JP6962206B2 - X-ray fluoroscope - Google Patents

Description

The present invention detects an X-ray emitted from an X-ray tube and passed through a subject by an X-ray detector, and obtains an image including a marker placed at a specific site of the subject or near a specific site of the subject. The present invention relates to an X-ray fluoroscope that is acquired and detects the position of a specific site or a marker from an image including a marker placed at the specific site of the subject or in the vicinity of the specific site of the subject.

In radiotherapy, which irradiates an affected area such as a tumor with radiation as a treatment beam such as X-rays or protons, it is necessary to accurately irradiate the affected area with radiation. However, not only may the subject move his / her body, but the affected area itself may also move. For example, tumors near the subject's lungs migrate significantly based on respiration. Therefore, a radiotherapy device having a configuration in which a gold marker having a spherical shape is placed near the tumor, the position of the marker is detected by an X-ray fluoroscope, and the irradiation of therapeutic radiation is controlled has been proposed. (See Patent Document 1).

In such a radiotherapy apparatus, a first X-ray imaging system composed of a first X-ray tube and a first X-ray detector and a second X-ray imaging system composed of a second X-ray tube and a second X-ray detector are used. A marker placed in the body is photographed, and three-dimensional position information is obtained by using a two-dimensional fluoroscopic image obtained by the first X-ray imaging system and a two-dimensional fluoroscopic image obtained by the second X-ray imaging system. In this way, X-ray fluoroscopy is continuously performed, and the three-dimensional position information of the marker is calculated in real time to detect and track the marker of the moving portion with high accuracy. Then, by controlling the irradiation of the therapeutic radiation based on the position information of the detected marker, it is possible to execute the irradiation with high accuracy according to the movement of the tumor. When obtaining the position information of this marker, image recognition such as template matching using a template image and machine learning using a classifier is executed.

Further, the first X-ray imaging system composed of the first X-ray tube and the first X-ray detector and the second X-ray imaging system composed of the second X-ray tube and the second X-ray detector are configured to be movable, and a plurality of angular positions are configured. An X-ray fluoroscope that detects a marker of a moving portion with high accuracy by photographing the marker from the marker and calculating the three-dimensional position information of the marker in real time has also been proposed (see Patent Document 2).

As described above, in order to detect the movement of the tumor using the marker, it is necessary to place the marker in the body of the subject in advance. On the other hand, in recent years, a method called markerless tracking has been proposed in which a specific site such as a tumor region of a subject is used instead of a marker to omit the placement of a marker.

Japanese Patent No. 3053389 Japanese Unexamined Patent Publication No. 2014-128412

Since such an X-ray fluoroscope has a configuration in which the position of a specific part or marker is detected using an X-ray image collected by an X-ray detector such as a flat panel detector, its detection performance is X-ray detection. It depends on the image quality of the X-ray image detected by the device. On the other hand, when the treatment beam is irradiated to the patient from the radiotherapy device, scattered rays are generated. When this scattered ray is incident on the X-ray detector that is acquiring the X-ray image, the contrast of the X-ray image acquired by the X-ray detector is lowered, or a phenomenon such as a difference in brightness occurs. The tracking performance of a specific part or marker using a line image is reduced. Such a phenomenon becomes particularly remarkable when a treatment beam having a high dose rate is used.

FIG. 8 is a timing chart showing the relationship between the irradiation of the conventional treatment beam, the irradiation of X-rays, and the operation of the flat panel detector (FPD) as an X-ray detector.

In the embodiment shown in FIG. 8, for convenience of explanation, a case where one X-ray image is acquired every 30 msec is shown. As for the X-ray image, in the case of 30 FPS (Frames Per Second), which is a general frame rate, one X-ray image is acquired every 33 msec. In the embodiment shown in FIG. 8, the treatment beam is irradiated every 5 msec, X-rays are emitted from the X-ray tube for a time of 3 msec, and the flat panel detector receives a charge signal to the capacitance every 15 msec. The accumulation and the reading of the charge signal accumulated in the capacitance are repeated. The timing of accumulating and reading out the flat panel detector has been fixed in the past, and has not been changed for each fluoroscopy.

In such a case, the treatment beam is irradiated six times while the flat panel detector acquires one X-ray image. Due to the influence of the irradiation of the treatment beam, the contrast of the X-ray image acquired by the flat panel detector is lowered, or a phenomenon such as a difference in brightness occurs, and the tracking of a specific site or marker using this X-ray image occurs. Performance will be reduced.

The present invention has been made to solve the above problems, reduce the influence of the treatment beam during fluoroscopy, and reduce the tracking performance of a specific site or marker using an X-ray image acquired by a flat panel detector. It is an object of the present invention to provide an X-ray fluoroscope capable of suppressing the above.

According to the first invention, when a subject is irradiated with a treatment beam by a treatment beam irradiator, X-rays irradiated from an X-ray tube and passed through the subject are detected by an X-ray detector, and the subject is described. By collecting an X-ray image including a marker placed in the body of the examiner or an X-ray image including a specific part of the subject, the marker or the identification that moves with the body movement of the subject. An X-ray fluoroscope that detects the position of a site, the X-ray detector is a plurality of pixel electrodes arranged in a matrix corresponding to pixels and acquiring a charge signal corresponding to an incident X-ray dose, and each of the above. A plurality of capacitances connected to pixel electrodes and accumulating charge signals, and a data bus line for reading charge signals accumulated in the plurality of capacitances are provided, and the plurality of pixels in the X-ray detector are provided. The region selection means for selecting a part of the pixel electrodes as the pixel electrodes used for X-ray detection and the read time of the charge signal from the capacitance corresponding to the pixel electrodes selected by the region selection means. It is characterized in that it is provided with a read-out time changing means for changing all the pixel electrodes to a shorter time as compared with the case where all the pixel electrodes are used for X-ray detection.

In the second invention, the storage time changing means for changing the storage time of the charge signal in the capacitance is further provided.

In the third invention, a reset means for resetting the charge signal accumulated in the capacitance immediately before starting the accumulation of the charge signal in the capacitance corresponding to the pixel electrode is further provided.

In the fourth invention, the region selection means selects a pixel electrode to be used for X-ray detection based on the movement range of the marker or the position of the specific portion that moves with the body movement of the subject. ..

In the fifth invention, even during the period of irradiating the subject with the treatment beam by the treatment beam irradiation device, the charge signal is accumulated in the capacitance and the charge signal is read out from the capacitance. conduct.

According to the first to fifth inventions, by limiting the pixel electrodes used for X-ray detection by the region selection means, the time for reading the charge signal from the capacitance corresponding to the selected pixel electrodes is shortened. By changing the read time of the charge signal within the range of the read time after shortening by the read time changing means, the influence of the treatment beam at the time of X-ray fluoroscopy is reduced, and the X-ray image acquired by the flat panel detector is used. It is possible to suppress a decrease in the tracking performance of a specific site or marker using the above.

According to the second invention, by changing the accumulation time of the charge signal in the capacitance within the range in which the X-ray image can be acquired by the accumulation time changing means, the influence of the treatment beam at the time of X-ray fluoroscopy is further increased. It is possible to reduce it.

According to the third invention, by resetting the charge signal accumulated in the capacitance immediately before the start of accumulation of the charge signal in the capacitance by the reset means, the influence of the treatment beam at the time of fluoroscopy is affected. It can be further reduced.

It is a perspective view which shows the X-ray fluoroscopy apparatus which concerns on this invention together with the treatment beam irradiation apparatus 90. This is an equivalent circuit with the flat panel detector 21 viewed from the side. This is an equivalent circuit in which the flat panel detector 21 is viewed in a plan view. It is a block diagram which shows the main control system of the X-ray fluoroscopy apparatus which concerns on 1st Embodiment of this invention. 6 is a timing chart showing the relationship between the irradiation of the treatment beam, the irradiation of X-rays, and the operation of the flat panel detector 21 as an X-ray detector according to the first embodiment of the present invention. It is a block diagram which shows the main control system of the X-ray fluoroscopy apparatus which concerns on 2nd Embodiment of this invention. 6 is a timing chart showing the relationship between the irradiation of the treatment beam, the irradiation of X-rays, and the operation of the flat panel detector 21 as an X-ray detector according to the second embodiment of the present invention. It is a timing chart which shows the relationship between the irradiation of a conventional treatment beam, the irradiation of X-rays, and the operation of a flat panel detector as an X-ray detector.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an X-ray fluoroscope according to the present invention together with a treatment beam irradiation device 90. A radiotherapy device is configured by these X-ray fluoroscopy devices and a treatment beam irradiation device 90.

The treatment beam irradiation device 90 irradiates the subject on the examination table 27 with radiation, and the gantry 92 is oscillatingly installed with respect to the base 91 installed on the floor of the treatment room. And a treatment beam irradiation unit 93 arranged in the gantry 92 for emitting the treatment beam. The gantry 92, together with the treatment beam irradiation unit 93, has a structure that can rotate within a range of 360 degrees with respect to the base 91. Therefore, according to the treatment beam irradiation device 90, the irradiation direction of the treatment beam emitted from the treatment beam irradiation unit 93 can be changed by rotating the gantry 92 to an arbitrary angle with respect to the base 91. .. Therefore, it is possible to irradiate the affected part such as a tumor in the subject with a treatment beam from various directions.

The X-ray fluoroscope used together with the treatment beam irradiation device 90 performs X-ray fluoroscopy for tracking a moving object to identify the position of the affected portion of the subject. That is, at the time of radiotherapy using the above-mentioned treatment beam irradiation device 90, it is necessary to accurately irradiate the affected portion that moves with the body movement of the subject. Therefore, in this X-ray fluoroscope, a subject is seen through from two different directions, and image recognition is performed on the perspective image to obtain a specific part of the subject or a specific part of the subject. The position of markers placed in the vicinity (hereinafter collectively referred to as "markers, etc.") is detected, and the three-dimensional position information of the markers, etc. is calculated to detect the markers, etc. with high accuracy, so-called. , It is configured to track moving objects.

As one embodiment of this image recognition, a template in which an image of a marker placed near a specific part of a subject is registered in advance as a template, and the position of the marker is detected and tracked using this template. Matching is used. Instead of placing a marker near the affected area in the subject, moving object tracking using an image of a specific site such as a tumor in the subject as a marker may also be adopted.

Further, as another embodiment of this image recognition, a classifier is created by learning from a large number of correct and incorrect image images registered in advance for a marker or the like, and the marker or the like is used by using the classifier. Machine learning is used to detect and track location. As such machine learning, for example, SVM (Support Vector Machine / Support Vector Machine) can be used. This SVM is one of the learning models having the fastest speed and the highest recognition performance among many methods when performing pattern recognition. Further, as machine learning having excellent recognition performance, a neural network such as Boosting based on Har-like features or Deep Learning may be used instead of SVM.

This X-ray fluoroscope includes a first X-ray tube 11a, a second X-ray tube 11b, a third X-ray tube 11c, a fourth X-ray tube 11d (collectively referred to as "X-ray tube 11"), and a first. It includes a flat panel detector 21a, a second flat panel detector 21b, a third flat panel detector 21c, and a fourth flat panel detector 21d (collectively referred to as "flat panel detector 21"). The X-rays emitted from the first X-ray tube 11a pass through the subject on the examination table 27 and then are detected by the first flat panel detector 21a. The first X-ray tube 11a and the first flat panel detector 21a form a first X-ray imaging system. The X-rays emitted from the second X-ray tube 11b pass through the subject on the examination table 27 and then are detected by the second flat panel detector 21b. The second X-ray tube 11b and the second flat panel detector 21b form a second X-ray imaging system. The X-rays emitted from the third X-ray tube 11c pass through the subject on the examination table 27 and then are detected by the third flat panel detector 21c. The third X-ray tube 11c and the third flat panel detector 21c form a third X-ray imaging system. The X-rays emitted from the 4th X-ray tube 11d pass through the subject on the examination table 27 and then are detected by the 4th flat panel detector 21d. The 4th X-ray tube 11d and the 4th flat panel detector 21d constitute a 4th X-ray imaging system.

When performing X-ray fluoroscopy for tracking a moving object, two X-ray imaging systems of the first X-ray imaging system, the second X-ray imaging system, the third X-ray imaging system, and the fourth X-ray imaging system are used. Selected and used.

The examination table 27 includes a base 28 and a subject mounting unit 29, which is also called a couch. The subject mounting portion 29 is movable and rotatable in six axial directions with respect to the base portion 28.

Next, the configuration of the flat panel detector 21 described above will be described. FIG. 2 is an equivalent circuit in which the flat panel detector 21 is viewed from the side. Further, FIG. 3 is an equivalent circuit in which the flat panel detector 21 is viewed in a plan view.

As shown in these figures, the flat panel detector 21 includes a glass substrate 41, a TFT (thin film transistor) 42 formed on the glass substrate 41, and a conversion film such as a-Se deposited on the TFT. 43 and a common electrode 44 arranged on the conversion film 43 are provided.

The TFT has pixel electrodes 45, which are charge collecting electrodes, arranged in a vertical and horizontal matrix, that is, in a two-dimensional array. For example, 1024 x 1024 pixel electrodes 45 are arranged in the matrix direction. In FIGS. 2 and 3, a case where 3 × 3 are arranged in the matrix direction is schematically shown. A switching element 46 and a capacitance (capacitor) 47 are connected to each pixel electrode 45.

Each pixel electrode 45 is connected to the source S of each switching element 46. A plurality of gate bus lines 52 are connected to the gate driver 51 shown in FIG. 3, and these gate bus lines 52 are connected to the gate G of the switching element 46. On the other hand, as shown in FIG. 3, a plurality of data bus lines 55 are connected to the multiplexer 53 that collects charge signals and outputs them as one signal via an amplifier 54, and these data bus lines 55 are connected. , It is connected to the drain D of each switching element 46.

In the flat panel detector 21, when an X-ray image that has passed through the subject on the subject mounting portion 29 is projected onto the conversion film 43, a charge signal (carrier) proportional to the shading of the image is converted. It occurs in the membrane 43. This charge signal is collected by the pixel electrodes 45 arranged in a two-dimensional array and stored in the capacitance 47. Then, with the bias voltage applied to the common electrode 44, the gate G of each switching element 46 is turned on by applying the voltage to the gate bus line 52 by the gate driver 51. As a result, the charge signal accumulated in the capacitance 47 is read out to the data bus line 55 via the source S and the drain D in the switching element 46. The charge signals read out to each data bus line 55 are amplified by the amplifier 54, combined into one charge signal by the multiplexer 53, and output. This charge signal is digitized by the A / D converter 5 and output as an X-ray detection signal.

FIG. 4 is a block diagram showing a main control system of the X-ray fluoroscope according to the first embodiment of the present invention. In this figure, only the control system of the main part of the present invention is shown in the control system of the X-ray fluoroscope.

The X-ray fluoroscopy device according to the present invention includes a control unit 30 that controls the entire device and an input unit 31 into which various information is input by an operator. The control unit 30 is connected to each controller 39 in the flat panel detector 21. As a functional configuration, the control unit 30 includes an area selection unit 32 that selects a pixel electrode 45 to be used for X-ray detection among a plurality of pixel electrodes 45 in the flat panel detector 21, and a pixel selected by the area selection unit 32. The read-out time changing unit 33 that changes the read time of the charge signal from the capacitance 47 corresponding to the electrode 45, and the capacitance immediately before starting the accumulation of the charge signal in the capacitance 47 corresponding to the pixel electrode 45. A reset unit 35 for resetting the charge signal stored in the 47 is provided.

The controller 39 in the flat panel detector 21 transmits a command to the gate driver 51 and the switching element 46 in the flat panel detector 21 based on a command from the control unit 30, thereby transmitting a command to the capacitance 47 in the flat panel detector 21. The charge signal is read from the capacitor 47, the charge signal is stored in the capacitance 47, and the charge signal that can be stored in the capacitance 47 is reset.

Next, the operation when performing X-ray fluoroscopy by the X-ray fluoroscopy device according to the present invention will be described. FIG. 5 is a timing chart showing the relationship between the irradiation of the treatment beam, the irradiation of X-rays, and the operation of the flat panel detector 21 as an X-ray detector according to the first embodiment of the present invention.

When X-ray fluoroscopy is performed by the X-ray fluoroscope according to the first embodiment of the present invention, the pixel electrode 45 used for X-ray detection is selected from the plurality of pixel electrodes 45 in the flat panel detector 21. Then, by limiting the number of pixel electrodes 45 used for X-ray detection to the minimum necessary, it is possible to shorten the reading time of the charge signal from the capacitance 47 corresponding to the selected pixel electrodes 45. .. Then, the reading time of the pixel electrode 45 is changed to a short time. As a result, the time required for collecting one image (one frame) in X-ray fluoroscopy is shortened, and the number of treatment beams irradiated during that period is reduced. Reduces the effect of scattered radiation generated on the X-ray image.

That is, in the conventional X-ray fluoroscope, since the entire region of the flat panel detector 21 is used, the read time of the charge signal from the capacitance 47 is always constant, but the X-ray fluoroscopy according to the present invention. In the apparatus, the read time of the charge signal is shortened by using only a part of the pixel electrodes 45, whereby the read time of the charge signal can be changed in a shorter time.

In the X-ray fluoroscope according to the first embodiment, first, the pixel electrode 45 used for X-ray fluoroscopy is selected from the plurality of pixel electrodes 45 in the flat panel detector 21. At this time, the operator uses the input unit 31 shown in FIG. 4 to select the pixel electrode 45 to be used. As a result, the area selection unit 32 in the control unit 30 transmits the selection signal of the pixel electrode 45 to be used to the flat panel detector 21. When selecting the pixel electrode 45, the moving range of the marker or the like in the subject is taken into consideration. When selecting the pixel electrode 45, the pixel electrode 45 to be used may be selected while performing fluoroscopy in advance.

Next, the read time of the charge signal from the capacitance 47 corresponding to the selected pixel electrode 45 is set. At this time, since the number of pixel electrodes 45 used is reduced as compared with the conventional case, it is possible to set the read time of the charge signal to be shorter. At this time, the operator sets the read time of the charge signal using the input unit 31 shown in FIG. As a result, the read time change unit 33 in the control unit 30 transmits the charge signal read time change signal to the flat panel detector 21.

In the embodiment shown in FIG. 5, the read time of the charge signal is set to 8 msec. In the conventional timing chart shown in FIG. 8, the read time of the charge signal is 15 msec. By shortening the reading time of the charge signal and shortening the time required for collecting one image in X-ray fluoroscopy in this way, the number of treatment beams irradiated during that period is reduced, thereby treating. The effect of scattered rays generated by beam irradiation on the X-ray image is reduced.

Incidentally, the accumulation in the X-ray fluoroscopic apparatus, just before starting the accumulation of the charge signal to the capacitance 47 which correspond to the pixel electrode 45 that is selected, the reset unit 35 shown in FIG. 4, the capacitance 47 The charged signal is being reset. That is, before starting the accumulation of charges in the capacitance 47 for collecting the data for one image in X-ray fluoroscopy, the charge signal accumulated in the capacitance 47 is stored under the control of the reset unit 35. It is discharged via the bus line 55. As a result, it is possible to eliminate the influence of the scattered rays accumulated in the capacitance 47 by irradiating the treatment beam after reading the charge signal.

Next, other embodiments of the present invention will be described. FIG. 6 is a block diagram showing a main control system of the X-ray fluoroscope according to the second embodiment of the present invention. In this figure, only the control system of the main part of the present invention is shown in the control system of the X-ray fluoroscope. Further, FIG. 7 is a timing chart showing the relationship between the irradiation of the treatment beam, the irradiation of X-rays, and the operation of the flat panel detector 21 as an X-ray detector in the second embodiment of the present invention. The same reference numerals as those of the above-described first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 6, the X-ray fluoroscope according to the second embodiment of the present invention changes the accumulation time of the charge signal in the capacitance 47 with respect to the X-ray fluoroscope according to the first embodiment. A storage time changing unit 34 is further provided.

When X-ray fluoroscopy is performed by the X-ray fluoroscope according to the second embodiment of the present invention, the accumulation time of the charge signal in the capacitance 47 is accumulated by the accumulation time changing unit 34 according to the body thickness of the subject and the like. To change. In the conventional X-ray fluoroscope, the accumulation time of the charge signal in the capacitance 47 is always constant regardless of the body thickness of the subject, but the X-ray according to the second embodiment of the present invention. In the fluoroscopic device, the accumulation time of the charge signal in the capacitance 47 is changed to a shorter time according to the body thickness of the subject and the like.

In the X-ray fluoroscope according to the second embodiment, first, the charge signal accumulation time is set in consideration of the body thickness of the subject and the like. At this time, by using the input unit 31 by the operator shown in FIG. 6 to set this time. As a result, the storage time changing unit 34 in the control unit 30 transmits a change signal for changing the storage time to the flat panel detector 21.

In the embodiment shown in FIG. 7, the charge signal accumulation time is set to 8 msec. In the conventional timing chart shown in FIG. 8, the charge signal accumulation time is 15 msec. By shortening the accumulation time of the charge signal in this way and shortening the time required for collecting one image in X-ray fluoroscopy, the number of treatment beams irradiated during that period is further reduced, and thus the number of treatment beams irradiated during that period is further reduced. The effect of scattered radiation generated by irradiation of the treatment beam on the X-ray image is further reduced.

When comparing the case of the second embodiment shown in FIG. 7 with the conventional case shown in FIG. 8, the time required for collecting one image in this second embodiment is about half of the conventional case. It has become. Therefore, images are collected at a frame rate twice that of the conventional one. At this time, if such a frame rate is not required, for example, an X-ray image may be acquired every other frame.

Further, in the second embodiment shown in FIG. 7, if the period of the treatment beam, the accumulation time of the charge signal, and the read time of the charge signal are synchronized, the scattered radiation in each X-ray image continuously collected. The influence of the above can be made constant, and the scattered radiation correction by image processing becomes easy. For example, when the period of the treatment beam is 5 msec, the above effect can be obtained by setting both the charge signal accumulation time and the charge signal read-out time to 10 msec.

11a 1st X-ray tube 11b 2nd X-ray tube 11c 3rd X-ray tube 11d 4th X-ray tube 21a 1st flat panel detector 21b 2nd flat panel detector 21c 3rd flat panel detector 21d 4th flat panel detector 27 Examination table 29 Person mounting unit 30 Control unit 31 Input unit 32 Area selection unit 33 Read time change unit 34 Accumulation time change unit 35 Reset unit 39 Controller 41 Glass substrate 42 TFT
43 Conversion film 44 Common electrode 45 Pixer electrode 46 Switching element 47 Capacitance 51 Gate driver 52 Gate bus line 53 multiplexer 54 Amplifier 55 Data bus line

Claims (5)

When the subject is irradiated with the treatment beam by the treatment beam irradiation device, the X-rays irradiated from the X-ray tube and passed through the subject are detected by the X-ray detector and placed in the subject's body. By collecting an X-ray image including the marker or an X-ray image including a specific part of the subject, the position of the marker or the specific part that moves with the body movement of the subject is detected. It is an X-ray fluoroscope
The X-ray detector includes a plurality of pixel electrodes arranged in a matrix corresponding to pixels to acquire a charge signal corresponding to an incident X-ray dose, and a plurality of static electricity detectors connected to each of the pixel electrodes and accumulating a charge signal. It is provided with an electric capacity and a data bus line for reading charge signals accumulated in the plurality of capacitances.
An area selecting means for selecting a pixel electrode to be used the multiple pixel electrodes sac Chi X-ray detector in the X-ray detector,
A controller that causes the data bus line to read a charge signal from the capacitance corresponding to the pixel electrode selected by the region selection means at a predetermined read time.
When some pixel electrodes are selected by the region selection means, the read time of the charge signal from the capacitance corresponding to the part of the pixel electrodes is compared with the case where all the pixel electrodes are selected. Read time setting means for setting to a short time,
Said predetermined read time, X-rays fluoroscope, characterized in that Ru and a read time changing means for changing the read time set in the reading time setting means. In the X-ray fluoroscope according to claim 1,
The controller is configured to accumulate the charge signal acquired by the pixel electrode corresponding to the capacitance in the capacitance in a predetermined accumulation time.
A storage time setting means for setting the accumulation time of the charge signal in the capacitance, and
An X-ray fluoroscopic apparatus further comprising a storage time changing means for changing the predetermined storage time to a storage time set by the storage time setting means. In the X-ray fluoroscope according to claim 1 or 2.
An X-ray fluoroscope further comprising a reset means for resetting the charge signal accumulated in the capacitance immediately before starting the accumulation of the charge signal in the capacitance corresponding to the pixel electrode. In the X-ray fluoroscope according to any one of claims 1 to 3.
The region region selection means is an X-ray fluoroscope that selects pixel electrodes to be used for X-ray detection based on the movement range of the marker or the position of the specific portion that moves with the body movement of the subject. .. In the X-ray fluoroscope according to any one of claims 1 to 4.
An X-ray fluoroscope that accumulates a charge signal in the capacitance and reads out the charge signal from the capacitance even during the period in which the subject is irradiated with the treatment beam by the treatment beam irradiation device. ..

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