JPH10328319A - Radiotherapy system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiotherapy system which is equipped with a radiotherapy planning device (CT simulator) having as base body an X-ray CT device capable of drafting a treatment plan to match an irradiation field of a radiotherapy apparatus just as a radiotherapy planning device (X-ray simulator) having a radiography device as base body. SOLUTION: A radiotherapy planning device 110 includes a scanner 1, a first projector 2, a second projector 3, a photographing base 5, a first communication circuit 7, a first console 8, an isocenter setting means 9, a virtual ray source setting means 10, a data storing means 11 and an arithmetic means 12. The isocenter setting means 9 and the virtual ray source setting means 10 set an isocenter and a virtual ray source based on a tomographic image and a scanogram image and the arithmetic means 12 generates and displays a transmission image based on the tomographic image assigned by the isocenter and the virtual ray source previously set to set an irradiation field on the transmission image. This enables drafting of a treating plan to match the irradiation field of a radiotherapy apparatus just as for the irradiation field settable by an X-ray simulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotherapy system and, more particularly, to a technology effective when applied to a radiotherapy planning apparatus using an X-ray CT apparatus.

[0002]

2. Description of the Related Art A conventional radiotherapy system is disclosed in Japanese Patent Application No. Hei.
As described in JP-A-9138, a CT image, which is a tomographic image or a three-dimensional image of the subject, is reconstructed from an X-ray projection image obtained by imaging the subject, and a radiation treatment planning of the subject is performed based on the CT image. A radiation treatment planning device (hereinafter, referred to as a treatment planning device) for creating a target, and a radiation treatment device (hereinafter, referred to as a treatment device) that actually irradiates a subject with radiation based on the treatment plan. .

[0003] The treatment planning device and the treatment device are, for example,
It is connected by a communication line such as RS-232C or Ethernet, and information about the treatment plan determined by the treatment planning device is transferred to the treatment device via this communication line. The treatment plan information at this time was the size of the irradiation area, the irradiation angle of the radiation, and the like. However, the size of the irradiation area and the irradiation angle of the radiation were merely transfer of the so-called reference data calculated by the treatment planning apparatus.

Further, the X-ray CT apparatus includes an X-ray source and an X-ray detector in the body axis direction of the subject, for example, in order to position the tomographic image when capturing the tomographic image of the subject. X-rays were emitted from an X-ray source while relatively moving in parallel, and an image (referred to as a scanogram image) similar to an X-ray fluoroscopic image was obtained.

[0005] The treatment planning apparatus includes an X-ray simulator having an X-ray imaging apparatus as a base. This X-ray simulator has been proposed to set the positional relationship between the radiation source of the treatment radiation of the radiation treatment apparatus and the subject substantially the same, and to formulate a treatment plan suitable for the irradiation field of the treatment radiation.

On the other hand, a treatment planning apparatus based on an X-ray CT apparatus (hereinafter referred to as a CT simulator) is useful for treatment planning by visualizing deep information of a subject from tomographic images and three-dimensional images. On the other hand, it was not possible to formulate a treatment plan suitable for the irradiation field of therapeutic radiation unlike an X-ray simulator.

Further, as disclosed in Japanese Patent Application Laid-Open No. 8-164217, a CT simulator interpolates tomographic images continuous in the body axis direction of a subject, and converts these tomographic images along the body axis. Intermediate three-dimensional data was created, a transmission image was created by limiting the integration range, and this transmission image was displayed on the screen. The relationship between this transmission image and the irradiation field of the treatment apparatus was displayed as an image. Stayed in reference.

[0008]

However, there is an expectation for the development of a treatment planning apparatus that can make use of the deep information of the conventional CT simulator described above and can formulate a treatment plan suitable for the irradiation field of the therapeutic radiation like an X-ray simulator. It had been.
In addition, development of a radiation therapy system in which the treatment planning device sets an irradiation field that can match the irradiation field of the treatment device, and can match the set irradiation field with the irradiation field of the treatment device has also been expected.

[0009] The present invention proposes a radiotherapy system including the above-mentioned treatment planning apparatus.
It is an object of the present invention to provide a radiation therapy system in which a CT simulator, such as an X-ray simulator, which can formulate a treatment plan suitable for an irradiation field of a treatment device is used as a treatment planning device. Also,
Another object of the present invention is to set a radiation field on a transmission image obtained by a treatment planning apparatus, and to match a radiation field set in the transmission image with a radiation irradiation field of the treatment apparatus.
An object of the present invention is to provide a radiotherapy system using a simulator as a treatment planning device.

[0010]

According to the first aspect of the present invention, projection data of an object set on an imaging table is photographed, and a tomographic image or a scanogram image is formed from the projection data. Based on the scanogram image, a treatment planning device that creates irradiation plan data of the radiation to be irradiated on the subject, the treatment planning device is connected to the communication line, and the irradiation plan data obtained through the communication line A radiation treatment system having a treatment device that performs radiation treatment based on the isocenter and a virtual ray source of the treatment device based on the tomographic image and the scanogram image; and It is characterized in that there is provided means for creating a transmission image from a tomographic image specified by the radiation source.

Thus, the setting means sets the isocenter and the virtual ray source based on the tomographic image and the scanogram image, and the creating means sets the isocenter and the virtual ray source to the tomographic image designated by the set isocenter and the virtual ray source. By creating a transmission image based on this, a treatment plan suitable for the irradiation field of the treatment apparatus, such as an irradiation field that can be set by an X-ray simulator, can be made.

According to a second aspect of the present invention, the treatment planning apparatus further comprises means for displaying the transmission image, and means for inputting an irradiation field of the treatment apparatus on the displayed transmission image. It is characterized by the following. Thus, the display means displays the transmission image on a display device such as a TV monitor, and the input means inputs the irradiation field on the displayed transmission image, thereby displaying the irradiation field on the obtained transmission image. The irradiation field set in the transmission image and the irradiation field of the treatment apparatus can be matched.

According to the third aspect of the present invention, furthermore, means for displaying a plurality of tomographic images corresponding to the transmission image and the beam cone from the virtual ray source together, and displaying the tomographic image on the displayed tomographic image. It is characterized by comprising a means for inputting a beam cone. Thereby, the means for displaying the tomographic image and the beam cone together displays the plurality of tomographic images corresponding to the transmission image and the beam cone from the virtual source together on a display device such as a TV monitor. By inputting the beam cone on the displayed tomogram by the beam cone input means, it is possible to adjust and input an appropriate beam cone for each tomogram, so that the aperture of the multi-leaf (not shown) of the treatment apparatus can be adjusted. Since it can be used for adjustment control data, a more detailed irradiation field of the treatment apparatus can be set by the treatment planning apparatus.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the radiation therapy system of the present invention will be described with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a block diagram showing a schematic configuration of a radiotherapy system according to an embodiment of the present invention. The radiation treatment system includes a scanner 1, a first projector 2, a second
Projector 3, imaging table 5, first communication line 7, first console 8, isocenter setting means 9, virtual source setting means 1
0, a treatment planning device (X-ray CT device) 110 including a data storage unit 11 and a calculation unit 12, a second communication line 109, a treatment gantry 101, and an irradiation head 10.
2, positioning jig 104, treatment table 105, microtron main body 106, control device 107, and second console 10
8 having a treatment device 111.

In FIG. 1, a scanner 1 includes an X-ray tube device for irradiating X-rays, an X-ray detector arranged opposite to the X-ray tube device, and rotation of the X-ray tube device and the X-ray detector. It is a well-known scanner having a mechanism, collects X-ray projection data for each preset rotation angle, and outputs the X-ray projection data to the first console 8.

Further, in order to obtain a desired position of the tomographic image of the subject 4, the X-ray tube apparatus and the X-ray detector are relatively translated in the body axis direction of the subject 4, and a scanogram image is obtained. X-ray projection data for obtaining a line image is collected, and the X-ray projection data for the scanogram image is also collected on the first console 8.
Output to

The first projector 2 is a known laser output device for irradiating the subject 4 on the imaging table 5 with a known laser beam. In the present embodiment, in particular, the laser beam output portion is provided by the scanner 1. For example, a laser output portion (laser beam irradiating means) can be moved in the direction perpendicular to the body axis direction of the subject 4 and parallel to the installation floor of the apparatus (hereinafter referred to as X direction) on the front surface of the opening. ) In the X-axis direction, and a projector driving means for driving a laser output portion based on an examiner's instruction from the first console 8, that is, a support moving means. Having.
Further, in order to detect the amount of movement of the laser output portion, for example, a position measuring means such as a well-known encoder is connected to the projector driving means, and the encoder output is used as the scanner 1.
And a scanner controller (not shown) for controlling the operation of the imaging table 5.

The basic configuration of the second projector 3 is the same as that of the first projector 2, but a guide rail (not shown).
, That is, the direction in which the laser beam moves is the vertical direction of the imaging table 5 perpendicular to the body axis of the subject and perpendicular to the installation surface of the apparatus (hereinafter, referred to as the Y-axis direction).

The imaging table 5 is a well-known imaging table. The imaging table 5 is a part on which the subject 4 is mounted, a horizontal moving mechanism for moving the imaging table 4 in the body axis direction of the object 4, And a vertical movement mechanism for moving the board in a direction perpendicular to the floor surface. In addition, the imaging table 5 can be operated to move the couch top in the vertical direction and the body axis direction of the subject (hereinafter, referred to as the Z-axis direction) based on the examiner's instruction from the first console 8.

The first communication line 7 is a communication line for connecting the first console 8 and a scanner control device (not shown), and is, for example, a communication line formed of a well-known RS-232C or Ethernet. .

The first console 8 has a computing means 12 for performing image processing for reconstructing a scanogram image, a tomographic image and a three-dimensional image of the subject from the measurement data. So-called,
This is a well-known operation console with a built-in image processing device, and has a well-known display means for displaying an image processing result. In addition, since a well-known method is used for reconstructing a three-dimensional image, description thereof is omitted here.

The isocenter setting means 9 sets, for example, the center point of the irradiation field in the treatment apparatus based on the tomographic image, scanogram image and three-dimensional image displayed on the display means. The examiner moves a cursor (not shown) such as a trackball or a mouse to the desk 8 on any of the images by the examiner. When the cursor is moved to the center point, the center is inputted by a key input of a keyboard (not shown). When the point is determined, the isocenter is set. In the above description, an example is shown in which the isocenter is set at the center of the irradiation field, but the isocenter can be set arbitrarily as long as it is within the irradiation field.

The virtual source setting means 10 is used to simulate the position of the source of the treatment apparatus in calculation. In many treatment apparatuses, if the irradiation angle of radiation is set, the isocenter and the source are set. Since it is known that is determined by a certain distance in the irradiation angle direction, a virtual source is set by determining the isocenter and the irradiation angle.

The data storage means 11 is a well-known storage means, for example, a well-known semiconductor memory, a magnetic disk device or a magneto-optical disk device. The data storage unit stores the projection data and various images, and also stores the coordinate position in the XYZ coordinate system of the alignment mark 20 written on the body surface before the subject 4 is lowered from the imaging table 5. .

The calculating means 12 is realized by, for example, a program operated on a well-known information processing device built in the first console 8. The procedure for creating a transmission image in this program will be described. First, a tomographic image determined by the isocenter setting means 9 and the virtual source setting means 10 is displayed on the display device. Next, a line segment is drawn from the virtual source for each pixel of the image matrix set on the image, and this is set as the trajectory of the primary line of the X-ray from the treatment apparatus simulated in calculation. Next, a CT image on voxels (pixels of a three-dimensional image) passing through the trajectory is integrated to create a transmission image. In addition, a more detailed transmission image can be created by integrating by applying a weight ratio proportional to the effective length passing on the voxel. The detailed method of creating a transmission image is described in “Radiation Therapy Planning System” published by Shinohara Publishing Co., Ltd. on April 20, 1992, pp. 124-12.
See the description on page 6.

A method of specifying a tomographic image from the isocenter and the virtual ray source will be described with reference to FIG.
FIG. 2 sets an isocenter and a virtual radiation source based on a scanogram image and a tomographic image, creates and displays a transmission image,
It is explanatory drawing which shows the aspect which also displays the beam cone referred to.

As shown in FIG. 2A, a scanogram image 120 and a tomographic image 121a are displayed on the monitor screen. On the scanogram image 120, a line 131a indicating the direction of the body axis of the subject within the isocenter position, and a line 130a indicating the position of the body axis of the subject in the vertical direction
Is also displayed. The examiner is on line 130a, 131a
By selecting on the above-mentioned pointing device and moving it on the image, the body axis direction of the subject in the isocenter coordinates and the vertical direction thereof can be determined. Here, in conjunction with the movement of the line 131a, a tomographic image of this line position,
Either a tomographic image at a position near the line position or a tomographic image 121 obtained by interpolating a plurality of images near the line position is displayed on the right side of the drawing. Tomographic image 121
Is a line 1 that indicates the position of the subject in the direction perpendicular to the body axis.
30b and a line 132b indicating the depth direction of the subject are displayed together. The examiner can select the lines 130b and 132b with the above-mentioned pointing device and move them on the image to determine the direction perpendicular to the body axis of the subject in the isocenter coordinates and the depth direction. Here, the isocenter is set at the center of the tumor 140. By such an operation, the isocenter position is determined and stored in the data storage means 11, and a plane which intersects perpendicularly with a straight line connecting the isocenter and a virtual radiation source located at a predetermined distance in the radiation irradiation direction and includes the isocenter Create a transmission image on top. The procedure for creating a transmission image is described in the above-mentioned document. FIG. 2B shows the transmission image 122 created in this way on a monitor, and the transmission image and a line 130c and a line 131c indicating the isocenter position are displayed together. As described above, the examiner can directly set the irradiation field 133 on the transmission image 122 using a pointing device or a keyboard (not shown). FIG.
(C) is an example in which the tomographic image 121b corresponding to the line 131c of the transmission image 122 and the beam transmission path lines (beam line cones) 134e and 134f calculated by the calculation means 12 are displayed together, and the line 130 indicating the isocenter is displayed.
d and 132d are also displayed. Since a well-known method is used for calculating the beam cone, the description is omitted. The examiner then checks the beam transmission path line 134
Needless to say, e and 134f can be arbitrarily adjusted on the image and correspond to the irradiation field for the transmission image 122. In this way, the irradiation field can be accurately set on the transmission image, and the irradiation field set here can be transmitted to the treatment apparatus 111 via the second communication line 109.

Referring again to FIG. 1, the treatment device 111 will be described. The treatment gantry 101 is a known treatment gantry, and is an irradiation head 10 that irradiates an electron beam generated in the microtron main body 106 in a predetermined irradiation field.
2 and a light projector (not shown) for setting the isocenter position IC of the electron beam to be irradiated.

The positioning jig 104 comprises a well-known fixing table, fixing belt, and fixing mat, and is a jig for fixing the subject 4 so that the body position of the subject 4 does not move. The treatment table 105
It comprises an X-direction moving table, a Y-direction moving table, a Z-direction moving table, an elevating device, a treatment table support table, and a turntable. And three-dimensionally move in the Z-axis direction.

The microtron main body 106 is a well-known high-energy electron beam generator, although the internal mechanism is not disclosed. The control device 107 is a well-known control device, and, based on an examiner's instruction input from the second console 108,
The movement of the treatment gantry 101 and the treatment table 105 and the control of the microtron main body 106 are performed.

The second console 108 is a device for inputting the instructions of the examiner, performs arithmetic processing based on the input data, and, for example, a rotary encoder (for example, a rotary encoder) installed on the treatment gantry 101 and the treatment table 105. A display of the positions of the treatment gantry 101 and the treatment table 105 based on a signal from a position sensor (not shown) including a detection unit, and a current X-ray irradiation amount and the like are displayed.

The second communication line 109 is connected to the treatment planning device 1
This is a well-known communication line for connecting the first console 8 of 10 and the second console 108 of the treatment apparatus 111, and uses, for example, well-known RS-232C or Ethernet.

Next, the operation of the radiotherapy system according to the present embodiment will be described with reference to FIG. First, an examiner (not shown) mounts the subject 4 on the imaging table 5 in a supine position, and lifts the couch top to a predetermined height by the vertical movement mechanism of the imaging table 5.

Next, when the examiner instructs the first console 8 to collect projection data of the subject 4, the horizontal moving mechanism moves the subject 4 on the couch top into the opening of the scanner 1. Then, the collection of the projection data of the subject 4 is started. The collected projection data is sequentially transmitted to the first communication line 7
Is sent to the first console 8 via the controller and stored in the projection data storage means (not shown) of the first console 8. Note that the acquisition operation is the same as that of the conventional X-ray CT apparatus, and thus the description thereof is omitted.

Next, when the collection of the projection data of the subject 4 is completed, the scanogram image and the tomographic image are reconstructed by the calculating means 12. The reconstruction of these images is based on a well-known method, and a description thereof will be omitted. Then
The examiner performs a radiation treatment plan. The radiation treatment plan sets an isocenter and a virtual radiation source from the reconstructed scanogram image and tomographic image by the above-described method, creates a transmission image based on the set isocenter and the virtual radiation source, and generates a treatment image. This is performed in the procedure of setting a calculated irradiation field that coincides with the irradiation field. At this time, information on the radiation irradiation position such as the irradiation field is stored in the data storage unit 11.

Next, a mark 20 is placed on the body surface of the subject 4 at the intersection of each light of the first projector 2 and the second projector 3 so as to clearly indicate the isocenter position. Next, when the radiation treatment plan is completed, the examiner moves the subject 4 placed on the stretcher to the treatment table 105 of the treatment apparatus 111, and performs radiation based on the mark 20 indicating the isocenter position and the set irradiation field. Treatment will be given. However, in the present embodiment, the treatment device 111 is the same device as a conventional radiation treatment device, and thus the description is omitted.

Next, the operation of the radiotherapy system of the present embodiment viewed from the flow of data will be summarized and described. FIG.
5 is a flowchart showing an operation of the radiotherapy system according to the embodiment of the present invention.

The treatment planning device (X-ray CT device) 110
The projection data is collected, and a scanogram image and a tomographic image are created (Step 1). The treatment planning device 110 sets an isocenter based on the scanogram image and the tomographic image (step 2). The treatment planning device 110 simulates a radiation source of the treatment device based on the scanogram image and the tomographic image (a predetermined distance in the irradiation direction from the isocenter),
Set as a virtual source (step 3). The treatment planning device 110 creates a transmission image from the tomographic image determined based on the isocenter and the virtual ray source (Step 4). The treatment planning device 110 displays the transmission image, the tomographic image, and the like on the display device provided therein (step 5). The examiner is the first
An irradiation field is set in the displayed transmission image by inputting a pointing device (not shown) of the operation console 8 (step 6). The treatment planning apparatus 110 calculates a beam cone based on the set irradiation field (step 7). The treatment planning apparatus 110 displays the calculated beam cone and the tomographic image together (step 8).

By this display, the examiner can confirm whether or not the set irradiation field is appropriate by observing the beam cone displayed together with the tomographic plane of the subject. In addition, beam beam cones are confirmed over a plurality of tomographic images, and, for example, a beam beam cone adjusted so that radiation is appropriately irradiated to a tumor is controlled by a multi-leaf (not shown) that forms an irradiation field of a treatment apparatus. It can also be used as data.

As described above, in this embodiment, the isocenter setting means 9 and the virtual ray source setting means 10 set the isocenter and the virtual ray source based on the tomographic image and the scanogram image, and The means 12 creates a transmission image based on the set isocenter and the tomographic image specified from the virtual ray source, so that a treatment plan suitable for the irradiation field of the treatment apparatus, such as an irradiation field that can be set by an X-ray simulator, can be created. The above-mentioned CT simulator can be designed.

Further, the display means displays the transmission image on a display device such as a TV monitor, and the pointing device inputs an irradiation field on the displayed transmission image.
An irradiation field is set on the obtained transmission image, and the irradiation field set in the transmission image and the irradiation field of the treatment apparatus can be matched.

The present invention is not limited to what has been described in the embodiments described above, but includes all the technologies that substantially fulfill the functions of the constituent elements described in the claims and the respective forms of their combinations. Needless to say.

[0044]

The present invention has the effect of providing a radiation therapy system including a CT simulator, such as an X-ray simulator, capable of drafting a treatment plan suitable for the irradiation field of the treatment apparatus.

Further, an irradiation field is set on the obtained transmission image, and a radiation treatment system is provided in which a CT simulator capable of matching the set irradiation field with the radiation irradiation field of the treatment apparatus is provided in the treatment planning apparatus. To play.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a radiotherapy system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a mode in which an isocenter and a virtual ray source are set, a transmission image is created and displayed, and a beam cone to be referred to is also displayed.

FIG. 3 is a flowchart showing the operation of the radiotherapy system according to the embodiment of the present invention.

[Explanation of symbols]

 9 Isocenter setting means 10 Virtual source setting means 11 Data storage means 12 Calculation means

Claims (3)

[Claims] 1. A projection image of a subject set on an imaging table is photographed, a tomographic image or a scanogram image is formed from the projection data, and a radiation image to be irradiated on the subject is formed based on the tomographic image or the scanogram image. A radiation treatment planning apparatus for creating irradiation plan data; and a radiation treatment apparatus connected to the radiation treatment planning apparatus via a communication line and performing radiation treatment based on the irradiation plan data obtained via the communication line. In the radiation therapy system, the radiation therapy planning device is configured to set an isocenter and a virtual source of the radiation therapy device based on the tomographic image and the scanogram image, and from a tomographic image specified by the isocenter and the virtual source. A radiotherapy system comprising means for creating a transmission image. 2. The radiation treatment planning apparatus further comprises means for displaying the transmission image, and means for inputting an irradiation field of the radiation treatment apparatus on the displayed transmission image. Item 7. A radiotherapy system according to Item 1. 3. The radiation treatment planning apparatus further comprises: means for displaying a plurality of tomographic images corresponding to the transmission image together with a beam cone from the virtual ray source; and a beam on the displayed tomographic image. The radiation treatment system according to claim 1 or 2, further comprising means for inputting a line cone.