JPH10192427A - Radiotherapy planning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish adjustability for the irradiation field shape preset on the basis of the image of a BE plane including an ill affected zone having a smaller share in the body thickness of the specimen or any of the major internal organs. SOLUTION: This radiotherepy planning device is composed of a preparing means for the three-dimensional volume data of a specimen, a preparing means to prepare the image data IBE of a BE plane orthogonally intersecting the fundamental line passing the iso-center and a radiations source and to slice the inside of the specimen on the basis of the obtained three-dimensional volume data, a display means which superposes the irradiation field shape of the BE plane as the data RD on the image data IBE of the BE plane and displays the superposed image data (IBE and RD) in a monitor 47, and an adjusting means to adjust the irradiation field shape RD of the BE plane on the basis of the superposed image data (IBE and RD) given on the monitor 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation treatment planning apparatus for irradiating a lesion directly to a patient to make a treatment plan in the radiation treatment apparatus for treating the lesion. The present invention relates to a radiation treatment planning device capable of adjusting an irradiation field shape.

[0002]

2. Description of the Related Art A radiation therapy apparatus for directly irradiating a lesion (target) of a patient with radiation such as electron acceleration rays or X-rays to treat the lesion is used as a therapy apparatus for performing a root treatment especially among cancer treatments. In recent years, has attracted very attention.

In order to perform treatment using such a radiation therapy apparatus, various preparatory operations are required. The first step is to acquire an image of a diseased part using, for example, an X-ray CT scanner. Then, in the second stage, the position, size, shape, number, etc. of the lesion are accurately grasped using the image, and the position and dose distribution of the isocenter (I / C), irradiation particles (field of view, After selecting the angle, the number of portals, etc.), determine whether or not only the lesion can be irradiated properly. Further, in the third stage, setting of the I / C using the I / C, the dose distribution and the irradiation conditions determined by the X-ray simulator,
A patient is positioned by fluoroscopy, a body surface marking (I / C, irradiation field), and a simulation based on the determined irradiation method is performed.

[0004] When the simulation is completed in this way, the treatment by the radiotherapy apparatus is usually performed after an appropriate period. Prior to this treatment, the irradiation field is collated with the collation perspective image, the patient is positioned by the I / C mark among the body surface marks attached to the patient, and the collimator is collated by the irradiation field mark representing the irradiation range of the radiation. The irradiation range of the transmitted radiation is set. After this,
The actual radiation treatment is performed according to the prescribed irradiation method.

[0005] By the way, since radiotherapy is a treatment method in which a subject is directly irradiated with radiation as described above, a treatment plan including positioning of a lesion is made more elaborately, and the treatment plan is made more elaborately. It is required to perform highly accurate treatment based on the medical treatment.

Under such circumstances, when setting a treatment plan, a transmission image of a subject is used in setting an irradiation field shape, and a reconstructed axial image is used in setting a ray cone.

That is, an irradiation field shape set based on the aperture shape of a collimator such as a multi-leaf shape is displayed on a transmission image as a reference image, and the displayed illumination field shape is finely adjusted to open the collimator. By adjusting the shape, the irradiation field corresponding to the lesion (target) was determined. When an image of a diseased part is acquired by an X-ray CT scanner, a transmission image reconstructed from a CT image is often used as a reference image for determining an irradiation field. The transmission image in the radiation treatment plan is an image viewed from the therapeutic radiation source (that is, the line of sight expands from one point).
Three-dimensional voxel data is formed intermediately from a plurality of three-dimensional CT images (tomographic images), and an image created from the three-dimensional voxel data is preferably used. A CT image (tomographic image) is used as the axial image. Conventionally, the length of a calculation path for creating a transmission image extends over the entire subject (all thickness) in the direction of the line of sight from the radiation source.

On the other hand, in the treatment plan of radiation therapy,
An apparatus incorporating a digging process in a three-dimensional image display is known, for example, from Japanese Patent Application No. 6-56374.

In the drilling process in this radiation treatment plan, for example, an original ROI corresponding to the irradiation field shape based on the opening shape of a collimator such as a multi-leaf shape
A cross section orthogonal to the basic line passing through the source and the I / C and slicing the inside of the subject (a cross section having a slice thickness much smaller than the thickness (body thickness) along the basic line direction of the subject; Hereinafter, this cross section is referred to as BE surface (Beam's Eye Vie
w)), a depth h to the BE surface including the lesion is specified, and a conical shape is determined based on the positional relationship of the optical system, that is, the distance from the radiation source to the body surface and the specified depth h. Correction based on the radiation beam spreading to the depth h
The size of the ROI (collimator aperture) is automatically corrected according to the size. And the specified internal depth h
By projecting pixel values of a predetermined thickness onto the designated surface with respect to the ROI surface at the position of, a drilling image of a surface inside the ROI (internal ROI surface) is created and combined with the surface image.

[0010] By using the above-described drilling process, an ROI having a shape linked to the degree of opening of the collimator, that is, an ROI corresponding to the irradiation field shape, is set at the stage of treatment planning, and drilling of the internal ROI surface within the BE surface Since the image can be recognized, it is possible to accurately grasp the size and positional relationship between the irradiation field shape corresponding to the ROI and the lesion in the BE plane.

[0011]

However, in the transmission image according to the above-mentioned conventional method, since the integration path is used over the entire area (all thickness) in the line of sight of the subject, the transmission image of the subject is not used. In a lesion or an important organ that accounts for a small percentage of the body thickness (total thickness), the contrast of the lesion or the important organ is low, and it has been difficult to identify the position of the lesion or the important organ. In addition, because of the difficulty in identifying the location of the lesion and important organs, it is necessary to determine whether the irradiation field shape is an appropriate shape that is suitable for the lesion and has a sufficient margin for the important organs. There was a risk that it would be difficult to confirm the

[0012] On the other hand, the conventional drilling process is mainly performed by RO
It is used for recognizing the positional relationship between the I shape (irradiation field shape) and the lesion, and the information given by the drilling process is as follows:
Only the information within the internal ROI plane. That is, in the conventional drilling processing, information outside the ROI on the BE surface, in other words, information outside the irradiation field on the BE surface has not been obtained at all. For this reason, for example, BE
Even when an important organ exists in a region outside the irradiation field on the surface, it is not possible to recognize the existence of the important organ, and it has been difficult to set a sufficient margin or the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has been made based on an image of a BE surface including a lesion or an important organ, which occupies a small portion of the body thickness of a subject. It is an object of the present invention to provide a radiation treatment planning apparatus capable of adjusting a field shape.

[0014]

According to a first aspect of the present invention, there is provided a radiotherapy planning apparatus, comprising: an X-ray isocenter of an object based on an image obtained by irradiating the object with X-rays; A radiation treatment planning apparatus for planning a radiation treatment by setting a position and an irradiation field that is an irradiation range of radiation irradiated to the subject; a generating unit configured to generate three-dimensional volume data of the subject; Creating means for creating image data of a BE plane orthogonal to a line passing through a source and an isocenter and slicing the inside of the subject based on the three-dimensional volume data; and the BE plane as an irradiation field shape on the BE plane as data Display means for superimposing the superimposed image data on the monitor and displaying the superimposed image data on a monitor; And a adjusting means for adjusting an irradiation field shape in the BE surface on the basis of data.

In a preferred embodiment, the adjusting means includes:
Correction means for correcting the irradiation field shape data in the superimposed image data displayed on the monitor on the monitor,
The irradiation field shape on the BE surface is adjusted based on the corrected irradiation field shape data.

In particular, the generating means has means for acquiring a plurality of axial image data of the subject, and means for generating the three-dimensional volume data based on the acquired plurality of axial image data. With
Means for displaying, on the monitor, an axial image including the isocenter from the plurality of axial image data of the subject, and a predetermined slice position orthogonal to the line on the axial image displayed on the monitor (for example, Means for designating at least a part of the lesion of the specimen).
The E-plane image data creating means creates BE-plane image data corresponding to the designated slice position based on the three-dimensional volume data.

In particular, the slice thickness of the BE surface is:
The thickness is smaller than the body thickness of the subject and includes at least a part of a lesion of the subject.

In a preferred embodiment, the slice position designating means is configured so that the slice position can be sequentially moved and designated.

According to the present invention, the BE surface orthogonal to the line passing through the radiation source and the isocenter and slicing the inside of the subject, that is, thinner than the body thickness of the subject, for example, at least one of the lesions of the subject The image data of the BE surface having a thickness including the portion is created from the three-dimensional volume data. Then, the data (shape data) representing the irradiation field shape on the BE surface is superimposed on the image data on the BE surface, and the superimposed image data is displayed on a monitor, for example, as compared with the conventional transmission image display (full thickness). Lesions, important organs, and the like, which occupy a small portion of the body thickness of the subject, are displayed with higher contrast on the BE surface.

In this configuration, the adjusting means adjusts the irradiation field shape on the BE surface based on the superimposed image data displayed on the monitor.

That is, the irradiation field shape data representing the irradiation field shape on the BE surface displayed on the monitor is corrected by the correcting means based on, for example, the size and position of a lesion or important organ on the BE surface. The irradiation field shape on the BE surface is adjusted based on the corrected irradiation field shape data. Therefore, an optimal irradiation field shape can be set according to the position of a lesion, the position of an important organ, and the like.

The position of the BE surface (slice position)
Can be specified on an axial image including the isocenter displayed on the monitor, so that an image of the BE surface at a desired position along the line can be displayed.

Since the slice position on the BE surface can be sequentially moved and designated, the shape of the irradiation field and the inside and outside thereof can be confirmed and finely adjusted in the entire range in the line direction (the thickness direction of the subject). Can be performed.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an entire radiotherapy system including a radiotherapy planning apparatus according to an embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, this radiation treatment planning system is used for a radiation treatment planning device as a radiation treatment planning device for consistently performing image treatment, treatment planning and positioning (simulation) during radiation treatment. A CT system 1 and a radiation treatment apparatus 2 for performing radiation treatment in accordance with treatment plan data planned and simulated by the radiation treatment planning CT system 1, and a collimator described later incorporated in the radiation treatment apparatus 2 are provided. For automatic control, the radiation treatment planning CT system 1 and the radiation treatment apparatus 2 are connected by a signal line 3 as a signal transmission line. In the middle of this signal line 3,
A collating and recording device 4 that allows the operator to finely adjust the degree of opening of the collimator during actual radiation treatment is inserted. Further, the radiation treatment planning CT system 1 includes a treatment planning dedicated processor 5 for performing specialized arithmetic processing such as radiation dose distribution calculation and a laser printer 6 for outputting plan data via transmission lines 7 and 8. Each is connected.

Of these components, the radiation treatment planning CT system 1 (hereinafter simply referred to as CT system) will be described first.

The CT system 1 is configured by applying a normal X-ray CT scanner, and includes a gantry 11, a bed 12 and a control console 13 as shown in FIG. It is a device driven by the method.
A top plate 12a is provided on the upper surface of the bed 12 so as to be slidable in the longitudinal direction (Z axis (body axis direction)), and the subject P is placed on the upper surface of the top plate 12a. Is placed. The top plate 12a is inserted into the diagnostic opening OP of the gantry 11 so as to be able to advance and retreat by driving a slide mechanism represented by the electric motor 12.

As shown in FIG. 2, the gantry 11 has a pair of opposed X's sandwiching the subject P inserted into the opening OP thereof.
It incorporates a ray tube 20 and an X-ray detector 21. The weak current signal corresponding to the transmitted X-ray detected by the X-ray detector 21 is converted into a digital amount by the data collection unit 22 and sent to the console 13. In FIG. 2, reference numeral 23 denotes a collimator and a filter in the gantry 11, and reference numeral 24 denotes X.
Shows a line fan beam.

Further, when the isocenter is marked on the front side of the gantry 11, that is, inside the front cover 11a located on the bed 12 side, the operation is performed.
The positioning laser projectors 27a, 27b, and 27c are provided.

The console 13 includes, in addition to a main control unit 40 for overall control of the CT system, a bed control unit 41 and a gantry control unit 4 which operate in response to commands from the main control unit 40.
2 and are interconnected via an internal bus. The main controller 40 is also connected to an X-ray controller 43 outside the console, and includes a high-voltage generator 44 that operates according to a drive signal from the X-ray controller 43. The high voltage generated by the high voltage generator 44 is supplied to the X-ray tube 20, and X-ray irradiation is performed. Further, the console 13 receives an acquisition signal from the data acquisition unit 22 and reconstructs image data, an image reconstruction unit 45, an image memory 46 for storing image data, and a display (monitor) for displaying a reconstructed image.
47, and an input device 48 for the operator to give a command to the main control unit 40. Each of the control units and the controllers 40 to 43 is equipped with a computer, and operates based on a program stored in its memory in advance.

The internal bus of the console 13 is further connected to an extension board 49 of a signal line, and a projector controller 49 for controlling marker irradiation positions of the projectors 27a to 27c is connected to the extension board 48 via a signal line 51. ing. The projector controller 49 is supplied with the position data of the isocenter of the subject P from the main control unit 40. In response to this data supply, the projector controller 50 sets the illumination units of the three projectors 27a to 27c. Automatically control the position of.

Next, the radiation therapy apparatus 2 will be described.

The radiotherapy device 2 (hereinafter simply referred to as a therapy device) in the present embodiment performs treatment using X-rays. As shown in FIG. 1, a treatment table 52 for placing a subject P,
A gantry 53 rotatable around the body axis (Z) direction of the subject P, a gantry support 54 for rotatably supporting the gantry 53, and a console (not shown) are provided.

The treatment table 52 has a top plate 52a on its upper side. Since the height of the treatment table 52 can be adjusted by an internal driving mechanism, the table 52a can be moved up and down (in the Y-axis direction). In addition, the treatment table 52 can move the top plate 52a within a predetermined range in the longitudinal direction (Z direction) and the lateral direction (X direction) by driving another internal driving mechanism. By operating the mechanism, rotation of the top plate support and rotation about the isocenter are possible. These operations of the treatment table 52 are necessary when positioning the subject P on the top plate 52a and irradiating radiation, and are controlled by control signals from the console.

On the other hand, the gantry 53 is provided with an irradiation head 53a for deflecting the accelerated electrons from the klystron and hitting the target, and irradiating the subject P with an X-ray beam generated therefrom. The irradiation head 53a includes a target,
That is, the collimator 55 that determines the irradiation field on the body surface of the subject P is provided between the radiation source S and the irradiation port. In this embodiment, the collimator 55 is a multi-leaf collimator (Multi-Leaf
Collimator). That is, as shown in FIG.
Two leaf groups 56A and 56B, each of which is composed of a plurality of plate-like tungsten leaves 56.
They are arranged facing each other with the line path interposed therebetween in an upright state, and the leaves 56 ...
Each of the moving mechanisms 5 has a lead screw as a main part.
7... 57 can be driven independently in the length direction (Z direction) of each leaf. The moving mechanisms 57... 57 are driven in accordance with control signals supplied from the console.
The size and shape (that is, equivalent to the size and shape of the irradiation field on the body surface) of the irradiation opening formed by the three leaf groups 56A and 56B can be changed in real time.

Further, the gantry support 54 is rotatable clockwise or counterclockwise around the entire gantry 53 by its built-in drive mechanism. The operation of this drive mechanism is performed based on a control signal from the console.

The console of the treatment apparatus 2 has a main control section for managing the entire treatment apparatus 2, a collimator control section, and the like.

Next, the operation of this configuration will be described with reference to FIGS.

According to the CT system 1 of the present embodiment, at the time of treatment planning, each component of the gantry 11 and the console 1 are controlled via the main control unit 40 of the console 13.
3 by controlling the other components, the X-ray controller 43, and the high-voltage generator 44 to obtain the position coordinates of the I / C of the subject P, display the position of the ray cone of the radiation, and respond to the shape of the lesion. Make a treatment plan such as setting of the irradiation field shape to be performed.

That is, the CT system 1 includes the main control unit 4
Under the control of 0, a plurality of CT images (axial images) of the subject P are photographed, and three-dimensional voxel data is formed intermediately from the plurality of axial image data. Store in memory. Then, from the three-dimensional voxel data, transmission image data viewed from the therapeutic radiation source is created and displayed on the display 47 together with the axial image. After a transmission image and a plurality of axial images serving as a reference for a treatment plan are created and displayed in this way, a specific treatment plan is entered.

For example, the z coordinate of the isocenter (I / C) representing the center position (X, Z plane) of the lesion in the transmission image on the display 47 is designated via the input device 48. Further, from among the axial images sequentially displayed on the display 47, the axial image I at the slice position based on the z coordinate is used.
A1 is designated, and the x and y coordinates of the I / C representing the center position (X, Y plane) of the lesion in the axial image IA1 are designated (see FIG. 4; FIG. Therefore, the subject P has a cylindrical shape.)

Then, the shape of the irradiation field is set based on the shape of the lesion displayed on the transmission image. At this time, in this embodiment, since a multi-leaf collimator is employed, an arbitrary shape based on the shape of the lesion is specified by, for example, ROI setting in the input device 48, and the specified data is determined by the main control. Each leaf 56 through the part 40 ...
The data is converted into opening shape data by 56, and the rotation direction of the entire collimator 55 is also calculated via the main control unit 40. FIG. 4 conceptually shows the irradiation field shape RF.

The rotation direction is determined in consideration of the direction in which the entire collimator 55 is rotated in the XZ plane, and each leaf 56 forms an opening shape having the least error with respect to the set irradiation field. . Thus, the main control unit 40
The irradiation field shape data including the rotation direction data and the aperture shape data obtained by the above are held in the internal memory of the main control unit 40. When a lead block is used without using a multi-leaf collimator, a polygonal irradiation field shape that is most similar to the irradiation field shape is usually set.

Then, a line cone is superimposed and displayed on the axial image IA1 including the I / C.

After the acquisition of the I / C position coordinates, the display of the position of the ray cone of radiation, and the setting of the irradiation field shape corresponding to the shape of the lesion, the CT system 1 of the present configuration performs the following operations. The BE surface display processing including the irradiation field shape and the fine adjustment processing of the irradiation field shape are performed as necessary. Hereinafter, the BE surface display processing including the irradiation field shape and the irradiation field fine adjustment processing as necessary will be described with reference to FIGS.

That is, the main control unit 1 of the CT system 1
Displays the axial image IA1 on which the line cones LNa and LNb are superimposed and displayed on the left side of the display 47 as shown in FIG. At this time, the operator specifies a desired slice position on the axial image IA1 displayed via the mouse or the like of the input device 48, for example, a slice position ST including the lesion TU (FIG. 6; step S1). Main control unit 40
Is based on the three-dimensional voxel data stored in the internal memory, and is orthogonal to the cross section along the slice position ST specified by the input device 48, that is, the basic line passing through the source S and the I / C, and The image data of the BE surface (see FIG. 4) of a predetermined thickness (thickness smaller than the body thickness of the subject P and including at least a part of the lesion) for slicing the inside is generated (step S2).

Then, the main controller 40 stores the irradiation field shape data stored in the internal memory, that is, the irradiation field shape data on the body surface based on the shape of the multi-leaf collimator 55 set in the treatment plan. Correction (enlargement / reduction) based on the slice position and the optical positional relationship (distance from the radiation source S to the slice position) generates irradiation field shape data DBE on the BE surface (step S).
3). Then, the irradiation field shape data DBE is input to the input device 48.
Is superimposed on the BE surface image data as original ROI shape data that can be reset by a mouse or the like (step S4), and the BE on which the ROI shape data RD is superimposed.
Axial image IA1 in which surface image data IBE is displayed in advance
At the same time, they are displayed side by side on the right side of the display 47 (see FIG. 5; step S5).

The image I BE of the BE surface displayed on the display 47
Since the slice thickness of the BE surface is very thin compared to the body thickness, the contrast of the lesion TU and the important organs OR near the lesion TU can be displayed with high contrast and the visibility is high. ing.

Also, unlike the case where only an image in the irradiation field shape is displayed as in the conventional drilling process, the BE surface in the subject P including the inside and outside of the irradiation field shape RD is displayed. The organ OR can be easily and accurately compared with the ROI shape RD corresponding to the irradiation field shape DBE. So make sure you have enough margin,
Irradiation field shape adjustment for setting a sufficient margin can be easily performed as needed.

For example, as shown in FIG. 7, when the right corner RDA of the ROI shape data RD is close to the important organ OR and a sufficient margin is not set (NO in the judgment in step S6). ), The operator uses the input device 48
By operating the mouse or the like, the right corner portion RDA of the ROI shape data RD is separated from the important organ OR as necessary (refer to the broken line portion RDA '), and the ROI shape data RD is corrected (RD → RD'). The irradiation field shape data DBE on the BE surface corresponding to the ROI shape data RD can be finely adjusted (DBE → DBE ') (step S).
7).

Then, the main control unit 40 sets the irradiation field shape based on the opening shape of the collimator 55 set in the treatment plan, that is, stored in the internal memory, so that the irradiation field shape data on the BE surface becomes DBE '. The data can be finely adjusted (step S8), and the finely adjusted irradiation field shape data is stored again in the internal memory of the main control unit 40, and used for radiation therapy.

As described above, in the present configuration, in order to finely adjust the irradiation field shape once planned and set, first, irradiation field shape data on the BE surface is generated based on this irradiation field shape. Then, by finely adjusting the irradiation field shape data on the BE surface based on the positional relationship between the normal region such as an important organ or the like and the irradiation field shape displayed in the image data on the BE surface including inside and outside of the irradiation field shape, In addition, it is possible to set a precise irradiation field shape suitable for the shape of a lesion part with a sufficient margin for a normal part, and to make a highly accurate treatment plan.

Further, in the present configuration, since the image of the BE surface along the slice position specified through the position specifying device such as the mouse of the input device 48 can be displayed, the configuration shown in FIGS. ), The slice position is moved (that is, the distance from the source S is changed) by operating the mouse (slice position ST1 → ST2 →
ST3), images IBE1 to IBE1 to BE surfaces (BE1 to BE3) corresponding to the moved slice positions ST1 to ST3, respectively.
ROI shape R corresponding to irradiation field shape data DBE1 to DBE3 on IBE3 and its BE plane (BE1 to BE3)
D1 to RD3 can be superimposed and displayed. Also, by modifying the ROI shapes RD1 to RD3 on each image,
Irradiation field shape data D corresponding to each ROI shape RD1 to RD3
BE1 to DBE3 can also be fine-tuned. That is, since the irradiation field shape and the inside and outside thereof can be confirmed and finely adjusted in the entire range of the basic line direction (body thickness direction) of the subject P, a more accurate irradiation field shape can be set, An accurate treatment plan can be made.

In this configuration, the display and fine adjustment of the irradiation field shape on the BE surface are performed based on the irradiation field shape set on the transmission image. MPR, MIP, etc.), and fine adjustment may be performed by displaying the irradiation field shape on the BE surface on a monitor based on the set irradiation field shape. Also, a plurality of types of images having different properties, which are the basis for determining the irradiation field shape, may be prepared and selectable.

In this configuration, the image data I on the BE surface
Although the BE and the axial image IA1 are displayed side by side on the display 47, the present invention is not limited to this. The BE and the axial image IA1 may be displayed on separate displays or switched to the same display 47 as necessary. It may be displayed while displaying.

[0056]

As described above, according to the radiation treatment planning apparatus according to the present invention, unlike the case of displaying only the image in the irradiation field shape as in the conventional drilling processing, the inside and outside of the irradiation field shape are different. By displaying an image of the BE surface in the subject including the above, a lesion, an important organ, or the like, which occupies a small portion of the body thickness of the subject, is displayed with high contrast. Then, for example, by comparing the important organ and the irradiation field shape based on the image on the BE surface, it is possible to easily adjust the irradiation field shape on the BE surface and set a sufficient margin or the like. . Therefore, a highly efficient and accurate treatment plan can be made.

Further, in the present invention, B is operated by operating a mouse or the like.
Since the slice position of the E plane can be sequentially moved and designated, the BE plane corresponding to each slice position and this B plane in the entire range in the line direction (body thickness direction of the subject) can be designated.
The irradiation field shape on the E plane can be superimposed and displayed, and the inside and outside of the irradiation field shape on the BE plane can be confirmed and the irradiation field shape can be finely adjusted. As a result, a very excellent and accurate irradiation field shape can be set based on all conditions in the body thickness direction of the subject, and a good treatment plan can be made.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an example of a radiotherapy system to which a radiotherapy planning apparatus of the present invention is applied.

FIG. 2 is a block diagram of a CT system as a radiation treatment planning device.

FIG. 3 is a schematic perspective view of a multi-leaf collimator mounted on the radiation therapy apparatus.

FIG. 4 is a diagram for explaining an I / C, an irradiation field shape, an axial image, and a BE surface.

FIG. 5 is a diagram showing a state in which an axial image showing a line pyramid and an image on a BE surface are displayed on the same display device.

FIG. 6 is a schematic flowchart showing an example of the processing of the entire CT system centering on a main control unit.

FIG. 7 is a view for explaining fine adjustment processing of the irradiation field shape.

FIGS. 8A to 8C are diagrams showing BE plane images at respective slice positions according to a BE plane slice position moving operation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 CT system for radiation treatment planning 2 Radiation treatment device 3 Signal line 11 Gantry 12 Bed 13 Console 20 X-ray tube 21 X-ray detector 22 Data collection unit 40 Main control unit 41 Bed control unit 42 Mount control unit 43 X-ray controller 44 High voltage generator 45 Image reconstruction device 47 Display device 48 Input device 53 Mount 53a Irradiation head 55 Collimator 56 Leaf 56A, 56B Leaf group 57 Moving mechanism

Claims (7)

[Claims] 1. A method according to claim 1, further comprising: setting an isocenter position of the subject and an irradiation field, which is an irradiation range of radiation irradiated to the subject, based on an image obtained by exposing the subject to X-rays. A radiation treatment planning apparatus for planning a radiation treatment, comprising: a generating unit for generating three-dimensional volume data of the subject; and image data of a BE plane orthogonal to a line passing through a radiation source and an isocenter and slicing the inside of the subject Generating means for generating, based on the three-dimensional volume data, display means for superimposing the irradiation field shape on the BE surface as image data on the image data on the BE surface, and displaying the superimposed image data on a monitor; Adjusting means for adjusting the shape of the irradiation field on the BE surface based on the superimposed image data displayed on the Radiation treatment planning system to. 2. The image processing apparatus according to claim 1, wherein the adjustment unit includes a correction unit configured to correct the irradiation field shape data in the superimposed image data displayed on the monitor on the monitor, and the BE surface is corrected based on the corrected irradiation field shape data. 2. The radiation treatment planning apparatus according to claim 1, wherein the irradiation field shape is adjusted. 3. The apparatus according to claim 1, wherein the generating unit includes a unit configured to acquire a plurality of axial image data of the subject, and a unit configured to generate the three-dimensional volume data based on the acquired plurality of axial image data. Means for displaying, on the monitor, an axial image including the isocenter from the plurality of axial image data of the subject, and specifying a predetermined slice position orthogonal to the line on the axial image displayed on the monitor 3. The BE plane image data creating unit creates the BE plane image data corresponding to the designated slice position based on the three-dimensional volume data. Radiation treatment planning device. 4. The radiation treatment planning apparatus according to claim 3, wherein the slice position on the BE plane is designated so as to slice at least a part of the lesion of the subject. 5. The radiation treatment planning apparatus according to claim 4, wherein the slice thickness of the BE surface is smaller than the body thickness of the subject and includes at least a part of a lesion of the subject. 6. The radiation treatment planning apparatus according to claim 5, wherein the axial image including the superimposed image data and the isocenter is displayed on the monitor in parallel. 7. The radiation treatment planning apparatus according to claim 6, wherein said slice position designation means is configured to sequentially move and designate said slice position.