron, another accelerator such as a circular accelerator (for example, a synchrotron), a linear accelerator, or an electrostatic accelerator may be used.

One end (upstream end) of the beam transport path 12 is connected to the accelerator 11 . The beam transport path 12 includes a beam adjuster 15 that adjusts the charged particle beam L. As shown in FIG. The beam adjustment unit 15 includes a horizontal steering electromagnet and a horizontal/vertical steering electromagnet for adjusting the axis of the charged particle beam L, a quadrupole electromagnet for suppressing the divergence of the charged particle beam L, and a quadrupole electromagnet for shaping the charged particle beam L. It has a slit or the like. The beam transport path 12 only needs to have the function of transporting the charged particle beam L, and the beam adjuster 15 may be omitted.

The charged particle beam L transported by the beam transport path 12 is irradiated onto the target 8 while the irradiation position is controlled by the charged particle beam scanning unit 13 . It should be noted that the charged particle beam scanning unit 13 may be omitted so that the same portion of the target 8 is always irradiated with the charged particle beam L.

The target 8 generates a neutron beam N by being irradiated with the charged particle beam L. As shown in FIG. The target 8 is made of, for example, beryllium (Be), lithium (Li), tantalum (Ta), or tungsten (W), and has a plate shape. However, the target is not limited to a plate shape, and may be liquid or the like. The neutron beam N generated by the target 8 is irradiated toward the patient S in the irradiation room 2 by the neutron beam irradiation unit 20 .

The neutron beam irradiation unit 20 includes a moderator 21 that slows down the neutron beams N emitted from the target 8, and a shield 22 that shields radiation such as neutron beams N and gamma rays from being emitted to the outside, The moderator 21 and shield 22 constitute a moderator.

The moderator 21 has, for example, a laminated structure composed of a plurality of different materials. Specifically, for example, when the output from the accelerator 11 is a proton beam of 30 MeV and a beryllium target is used as the target 8, the material of the moderator 21 can be lead, iron, aluminum, or calcium fluoride.

The shield 22 is provided so as to surround the moderator 21, and has a function of shielding the neutron beams N and radiation such as gamma rays generated along with the generation of the neutron beams N from being emitted to the outside of the shield 22. have The shield 22 may or may not be embedded at least partially in the wall W1 separating the charged particle beam generation chamber 14 and the irradiation chamber 2 . A wall portion 23 forming a part of the side wall surface of the irradiation chamber 2 is provided between the irradiation chamber 2 and the shield 22 . The wall portion 23 is provided with a collimator mounting portion 23a serving as an output port for the neutron beams N. As shown in FIG. A collimator 31 for defining the irradiation field of the neutron beam N is fixed to the collimator mounting portion 23a. By changing the aperture shape of the collimator 31, the irradiation field of the neutron beam N can be defined. Note that the collimator 31 may be attached to the mounting table 3 without providing the collimator attachment portion 23 a to the wall portion 23 .

In the neutron beam irradiation unit 20 described above, the target 8 is irradiated with the charged particle beam L, and the target 8 generates the neutron beam N accordingly. The neutron beam N generated by the target 8 is moderated while passing through the moderator 21, and the neutron beam N emitted from the moderator 21 passes through the collimator 31 and is mounted on the mounting table 3. Irradiation is performed on a patient S who is present. Here, as the neutron beam N, a thermal neutron beam or an epithermal neutron beam with relatively low energy can be used.

The position detection system 120 includes a calculation section 121 , a detection section 122 , an emission section 123 , a first marker section 124 and a second marker section 125 . Such a position detection system 120 is configured by a motion capture system. A motion capture system can digitally measure the position and orientation of an object continuously over time.

The emitting part 123 emits electromagnetic waves (first electromagnetic waves) toward the mounting table 3 . Thereby, the emitting part 123 can apply the first electromagnetic wave to the marker parts 124 and 125 existing around the mounting table 3 . In this embodiment, the emitting part 123 emits infrared rays as electromagnetic waves. The detection unit 122 detects infrared rays (hereinafter sometimes referred to as reflected waves) reflected by the marker units 124 and 125 . The detection unit 122 transmits information on the detected reflected wave to the calculation unit 121 . In a motion capture system, a motion capture camera 127 comprises a detector 122 and an emitter 123 . The motion capture camera 127 transmits data obtained by shooting to the calculation unit 121 . Position detection system 120 includes multiple motion capture cameras 127 . That is, the position detection system 120 includes multiple pairs of sensing units 122 and emitting units 123 . The installation location of the motion capture camera 127 will be described later.

The first marker portion 124 is a member that is attached to the patient S placed on the mounting table 3 and reflects infrared rays emitted from the emitting portion 123 . Since the first marker part 124 is attached to the patient S, it moves according to changes in the patient's S position and posture. Therefore, the first marker part 124 reflects infrared rays at a position corresponding to the position and posture of the patient S in the three-dimensional space. The installation position of the first marker portion 124 will be described later.

The second marker part 125 is a member that is attached to at least one of the neutron beam irradiation part 20 and the mounting table 3 and that reflects infrared rays from the emission part 123 . The second marker part 125 is attached to the neutron beam irradiation part 20 and the treatment third, which are in a state of being fixed at a specific position at least during treatment. Therefore, the second marker part 125 reflects infrared rays at a fixed position in the three-dimensional space, at least during treatment. The installation position of the second marker portion 125 will be described later.

The calculation unit 121 acquires the reflected wave from the first marker unit 124 and the reflected wave from the second marker unit 125 via the detection unit 122 . The computing unit 121 computes the positions of the marker units 124 and 125 in the three-dimensional coordinates based on the acquired reflected waves. The computation unit 121 computes the relative positional relationship between the patient S and the neutron beam irradiation unit 20 based on the position of the first marker unit 124 and the position of the second marker unit 125 . Based on the positions of the plurality of first marker portions 124, the calculation unit 121 calculates the patient representative points (for example, the positions of the plurality of first marker portions 124 (124A, 124B, 124C) as shown in FIG. ) may be calculated. Further, the computing unit 121 may compute the position of the device representative point (for example, the center point CP of the irradiation hole 31a of the collimator 31 shown in FIG. 5) based on the positions of the plurality of second marker units 125 . The calculation unit 121 quantitatively (quantifies) the relative positional relationship between the patient S and the neutron beam irradiation unit 20 by grasping the relative positional relationship in the three-dimensional coordinates between the patient representative point and the device representative point. ) can be grasped.

The calculation unit 121 can determine the displacement of the patient S in the relative positional relationship between the patient S and the neutron beam irradiation unit 20 . For example, the calculation unit 121 refers to the positional relationship between the patient representative point and the apparatus representative point described above, and calculates the distance of the patient representative point to the apparatus representative point in the X-axis direction, the Y-axis direction, and the distance in the Z-axis direction. When it is determined that at least one of them has deviated from the allowable range, it can be determined that the position of the patient S has deviated. Such allowable values are set in advance before treatment. For example, the reference position (ideal position) of the patient representative point with respect to the device representative point is determined, and the allowable deviation from the reference position is determined in the X-axis direction, Y-axis direction, and Z-axis direction. . Note that the setting of such a reference position may be performed by the treatment planning apparatus 130 performing a simulation using a 3D model. Alternatively, the reference position may be set by having the patient S take an actual posture during treatment in front of the neutron beam irradiation unit 20 before treatment.

Moreover, the calculating part 121 performs a notification process, when it determines with the position of the patient S having shifted|deviated. The notification process may be performed by display on a display or guidance by voice. Alternatively, the notification process may be performed by interlocking the neutron capture therapy device 110 . At this time, the calculation unit 121 can grasp the direction and amount of deviation from the reference position or the allowable range in the XYZ coordinates. Therefore, the calculation unit 121 may quantitatively provide information about which direction and how much the patient S should be moved.

Next, a specific installation example of the marker units 124 and 125 and a specific calculation example will be described with reference to FIGS. 4 and 5. FIG. The second marker part 125 is preferably arranged at a position where the center point CP (see FIG. 5) of the irradiation hole 31a of the collimator 31 can be easily determined. Since the center point CP of the irradiation hole 31a of the collimator 31 through which the neutron beam passes cannot be set at the center point CP itself, the second marker part 125 is arranged on the surface of the irradiation hole 31a of the collimator 31 or the surface of the wall part 23. is preferred. When arranging the second marker part 125 on the wall part 23 , it is preferable to arrange it near the collimator 31 . Moreover, it is preferable that at least two second marker portions 125 are installed in order to determine the center point CP. Also, in anticipation of occurrence of second marker portions 125 that cannot be photographed by the motion capture camera 127 due to obstruction by the patient S, it is preferable to set three or more second marker portions 125 . In the example shown in FIG. 4, three second marker portions 125A, 125B, 125C are provided on the surface of the wall portion 23 near the collimator 31 so as to surround the collimator 31 . The second marker portion 125A is provided on the upper side of the collimator 31, the second marker portion 125B is provided on the right side of the collimator 31, and the second marker portion 125C is provided on the left side of the collimator 31.

It is preferable that one first marker section 124 has a positional relationship such that it is photographed by at least three motion capture cameras 127 . Also, it is preferable that one second marker section 125 has a positional relationship such that it is photographed by at least two, preferably three motion capture cameras 127 . For example, three motion capture cameras 127 may be provided, each capable of photographing three first marker units 124 and three second marker units 125 . However, if the marker portions 124 and 125 that are hidden by the patient S or the mounting table 3 are generated from the position of a certain motion capture camera 127, the number of motion capture cameras 127 capable of capturing images from other positions may be increased. The motion capture camera 127 is preferably arranged at a position where the marker portions 124 and 125 are not hidden by the mounting table 3, the patient S, or the like. It is preferable that the motion capture camera 127 be positioned so as to look into the collimator 31 . Therefore, the motion capture camera 127 is preferably arranged above the collimator 31 or on the side wall of the irradiation chamber 2 and close to the wall 23 . In the example shown in FIG. 4 , the motion capture camera 127A is provided above the collimator 31 in the wall section 23 . The motion capture camera 127B is provided on the side wall of the irradiation chamber 2 at a position near the wall 23 and near the ceiling. The motion capture camera 127C is provided on the side wall of the irradiation chamber 2 at a position near the wall 23 and near the floor.

The first marker part 124 is attached to a site of the patient S near the collimator 31 . For example, the first marker portion 124 may be provided at an ear hole, mole, nose tip, eye corner, and the like. It is preferable that at least three first marker portions 124 are provided so that a representative point of the patient S can be determined in three-dimensional coordinates. In the example shown in FIG. 5, the first marker portion 124A is provided near the ear canal, the first marker portion 124B is provided near the head, and the first marker portion 124C is provided at the tip of the nose. .

Here, an example of the processing of the calculation unit 121 during treatment will be described with reference to the flowchart of FIG. The calculation unit 121 acquires the position of the neutron beam irradiation unit 20 by acquiring the positions of the second marker units 125A, 125B, and 125C captured by the motion capture cameras 127A, 127B, and 127C (step S10). At this time, the calculation unit 121 calculates the center point CP of the irradiation hole 31a as the apparatus representative point. For example, the positional relationship between the second marker portions 125A, 125B, and 125C and the center point CP is grasped in advance before treatment, and the calculation unit 121 calculates the positional relationship information and the second marker obtained in S10. By comparing the position information of the marker portions 125A, 125B, and 125C, the center point CP is determined.

Here, the calculation unit 121 sets the reference position of the patient representative point based on the position of the center point CP (step S20). The calculation unit 121 sets the reference position by reading data that is predetermined before treatment. Next, the calculation unit 121 acquires the position of the patient S by acquiring the positions of the first marker units 124A, 124B, and 124C captured by the motion capture cameras 127A, 127B, and 127C (step S30). For example, when the ideal position of the center of gravity GP is set as the reference position SP, the calculator 121 calculates the center of gravity GP as the patient representative point. Alternatively, when the ideal positions of the first marker portions 124A, 124B, and 124C are set to the reference positions PA, PB, and PC (see FIG. 5B), the calculation portion 121 calculates the first marker portions 124A, 124B , 124C is set as a patient representative point.

Next, the calculation unit 121 compares the positional relationship between the reference position SP and the patient representative point to determine whether there is any deviation in the position of the patient S (step S40). As shown in FIG. 5A, when the center of gravity GP matches the reference position SP, the calculation unit 121 determines that the position of the patient S does not shift. On the other hand, as shown in FIG. 5B, when the center of gravity GP is arranged at a position different from the reference position SP, the calculation unit 121 considers the magnitude of the displacement amount, It is determined whether or not there is When the reference positions PA, PB, and PC are used, as shown in FIG. The unit 121 determines whether or not there is any deviation in the position of the patient S by considering the magnitude of the deviation amount at each point.

For example, as shown in FIG. 7A, the permissible range of the amount of deviation from the reference position SP is defined for each of the X-axis direction, the Y-axis direction, and the Z-axis direction. The calculation unit 121 determines that the position of the patient S is shifted when the center of gravity GP is arranged outside the rectangular parallelepiped set by the allowable range. Also, as shown in FIG. 7B, an allowable value for the amount of deviation is defined with respect to the reference position SP. The calculation unit 121 determines that the position of the patient S is shifted when the center of gravity GP is located outside the sphere whose radius is set to the allowable value. The same is true when using the reference positions PA, PB, and PC.

When determining in S40 that there is no deviation, the calculation unit 121 determines whether or not the treatment has been completed (step S50). If it is determined that the treatment has been completed, the processing shown in FIG. 6 ends. On the other hand, if it is determined that the treatment has not been completed, the process is repeated from S30. Thereby, the position of the patient S is constantly monitored during treatment.

When determining that there is a deviation in S40, the calculation unit 121 performs notification processing to the effect that there is a deviation (step S60). At this time, irradiation of the neutron beam may be stopped. Further, the calculation unit 121 may display the direction of deviation and the amount of deviation. After S60 ends, the process is repeated from S30, or the process shown in FIG. 6 is temporarily terminated.

Next, the action and effect of the neutron capture therapy system 100 according to this embodiment will be described.

The neutron capture therapy system 100 described above includes a position detection system 120 that detects the position of the patient S. As shown in FIG. The position detection system 120 is attached to the emitting portion 123 that emits the first electromagnetic wave toward the mounting table 3 and the patient S placed on the mounting table 3 and reflects the first electromagnetic wave from the emitting portion 123. A first marker unit 124 and a calculation unit 121 that acquires a reflected wave from the first marker unit 124 and calculates the position of the first marker unit 124 in three-dimensional coordinates. For example, when trying to detect the patient S placed on the mounting table 3 with a CT device, the CT device and the neutron beam irradiation unit 20 interfere with each other, so the measurement cannot be performed. Such a problem is peculiar to the neutron capture therapy system in which the patient S has to fix his posture with the affected area brought close to the irradiation hole 31a of the neutron beam irradiation unit 20 among radiation therapy. On the other hand, since the position detection system 120 detects the position using electromagnetic waves, it is possible to quantitatively obtain the position of the first marker unit 124 while avoiding the interference between devices as described above. can. Therefore, the position detection system 120 can quantitatively acquire the position of the patient S in three-dimensional coordinates based on the position of the first marker section 124 . As a result, the position detection system 120 can three-dimensionally and quantitatively determine whether or not the patient S is displaced from the neutron beam irradiation unit 20. can be obtained quantitatively. As described above, the positional accuracy of the patient S with respect to the neutron beam irradiation unit 20 can be improved.

The position detection system 120 further includes a second marker unit 125 attached to at least one of the neutron beam irradiation unit 20 and the mounting table 3 and reflecting the first electromagnetic wave from the emission unit 123. A reflected wave from the second marker portion 125 is acquired, and the position of the second marker portion 125 in the three-dimensional coordinates is calculated. In the neutron capture therapy system 100, the positions of the neutron beam irradiation unit 20 and the mounting table 3 are fixed during therapy. Therefore, the position detection system 120 can quantitatively acquire the position of the neutron beam irradiation section 20 in three-dimensional coordinates based on the position of the second marker section 125 . This makes it easier for the position detection system 120 to determine the displacement of the patient S with respect to the neutron beam irradiation unit 20 .

The computation unit 121 computes the relative positional relationship between the patient S and the neutron beam irradiation unit 20 based on the position of the first marker unit 124 and the position of the second marker unit 125 . Thus, the displacement of the patient S with respect to the neutron beam irradiation unit 20 can be determined based on the relative positional relationship between the patient S and the neutron beam irradiation unit 20 in the position detection system 120 and the three-dimensional coordinates.

The emitting portion 123 emits infrared rays as the first electromagnetic waves, and the first marker portion 124 reflects the infrared rays. By using infrared rays as electromagnetic waves, the position of the first marker section 124 can be obtained accurately without affecting the device.

At least two second marker portions 125 are provided on the surface of the irradiation hole 31a through which the neutron beam passes or the surface of the wall portion 23 in which the irradiation hole 31a is formed in the neutron beam irradiation portion 20 . In this case, the computing unit 121 can accurately acquire the center point CP of the irradiation hole 31a based on at least two second marker units 125 near the irradiation hole 31a through which the neutron beam is emitted. By determining the displacement of the patient S with respect to the center point CP of the irradiation hole 31a, the patient S can be irradiated with the neutron beam more accurately.

The neutron capture therapy system 100 according to this embodiment includes a position detection system 120 that detects the position of the patient S. Position detection system 120 is configured by a motion capture system. For example, when trying to detect the patient S placed on the mounting table 3 with a CT device, the CT device and the neutron beam irradiation unit 20 interfere with each other, so the measurement cannot be performed. On the other hand, the motion capture system can quantitatively acquire the position of the patient S in three-dimensional coordinates while avoiding the interference between devices as described above. As a result, the position detection system 120 can three-dimensionally and quantitatively determine whether or not the patient S is displaced from the neutron beam irradiation unit 20. can be obtained quantitatively. As described above, the positional accuracy of the patient S with respect to the neutron beam irradiation unit 20 can be improved.

The invention is not limited to the embodiments described above.

For example, although an optical motion capture system was used in the above-described embodiments, other types of motion capture systems may be used. Depending on the method, the motion capture camera 127 in which the emission unit 123 and the detection unit 122 are integrated may not be used. Also, a motion capture system using electromagnetic waves such as Wifi may be used.

The first electromagnetic waves emitted by the emitting portion 123 are not limited to infrared rays. For example, the emission part 123 may emit visible light, ultraviolet rays, or the like, or may emit ultrasonic waves. Also, the first marker portion 124 is not limited to reflecting the first electromagnetic wave, and may receive the first electromagnetic wave from the emitting portion 123 and emit a second electromagnetic wave different from the first electromagnetic wave. The second marker part 125 may also receive the first electromagnetic wave from the emitting part 123 and emit a third electromagnetic wave different from the first electromagnetic wave. For example, the emitting section 123 is an external excitation source that generates an electromagnetic field, the marker sections 124 and 125 are elements that resonate in the electromagnetic field and emit signals, and the detection section 122 detects signals from the marker sections 124 and 125. It may be a measurement sensor that Alternatively, the emitting portion 123 may be a radio wave source that emits radio waves, the marker portions 124 and 125 may be reflecting members that reflect radio waves, and the detection portion 122 may be a measurement sensor that detects the reflected radio waves.

In the above-described embodiment, the center of gravity GP is set as the patient representative point, and the deviation of the position of the patient S is determined using the deviation of the center of gravity GP from the reference position SP. Alternatively, the reference position is set with respect to the position of the first marker portion 124 itself. However, the method of obtaining representative points and the method of obtaining reference positions are not particularly limited, and may be changed as appropriate.

3... Mounting table 20... Neutron beam irradiation part 23... Wall part 31a... Irradiation hole 100... Neutron capture therapy system 120... Position detection system (position detection part) 121... Operation part 123... Emission part, 124 -- the 1st marker part, 125 -- the 2nd marker part.

Claims (3)

A neutron capture therapy system for irradiating a patient with a neutron beam,
a mounting table on which the patient is mounted;
a neutron beam irradiation unit that irradiates the patient placed on the mounting table with the neutron beam;
A position detection unit that detects the position of the patient,
The position detection unit is
an emission unit that emits a first electromagnetic wave toward the mounting table;
It is attached to the patient placed on the mounting table, reflects the first electromagnetic wave from the emitting part, or receives the first electromagnetic wave and emits a second electromagnetic wave different from the first electromagnetic wave. a first marker portion;
a calculation unit that acquires the reflected wave from the first marker unit or the second electromagnetic wave and calculates the position of the first marker unit in three-dimensional coordinates ;
The position detection unit is attached to at least one of the neutron beam irradiation unit and the mounting table, and reflects the first electromagnetic wave from the emission unit or receives the first electromagnetic wave and differs from the first electromagnetic wave. further comprising a second marker portion that emits a third electromagnetic wave;
The calculation unit acquires the reflected wave from the second marker unit or the third electromagnetic wave, calculates the position of the second marker unit in three-dimensional coordinates,
The neutron capture therapy system , wherein the computing unit computes a relative positional relationship between the patient and the neutron beam irradiation unit based on the position of the first marker unit and the position of the second marker unit . the emitting unit radiates infrared rays as the first electromagnetic wave,
The neutron capture therapy system according to claim 1 , wherein said first marker portion reflects said infrared rays. 3. The second marker part according to claim 1 or 2 , wherein at least two of the second marker parts are provided on the surface of the irradiation hole through which the neutron beam of the neutron beam irradiation passes, or the wall part in which the irradiation hole is formed. neutron capture therapy system.

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