JP2013240443A - Therapy plan supporting apparatus and radiotherapy system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the radiation dose from becoming excessive in the radiotherapy.SOLUTION: A therapy plan supporting apparatus includes: a data storage part; an image storage part 128; a tissue region determining part; a therapy plan making part 104; a comparison part; and a display part 120. The data storage part 128 stores tissue region data indicating a plurality of tissue regions in a human body and a permissible dose relative to the radiation in each tissue region. The image storage part 108 stores image data of a subject. The tissue region determining part determines a tissue region from the image data of the subject on the basis of the tissue region data. The therapy plan making part 104 finds a condition for irradiating the subject with therapeutic radiation, and a dose distribution in the condition for irradiation. The comparison part compares a permissible dose corresponding to the tissue region determined by the tissue region determining part with the dose distribution. The display part 120 displays information reflecting the result of comparison by the comparison part.

Description

  Embodiments described herein relate generally to a treatment plan support apparatus and a radiation treatment system.

  In radiation therapy, radiation is applied to a diseased site such as cancer by utilizing the action of radiation to kill cells of a living organism. For example, a linear accelerator is used as a radiation therapy apparatus (see, for example, Patent Document 1). The linear accelerator irradiates, from a radiation irradiator, radiation generated by applying an accelerated electron beam to a target on a diseased part of a patient lying on a treatment table.

  In radiotherapy, various preparation operations are performed in advance. In the first stage, for example, an image of a diseased part is acquired by an X-ray CT apparatus. In the second stage, the position, size, and outline (shape) of the diseased part are grasped based on the image of the diseased part, and the isocenter position and dose distribution, irradiation method (field of view, angle, number of gates, etc.) ), It is determined whether radiation can be intensively applied to the diseased part while suppressing the irradiation dose to the normal region around the diseased part. In the third stage, patient positioning by fluoroscopy, body surface marking, simulation by the determined irradiation method, and the like are performed.

  The above-mentioned isocenter refers to “the center of the minimum sphere formed by the beam axis of the symmetric irradiation field by the rotation of the gantry and the rotation of the irradiation field limiting system in the treatment apparatus in which the gantry rotates” (for example, paragraph [ [0005] and [0008]). The isocenter in the radiotherapy apparatus in which the gantry rotates means, for example, an irradiation center that is an intersection of radiation when irradiating the target site (disease site) from different angles, and coincides with the rotation center of the gantry.

  In conventional radiotherapy, an operator such as a doctor manually inputs each parameter of irradiation conditions such as an irradiation dose and an irradiation direction into a treatment plan creation apparatus at the time of treatment plan. Based on the input information, the treatment plan creation device calculates and outputs a dose distribution.

JP 7-255719 A JP 2008-046422 A

  In the conventional treatment plan, since the operator checked whether there was a problem with the dose distribution calculated by the treatment plan creation device, it took time to check whether the input content was in the proper range. . Also, if you enter a value that is too large for a parameter, you may not be able to notice it by skipping the check. In this case, the patient may be exposed to an excessive dose.

  For this reason, the technique which prevents easily that an irradiation dose becomes excessive in radiotherapy was requested | required.

  Hereinafter, several examples of the modes that the embodiment of the present invention can take will be described for each mode.

(1) In one embodiment, the treatment plan support apparatus includes a data storage unit, an image storage unit, a tissue region determination unit, a treatment plan creation unit, a comparison unit, and a display unit.
The data storage unit stores tissue region data indicating a plurality of tissue regions in the human body and an allowable dose for radiation for each tissue region.
The image storage unit stores image data of the subject.
The tissue region determination unit determines the tissue region from the image data of the subject based on the tissue region data.
The treatment plan creation unit obtains a treatment radiation irradiation condition for the subject and a dose distribution under the irradiation condition.
The comparison unit compares the allowable dose corresponding to the tissue region determined by the tissue region determination unit and the dose distribution obtained by the treatment plan creation unit.
The display unit displays information reflecting the comparison result of the comparison unit.

  (2) In another embodiment, the treatment plan support apparatus includes a data storage unit similar to the above, an image storage unit similar to the above, a tissue region determination unit similar to the above, and a treatment plan creation unit. The treatment plan creation unit in this embodiment obtains the treatment radiation irradiation condition for the subject based on the allowable dose corresponding to the tissue region determined by the tissue region determination unit.

  (3) In one embodiment, a radiation therapy system includes the treatment plan support apparatus of (1) and a radiation therapy apparatus. In this embodiment, the treatment plan creation unit of the treatment plan support apparatus is configured to finally determine the irradiation condition of the therapeutic radiation after displaying the information reflecting the comparison result, and the radiation treatment apparatus It is configured to be able to irradiate radiation under the finally determined irradiation conditions.

  (4) In another embodiment, a radiotherapy system is configured to be capable of irradiating therapeutic radiation under the irradiation condition obtained by the treatment plan support apparatus of (2) and the treatment plan support apparatus. Device.

The block diagram which shows the whole structure of the radiotherapy system of this embodiment. The block diagram which shows the detailed structure of the treatment plan assistance apparatus of FIG. The table | surface which shows an example of tolerance dose data typically. The schematic diagram which shows an example of the subject image used for a treatment plan. As an example of tissue region data stored in the anatomical region database, FIG. 4 is a schematic diagram of a cross section in the same direction corresponding to the image in the treatment plan and the human body coordinate system shown in FIG. The schematic diagram which shows an example of a dose volume histogram. The schematic diagram which shows an example of the screen which designated the irradiation object area | region. The schematic diagram which shows an example of the screen which compared and displayed the dose of each tissue area | region based on the calculated dose distribution, and the allowable dose of each tissue area. The schematic diagram which shows an example of the warning screen displayed when there exists a tissue area | region which exceeds an allowable dose in the dose distribution of a treatment plan. The flowchart which shows an example of the flow of operation | movement of the radiotherapy system of this embodiment. The block diagram which shows the whole structure of the radiotherapy system which concerns on the modification of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

(Configuration of this embodiment)
FIG. 1 is a block diagram showing the overall configuration of the radiation therapy system 10 of the present embodiment. As shown in FIG. 1, the radiotherapy system 10 includes an image diagnostic apparatus 20, a treatment plan support apparatus 30, a radiotherapy apparatus 40, and a communication path 50 that connects these to each other.

  The radiation therapy apparatus 40 includes a system control unit 58, a bed driving device 60, a bed 62, a gantry (arm unit) 66, a stand 70, a high voltage supply device 74, and a diaphragm driving device 78. In the gantry 66, a treatment head 80 and an electron beam generator 84 are provided. The therapeutic head 80 includes therein a waveguide guide 90a, a bending magnet 90b, a target 90c, and a multi-segment aperture (collimator) 90d. A rotation drive device 92 is provided in the stand 70.

  The bed 62 can move in a predetermined direction under the control of the system control unit 58. That is, the bed driving device 60 moves the position of the bed 62 on which the subject P is placed according to the control of the system control unit 58.

The high voltage supply device 74 supplies an electric power necessary for irradiation with therapeutic radiation (electron beam in this example) for reducing or eliminating a diseased site such as cancer or tumor under the control of the system control unit 58. 84.
The electron beam generator 84 generates an electron beam EL for treatment of the subject P placed on the bed 62.

  The diaphragm driving device 78 adjusts the opening of the diaphragm 90d according to the control of the system control unit 58, thereby changing the irradiation range of the therapeutic radiation irradiated from the therapeutic head 80.

  Specifically, the electron beam EL generated by the electron beam generator 84 is accelerated by the waveguide guide 90a and enters the bending magnet 90b. The bending magnet 90b causes the electron beam EL to collide with the target 90c by directing the traveling direction of the incident electron beam EL downward. Thereby, therapeutic radiation (electron beam in this example) EB is generated. The generated therapeutic radiation EB is irradiated onto the subject P on the bed 62 after the irradiation shape and dose distribution are adjusted by the diaphragm 90d.

The gantry 66 is configured to hold the treatment head 80 and the electron beam generator 84 as one body and to rotate around the bed 62.
The stand 70 supports the gantry 66.

  The rotation driving device 92 rotates the gantry 66 around the connection portion between the gantry 66 and the stand 70 according to the control of the system control unit 58.

  The system control unit 58 stores the treatment plan input from the treatment plan support apparatus 30 in association with the subject information. The system control unit 58 controls the radiotherapy apparatus 40 as a whole, and causes the subject P on the bed 62 to be irradiated with the therapeutic radiation under the irradiation conditions according to the treatment plan by causing each unit to function as described above. In addition, although the structure which uses an electron beam as a therapeutic radiation is described here, this is only an example and the structure which uses other therapeutic radiations, such as an X-ray, a proton beam, a heavy particle beam, as the radiation treatment apparatus 40 may be sufficient. .

  The image diagnostic apparatus 20 is, for example, an X-ray CT apparatus (X-ray Computed Tomography), an X-ray diagnostic apparatus, a magnetic resonance imaging apparatus, or the like. The diagnostic imaging apparatus 20 creates a file of image data of the subject P by a known method such as magnetic resonance imaging or X-ray CT, for example, as volume data that is three-dimensional image data or two-dimensional image data including a plurality of slices. Generate.

  The diagnostic imaging apparatus 20 associates the accompanying information of the generated image data file with information about the gender and age of the subject P and the cross section from which direction in which position of the human body coordinate system.

  With the human body coordinate system, for example, the left-right direction of the subject is the X-axis direction, the front-rear direction of the subject with the abdominal side is the front and the back side is the back is the Y-axis direction, The vertical direction of the subject with the foot down is the Z-axis direction. In this embodiment, as an example, the XY plane of the human body coordinate system is an axial plane, the XZ plane of the human body coordinate system is a coronal plane, and the YZ plane of the human body coordinate system is a sagittal plane.

  The image data file generated by the diagnostic imaging apparatus 20 is input to the treatment plan support apparatus 30 via the communication path 50.

  FIG. 2 is a block diagram showing a detailed configuration of the treatment plan support apparatus 30 of FIG. The treatment plan support apparatus 30 includes, for example, a control unit 100, a treatment plan creation unit 104, an image storage unit 108, an image processing unit 112, an input unit 116, a display unit 120, a system bus 124, and data storage. Part 128.

  The control unit 100 performs system control of the entire treatment plan support apparatus 30 via the system bus 124.

  The input unit 116 includes various input devices such as a keyboard. The display unit 120 displays a screen for selecting a condition for the treatment plan. The operator inputs information on the subject P and sets at least some conditions of the treatment plan such as each parameter of irradiation conditions in the input unit 116. The irradiation conditions include the position of the isocenter, the position and contour of the irradiation target region (target region), the irradiation field, the irradiation angle, the number of irradiations, the irradiation dose, and the like. The set treatment plan conditions are input to the treatment plan creation unit 104 and the control unit 100.

  The treatment plan creation unit 104 creates a treatment plan including a dose distribution based on each condition of the treatment plan input from the input unit 116. “Creating a treatment plan” means, for example, setting a part of the above irradiation conditions, determining an unset irradiation condition based on the set irradiation condition, subject information, etc. The plan is to create it on a computer. That is, the treatment plan includes all set irradiation conditions.

  The image storage unit 108 acquires and stores the image data of the subject P generated by the image diagnostic apparatus 20.

  The data storage unit 128 includes an anatomical region database 132 and an allowable dose database 136. The “anatomical region” herein means, for example, a region of each tissue (hereinafter referred to as a tissue region) such as an organ, bone, nail, tooth, hair, skin, artery, etc. in the human body. The anatomical region database 132 stores tissue region data.

  The “tissue region data” here includes, for example, three-dimensional information such as a standard position, contour, and size for a large number of tissue regions in a human body such as a lens, each organ that is an internal organ, and a bone. It is data. The tissue region data is divided into two types according to gender and sex, and further divided into three types of adults, children, and fetuses according to the age, and is present and stored.

  The image processing unit 112 acquires the image data of the subject P from the image storage unit 108, and extracts each tissue region from the acquired image data based on the tissue region data (see FIGS. 4 and 5 described later).

  In the allowable dose database 136, each allowable dose for each tissue region of the human body including at least all risk organs is stored as allowable dose data. The risk organ is a tissue having a low allowable dose to radiation, such as a lens, testis, ovary, hematopoietic organ (spinal cord). Here, the allowable dose is, for example, a reference dose of normal tissue around the irradiation target area to which it is judged to be safe (the dose that causes an adverse event in the human body with a certain probability). ).

  FIG. 3 is a table schematically showing an example of the allowable dose data. The permissible dose data is divided into gender and gender, and the permissible dose is stored for each of the three sizes of adults, children, and fetuses according to body size. In addition, the numerical value of the allowable dose in FIG. 3 is shown for convenience of explanation, and is not related to the value actually used. In practice, for example, a value that conforms to the guidelines indicated by the International Commission on Radiological Protection (ICRP) may be used as the allowable dose.

  FIG. 4 is a schematic diagram illustrating an example of an image of the subject P used in the treatment plan, which is generated by the image diagnostic apparatus 20 and stored in the image storage unit 108. FIG. 4 corresponds to an axial cross section of the human body coordinate system in the abdomen, and each region such as the spleen 140a, stomach 142a, spinal cord 144a, adrenal gland 146a, and liver 148a is shown.

  FIG. 5 is a schematic diagram of a cross-section in the same direction corresponding to substantially the same position in the human coordinate system and the treatment plan image shown in FIG. 4 as an example of tissue region data stored in the anatomical region database 132.

  As described above, the anatomical region database 132 stores information such as standard positions and contours as three-dimensional data for a large number of tissue regions of the human body. Therefore, from this three-dimensional data, the image processing unit 112 can extract a desired cross-section (a cross-section corresponding to the same position as the treatment plan image) as a two-dimensional image as shown in FIG. FIG. 5 shows a standard arrangement of each tissue of the human body in the axial cross section of the abdomen, and shows regions such as the spleen 140x, stomach 142x, spinal cord 144x, adrenal gland 146x, and liver 148x.

  Hereinafter, an example of a technique for extracting each tissue region from the treatment plan image as shown in FIG. 4 will be described. The image processing unit 112 in FIG. 2 acquires the image data file of the subject P from the image storage unit 108, and then acquires the sex and age of the subject P from the accompanying information. Thereby, the image processing unit 112 acquires tissue region data of the corresponding sex after determining which tissue region data of the adult, the child, and the fetus is suitable according to the age.

  Next, the image processing unit 112 acquires, from the incidental information of the image data, the acquired image data is a cross section in which direction in which position of the human body coordinate system (axial cross section, coronal cross section, sagittal cross section, etc.). . Based on the acquired information, the image processing unit 112 extracts, from the tissue region data, a treatment plan image and a cross-sectional image corresponding to substantially the same position in the human body coordinate system.

  The image processing unit 112 performs, for example, pattern matching on the extracted cross-sectional image (see FIG. 5) of the tissue region data and the treatment plan image (see FIG. 4), thereby each tissue region from the treatment plan image. To extract.

  Thereby, the image processing unit 112 determines the name, position, and outline (range) of each tissue region such as the spleen 140a in the treatment planning image (see FIG. 4).

  Next, an example of a method for creating a treatment plan will be described. Based on each condition of the treatment plan input from the input unit 116, the treatment plan creation unit 104 irradiates the irradiation target region intensively while avoiding irradiation to the normal region around the irradiation target region as much as possible. The treatment plan is calculated with such a dose distribution. Here, the calculation result of the dose in each tissue region is not uniform in a normal case within the tissue region.

  FIG. 6 is a schematic diagram showing an example of a dose volume histogram. A dose volume histogram (DVH: Dose Volume Histogram) is a graph showing the ratio of the volume irradiated with a dose greater than a certain value in a frequency distribution. In FIG. 6, the vertical axis represents volume (%), and the horizontal axis represents irradiation dose (%). In addition, a bold solid curve in FIG. 6 shows a dose volume histogram as a normal tissue for one organ such as a kidney. In addition, a thick dashed line curve in FIG. 6 shows a dose volume histogram as an irradiation target region (disease site) for one organ such as a kidney.

  The curve of the dose volume histogram as a normal tissue is ideally ideal as it approaches the left side and the bottom side of the graph. In FIG. 6, for example, if 1 Gy is assumed to be an irradiation dose of 100%, it indicates that a dose of 80% (0.8 Gy) or more is irradiated to a volume of about 10% in a normal tissue. Further, in this example, it is shown that only a dose of 5% (0.05 Gy) or less is irradiated to the portion excluding the volume of about 60% of the normal tissue, that is, the portion of about 40% of the normal tissue.

  On the contrary, the curve of the dose volume histogram as the irradiation target region is ideally ideal as it approaches the right side and the upper side of the graph. In FIG. 6, for example, if 1 Gy is assumed to be an irradiation dose of 100%, it indicates that a dose of 80% (0.8 Gy) or more is irradiated to a volume 80% portion in the irradiation target region.

  Therefore, even if the dose distribution is calculated so as not to exceed the same dose for a certain tissue, the calculation result of the dose distribution differs depending on where the dose volume histogram is taken as a reference. Therefore, the treatment plan creation unit 104 sets a reference and calculates a dose distribution.

  FIG. 7 is a schematic diagram illustrating an example of a screen in which an irradiation target area is specified. Since an image for treatment planning as shown in FIG. 4 is displayed on the display unit 120, an operator such as a doctor can see the position and contour (range) of a diseased part such as cancer on the image while viewing the image for treatment planning. Can be determined. FIG. 7 shows a state in which a disease site to be eliminated or reduced is designated as an irradiation target region 162 on the image for treatment planning. In the example of FIG. 7, the irradiation target area 162 is a hatched area and is a part of the stomach 142a.

  In addition, the operator can input and set the position and contour information of the region where the therapeutic radiation is not particularly desired to be applied to the treatment plan creation unit 104 via the input unit 116. The region where the therapeutic radiation is not particularly desired is, for example, a risk organ or the like, and may be set according to the medical condition of the subject P. After designating the irradiation target region 162, the operator can input and set the irradiation dose, the irradiation direction, and the like to the treatment plan creation unit 104 via the input unit 116.

  In the example of FIG. 7, the treatment radiation having three irradiation directions is transmitted as indicated by a solid arrow, a dashed arrow, and a dashed-dotted arrow. Yes.

  FIG. 8 is a schematic diagram illustrating an example of a screen that displays a comparison display of the expected irradiation dose of each tissue region based on the calculated dose distribution and the allowable dose of each tissue region. In FIG. 8, an example of a dose distribution calculated by the treatment plan creation unit 104 is shown in contour lines for a total of three treatment radiation irradiations set as shown in FIG. 7.

  In FIG. 8, an expected irradiation dose for five contour regions is shown below the screen. The expected irradiation dose is highest in a black area in the center of the subject image on the upper side of the screen. In FIG. 8, as an example, a region where the expected irradiation dose is larger is indicated by being shaded darker.

  More specifically, the control unit 100 of the treatment plan support apparatus 30 in FIG. 2 acquires the dose distribution calculated as shown in FIG. 8 from the treatment plan creation unit 104, for example. Further, the control unit 100 acquires information on the subject P (whether it is an adult, a child, or a fetus or gender) and extraction results (name, position, outline, etc.) of each tissue region from the image processing unit 112. . Further, the control unit 100 acquires allowable dose data corresponding to the information of the subject P from the allowable dose database 136.

  And the control part 100 compares each allowable dose of each tissue area | region (as a normal tissue) which falls into the range irradiated with therapeutic radiation, and a dose distribution, The expected irradiation dose of each tissue area | region, The allowable dose of each tissue region is displayed on the display unit 120 for comparison as shown in FIG.

  Moreover, the control part 100 determines the presence or absence of the overdose area | region which is a tissue area | region which exceeds an allowable dose by said comparison. When the determination result is affirmative, the control unit 100 displays a warning message on the display unit 120 to notify the operator that there is a tissue region that exceeds the allowable dose in the created treatment plan.

  FIG. 9 is a schematic diagram illustrating an example of a warning screen displayed when there is a tissue region that exceeds the allowable dose in the dose distribution of the treatment plan. FIG. 9 shows a case where, in the dose distribution of FIG. 8, it is determined that the allowable dose is exceeded in a part of the spinal cord 144a (dose excess region 164) that is a risk organ because it is a hematopoietic organ.

  In this case, the control unit 100 causes the display unit 120 to identify and display the irradiation target region 162 as, for example, a shaded region and the overdose region 164 as, for example, a blacked region on the treatment plan image, as shown in FIG. . The identification display method may be other methods such as a chromatic color display different from the surroundings.

  Furthermore, the control unit 100 displays a warning message indicating how much the allowable dose is exceeded in which tissue in the warning window 170 on the display screen of the display unit 120. In the example of FIG. 9, since the subject P is an adult male and the allowable dose of the spinal cord is 0.5 Gy (see FIG. 3), the dose exceeds about 110% of 0.5 Gy in a part of the spinal cord. The effect is shown. The numerical examples of doses shown in FIGS. 8 and 9 are merely shown for the sake of specific and easy explanation, and are different from practical values.

  In FIG. 9, a condition change button 172 is displayed below the warning window 170 as an example. For example, in the case of a touch panel screen, the condition change is selected by pressing the condition change button 172. The operator can manually reset the irradiation condition by selecting the condition change with the condition change button 172. Note that when the condition change button 172 is selected, the treatment plan creation unit 104 may automatically recreate the treatment plan.

(Description of operation of this embodiment)
FIG. 10 is a flowchart showing an example of the operation flow of the radiation therapy system 10 of the present embodiment. The operation of the radiation therapy system 10 will be described below according to the step numbers in the flowchart shown in FIG.

  [Step S1] Image data of the subject P for treatment planning is generated by the diagnostic imaging apparatus 20 (see FIG. 1). The diagnostic imaging apparatus 20 adds the information about the gender and age of the subject P and the cross section from which direction in which position of the human body coordinate system to the accompanying information of the generated image data file, It inputs into the image memory | storage part 108 (refer FIG. 2) of the treatment plan assistance apparatus 30. FIG. Thereafter, the process proceeds to step S2.

  [Step S2] The image processing unit 112 of the treatment plan support apparatus 30 acquires the image data file of the subject P generated in Step S1 from the image storage unit 108. After acquiring the sex and age of the subject P from the supplementary information of the file, the image processing unit 112 acquires tissue region data that matches these sex and age from the anatomical region database 132.

Based on the acquired information, the image processing unit 112 extracts the image of the treatment plan and the image of the same direction cross-section corresponding to the same position in the human body coordinate system from the tissue region data, and then performs the treatment plan for example by pattern matching. Each tissue region is extracted (determined) from the image (see FIGS. 4 and 5). The image processing unit 112 stores the extracted data of each tissue region.
It should be noted that at the beginning of step S2, a risk organ that the therapeutic radiation is not particularly desired to be applied to can be designated by the operator with respect to the input unit 116 by name, for example, and the designated risk organ is displayed in the tissue region by the image processing unit 112. It may be configured to extract (determine) as Thereafter, the process proceeds to step S3.

  [Step S3] The control unit 100 of the treatment plan support apparatus 30 causes the display unit 120 to display information such as the names of the tissue regions extracted in step S2 together with the treatment plan image. An operator such as a doctor determines a diseased part based on this display image, and sets the position and contour of the irradiation target region 162 on the input unit 116 (see FIG. 7).

  Further, the operator can set the position and contour information of a region where the therapeutic radiation such as a risk organ is not particularly desired to be irradiated to the treatment plan creation unit 104 via the input unit 116. Further, the operator sets a part of irradiation conditions such as irradiation dose and irradiation direction. The treatment plan creation unit 104 automatically sets some irradiation conditions that have not been set.

  The treatment plan creation unit 104 creates (calculates) a treatment plan based on a part of the irradiation conditions set as described above and treatment plan conditions such as the sex and age of the subject P. At this time, the treatment plan creation unit 104 creates a treatment plan with a dose distribution such that radiation is intensively applied to the irradiation target region while avoiding irradiation of normal tissues around the irradiation target region as much as possible.

  When creating a treatment plan, the treatment plan creation unit 104 calculates a dose distribution so as not to exceed an allowable dose in, for example, a 10% region as a reference in a dose volume histogram (see FIG. 6). Where the reference is set to 0% to 100%, the operator may arbitrarily set the treatment plan creation unit 104 via the input unit 116 according to the type of organ. Alternatively, for this criterion, an appropriate value such as 10% may be set in advance for the treatment plan creation unit 104. Therefore, the reference numerical value of 10% is merely an example and does not limit the present embodiment. Thereafter, the process proceeds to step S4.

  [Step S4] The control unit 100 acquires data (name, contour, etc.) of each tissue region extracted from the treatment plan image from the image processing unit 112, and stores subject information such as sex and age as an image storage unit. It is acquired from the incidental information of the image data file stored in 108. The control unit 100 acquires from the allowable dose database 136 data of each allowable dose corresponding to each acquired tissue region and corresponding to the subject information. Thereafter, the process proceeds to step S5.

  [Step S5] The control unit 100 acquires the dose distribution of the treatment plan created in step S3 from the treatment plan creation unit 104. The control unit 100 causes the display unit 120 to compare and display each allowable dose of each tissue region (as a normal tissue) acquired in step S4 and the expected irradiation dose of each tissue region obtained from the dose distribution (see FIG. 8). ).

  The method of comparison display is not limited to the form of FIG. 8 in which the expected irradiation dose is shown in a contour line on the dose distribution chart and the allowable dose of each tissue region is attached to the dose distribution chart in terms of character information. . For example, the expected irradiation dose of each tissue region and the allowable dose of each tissue region may be displayed in comparison on the display unit 120 in a tabular format. Thereafter, the process proceeds to step S6.

  [Step S6] The control unit 100 determines whether or not there is an overdose region where the expected irradiation dose exceeds the allowable dose in each tissue region (as a normal tissue) acquired in Step S4. Hereinafter, this determination is referred to as “determination processing”.

  Note that the tissue to be determined in the determination process may be, for example, only a single organ whose contour or the like is set in step S3 by the operator as a region where it is not desired to irradiate therapeutic radiation, or may be a plurality of tissues. Or about the structure | tissue of determination object in determination processing, not only the structure | tissue set as an area | region which does not want to irradiate said therapeutic radiation but all the structures | tissues (extracted by step S2) included in the range to which therapeutic radiation hits. All organizations).

  As a result of the determination process, if an overdose region exists, the process proceeds to step S7. As a result of the determination process, when there is no overdose region, the control unit 100 displays that the overdose region does not exist on the display unit 120, and then shifts the process to step S9.

  [Step S7] The display unit 120 identifies and displays an overdose region on the treatment plan image in accordance with an instruction from the control unit 100 (see FIG. 9). Further, the display unit 120 displays information on how much the allowable dose has been exceeded in the overdose region in the warning window 170 in a manner such as how much the allowable dose is exceeded. As a result, the operator is notified that there is a tissue region that exceeds the allowable dose in the created treatment plan.

  The operator can confirm the creation result of the treatment plan based on the display information of the comparison result. And the operator can reset the conditions of a treatment plan by selecting the condition change button 172 of FIG. 9, for example.

  When the resetting of the treatment plan condition is selected in this manner, the operator proceeds to step S8 after resetting a part of the condition of the treatment plan by the operator.

  [Step S8] The treatment plan creation unit 104 performs re-creation processing for automatically re-creating a treatment plan. At this time, if the condition of the treatment plan is changed in step S7, the treatment plan is recreated according to the condition. If the condition is not changed, the treatment plan is recreated according to the condition set by the operator in step S3.

  Specifically, the treatment plan creation unit 104 acquires information about how much (%) the expected irradiation dose in the overdose area exceeds the allowable dose from the control unit 100. The treatment plan creation unit 104 recreates the treatment plan based on the information on how much the expected irradiation dose exceeds the allowable dose so that the predicted irradiation dose in the overdose area specified in step S6 is less than or equal to the allowable dose. To do.

  Here, “to be below the allowable dose” means, for example, a dose distribution that is 90%, 80%, or 60% of the allowable dose. The numerical value of 90%, 80%, or 60% here is only an example, and does not limit the present embodiment. In order to make the expected irradiation dose in the overdose area below the allowable dose, for example, the irradiation direction is deviated from the overdose area, or the irradiation field is narrowed so that the overdose area is not included as much as possible. After the treatment plan is recreated by the recreation process, the process returns to step S5.

  That is, if there is an overdose region as a result of the determination process in step S6, the re-creation process by the treatment plan creation unit 104 and the determination process by the control unit 100 are performed until there is no overdose region as a result of the determination process. It repeats sequentially by the loop of S5-S8.

  [Step S9] When step S9 is reached, there is no overdose region in the latest treatment plan displayed on the display unit 120. The operator selects whether or not the latest treatment plan is acceptable. When the operator finally determines (selects) that the treatment plan is acceptable, the process proceeds to step S10. The operator can also select to recreate the treatment plan by changing the condition of the treatment plan. In this case, the process returns to step S3.

  [Step S10] The control unit 100 transmits the treatment plan finally determined in step S9 to the radiotherapy device 40, and the system control unit 58 of the radiotherapy device 40 stores the received treatment plan. The treatment plan transmitted here includes the image data file of the subject P generated by the image diagnostic apparatus 20, subject information, and information (name, position) of each tissue region extracted by the image processing unit 112. , Contour, etc.).

  Therefore, the system control unit 58 omits regions that are not related to the irradiation target region, such as the body surface, from the alignment information of the subject when performing radiation therapy, so that the position of the region of interest such as the risk organ or the irradiation target region is determined. The alignment accuracy may be intensively improved. Thereby, radiotherapy can be performed with higher accuracy. Then, under the operation of the operator, the therapeutic radiation is irradiated to the subject P by the radiation therapy apparatus 40 so as to meet the irradiation conditions according to the treatment plan. The above is description of operation | movement of the radiation therapy system 10 of this embodiment.

(Effect of this embodiment)
Thus, in this embodiment, after each tissue region is automatically extracted from the subject image for treatment planning, the treatment plan is created. The control unit 100 automatically determines the presence / absence of an overdose region by comparing the allowable dose of each tissue region stored in advance with the expected irradiation dose of each tissue region obtained from the dose distribution of the created treatment plan, The judgment result is automatically displayed. For this reason, when the irradiation dose becomes excessive in the treatment plan, this is automatically notified, so that it is possible to easily prevent the irradiation dose from becoming excessive in the radiotherapy.

  Therefore, it is possible to prevent an error in the number of digits of irradiation dose in the treatment plan finally determined, misuse or forgetting to insert accessories such as a wedge filter, and excessive dose irradiation to a risk organ. As a result, the radiation therapy system 10 can perform highly reliable and safe radiation therapy.

  Further, different allowable doses are stored in advance in the allowable dose database 136 according to gender and age, and the allowable dose that matches the subject information is used in the determination process. Thereby, it is possible to accurately determine whether or not the allowable dose is exceeded for a risk organ or the like, that is, the safety of the treatment plan.

  Furthermore, as shown in FIG. 9, since it is automatically identified and displayed in which region the allowable dose is exceeded, the operator should refer to these display information when changing the conditions of the treatment plan. Can do.

  According to the embodiment described above, it is possible to easily prevent an irradiation dose from becoming excessive in radiotherapy.

(Supplementary items of this embodiment)
[1] In the above embodiment, the allowable dose for normal tissue is stored in the allowable dose database 136 in advance, and a warning screen is displayed and a treatment plan is recreated so that the irradiation dose for normal tissue does not exceed the allowable dose. Stated. The embodiment of the present invention is not limited to such an aspect.

  It may be configured such that the operator can input an allowable dose for the irradiation target region that is a diseased part, and the allowable dose data may be stored separately for the irradiation target region and the normal tissue. In this case, in step S6, whether or not the allowable dose is exceeded in the irradiation target region is also added, and if it is determined that there is an overdose region including the normal tissue and the irradiation target region, Similarly, a treatment plan is recreated.

  [2] FIG. 11 is a block diagram showing an overall configuration of a radiation therapy system 10 'according to a modification of the present embodiment. The radiation treatment system 10 ′ has a configuration in which the treatment plan creation unit 104 is made independent as the treatment plan creation device 180 from the treatment plan support device 30 of FIG. 2. Therefore, the treatment plan support apparatus 30 ′ of FIG. 11 has the same configuration as the treatment plan support apparatus 30 of FIG. 2 except that the treatment plan creation unit 104 is omitted, and thus the block diagram is omitted. In this way, the treatment plan creation unit 104 (treatment plan creation device 180) may be independent, and in this case as well, the same effect as in the above embodiment can be obtained.

  [3] The value of the allowable dose for each tissue region stored in the allowable dose database 136 may be changeable by an input to the input unit 116 according to the operator's judgment.

  [4] A correspondence relationship between the terms of the claims and the embodiments will be described. In addition, the correspondence shown below is one interpretation shown for reference, and does not limit the present invention.

  The function of the image processing unit 112 that extracts each tissue region from the image data of the subject P based on the tissue region data stored in the anatomical region database 132 is an example of the tissue region determination unit described in the claims. .

  The function of the control unit 100 that determines whether or not the allowable dose is exceeded for each tissue region extracted by the image processing unit 112 is an example of a comparison unit.

  [5] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

10, 10 'radiation therapy system 20 diagnostic imaging apparatus 30, 30' treatment plan support apparatus 40 radiation therapy apparatus 50 communication path 58 system controller 60 bed driving device 62 bed 66 gantry 70 stand 74 high voltage supply device 78 diaphragm driving device 80 Treatment head 84 Electron beam generator 90a Wave guide 90b Bending magnet 90c Target 90d Aperture 92 Rotation drive device 100 Control unit 104 Treatment plan creation unit 108 Image storage unit 112 Image processing unit 116 Input unit 120 Display unit 124 System bus 128 Data Storage unit 132 Anatomical region database 136 Allowable dose database 162 Irradiation target region 164 Overdose region 170 Warning window 172 Condition change button 180 Treatment plan creation device

Claims (11)

Tissue region data indicating a plurality of tissue regions in the human body, and a data storage unit in which an allowable dose for radiation for each tissue region is stored;
An image storage unit for storing image data of the subject;
A tissue region determination unit that determines a tissue region from the image data of the subject based on the tissue region data;
The treatment plan creation unit for obtaining the irradiation condition of the therapeutic radiation for the subject and the dose distribution under the irradiation condition,
A comparison unit that compares the allowable dose corresponding to the tissue region determined by the tissue region determination unit and the dose distribution calculated by the treatment plan creation unit;
A treatment plan support apparatus comprising: a display unit that displays information reflecting a comparison result of the comparison unit. The comparison unit performs a determination process for determining whether an expected irradiation dose based on the dose distribution in the tissue region exceeds the allowable dose by comparing the dose distribution and the allowable dose.
The treatment plan support apparatus according to claim 1, wherein the display unit displays result information of the determination process. As a result of the determination process, when the expected irradiation dose exceeds the allowable dose in the tissue region, the display unit identifies an overdose region exceeding the allowable dose in the subject image based on the image data of the subject. The treatment plan support apparatus according to claim 2, wherein the treatment plan support apparatus is displayed. The display unit displays information indicating how much the expected irradiation dose exceeds the allowable dose in the overdose region when the overdose region is identified and displayed. Treatment plan support device. The treatment plan creation unit acquires information on how much the expected irradiation dose exceeds the allowable dose from the comparison unit, and based on the acquired information, the expected irradiation dose is decreased in the overdose region. 5. The treatment plan support apparatus according to claim 3, wherein re-creation processing for automatically re-creating the treatment plan is performed. The data storage unit stores a plurality of allowable dose data different from each other according to gender and age,
The comparison unit acquires the sex and age of the subject, acquires the allowable dose data corresponding to the acquired sex and age from the data storage unit, and acquires the acquired allowable dose data and the dose The treatment plan support apparatus according to any one of claims 2 to 5, wherein the distribution is compared. Tissue region data indicating a plurality of tissue regions in the human body, and a data storage unit in which an allowable dose for radiation for each tissue region is stored;
An image storage unit for storing image data of the subject;
A tissue region determination unit that determines a tissue region from the image data of the subject based on the tissue region data;
A treatment plan support device, comprising: a treatment plan creation unit that obtains an irradiation condition of therapeutic radiation for the subject based on an allowable dose corresponding to the tissue region determined by the tissue region determination unit. The data storage unit stores a plurality of allowable dose data different from each other according to gender and age,
The treatment plan creation unit acquires the allowable dose data corresponding to the sex and age of the subject from the data storage unit, and obtains the irradiation condition based on the acquired allowable dose data. The treatment plan support apparatus according to claim 7. The said tissue area | region determination part extracts a risk organ from the image data of the said subject, and determines the said risk organ as the said tissue area | region. The one of the Claims 1 thru | or 8 characterized by the above-mentioned. Treatment plan support device. A treatment plan support device according to any one of claims 1 to 6, and a radiotherapy device,
The treatment plan creation unit is configured to finally determine an irradiation condition of the therapeutic radiation after displaying the information reflecting the comparison result,
The radiotherapy apparatus is configured to be capable of irradiating radiation under an irradiation condition finally determined by the treatment plan creation unit. Radiation therapy comprising: the treatment plan support apparatus according to claim 7 or claim 8; and a radiation treatment apparatus configured to be able to irradiate therapeutic radiation under irradiation conditions obtained by the treatment plan support apparatus. system.