JP2004057438A - Three-dimensional x-ray measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional X-ray measuring apparatus, established without any obstacle to the existing radiotherapy apparatus, endoscope surgical treatment apparatus and thighbone digging apparatus. <P>SOLUTION: This 3-dimensional X-ray measuring apparatus is composed of an X-ray source for generating X rays, an X-ray detector 102 for detecting X-rays transmitted through an object 123, a support rod 103 supporting the above, and a strut 104 having a rotary mechanism for rotating the support rod 103. A center line 106 connecting between the X-ray source and the center of the detecting surface of the X-ray detector is inclined to the rotation axis 105 of the support rod 103. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an X-ray measurement apparatus capable of obtaining a three-dimensional image of a target portion of a subject without impeding operation during operation of a radiotherapy apparatus, an endoscopic surgical operation apparatus, a femoral excavator, or the like. About.
[0002]
[Prior art]
The present invention relates to an X-ray measurement device that is added to improve the functions of medical devices such as an existing radiotherapy device, an endoscopic surgical operation device, and a femoral excavation device. The present invention relates to an X-ray measurement device capable of obtaining a three-dimensional image of a target portion of a subject without obstructing operation.
[0003]
There is radiation therapy that irradiates tumors to destroy cancerous tissue. In radiation therapy, very intense radiation is applied. In order to reduce the effect on normal tissues, it is required that the radiation be accurately delivered to the tumor. A treatment plan using three-dimensional data measured by CT or the like in advance is performed.
[0004]
In order to perform accurate irradiation, it is necessary that the position of the tumor obtained as a measurement result and the irradiated radiation do not shift between the time of three-dimensional data measurement and the time of radiotherapy. For this purpose, a subject is fixed using a fixture. However, a soft trunk is more difficult to fix than a head and neck surrounded by a hard skull. Further, even if it can be fixed, the position of the tumor moves in the trunk due to respiratory movement or the like.
[0005]
Therefore, conventionally, as described on page 86 of the new medical treatment, December, 2001, a method of restricting respiratory movement by compression or forced respiration, a method of monitoring and synchronizing respiratory movement, and a method of using a marker in a tumor To track the location of the tumor. However, the conventional respiratory restriction method has a problem that burdens the patient. The conventional respiration monitoring method has a problem that it takes time. The conventional marker method has a problem that it can be applied only to a specific tumor.
[0006]
In order to solve these problems, it is desired to correct the irradiation position in real time by detecting the position of the tumor three-dimensionally and in real time during irradiation.
[0007]
2. Description of the Related Art There is an endoscopic surgery in which a robot arm with a tip is inserted through a small hole formed in the body surface without performing thoracotomy or laparotomy. As described in the December 2000 issue of the Japan Society of Computer Aided Surgery, page 90, a system has been developed that has a special console capable of operating an extended arm and that can precisely and precisely move the arm. .
[0008]
The surgeon performs an operation while viewing a stereoscopic image obtained from a camera attached to the tip of the endoscope. The arm has a plurality of joints and can freely move in a body cavity. However, the insertion position of the endoscope and the space in the body cavity are limited, and there has been a problem that sufficient three-dimensional information cannot be obtained with the endoscope camera.
[0009]
In order to solve these problems, it is desired to detect the tip of the arm and the position of the operation target three-dimensionally during the operation.
[0010]
There are hip replacement surgery in which the hip joint is replaced with an artificial hip joint, and hip replacement surgery in which the hip joint is replaced with a new hip joint. In the replacement surgery, the femur is excavated to receive the foot of the hip prosthesis, and in the replacement surgery, the cement that fixes the foot of the hip prosthesis is excavated. The gap between the drilled hole and the hip prosthesis is filled with padding or adhesive. Since the femur and the hip prosthesis are integrated and last longer as the number of these interventions is smaller, accurate three-dimensional excavation is desired.
[0011]
Conventionally, these excavations are manually performed by using only humans, but it is difficult to perform three-dimensional accurate excavation. Therefore, as described in the December 2000 issue of the Japan Society of Computer Aided Surgery, page 165, a system for controlling and excavating a robot arm based on three-dimensional data measured in advance by CT or the like has been developed. I have.
[0012]
During the operation, the excavation robot and the femur are fixed so that the position of the femur does not shift. However, fixation had a problem of putting a burden on patients. In addition, there is a problem that the femur is connected to the patient and may move.
[0013]
In order to solve these problems, it is desired to correct the excavation position by detecting the positions of bones and holes three-dimensionally and in real time during excavation.
[0014]
For example, as in JP-A-2001-259059, there is a case where a radiation irradiating nozzle and an X-ray irradiator for detecting a radiation irradiating position in advance in real time are mounted on a rotating gantry as an integrated system. Many of such treatment devices do not include a device for detecting a position to be treated three-dimensionally and in real time during a treatment operation.
[0015]
[Problems to be solved by the invention]
For this reason, a device for detecting a treatment position three-dimensionally and in real time during treatment by a medical device can be easily added to an existing medical device, and it is desired to correct the treatment position in real time. . An object of the present invention is to provide a three-dimensional image of a site of interest (treatment position) of a subject during operation of a medical device such as a radiotherapy device, an endoscopic surgical operation device, or a femoral excavation device without interfering with the operation. It is an object of the present invention to propose an additional X-ray measuring apparatus capable of obtaining the following.
[0016]
Existing medical treatment equipment such as radiotherapy equipment, endoscopic surgery equipment, and femoral drilling equipment have a structure that is easy to operate itself, but X-ray measurement that can obtain a three-dimensional image When an additional device is added, it is necessary to devise a device that does not hinder the operation of these medical devices and that can accurately obtain three-dimensional position information of a target site (treatment position). . In addition, a three-dimensional image can be obtained continuously, and the obtained three-dimensional image has a high spatial resolution, a wide field of view, and is a three-dimensional X-ray measurement device that takes into account the low exposure of the patient. It is necessary.
[0017]
A further point to be considered is to provide a three-dimensional X-ray measurement apparatus that can be added with only simple adjustments regardless of the size of an existing medical apparatus.
[0018]
[Means for Solving the Problems]
Since the existing medical device has a structure that is easy to operate itself, generally, the radiation irradiating device is located at a position where the target part (treatment position) of the patient lying on the back of the medical device is looked down from directly above. Alternatively, a treatment instrument such as a robot arm is arranged. Then, a certain range of expansion centering on a line overlooking the site of interest from directly above is required as an area exclusively used for operation of the existing medical device. Therefore, in the present invention, the center line connecting the X-ray source of the three-dimensional X-ray measuring device and the center of the detection surface of the X-ray detector is inclined at a predetermined angle with respect to the line from directly above and looking down on the target portion. The goal is achieved by doing so.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention in which a three-dimensional X-ray measurement apparatus is added to an existing radiation therapy apparatus will be described.
[0020]
(Example 1)
FIG. 1 is a cross-sectional view schematically showing an example in which the three-dimensional X-ray measurement apparatus according to the first embodiment of the present invention is added to an existing radiation therapy apparatus. However, hatching indicating a cross section is omitted for simplification of the drawing.
[0021]
The existing radiation therapy apparatus has a structure in which a radiation source 121 is held at one end of an L-shaped holding rod 122. 130 is a support, and holds the holding rod 122 rotatably. The axis of rotation is indicated by 105. The bed 124 is positioned so that the radiation source 121 is positioned directly above the site of interest 126 of the subject 123 lying on his back on the bed 124, and radiation from the radiation source 121 in the area 127 is treated. The target 123 of the person 123 is irradiated. The intensity of the radiation applied to the site of interest 126 and the area or shape of the region 127 are adjusted by a collimator (not shown) provided on the front surface of the radiation source 121 according to the treatment guideline.
[0022]
The three-dimensional X-ray measurement apparatus of the present invention includes an X-ray source 101 and an X-ray detector 102, and the X-ray source 101 and the X-ray detector 102 are held at both ends of a C-shaped support rod 103. . Reference numeral 104 denotes a support and rotatably holds the support bar 103. The height is adjusted by a height adjusting device (not shown) provided on the column 104 so that the rotation axis coincides with the rotation axis 105 of the existing radiotherapy apparatus. Reference numeral 107 denotes a horizontal axis adjustment device that adjusts the position of the column 104 in the direction of the rotation axis 105 and in the direction perpendicular to the rotation axis 105. A line 106 connecting the X-ray source 101 and the X-ray detector 102 of the three-dimensional X-ray measurement apparatus is configured to penetrate a region of interest 126 of a patient 123 lying on his back on a bed 124. Then, the column 104 is positioned by the horizontal axis adjusting device 107. By setting the line 106 connecting the X-ray source 101 and the X-ray detector 102 to penetrate the target portion 126, the target portion 126 can be set at the center of the three-dimensional image. The support bar 103 is held by the support 104 so that the line 106 connecting the X-ray source 101 and the X-ray detector 102 can slide along the C-shape while maintaining the relationship of penetrating the site of interest 126.
[0023]
An X-ray shielding collimator (not shown) is provided between the X-ray source 101 and the patient 123 to suppress the X-ray exposure of the patient 123. For example, the collimator is adjusted so that the irradiation range of the X-ray source 101 matches the detection surface of the X-ray detector 102. The collimator is composed of four blades, up, down, left and right. The inclination of the detector 102 with respect to the center line 106 is detected, the blade is moved according to the inclination, and the aperture is adjusted. The aperture is largest when the detector 102 is perpendicular to the center line 106, and becomes smaller as the detector 102 is inclined from the center line 106.
[0024]
The radiation therapy apparatus radiates radiation of the area of the area 127 from the radiation source 121 to the target region 126 of the patient 123 while rotating the rotation axis 105 about the rotation axis 105 in the direction perpendicular to the plane of the drawing and within the range required for treatment. As will be described later, the three-dimensional X-ray measurement apparatus continuously monitors the target portion 126 of the patient 123 and outputs the current position of the target portion 126 in real time.
[0025]
Although not shown in the figure, a so-called personal computer having necessary programs is provided, and a detector (flat panel sensor, a combination of an X-ray image intensifier and a CCD camera, an imaging plate, , A CCD detector, a solid state detector, etc.) to output a position signal corresponding to the current position of the region of interest 126 of the patient 123 to be irradiated with radiation from the radiation source 121 according to the treatment guideline. The radiation therapy device is controlled. The deviation of the current position of the site of interest 126 output from the planned position in real time is controlled by the above-described collimator.
[0026]
As described above, the existing radiation therapy apparatus has the best structure in consideration of its own workability. Therefore, generally, as shown in FIG. It will be in. The radiation source 121 irradiates radiation into an area 127 surrounded by a two-dot chain line. Irradiation must be performed from various directions to the site of interest 126 based on the treatment plan, and the rotation of the radiation source 121 is controlled. As a result of the rotation, the radiation irradiation range 127 includes the region of interest 126 and moves from various directions on a plane perpendicular to the rotation axis 105 to the region of interest 126. Therefore, if there is a target that blocks radiation on a plane that includes the site of interest 126 and that is perpendicular to the rotation axis 105, it will hinder radiation treatment.
[0027]
The support bar 103 of the three-dimensional X-ray measurement apparatus according to the first embodiment of the present invention has a C-shape, and an X-ray source 101 and a detector 102 are installed at both ends. The position of the X-ray source and the detector can be moved by sliding the support bar 103 along the C-shape with the support 104. Thus, according to the present invention, it is possible to prevent the X-ray source and the detector from entering the radiation irradiation area of the radiation source 121. The position of the support bar 103 near the installation end of the detector 102 (shaded portion) passes through the radiation irradiation area of the radiation source 121 when the support bar 103 is rotated 360 ° about the rotation axis 105. If the rotation of the support rod 103 and the irradiation of the radiation by the radiation source 121 are synchronized, the treatment by the irradiation of the radiation does not become an obstacle. The rotation angle of the support rod 103 around the rotation axis 105 is smaller than 360 ° so that the position of the support rod 103 near the installation end of the detector 102 does not pass through the radiation irradiation area of the radiation source 121. This does not impede treatment by irradiation.
[0028]
FIG. 2 shows the relationship between the rotation of the support bar 103 of the three-dimensional X-ray measuring apparatus according to the first embodiment of the present invention and the radiation irradiation area 127 of the radiation source 121 of the radiation therapy apparatus. The state seen in the direction is schematically shown. As described above, with the rotation of 360 °, the position of the support bar 103 near the installation end of the detector 102 passes through the irradiation area of the radiation from the radiation source 121. If the irradiation of the radiation by 121 is synchronized, there is no obstacle to the treatment by the irradiation of the radiation.
[0029]
The rotation angle of the support rod 103 around the rotation axis 105 is smaller than 360 °, and the line 106 connecting the X-ray source 101 and the X-ray detector 102 is rotated to the left in FIG. By controlling so that the position of the support bar 103 close to the installation end of the detector 102 can be prevented from passing through the irradiation area of the radiation by the radiation source 121, the obstacle to the treatment due to the irradiation of the radiation is reduced. It will not be. In this case, when the radiation source 121 is rotationally moved in accordance with the treatment plan, the range 127 is rotationally moved correspondingly, so that the position A and the position B are also controlled to be rotationally moved correspondingly. It is clear that. The angle between the position A and the position B is desirably 180 ° or more. If the angle is 180 ° or more, there is no problem in performing the three-dimensional reconstruction processing using the data obtained with the rotation of the support bar 103. This reconstruction processing can be performed by, for example, the Feldkamp method, as is well known.
[0030]
In the first embodiment, the X-ray detector 102 is arranged parallel to the rotation axis 105 and has a certain angle with respect to a line 106 connecting the X-ray source 101 and the X-ray detector 102. Obviously, the detector 102 may be arranged to be perpendicular to the line 106. FIG. 3 is an explanatory diagram for simply explaining the advantages and disadvantages of both. The detection surface of the X-ray detector 102 parallel to the rotation axis 105 is indicated by a solid line 151, the irradiation range of the X-rays by the X-ray source 101 is indicated by a solid line 153, and the detection surface of the X-ray detector 102 perpendicular to the center line 106 is indicated by a solid line. A broken line 152 indicates an irradiation range of X-rays by a broken line 154. Now, when the region of interest 126 is surely covered by the X-ray irradiation range indicated by the solid line 153 and there is no unnecessary irradiation range, the detection surface expands as indicated by the solid line 151. On the other hand, when X-rays are detected on a plane 152 that is the same as the detection plane indicated by the solid line 151 and is perpendicular to the center line 106, irradiation of X-rays in a range indicated by a broken line 154 is detected.
[0031]
Since the number of the sensor elements of the X-ray detector 102 is the same, the spatial resolution of the detection surface of the solid line 151 is higher than that of the detection surface of the dashed line 152 when the target portion 126 is detected. On the other hand, since the irradiation range 154 of the detection surface indicated by the broken line 152 is wider than the irradiation range 153 of the detection surface indicated by the solid line 151, the field of view of the detector 152 of the broken line is wider than that of the detector 151 of the solid line. That is, the detection surface 152 is more advantageous than the detection surface 151 in that monitoring including the vicinity of the target portion 126 can be performed.
[0032]
In the first embodiment, the column 104 is provided with the height adjusting device (not shown) and the horizontal axis adjusting device 107. Therefore, the versatility of the three-dimensional X-ray measuring device with respect to the existing treatment device is increased, and the manufacturing cost is increased. And the cost can be reduced.
[0033]
(Example 2)
FIG. 4 is a side view of the three-dimensional X-ray measurement apparatus according to the second embodiment. Also in this case, hatching or the like showing a cross section as in Example 1 is omitted. This embodiment is the same as the first embodiment except that the X-ray source 101 and the detector 102 are separately installed on the rotating gantry 141 and the rotating gantry 142, respectively. The gantry 141 and the gantry 142 are spaced apart from each other so as not to include a region that blocks the irradiated radiation in a region 127 surrounded by a two-dot chain line of the radiation source 121. The gantry 141 is provided with the X-ray source 101, and the gantry 142 is provided with the X-ray detector 102. The X-ray source 101 and the X-ray detector 102 are installed on each gantry so that the center line 106 connecting the X-ray source 101 and the X-ray detector 102 passes through the site of interest 126 of the patient 123. The gantry 141 and the gantry 142 are supported by the columns 104 and 104 ′ that rotatably hold the respective gantry, and the rotation axis coincides with the rotation axis 105 of the existing radiation treatment apparatus, as in the first embodiment. The height of the support 104 is adjusted by a height adjustment device (not shown) provided on the support 104, and the position of the support 104 can be adjusted in the direction of the rotation shaft 105 and the direction perpendicular to the rotation shaft 105 by the horizontal axis adjustment devices 107 and 107 '. You. The gantry 141 and the gantry 142 may rotate in the same direction in synchronization with each other, or may perform reciprocal rotation as in FIG. If each gantry transmits and receives necessary signals via a slip ring, it is easy to make a continuous rotational movement.
[0034]
In each of the above embodiments, the description has been given assuming a radiation therapy apparatus as an existing therapy apparatus. However, the present invention can be similarly applied to an endoscopic surgical operation apparatus, a femur excavator, and the like. The radiation irradiation source and the irradiation area in the above embodiment may be replaced with the robot arm of the above apparatus and the access to the site of interest 126 of the patient 123. Also, the description has been given on the assumption that the main treatment of the existing treatment apparatus is performed from directly above the patient 123, but, for example, the main body device of the robot arm is installed right beside the target part 126 of the patient 123. In such a case, it is clear that the portion immediately above the above description should be read as being right beside.
[0035]
【The invention's effect】
According to the present invention, the center line connecting the X-ray source of the three-dimensional X-ray measuring apparatus and the center of the detection surface of the X-ray detector is inclined with respect to the rotation axis, so that the existing radiotherapy apparatus or endoscopic surgery can be performed. The three-dimensional position information of the treatment target can be obtained in real time without impairing the functions and operations of other devices such as a surgical device and a femoral excavator. This makes it possible to monitor the three-dimensional position of the site of interest during treatment, thereby improving the safety of treatment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an example in which a three-dimensional X-ray measurement apparatus according to a first embodiment of the present invention is added to an existing radiation therapy apparatus.
FIG. 2 shows the relationship between the rotation of the support bar 103 of the three-dimensional X-ray measurement apparatus of the first embodiment and the irradiation area 127 of the radiation source 121 of the radiation therapy apparatus in a direction parallel to the paper surface from the right side of FIG. The figure which shows the state which looked at typically.
FIG. 3 is an explanatory diagram for simply explaining the advantages and disadvantages of two forms of the detection surface of the X-ray detector 102 according to the first embodiment.
FIG. 4 is a cross-sectional view schematically showing an example in which a three-dimensional X-ray measurement apparatus according to a second embodiment of the present invention is added to an existing radiation therapy apparatus.
[Explanation of symbols]
101: X-ray source, 102: detector, 103: support bar, 104: support, 105: rotation axis, 106: center line, 107: horizontal axis adjustment device, 123: subject, 124: bed, 126: site of interest, 127: irradiation area, 130: support.

Claims (4)

In an X-ray measuring apparatus including an X-ray source for generating X-rays, an X-ray detector for detecting X-rays transmitted through a subject, a support for supporting the X-rays, and a rotating mechanism for rotating the support, an X-ray source and an X-ray A three-dimensional X-ray measurement apparatus, wherein a center line connecting the centers of the detection surfaces of the line detectors is inclined with respect to a rotation axis of the rotation mechanism. The three-dimensional X-ray measurement apparatus according to claim 1, wherein the X-ray source and the detector are installed at both ends of a C-shaped support. The three-dimensional X-ray measurement apparatus according to claim 1, wherein an X-ray shielding collimator that moves in accordance with an inclination of a detection surface of the detector with respect to the center line is provided between the X-ray source and the subject. The X-ray measurement apparatus according to claim 1, wherein the X-ray source and the detector are installed on independent rotating gantry mechanisms, and both gantry mechanisms are rotated in the same direction in synchronization.

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