JPH10309324A - Clinic planning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compare the distribution of dosage in a concerned tissue with the number of irradiation directions as a parameter by simultaneously displaying the distribution of dosage in a concerned tissue area with a certain number of irradiation directions and the distribution of dosage in that area with the other number of irradiation directions. SOLUTION: Inside a window 1201 for DVH comparison as a graph expressing the relation of dosage and tissue volume, a reference DVH window 1202 and a DVH window 1203 for comparison are displayed and that distribution of dosage to be displayed is selected while designating a reference number by operating a scroll bar 1206 for reference dosage distribution selection and a scroll bar 1207 for comparative dosage distribution selection respectively through a mouse cursor. At the same time, as the DVH compared result 1205, the difference is displayed in a compared result window 1204 displayed in the window 1201 for DVH comparison. Thus, the distribution of dosage in the concerned tissue can be compared with the number of irradiation directions as a parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for planning a radiation treatment plan which minimizes exposure to normal tissues and effectively gives a dose to a tumor.

[0002]

2. Description of the Related Art In radiotherapy, it is necessary to minimize exposure to normal tissues and to give a sufficient therapeutic effect dose to target tissues such as tumors. Therefore, a treatment plan that uses image data captured by an image diagnostic device such as an X-ray CT device to determine from which direction and how much radiation should be irradiated before treatment based on the dose distribution calculation result before treatment. Required. The treatment plan is implemented by software implemented on a computer system. In the treatment plan, first, a three-dimensional region of a target tissue and a notable normal tissue is set using image data, and the coordinates are stored in a memory. Next, the three-dimensional dose distribution in the human body is calculated according to a physical model using image data based on the irradiation range (called the irradiation field) determined based on the size of the target tissue and the temporarily determined irradiation direction and irradiation intensity. calculate. DVH (Dose Volume Histogr) is a graph showing the relationship between dose and tissue volume for the target tissue and normal tissue stored in the memory.
am), a two-dimensional iso-dose diagram in which the dose distribution is superimposed on the tomographic image with contour lines, or the dose distribution is superimposed on the human body tissue in the form of three-dimensional data and displayed translucently and three-dimensionally3
It is evaluated by a dimension composite display. If the dose distribution is judged to be desirable, the provisionally determined irradiation direction and irradiation intensity are adopted for the treatment; otherwise, the irradiation direction and irradiation intensity are determined again, and the dose distribution calculation and the evaluation of the results are performed. Do.

[0003] The irradiation direction is set in a range avoiding normal tissues (referred to as important tissues) which normally exist around the target tissue and should not be irradiated. At this time, for example, when the irradiation directions are arranged uniformly in that range, it is generally unknown how many irradiation directions are required.
Therefore, the number of irradiation directions may be increased more than necessary, and a treatment plan with a large dose to the patient may be created, or a treatment plan with an insufficient number of treatment directions may be created. There is. Conventionally, as described in Kiyoshiya Inamura = "Radiation Therapy Planning System", Shinohara Publishing, (1992), the number of irradiation directions is determined from the viewpoint of patient restraint time during irradiation, or determined based on experience. Often. Therefore, there was no support means for determining the number of irradiation directions.

[0004]

By using a display method that allows the dose distribution of a tissue region of interest in a certain number of irradiation directions to be compared with the dose distribution in that region in another number of irradiation directions, the irradiation direction is used. Provide supportive means for determining numbers. In other words, a support means capable of comparing the dose distribution in the target tissue using the number of irradiation directions as a parameter is provided.

[0005]

Means for Solving the Problems In order to solve the problems, the following means are required and provided.

[0006] 1. Tissue Area Setting Method In the present invention, the three-dimensional data stored in the three-dimensional array
From 3D image data, for example, a semi-automatic extraction method such as a method using an image density threshold or a region expansion method using tissue connection information, or a region specification to manually trace a tissue contour in each slice image By law
Provides a means to obtain three-dimensional coordinates of whole human tissue, target tissue, and important tissue. One target tissue and a plurality of important tissues can be set. It is assumed that margins for these organizations can be set and modified.

[0007] 2. Dose distribution calculation Dose distribution of tissue is obtained by performing a calculation process assuming a certain physical model on three-dimensional image data that is the tissue distribution in the human body obtained from an image diagnostic apparatus such as an X-ray CT apparatus. For the calculation method, various algorithms such as the first to third generations and the Monte Carlo method have been devised depending on the physical model. As the generation grows, the physical model becomes more elaborate and more accurate, but requires more computation time. Although the Monte Carlo method is currently considered the most accurate calculation method, it is not used for actual treatment planning due to the enormous calculation time. Practical calculation methods are first and second generation algorithms. However, even the second generation algorithms take considerable computation time, so the first
It is common to use generational algorithms for treatment planning. Since the present invention does not depend on the content of the dose distribution calculation,
It does not specify a specific method, but simply provides a means for calculating the dose distribution. The dose distribution can be basically executed by setting the irradiation direction, irradiation intensity, and irradiation field. The irradiation intensity can be set arbitrarily for each irradiation direction, and an appropriate value can be automatically given depending on the irradiation direction by some processing.

[0008] 3. DVH (Dose Volume Histogram) In the present invention, (1) the horizontal axis represents the dose and the vertical axis represents the volume, and the target tissue, the normal tissue, or the entire photographed human tissue is taken as an area. The DVH is provided with a graph showing the tissue volume, and (2) a graph showing the total sum of the lateral side of the tissue which is equal to or more than the dose value for each dose value. With DVH, you can see how much of the target tissue is irradiated above the lethal dose, and how much of the normal tissue is below the tolerable dose. By looking at the DVH of the whole human tissue, it is possible to judge that it is desirable to have as much volume as possible in the low dose range, and to know how much dose is distributed throughout. DVH can be selected from (1) and (2), and the horizontal and vertical scales of the graph can be changed independently. The above operations can be executed interactively, and the results can be viewed immediately. DVH can quantitatively evaluate the dose distribution that is the calculation result. In the present invention, for some of the irradiation conditions, which is one of the irradiation conditions, the curves are superimposed on the same graph, or a plurality of DVHs are displayed in parallel at different positions. Suppose it is possible.

FIG. 9 is a conceptual diagram showing the state of DVH before and after changing the irradiation conditions. This is a representation of DVH in a normal tissue in the type of (2) above. It is better that the amount of tissue that is a high dose because it is a normal tissue is as small as possible. Fig. 9 (a)
Before the change, the tissue volume spreads to the high dose range, but after the change in FIG. 9 (b), the tissue volume concentrates in the low dose range. That is, as a result of resetting the irradiation conditions, it is immediately understood that the number of irradiation directions can be changed to an appropriate direction. Conversely, as a result of resetting the irradiation conditions, if the graph shown in FIG. 9 (b) becomes as shown in FIG. 9 (a), it is immediately recognized that the method of increasing or decreasing the number of irradiation directions was inappropriate. Recognize. Further, when the number of irradiation directions exceeds a certain value, the DVH may not change even if the number of irradiation directions is further increased. In such a case, it is possible to determine the number of irradiation directions by checking the change in DVH. As above
By making such a determination in the DVH, the number of irradiation directions can be adjusted to an appropriate value.

4. Two-Dimensional Isodose Map The present invention provides a means for superimposing and displaying isodose lines connecting points having equal dose values on a human tomographic image. This is the two-dimensional contour map, which is the same as the contour map. The number of isodose lines can be specified. In the present invention, a tissue set by the tissue area setting method is contoured and displayed on a tomographic image.
For this reason, the contour and the dose line overlap, making it difficult to see. Therefore, a method is adopted in which a region between adjacent dose lines is overlaid on the tissue as a translucent color. The translucent color can be specified. Hereinafter, this method is referred to as a two-dimensional isodose map, which is provided in the present invention. The slice images can be paged to see an isodose map superimposed within each slice image. The above operations can be executed interactively, and the results can be viewed immediately. The two-dimensional iso-dose map can quantitatively grasp the positional relationship between the tissue and the dose distribution. In the present invention, some of the irradiation conditions, which are one of the irradiation conditions, are changed. In contrast, it is assumed that a plurality of two-dimensional iso-dose diagrams can be displayed by displaying them in parallel at different positions or by displaying flickers at the same position.

FIG. 10 is a conceptual diagram showing an isodose diagram before and after the irradiation condition is changed. It is better for the target tissue to have as few low dose areas as possible. Before the change in Fig. 10 (a), 9
The high dose of 0% target dose line does not cover all target tissues, but after the change in FIG. 10 (b), target tissue is completely covered by 90% target dose line in this slice plane. That is, as a result of resetting the irradiation conditions, it is immediately understood that the number of irradiation directions can be changed to an appropriate direction. Conversely, as a result of resetting the irradiation conditions, if the graph shown in FIG. 10 (b) becomes as shown in FIG. 10 (a), it is immediately apparent that the method of increasing or decreasing the number of irradiation directions was inappropriate. Recognize. Further, when the number of irradiation directions becomes a certain value or more, even if the number of irradiation directions is further increased, the isodose diagram may not change. In such a case, it is possible to determine the number of irradiation directions by checking the change of the isodose map. As described above, if such determination is made in the isodose diagram, the number of irradiation directions can be adjusted to an appropriate value.

5. Three-Dimensional Composite Display The present invention provides a method of superimposing a tissue and a dose distribution as they are on three-dimensional data, and displaying the two on a two-dimensional projection plane in a translucent manner. A tissue having a certain image threshold or more and a dose distribution having a certain dose threshold or more are translucently superimposed and displayed, and these thresholds and transparency can be arbitrarily adjusted. In this three-dimensional composite display, it is assumed that the display target can be displayed by rotating it arbitrarily, or the interior can be displayed by cutting it at an arbitrary cutting plane. It is also assumed that an isodose map can be displayed within an arbitrary cut plane. The above operations can be executed interactively, and the results can be viewed immediately. In the third-order main display, the three-dimensional positional relationship between the tissue and the dose distribution can be intuitively grasped. In the present invention, for some of the irradiation conditions, which are one of the irradiation conditions, some are displayed in parallel at different positions, or a plurality of 3 are displayed by flickering at the same position.
It is assumed that a dimension composite display can be displayed.

FIG. 11 is a conceptual diagram showing a three-dimensional composite display before and after the change of the irradiation condition. As in the case of the iso-dose diagram, it is better that the region where the dose is low is as small as possible in the target tissue. Before the change in Fig. 11 (a), a high dose of 90% target dose did not cover all target tissues,
After the change in FIG. 11 (b), the target tissue is completely 90 three-dimensionally.
% Target dose surface. That is, as a result of resetting the irradiation conditions, it is immediately understood that the number of irradiation directions can be changed to an appropriate direction. Conversely, as a result of resetting the irradiation conditions,
If the graph as shown in FIG. 11B becomes as shown in FIG. 11A, it is immediately apparent that the method of increasing or decreasing the number of irradiation directions was inappropriate. In addition, when the number of irradiation directions exceeds a certain value, the three-dimensional composite display may not change even if the number of irradiation directions is further increased. In such a case, it is possible to determine the number of irradiation directions by checking the change of the three-dimensional composite display. If such a determination is made in the three-dimensional composite display as described above, the number of irradiation directions can be adjusted to an appropriate value.

6. Difference Display In the present invention, in each of the DVH, the two-dimensional iso-dose diagram, and the three-dimensional composite display, a means for displaying a difference between dose distributions when irradiation conditions are different is provided. With these displays, it is possible to precisely examine how the difference in the irradiation conditions causes a change in the dose distribution. When the number of irradiation directions exceeds a certain value or more, the display does not change even if the number of irradiation directions is further increased.The difference display is convenient for determining which stage of the irradiation direction should be adopted based on the censoring error. Function.

(1) DVH FIG. 12 shows a display example of the DVH difference. It is assumed that dose distributions having different irradiation conditions are already stored in a memory or an external storage device with reference numbers. First, the wind
Specify the reference number of the dose distribution to be displayed on A and B using the scroll bar and display those DVHs. The difference display is (B + A / B
-A) button. This is a toggle button that alternately switches between the difference display of the DVHs of the windows A and B and the overlap display thereof.

(2) Two-dimensional isodose diagram FIG. 13 shows a display example of a difference between the two-dimensional isodose diagrams. The method of executing the difference display is the same as that of DVH. However, in the difference of the two-dimensional iso-dose diagram, the difference is displayed in a dose distribution region equal to or higher than a certain dose value, and thus a dose threshold is specified. This is equivalent to taking a difference with respect to the size of the inner region of the isodose line having a two-dimensional isodose diagram. Since the obtained difference has a plus part and a minus part, those colors are displayed in different colors. It is also possible to link or unlink the two-dimensional isodose map and the cross-sectional position of the difference. However, the sectional positions of the windows A and B are always linked. Also,
In window A, flicker display in which isodose lines of windows A and B are alternately displayed at certain time intervals is also possible. (3) Three-dimensional composite display FIG. 14 shows a display example of the difference of the three-dimensional composite display. The execution method of the difference display is the same as the two-dimensional equal dose display. However, 3
It is also possible to link the dimension combination display and the rotation display of the difference with each other, or to make the display unlinked. However, the wind
A and B rotation displays are always linked. Rotation display is window
By dragging the inside of A or B by a distance which is the mouse cursor, the rotation axis and the rotation angle are determined from the position and the movement amount of the mouse cursor, and the rotation display is executed.

Next, how to use the above means,
The following example describes whether the problem can be solved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an example of a treatment apparatus, a total treatment system, and a treatment planning apparatus to which the present invention can be applied will be described, and a configuration example of a treatment planning system capable of realizing the present invention will be described. Next, a difference display example is shown for each of the DVH, the two-dimensional isodose diagram, and the three-dimensional composite display. Finally, some specific embodiments of the present invention will be described.

FIG. 5 shows an example of the treatment apparatus. Gantry 501
Can rotate in a vertical plane, and its rotation angle is referred to as a gantry rotation angle 502. Within the gantry is a radiation source 503 from which the emitted radiation passes through the irradiation head 504 and is emitted in a suitable spread. The patient is put to bed 505. The bed is rotatable in a horizontal plane, and its rotation angle is a bed rotation angle 506.

FIG. 6 shows an example of a total treatment system. The tomographic image of the human body obtained from the X-ray CT apparatus 601 is input to the treatment planning apparatus 602. Various parameters 603 are input to the treatment planning device 602, and irradiation conditions are determined by calculation processing in the treatment planning device 602. Radiation irradiation conditions are treatment equipment
The energy is input to the control device 605 in the 604, and the energy to the accelerator 606, the rotation angle of the gantry 607, the size of the irradiation field of the irradiation head 608, the horizontal / vertical parallel movement position and the rotation angle of the bed 609, etc. according to the irradiation conditions. Are controlled by the control device 605.

The treatment planning device 602 refers to a computer system as shown in FIG. This system is a computer
In addition to 701, the input device 702 includes an input device 702 for inputting data, a display device 703 for displaying results, and a storage device 704 for storing treatment planning software and output results.

FIG. 8 shows an example of the contents of the treatment planning device 602. In the treatment planning device 602, calculation processing portions such as a tissue region setting 801, a dose distribution calculation 803, and a display calculation 804 are performed through an interface 801 serving as an input / output unit.
It is connected to input / output data in a storage device or display device such as drawing data 806, parameters 807, result display 808, and irradiation conditions 809. In the treatment plan, first, after image data 805 is input, an extraction result is obtained by inputting a rendering range and the like as a parameter 807 in accordance with the processing of the tissue region setting 801. The result is stored in the storage device as rendering data 806. Next, every time the irradiation condition 809 is input, the process of the dose distribution calculation 803 is repeated to obtain the final irradiation condition 809 and store it in the storage device together with the dose distribution data 810. During this process, the display calculation 804 displays the dose distribution, for example, as a result display 808.
Output as

FIG. 12 shows an example of a DVH difference display. Here, it is assumed that the dose distribution to be compared is stored in a memory or an external storage device with a reference number in advance. By default, the reference D is in the DVH comparison window 1201
There are a VH window 1202, a DVH window 1203 for comparison, and a comparison result window 1204. The dose distribution displayed on the reference DVH window 1202 and the comparison DVH window 1203 can be changed by operating the scroll bar 1206 for selecting the reference dose distribution and the scroll bar 1207 for selecting the dose distribution for comparison with the mouse cursor. Select by specifying. PVH comparison result 1205 by default in comparison result window 1204
To display the difference. However, if the user selects the toggle button 1208 for selecting the superimposed display / difference display of the comparison result, the reference DVH window 1202 and the comparison D
It is possible to select whether to display the DVHs in the VH window 1203 in a superimposed manner or to display the difference between them.

FIG. 13 shows an example of the difference display of the two-dimensional isodose map. Here, it is assumed that the dose distribution to be compared is stored in a memory or an external storage device with a reference number in advance. By default, the window for comparison of the contour map
In 1301, there is a reference isodogram window 1302 and a comparison isodogram window 1303. The dose distributions displayed in the reference isodogram window 1302 and the comparison isodogram window 1303 are a scroll bar 1307 for selecting a reference dose distribution and a scroll bar 13 for selecting a dose distribution for comparison.
Select 08 by operating the mouse cursor and specifying the reference number. By default, the comparison result window 1304 is not displayed, but the display / non-display selection button 1309 for the comparison result window can be used to select whether to display or not display. In the difference display of the dose distribution, the dose distribution difference (plus portion) 1305 and the dose distribution difference (minus portion) 1306 are displayed in different colors in the comparison result window 1304. The cross-sectional position of the reference dose graph window 1302, the comparison dose graph window 1303, and the contour dose graph in the comparison result window 1304 are linked by the interlock / non-link selection button 1310 of the slice position of the comparison result. You can choose to be unlinked or unlinked. The cross-sectional positions of the isodose map in the reference isodogram window 1302 and the comparison isodogram window 1303 are always linked. In the difference display, a difference is calculated for a region equal to or more than a certain dose. Therefore, the dose threshold is specified by the scroll bar 1311 for specifying the dose threshold in the dose distribution difference display. The scroll bar 1312 for specifying the slice position is used to specify the cross-sectional position, and the specified cross-sectional position is displayed in the slice number display frame 1313.
Is displayed as a number. The flicker display / non-display selection button 1314 displays the reference isodogram window 1302 and the isodose lines in the comparison isodogram window 1303 in the reference isodogram window 1302 at a certain time interval. The user can select whether to display the flicker display alternately or not.

FIG. 14 shows a difference display example of the three-dimensional composite display. Here, it is assumed that the dose distribution to be compared is stored in a memory or an external storage device with a reference number in advance. By default, a reference three-dimensional composite display window 1402 and a comparative three-dimensional composite display window 1403 are included in the three-dimensional composite display comparison window 1401. The dose distribution to be displayed in the reference three-dimensional composite display window 1402 and the comparative three-dimensional composite display window 1403 is a scroll bar 1407 for selecting a reference dose distribution and a scroll bar 1408 for selecting a dose distribution for comparison, respectively, with a mouse cursor. Select by operating and specifying the serial number. By default, the comparison result window 1404 is not displayed, but the display / non-display selection button 1409 of the comparison result window can be used to select whether to display or not display. In the difference display of the dose distribution, the dose distribution difference (plus portion) 1405 and the dose distribution difference (minus portion) 1406 are displayed in different colors in the comparison result window 1404. A reference three-dimensional composite display window 1402 and a comparison three-dimensional composite display window 1403 can be selected with the interlocking / non-interlocking selection button 1410 for rotation display of the comparison result.
Whether the rotation display of the dose distribution in the comparison result window 1404 is linked or not linked can be selected. The dose distribution of the reference three-dimensional composite display window 1402 and the dose distribution of the comparison three-dimensional composite display window 1403 are always linked. In the difference display, a difference is calculated for an area equal to or larger than a certain dose. Therefore, the dose threshold is specified by the scroll bar 1411 for specifying the dose threshold in the three-dimensional dose distribution difference display. In the rotation display, in any of the reference three-dimensional composite display window 1402, the comparison three-dimensional composite display window 1403, and the comparison result window 1404, by dragging 1412 with the mouse cursor in the window, the drag position, direction, And the rotation axis, rotation angle,
And the direction of rotation. However, when the difference display is not interlocked, the rotation is not performed even if the user drags in the comparison result window 1404.

Hereinafter, four embodiments will be described.

1. Example 1 This example is a treatment plan evaluation means DVH, isodose map, and any of the three-dimensional composite display is not displayed preferentially, all have the same rank, This is the most common example.

(Step 101) Image data input The CT image stored in the storage device of the computer is read into the memory controlled by the software of the present treatment planning system.

(Step 102) Tissue region setting The regions of the whole human body tissue, the target tissue, and the important tissue are set by the above-mentioned manual or semi-automatic method. For the target tissue and important tissue, the margin is set automatically or manually.

(Step 103) Irradiation condition setting The number of irradiation directions, irradiation directions, irradiation intensity, and irradiation field are set for the target tissue. The irradiation direction is set at an equal angle according to the number of irradiation directions. The irradiation intensity is set to a constant value for each irradiation direction by dividing the total irradiation intensity by the number of irradiation directions, or an appropriate value is set for each irradiation direction by some automatic calculation. In resetting the irradiation conditions, only the number of irradiation directions is changed.

(Step 104) Calculation of Dose Distribution A dose distribution is calculated in the whole human body tissue under given irradiation conditions.

(Step 105) Determination of DVH Display If it is desired to display DVH, the process proceeds to (Step 106), and if not, the process proceeds to (Step 108).

(Step 106) Display of DVH A target tissue or a plurality of important tissues is selected, and the DVH for the selected target is displayed.
(1) DVH with the abscissa plotting the dose and the ordinate plotting the volume, and displaying the tissue volume for each dose value in a graph. (2) The total sum of the tissue volume that exceeds each dose value for each dose value is displayed in a graph. You can select one of the displayed DVHs. The scale of the horizontal axis and the vertical axis of the graph can be changed independently. Also,
As in the window example of FIG. 12 described above, for the dose distribution with the number of irradiation directions changed, the DVH display is displayed in parallel at different positions, or the curve is superimposed on the same graph, or It is assumed that two differences can be displayed in parallel. These operations can be performed interactively,
You can see the result immediately.

(Step 107) Judgment of resetting irradiation condition If it is desired to reset the irradiation condition (step 103),
(Step 104), otherwise (Step 11)
Proceed to 2).

(Step 108) Judgment of Display of Isodose Map If it is desired to display an isodose map, the process proceeds to (Step 109); otherwise, the process proceeds to (Step 110).

(Step 109) Display of isodose map In this step 109, an isodose map is displayed. In this embodiment, a tissue set by the tissue area setting method is contoured and displayed on a tomographic image. For this reason, the contour and the dose line overlap, making it difficult to see. Therefore, a method is adopted in which a region between adjacent dose lines is overlaid on the tissue as a translucent color. The color of the area and the number of equal doses can be specified. The slice images can be paged to see an isodose map superimposed within each slice image. Also, the diagram explained above
For the dose distribution with the number of irradiation directions changed, as shown in the 13 window example, the isodose map display is flickered at the same position, displayed in parallel at different positions, or
It is assumed that two differences can be displayed in parallel. The above operations can be performed interactively, and the results can be seen immediately. After the end, the process proceeds to (Step 107).

(Step 110) Determination of Three-Dimensional Composite Display If it is desired to display three-dimensional composite display, the process proceeds to (Step 111), and if not, the process proceeds to (Step 112).

(Step 111) Three-dimensional composite display In this step 111, a three-dimensional composite display is displayed. Tissues above a certain image threshold and a dose distribution above a certain dose threshold are displayed translucently superimposed, and these thresholds and transparency can be arbitrarily adjusted. In 3D composite display,
It is possible to rotate the display object arbitrarily and to display the inside by cutting it at an arbitrary cutting plane. It is also possible to display an isodose map in an arbitrary cut plane.
In addition, as shown in the window example of FIG. 14 described above, for the dose distribution in which the number of irradiation directions is changed, three-dimensional composite display is displayed in parallel at different positions, or two differences are displayed in parallel. Suppose it is possible. The above operations can be performed interactively, and the results can be seen immediately.
After the end, the process proceeds to (Step 107).

(Step 112) Data Storage The extracted data, irradiation conditions and calculated dose distribution data set above are stored in the storage device of the computer, and the system is terminated.

In this embodiment, immediately after the calculation of the dose distribution, the evaluation means desired to be used can be selected immediately, and the display of the results by the selected evaluation means can be compared with each other while repeatedly setting the tissue area. .

2. Embodiment 2 In this embodiment, after the dose distribution calculation is completed, DVH is preferentially displayed as a treatment plan evaluation means, and the DVH obtained as a result can be compared with each other while repeatedly setting irradiation conditions. If another evaluation means is used, it is possible to shift from the DVH display mode to a desired evaluation means.

(Step 201) Image data input, (Step 202) tissue region setting, (Step 203) irradiation condition setting, (Step 204) dose distribution calculation are the same as (Step 101) to (Step 104) of the first embodiment. Therefore, the description is omitted.

(Step 205) Display of DVH In this step 205, the DVH is displayed. Contents are Example 1.
(Step 106).

(Step 206) Judgment of Resetting Irradiation Condition If the irradiation condition has been reset, the process proceeds to (Step 203). Otherwise, the process proceeds to the next step.

(Step 207) Judgment of Display of Isodose Map If it is desired to display an isodose map, the flow proceeds to [Step 208]; otherwise, the flow proceeds to the next step.

(Step 208) Display of isodose map An isodose map is displayed. The contents are the same as in Example 1 (Step 1
Same as 09). After the end, the process proceeds to (Step 206).

(Step 209) Judgment of three-dimensional combined display If it is desired to display three-dimensional combined display, the process proceeds to (step 211), and if not, the process proceeds to the next step.

(Step 210) Three-dimensional composite display A three-dimensional composite display is displayed. The content is the same as that of the first embodiment (step 111). After the end, the process proceeds to (Step 206).

(Step 210) Determination of DVH Display If it is desired to display DVH, the flow proceeds to (Step 205), and if not, the flow proceeds to the next step.

(Step 212) Data Storage The extracted data, irradiation conditions and calculated dose distribution data set above are stored in the storage device of the computer, and the system is terminated.

When the change in the number of irradiation directions before and after the change of the irradiation conditions is small, the difference in the dose distribution becomes small. that time,
In some cases, it is possible to distinguish the difference by DVH, which is the result of integrating the three-dimensional dose distribution. After confirming with the DVH, there are cases where the dose distribution display and the three-dimensional composite display are used for further detailed examination. This embodiment is an example particularly suitable for such a treatment plan.

3. Example 3 In this example, after the dose distribution calculation is completed, the 3D composite display is preferentially displayed as a treatment plan evaluation means, and while the tissue area setting is repeated, the resulting 3D composite display can be compared with each other. Things. If other evaluation means are used, it is possible to shift from the three-dimensional composite display mode to a desired evaluation means.

(Step 301) Image data input, (Step 302) Tissue area setting, (Step 303) Irradiation condition setting, (Step 304) Dose distribution calculation are the same as (Step 101) to (Step 104) in the first embodiment. Therefore, the description is omitted.

(Step 305) Three-dimensional composite display In this step 305, three-dimensional composite display is displayed. The content is the same as that of the first embodiment (step 111).

(Step 306) Judgment of resetting irradiation condition If it is desired to reset the irradiation condition, the process proceeds to (Step 303), and if not, the process proceeds to the next step.

(Step 307) Judgment of Display of Isodose Map If it is desired to display an isodose map, the flow proceeds to [Step 308]; otherwise, the flow proceeds to the next step.

(Step 308) Display of isodose map An isodose map is displayed. The contents are the same as those of the first embodiment (step 10
Same as 9). After the end, the process proceeds to (Step 306).

(Step 309) Judgment of DVH display If DVH display is desired, proceed to (Step 310), otherwise proceed to the next step.

(Step 310) Display of DVH In this step, the DVH is displayed. The content is the same as that of the first embodiment (step 106). When finished, (Step 30
Proceed to 6).

(Step 311) Determination of Three-Dimensional Composite Display Here, if it is desired to display three-dimensional composite display, the process proceeds to (Step 305); otherwise, the process proceeds to the next step.

(Step 312) Data Storage The extracted data, irradiation conditions and calculated dose distribution data set above are stored in the storage device of the computer, and the system is terminated.

When the number of irradiation directions is large before and after the change of the irradiation condition, the difference in the dose distribution becomes remarkable. At this time, in order to know the positional relationship between the tissue and the dose distribution in the three-dimensional space, a comparative study using a three-dimensional composite display is advantageous. This embodiment is an embodiment particularly suitable for such a treatment plan.

4. Embodiment 4 In this embodiment, after the dose distribution calculation is completed, only DVH is displayed as a treatment plan evaluation means, and the DVH display as a result can be compared with each other while repeatedly setting the tissue area.

(Step 401) Image data input, (Step 402) tissue region setting, (Step 403) irradiation condition setting, and (Step 404) dose distribution calculation are performed in the same manner as in (Step 101) to (Step 104) of the first embodiment. The description is omitted because it is similar.

(Step 405) Display of DVH In this step 405, the DVH is displayed. Contents are examples
This is the same as 1 (step 106).

(Step 406) Judgment of resetting of irradiation condition If it is desired to reset the irradiation condition, proceed to (Step 403), otherwise proceed to the next step.

(Step 407) Data Storage The extracted data, irradiation conditions and calculated dose distribution data set above are stored in the storage device of the computer, and the system is terminated. In the case of two-dimensional irradiation in which the irradiation direction is only a few directions and each direction is parallel to the cross section of the CT slice image, the positional relationship between tissue and dose distribution in three-dimensional space can be relatively easily imagined, and quantitative Sometimes a comparative study is enough. This embodiment is an example suitable for such a treatment plan.

[0068]

According to the present invention, several dose distributions obtained as a result of calculation by changing the number of irradiation directions can be compared and examined using DVH, an iso-dose diagram, and a three-dimensional composite display. By adjusting the number of irradiation directions based on this evaluation result, a more accurate treatment plan can be determined.

[Brief description of the drawings]

FIG. 1 is a flowchart of a first embodiment.

FIG. 2 is a flowchart of a second embodiment.

FIG. 3 is a flowchart of a third embodiment.

FIG. 4 is a flowchart of a fourth embodiment.

FIG. 5 is a diagram showing an example of a treatment device.

FIG. 6 is a diagram showing an example of a total treatment system.

FIG. 7 is a diagram illustrating an example of a computer system.

FIG. 8 is a diagram showing an example of an internal processing mechanism of the treatment planning device.

FIG. 9 is a diagram illustrating a DVH display example.

FIG. 10 is a diagram showing an example of an isodose diagram display.

FIG. 11 is a diagram showing a three-dimensional composite display example.

FIG. 12 is a diagram showing an example of a window for DVH comparison.

FIG. 13 is a diagram showing an example of a window for isodose diagram comparison.

FIG. 14 is a diagram showing an example of a three-dimensional composite display comparison window.

[Explanation of symbols]

101: image data input, 102: tissue area setting, 103: irradiation condition setting, 104: dose distribution calculation, 105: DVH display judgment, 1
06: DVH display, 107: Judgment of resetting irradiation conditions, 108: Judgment of isodose map display, 109: Equidose map display, 110: Judgment of 3D composite display, 111 ... 3D composite display, 112 ... Data storage

Claims (4)

[Claims] 1. An input device for inputting image data and an external command, a computer for processing the input image data according to an external command, and a processing result of a treatment planning device for displaying a processing result. In a radiation treatment system including a radiation treatment apparatus having control means for controlling the position and direction of the gantry, irradiation head, bed, and energy of the accelerator, the control means performs processing for setting the number of irradiation directions. A treatment planning system characterized by simultaneously displaying a dose distribution inside a tissue region of interest for each of the different irradiation directions. 2. The treatment planning system according to claim 1, wherein when simultaneously displaying the dose distribution inside the tissue region, the control means displays a graph representing the relationship between dose and volume in the tissue region. A treatment planning system characterized by: 3. The treatment planning system according to claim 1, wherein when simultaneously displaying the dose distribution inside the weaving area, the control means displays the tissue area at a predetermined cross-sectional position and the dose distribution on a plane. A treatment planning system characterized by displaying a two-dimensional iso-dose map superimposed on the treatment plan. 4. The treatment planning system according to claim 1, wherein the control means superimposes the tissue area and the dose distribution three-dimensionally when simultaneously displaying the dose distribution inside the tissue area. A treatment planning system characterized by performing a three-dimensional composite display.