JP2000317001A - Radiation medical treatment plan system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly extract bones required for specifying a human body position and the soft part tissue of a tumor or internal organs to be medically treated from a CT tomographic image in the case of a radiation medical treatment plan simultaneously on a transmissive image. SOLUTION: A system is constituted of a means 25 for selectively designating even a plurality kinds of tissue to be clearly displayed in the transmissive image generated from the tomographic image, the means 28 for generating a plurality of transmissive image which are obtained by respectively and clearly extracting a plurality kinds of tissue selected by the means 25 and the means 29 for displaying the plurality of transmissive images where tissue is clearly extracted in an observing device in parallel or the means 30 for synthesizing a plurality of transmissive images and generating one transmissive image.

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 technique effective when applied to a radiotherapy planning system using an X-ray CT apparatus.

[0002]

2. Description of the Related Art Radiotherapy is used to cure a patient's malignant tumor or to prevent recurrence after resection by surgery.
For implementation, it is necessary to plan the radiation irradiation center position and irradiation field shape for the patient.

[0003] In a radiotherapy planning apparatus for performing planning using a tomographic image of a patient taken by an X-ray CT apparatus, a radiation irradiation center position is set using a tomographic image, and an irradiation field is created from the CT tomographic image. The three-dimensional voxel data obtained is integrated along the path of the radiation from the radiation source, and is set using a transmission image created.

[0004]

As described above, in the conventional radiation treatment planning apparatus, a transmission image created from a CT tomographic image is used for the irradiation field planning. However, all voxel data is simply converted to the radiation path direction. In the transmission images integrated in the above, the bones necessary for specifying the position of the human body when planning the irradiation field and the soft tissues such as tumors and organs to be treated cannot be clearly drawn at the same time, and only the bones are drawn. Alternatively, a transmission image depicting only soft tissue was used, which hindered highly accurate planning of the irradiation field.

[0005] For this reason, the bones necessary for specifying the position of the human body and the soft tissues such as tumors and organs to be treated can be simultaneously and clearly depicted on the transmission image, and further, the operator can clearly see the transmission image. It has been demanded that a tissue desired to be drawn can be specified to obtain a transmission image optimal for planning, and that this transmission image can be used for planning.

[0006]

Means for Solving the Problems The object is to provide a means for an operator to designate a plurality of tissues to be clearly displayed in a transmission image created from a tomographic image by using a button operation of a graphical user interface or a tomographic image. Means for creating a plurality of transmission images clearly depicting each of the plurality of tissues selected by the means, and means for displaying a plurality of transmission images clearly depicting the respective tissues in parallel on an observation device Alternatively, it is provided with means for combining a plurality of transmission images clearly depicting each of the designated tissues to form one transmission image, or both, and performs radiation treatment on each transmission image created by the means. The problem is solved by providing the means for planning in the radiation treatment planning system.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of the entire system showing an embodiment of the present invention. This system uses the CT device 110
And a treatment planning device 111, and both devices have a communication line 5
Connected by The CT apparatus 110 includes a CT table 2 on which a patient 3 is placed, a scanner 1 for scanning a target site of the patient 3, and an operation console 4 for controlling these. Then, when the scan 1 is scanned by the console 4, the scan 1 captures a target part of the patient 3 and obtains a tomographic image thereof. The data of this tomographic image is CT
Under the control of the console 4, the data is sent to the treatment planning device 111 via the communication line 5. The tomographic image has, for example, a slice thickness of 10 mm and a size of 512 × 512 pixels, and 20 consecutive images are taken.

The treatment planning device 111 includes a magnetic memory 6 as an external memory and a memory 10 as an internal memory.
And a processing unit 12 having the arithmetic unit 11 and a mouse 8 or a keyboard 9 for giving instructions to the processing unit 12
And a monitor 7 for displaying the processing results of the processing device 12. The data of the tomographic image sent from the CT apparatus 110 via the communication line 5 is recorded on the magnetic disk 6. The operator reads out the data of the tomographic image from the magnetic disk 6 by operating the mouse 8 or the keyboard 9 and displays it on the monitor 7. The data of the tomographic image is arithmetically processed by the memory 10 and the arithmetic unit 11. Then, a transmission image as described later is displayed on the monitor 7.

Next, the processing procedure will be described with reference to FIGS. 2, 3 and 4. First, FIG. 3A shows a procedure for setting the isocenter. The operation of the console 4 shown in FIG. 1 starts tomographic imaging of the target site of the patient 3 (20). The scanner 1 scans a target site of the patient 3 (21).
The obtained tomographic image data is image-transferred to the treatment planning device 111 through the communication line 5 (22). The monitor 7
By the operation of the mouse 8 or the keyboard 9 by the operator, the scanogram image 120 and the tomographic image 121 created by the processing device 12 are displayed. The scanogram image 120 is similar to an X-ray photograph, and is a planar view of a target site (in this case, the chest) of the patient. Using the scanogram image 120 and the tomographic image 121, the center position of irradiating the lesion (tumor) at the target site of the patient with radiation, that is, the isocenter is positioned. On the scanogram image 120, for example, by dragging with the mouse 8, a line 131a indicating the position of the patient in the isocenter position in the left-right direction and a line 130a indicating the position of the patient in the body axis direction are displayed. The operator can select the lines 131a and 130a with the mouse 8 and move these lines on the image to determine the patient's left-right direction and body axis direction in the isocenter coordinates at an arbitrary position. In the tomographic image 121, a line 132a for specifying the position of the patient in the left-right direction and a line 130b for specifying the thickness direction of the patient are displayed. When the operator drags the line 130 a displayed on the scanogram image 120 with the mouse 8, the line 13 a on the tomographic image 121 is moved.
0b also moves in conjunction with it. Thus, the operator finds the tumor 140 and positions the isocenter (2).
3).

FIG. 3B shows a procedure for setting a radiation irradiation direction. As described above, since the irradiation direction of the radiation is set after the isocenter position is determined, the line 130b and the line 132a are displayed on the tomographic image 121 displayed on the monitor 7, and the intersection of these two lines is the isocenter. Radiation is emitted from the source of the radiation therapy device toward an isocenter, a point within the tumor 140. Therefore, the line 133 indicating the radiation direction is a line segment connecting the radiation source and the isocenter, and an arbitrary angle can be set by moving the line using the mouse 8 (24).

FIG. 3C shows an example of a procedure in which an operator selects and specifies a tissue to be clearly depicted on a transmission image. FIG. 3 (c-
1) is an example in which a push button displaying an organization name is displayed on a graphical user interface, and the operator designates the push button by operating the mouse 8 and clicking the push button. For example, a push button displayed as a bone is selected. Then, the range of +150 to +1000 of the CT value of the tomographic image is used for the integration calculation of the transmission image, and the range of -100 to +100 of the CT value of the tomographic image is used for the integration calculation of the transmission image when the soft part button is selected. Write it in the program in advance. On the other hand, FIG. 3C-2 shows an example in which the operator sets a region of interest 134 (bone) and 135 (lung) on the tomographic image 121 and designates a tissue to be clearly displayed in the transmission image. The range of the CT value inside the area is used for the integration calculation for creating the transmission image (25, 26).

FIG. 4A shows a method of creating a transmission image. 3
The dimensional voxel data is created by arranging a plurality of tomographic images in the direction of the body axis of the patient. The computer sets the virtual source 150 according to the radiation geometric shape of the radiation therapy apparatus, integrates the inside of the three-dimensional voxel data 160 with respect to voxels passing through the radiation path 151 from the source 150, and calculates the integration result of the transmitted image. By arranging it on the projection plane 170, a transmission image is obtained. At this time, as described above, C in the range of the tissue selected by the operator
Only the T value is integrated (27, 28).

The method of creating the transmission image will be described more specifically. As described in the above-described example, the three-dimensional voxel data 160 includes, for example, 20 tomographic images 160-1 to 160- in which one tomographic image is configured by a slice thickness of 5 mm × 256 vertical pixels × 256 horizontal pixels. It consists of twenty. In FIG. 4B, the first tomographic image 160-1
On the other hand, the voxel 180 through which the radiation path 151 from the source 150 passes is indicated by a white box. In this case, with respect to the voxel 180 through which the radiation path 151 passes, the transmission amount of the radiation is calculated by the computer, and the accumulated value is projected as a transmission image on the projection surface 170 on the film 171. Here, an example in which a transmission image is projected on the film 171 has been described, but this data is recorded on the disk 6 rather. Such processing is performed by tomographic images 160-1 to 160
-20 for all 20 films,
A transmission image of a tomographic image is projected on the top, and the projection data is stored on the magnetic disk 6. In the creation of the transmission image described above, according to FIG.
When bone is selected as the tissue to be emphasized, the CT value of the three-dimensional voxel data 160 of the tomographic image is +
Threshold value processing for the range of 150 to +1000 (2
6) Then, data belonging to this range is created as three-dimensional voxel data (27). Then, voxel data in this range is used to create transmission image data that is used for an integration operation for creating a transmission image (28), and the data is recorded on the disk 6. Further, when the soft part is selected as the tissue to be emphasized (FIG. 3 (c-1) and the processing 25), the threshold value processing of −100 to +100 of the CT value of the three-dimensional voxel data 160 is performed (26), The three-dimensional voxel data of this range is created (27), its transmission image is created (28), and the data is stored on the disk 6. Therefore, the disk 6 stores data of each tissue to be emphasized, in the above example, data of a transmission image of bone, soft tissue, and the like.

FIG. 4B shows the operation of the mouse 8 to extract data on bones from the disk 6, display a transparent image 180 a clearly showing the bone area on one side of the screen of the monitor 7, On the other screen, data on soft tissues (lungs and trachea) are read from the disk 6 and their tomographic images 180b are displayed in parallel (2).
9).

FIG. 4C shows an example in which a transmission image 180c in which a transmission image 180a in which a bone region is clearly displayed and a transmission image 180b in which a lung and a trachea as soft tissues are clearly displayed are synthesized. There is also a method of synthesizing transmission images by adding and increasing the ratio of transmission images in which tissues to be emphasized in addition averaging or addition are drawn (30).

FIG. 4D shows an example in which the operator operates the mouse 8 to write the irradiation field 190 on the synthesized transmission image 180c (31).

Using the transmission image created as described above,
When the irradiation field 190 is determined, radiation is emitted toward the irradiation field 190 (32), and one operation and procedure are completed (3).
3).

[0018]

As described above, according to the present invention, a bone necessary for specifying a human body position and a soft tissue such as a tumor or an organ to be treated are simultaneously displayed on a transmission image from a CT tomographic image in a radiotherapy planning. Radiation treatment that allows the operator to specify the tissue to be clearly depicted in the transmission image and create a transmission image that is optimal for planning, so that the radiation field of radiation treatment can be planned with high precision A planning device can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a processing flow.

FIG. 3 is a diagram showing a monitor screen for explaining a processing flow.

FIG. 4 is a view showing a monitor screen for explaining a flow of processing subsequent to FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 scanner 2 CT table 3 patient 4 CT console 5 communication line 6 magnetic disk 7 monitor 8 mouse 9 keyboard 10 memory 11 arithmetic unit

Claims (1)

[Claims] 1. A means for planning a central position, an irradiation direction, and a shape of an irradiation field of a radiation irradiation from a radiation source of a radiotherapy apparatus to a patient using a tomographic image of the patient taken by an X-ray CT apparatus. Means for designating a tissue to be clearly displayed on a transmission image before creating a transmission image from the tomographic image, and a transmission image in which each tissue specified by the means is clearly extracted. Means for producing, and a plurality of transmission images clearly depicting each of the specified tissues in parallel on a viewing device or a plurality of transmission images clearly depicting each of the specified tissues. Means for synthesizing one transmission image or both of them, and means for using the transmission image generated by said means for a radiation treatment plan. Radiation treatment planning system.