JPH11128219A - Radiotherapy system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to properly set an irradiation field by only a transmission image, by equipping a means to set a radiation irradiation suitable area by a CT image and a transmission image and a means to synthesize the information set by the setting means into a transmission image and to output. SOLUTION: A therapy programming device 110 makes a transmission image from a CT image based on an isocenter and a virtual beam source. The transmission image, CT image, etc. Are displayed on a display equipped on the therapy programming device 110. An operator judges upper, lower, right, and left end parts of an affected part to set the position of an auxiliary line referring the CT image. The auxiliary line generating part 12 generates each auxiliary line based on the position of the set addition line. A synthesis display processing part 13 synthesizes the transmission image and the auxiliary line. The operator sets an irradiation field to be referred to the therapy device according to the auxiliary line as a guide. A beam cone and the CT image can be displayed together and the position relation between the beam cone and the CT image can be confirmed and displayed by the operator at need.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiotherapy system in which a medical image diagnostic apparatus, such as an X-ray CT apparatus, capable of obtaining a tomographic image of an object to be treated is applied to a radiotherapy planning apparatus. The present invention relates to a radiotherapy system capable of suitably setting a radiation irradiation field in an apparatus to an appropriate radiation irradiation area.

[0002] Here, the appropriate radiation irradiation area is defined as a range in which a lesion such as a bone marrow or a lymph node, which is not suitable for irradiation, is irradiated when irradiating a lesion such as a malignant tumor of a treatment target. It means a region that is selected and set as a radiation field, with no problem even if the radiation is applied and a region having a high therapeutic effect.

[0003]

2. Description of the Related Art A conventional radiotherapy system is disclosed in Japanese Patent Application No. Hei.
As described in Japanese Patent Application No. 9138 and Japanese Patent Application No. 9-154290, a plurality of tomographic images or transmission images of an object to be treated photographed by an X-ray CT apparatus are reconstructed, and the object to be treated is based on these images. A radiation treatment planning device (hereinafter, referred to as a treatment planning device) for creating a radiation treatment plan, and a radiation treatment device (hereinafter, referred to as a treatment device) that actually irradiates a target based on the treatment plan. Was composed of

In such a treatment planning apparatus, a transmission image is displayed on a display (monitor or the like), and an operator uses a pointing device such as a mouse to transmit the radiation field to be transmitted to the treatment apparatus through the transmission field. The irradiation field has been set by confirming the appropriate radiation irradiation area of the object to be treated while superimposing a mark input by a pointing device on the image on the transmission image.

[0005] In many cases, such as when the lesion is located deep within the body to be treated, the transmitted image is not displayed. Therefore, by displaying the transmission image and the tomographic image together, the position and shape of the lesion can be changed by the operator. Was recognized. The operator sets the irradiation field by considering the recognized transmission image and tomographic image based on anatomical knowledge and experience.

[0006]

However, there is a problem that the operation of setting the irradiation field while displaying the tomographic image and the transmission image together is complicated for the operator.
Further, if the operator has little experience in the setting operation or the operator is unfamiliar with the setting operation, the patient (the subject to be treated) is made to wait in the setting operation, and the patient to be treated suffers. There is a problem that there is a possibility of giving. From such a background, many operators have demanded that the above-mentioned setting work can be performed only with a transmission image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and to satisfy the above needs, and an object of the present invention is to provide a radiotherapy system capable of appropriately setting an irradiation field only by a transmission image. is there.

[0008]

The object of the present invention is to obtain a plurality of tomographic images of an object to be treated set on an imaging table, obtain these tomographic images and a transmission image viewed from the irradiation direction of radiation from the tomographic images,
A treatment planning device for creating irradiation plan data of radiation for irradiating the object to be treated from the tomographic image and the transmission image; and irradiation plan data connected to the treatment planning device via a communication line and obtained through the communication line. A radiation treatment system having a treatment device for performing radiation treatment on the basis of the information, wherein the treatment planning device sets the radiation irradiation appropriate area by the tomographic image and the transmission image, respectively, and information set by the setting means. And a means for combining and outputting the transmitted image with the transmitted image.

[0009]

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 treatment planning device 110 and a treatment device 111.

The treatment planning apparatus 110 will be described using an X-ray CT apparatus as a representative example. An MRI apparatus, an ultrasonic diagnostic apparatus, a SPECT apparatus, and other medical image diagnostic apparatuses capable of capturing a tomographic image can be replaced with an X-ray CT apparatus. The treatment planning device 110 (X-ray CT device) includes a scanner 1, a first projector 2, a second projector 3, an imaging table 5, a first communication line 7, a first console 8, an isocenter setting unit 9, Virtual source setting unit 10, data storage unit 11, auxiliary line generation unit 1
2. It has a combined display processing unit 13 and a CPU 14.

The treatment device 111 includes a second communication line 109 for transferring the irradiation field data generated by the treatment planning device 110 from the treatment planning device 110 to the treatment device 111, a treatment gantry 101 supporting an irradiation head 102, which will be described later, An irradiation head 102 for irradiating a radiation to the treatment target, and a positioning jig 1 for setting a relative position between the irradiation head 102 and the treatment target
04, a treatment table 105 on which a subject is placed, a microtron main body 106 for generating radiation, a control device 107 for controlling these devices, and a control device 107 operated by an operator
And a second console 108 for inputting various commands to the computer.

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 a tomographic image of the subject 4, the X-ray tube device and the X-ray detector are connected to the subject 4.
X-ray projection data for obtaining an X-ray image referred to as a scanogram image by relative translation in the body axis direction of
The X-ray projection data for the scanogram image is also output to the first console 8.

The first projector 2 is a well-known laser output device for irradiating the object to be treated 4 of the imaging table 5 with a well-known laser beam. In the present embodiment, in particular, the laser beam output portion is a scanner 1. For example, a laser output portion (laser beam) can be moved in the direction perpendicular to the body axis direction of the treatment target 4 and parallel to the installation floor of the apparatus (hereinafter referred to as X direction). A guide rail (not shown) for guiding the irradiating means) in the X-axis direction, and a projector driving means for driving the laser output portion based on instructions from the examiner from the first console 8, that is, support. It has moving means. Also, in order to detect the amount of movement of the laser output part,
For example, a position measuring unit such as a well-known encoder is connected to the projector driving unit, and the output of the encoder is connected to a scanner control device (not shown) that controls the operation of the scanner 1 and the imaging table 5.

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

The imaging table 5 is a well-known imaging table, and includes a couch top on which the subject 4 is placed, a horizontal movement mechanism for moving the couch top in the body axis direction of the treatment target 4, A vertical movement mechanism for moving the couch top 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 treatment target (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 to a scanner control device (not shown), and is, for example, a communication line made of a well-known RS-232C or Ethernet. .

The first console 8 has an arithmetic unit 14 for performing image processing for reconstructing a scanogram image, a tomographic image, and a transmission image of a treatment target from measurement data. It is a so-called well-known operation console with a built-in image processing device, and has a well-known display means for displaying an image processing result. For the detailed method of creating the transmission image described here, see the description of “Radiation Therapy Planning System” published by Shinohara Publishing Co., Ltd. on April 20, 1992, pp. 124-126.

The isocenter setting section 9 sets, for example, the center of an irradiation field (hereinafter referred to as isocenter) in the treatment apparatus based on the tomographic image and the transmission image displayed on the display means. The examiner moves a cursor (not shown) such as a trackball or a mouse to the console 8 on any image by the examiner. When the cursor is moved to the center point, a key input of a keyboard (not shown) is performed. By determining the center point, an 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 unit 10 is used to set the position of the radiation source of the treatment device in order to simulate the position of the radiation source. In many treatment devices, if the radiation angle is set, the isocenter and the radiation 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 unit 11 is a well-known data storage unit, and uses, for example, a well-known semiconductor memory, a magnetic disk device, or a magneto-optical disk device. The data storage means 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. I do.

The auxiliary line generating section 12 generates an auxiliary line for supporting the setting of the irradiation field. First, in the case of the body axis direction of the treatment target, the auxiliary line position is set by displaying all of the plurality of tomographic images taken, searching for the lesion, and specifying the tomographic images at the start point and the end point, respectively. . Next, in the case of a direction parallel to the tomographic image of the object to be treated (tomographic direction), all the photographed tomographic images are displayed, and the maximum size of the lesion in the lateral direction of the displayed tomographic image is displayed. By selecting and inputting the size, the auxiliary line position is set.

The composite display processing unit 13 includes the auxiliary line generation unit 12
And the transmitted image is synthesized with the auxiliary line generated in step (1).
Specifically, the transmission image is stored in an image memory with a large bit depth built in a display (monitor), and the auxiliary lines are stored in a graphic memory with a small bit depth, and each is read out and displayed on the screen of the display. To superimpose. In such a display, even if the auxiliary line is moved by the mouse, it is only necessary to rewrite the data corresponding to the graphic memory having a small bit depth, so that even if the auxiliary line is moved by the mouse, it can be handled in real time.

The CPU 14 is, for example, a first console 8
The isocenter setting unit 9 and the virtual radiation source setting unit 1 are operated by a program operated on a known information processing device built in
0, control of each device of the data storage unit 11, the auxiliary line generation unit 12, and the combined display processing unit 13 are realized.

Next, the setting of the irradiation field will be described with reference to FIG. FIG. 2 is an explanatory diagram showing a mode until the combined display of the auxiliary line and the transmitted image and the beam cone are confirmed.

First, FIG. 2A shows an example of an isocenter setting procedure. A scanogram image 120 is displayed on the monitor 7.
And a tomographic image 121 are displayed. On the scanogram image 120, a line 130a indicating the position of the isocenter position in the horizontal direction of the drawing (coincident with the horizontal direction of the treatment target) and the position of the treatment target in the body axis direction are displayed. Is displayed. The operator can select the line 130a and the line 131a with the mouse and move them on the image to determine the horizontal direction and the body axis direction of the object to be treated in the isocenter coordinates. Here, when the line 131a is moved, the tomographic image 121 at this line position is displayed together with the movement of the line 131a.

In the tomographic image 121, a line 130b indicating the position in the left and right direction of the object to be treated and a line 132a indicating the vertical direction in the drawing (the depth direction of the object to be treated) are displayed. The position of the object to be treated in the isocenter coordinates can be determined in the left-right direction and the depth direction. In the figure, the center of the lesion 140 is set as the isocenter.

With the above operation, the isocenter position is determined and stored in the data storage unit 11, and a transmission image is created on a plane perpendicular to a straight line connecting this isocenter and the virtual radiation source of the radiotherapy apparatus.

FIG. 2B shows an example of a procedure for setting an auxiliary line on the transmission image and the tomographic image displayed on the screen of the display. First, the operator observes a tomographic image, identifies a lesion 140 to be subjected to radiation therapy from normal tissues, and examines the size of the lesion.

The tomographic image is observed by moving the tomographic image observation bar 180 on the transmission image using the mouse 8 or the keyboard 9 so that the tomographic image 121 at the position indicated by the observation bar 180 follows the movement of the observation bar 180. And displayed in real time.

When the operator operates the observation bar 180 to check the range of the lesion in the body axis direction, a state in which a tomographic image depicting the upper end of the lesion in the body axis direction is displayed on the screen. An instruction is given on the observation bar 180 with a mouse and double-clicked to determine, for example, a tomographic image at the upper end where a lesion is present. Thereby, the auxiliary line 160c indicating the upper end of the irradiation field among the auxiliary lines in the body axis direction of the treatment target is displayed on the transmission image. If the auxiliary center is displayed as a solid line, the auxiliary line is displayed as a dotted line with a different line type or a different color so that the auxiliary line can be distinguished from the line 131b or the like indicating another iso center. The same).

Similarly, the observation bar 180 on the transmission image is moved and operated with a mouse, and the observation bar is double-clicked while a tomographic image depicting the lower end of the lesion in the body axis direction is displayed. An auxiliary line 160d indicating the lower end of the irradiation field is displayed on the transmission image.

Next, the setting of the auxiliary line in the left-right direction of the object to be treated can be set by the operator sandwiching the lesion with two lines. Here, the auxiliary line in the left-right direction of the treatment target is parallel to the line 130b connecting the isocenter and the virtual source, and the auxiliary lines 150a and 150 are provided on both sides of the line 130b.
Set b. These auxiliary lines 150a and 150b are used to confirm a tomographic image having a lesion, search for the largest width of the object to be treated in the left-right direction, and set the auxiliary lines at the maximum width. It is suitable. However, when a site that is not preferable to be irradiated with radiation, such as a bone marrow or a lymph node, is included, it is possible to set so as not to irradiate the site.

The observation bar 180 on the transmission image can be moved at any time after setting the above-mentioned auxiliary line to observe a tomographic image. By double-clicking the observation bar 180, an auxiliary line in the body axis direction can be obtained. Can be arbitrarily modified. Similarly, the auxiliary line on the tomographic image can be corrected. With the above operation, a rectangular area including the isocenter can be specified for the isocenter on a plane perpendicular to the straight line connecting the isocenter and the virtual radiation source.

FIG. 2C shows a state in which auxiliary lines 150c, 150d, 160c and 160d are superimposed and displayed on the transmission image 122 in accordance with the position coordinates of the auxiliary lines set on the tomographic image as described above. Show. Also, lines 130c and 131b indicating the isocenter may be displayed together.

FIG. 2D shows an example in which the operator sets the irradiation field 133 on the transmission image 122 in the state shown in FIG. 2C. A mouse or keyboard is used to set the irradiation field.

FIG. 2E shows that the beam transmission path lines 134a and 134b on the plane of the tomographic image 121 are combined from the irradiation field 133 set in the transmission image 122 on the screen.
Shows a screen that is calculated and superimposed on the tomographic image 121 and displayed. Note that a line 13 indicating the isocenter position is provided for reference.
0d and 132b may be displayed together. The operator can move the beam transmission path lines 134a and 134b using a mouse or a keyboard as needed.
The irradiation field 133 set on the transmission image 122 can also be linked with the movement.

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 projector (not shown) for setting the isocenter position 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 position of the treatment target 4 so as not to move.

The treatment table 105 comprises an X-direction moving table, a Y-direction moving table, a Z-direction moving table, a lifting / lowering device, a treatment table support table, and a turntable. X axis, Y in system
Move three-dimensionally in the axis and Z-axis directions.

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 moves the treatment gantry 101 and the treatment table 105 and controls the microtron main body 106 based on an examiner's instruction input from the second console 108. I do.

The second console 108 is an input device for the examiner's instructions, and also performs arithmetic processing based on the input data and, for example, a rotary encoder (e.g., 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 operator (not shown) mounts the treatment subject 4 on the imaging table 5 in an upright posture, 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 the 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. And the acquisition of the projection data of the treatment target 4 is started. The collected projection data is sequentially sent to the first console 8 via the first communication line 7 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 treatment target 4 is completed, the scanogram image and the tomographic image are reconstructed by the calculating means 12. The reconstruction of these images is
This is based on a well-known method, and a description thereof will be omitted.

Next, the operator performs a radiation treatment plan. In the radiation treatment plan, an isocenter and a virtual source are set from the reconstructed scanogram image and tomographic image by the above-described method, and a transmission image is created based on the set isocenter and the virtual source, and Using a line as a guide, the procedure is performed to set a calculated irradiation field that matches the irradiation field of the treatment apparatus. At this time, information on the radiation irradiation position such as the irradiation field is stored in the data storage unit 11.

Next, the first projector 2 and the second projector 3 are placed on the surface of the subject 4 so as to clearly indicate the isocenter position.
A mark 20 is attached to a portion where each light intersects.

Next, when the radiation treatment plan is completed, the operator moves the subject 4 placed on the stretcher to the treatment table 105 of the treatment apparatus 111, and sets the mark 20 indicating the isocenter position and the irradiation field which has been set. Radiotherapy will be performed based on the However, the treatment device 111 according to the present embodiment is the same 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 301). The operator sets an isocenter based on the scanogram image and the tomographic image (step 302). The operator simulates the radiation source of the treatment apparatus on calculation based on the scanogram image and the tomographic image (a predetermined distance from the isocenter in the irradiation direction) and sets it as a virtual radiation source (step 303). The treatment planning apparatus 110 creates a transmission image from the tomographic image based on the isocenter and the virtual ray source (Step 304). Treatment planning device 110
Displays the transmission image, the tomographic image, and the like on a screen of a display device provided therein. The operator determines the upper, lower, left, and right ends of the lesion while referring to the tomographic image, and sets the position of the auxiliary line. The auxiliary line generation unit 12 generates each auxiliary line based on the set position of the auxiliary line (Step 305). The combined display processing unit 13 combines and displays the transmission image and the auxiliary line (Step 306). The operator sets multi-leaf opening degree data (irradiation field) to be transferred to the treatment apparatus using the auxiliary line as a guide (step 307). The operator can also display the beam cone of the treatment apparatus and the tomographic image together as necessary to confirm and display the positional relationship between the beam cone and the tomographic image (step 308).

As described above, according to the present embodiment, the operator can easily set the auxiliary line in the body axis direction of the treatment target while observing the tomographic image, and can display the transmitted image and the displayed tomographic image. By inputting two auxiliary lines whose width of the lesion is two while observing both, the auxiliary line in the left-right direction of the object to be treated can be set. Since the lines are superimposed and displayed on the transmission image, it is possible to guide the setting of the fine shape of the multi-leaf collimator of the treatment apparatus on the transmission image according to the rectangular area surrounded by a total of four auxiliary lines. . As a result, it is possible to easily and accurately set an irradiation field for a lesion to be treated.

The present invention is not limited to what has been described in the embodiments described above, but includes each technology that substantially exhibits the functions of the constituent elements described in each claim, and each combination thereof. Needless to say.

[0056]

The present invention has the effect of providing a radiotherapy system capable of properly setting an irradiation field only by a transmission image.

[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 combined display of an auxiliary line and a transmission image and a state until a beam cone is confirmed.

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

[Explanation of symbols]

 Reference Signs List 9 Isocenter setting unit 10 Virtual source setting unit 11 Data storage unit 12 Auxiliary line generation unit 13 Synthetic display processing unit 14 CPU

Claims (1)

[Claims] 1. A plurality of tomographic images of a treatment target set on an imaging table are obtained, and these tomographic images and transmission images viewed from a radiation irradiation direction are obtained from the tomographic images. A radiation treatment planning apparatus for creating irradiation plan data of radiation for irradiating the object to be treated, and a radiation treatment based on the irradiation plan data obtained through the communication line connected to the radiation treatment planning apparatus via a communication line. A radiation treatment system comprising: a radiation treatment planning apparatus, wherein the radiation treatment planning apparatus sets a radiation irradiation appropriate area of the treatment target by the tomographic image and the transmission image, respectively, and information set by the setting means. Means for synthesizing and outputting the transmitted image to the transmission image.