JP7553366B2 - DECISION SUPPORT SYSTEM, RADIATION THERAPY SYSTEM, AND DECISION SUPPORT METHOD IN DECISION SUPPORT SYSTEM - Google Patents

Description

The present invention relates to a decision support system, a radiation therapy system, and a decision support method in a decision support system.

The present invention relates to a radiation therapy system that preferably has a decision support function for adaptive therapy that responds to changes in the patient's internal structure during treatment.

The purpose of radiation therapy is to treat a patient by irradiating a target inside the body with focused radiation. Improving the concentration of the dose on the target reduces the dose to organs around the target, thereby reducing side effects.

In radiation therapy, a treatment plan is implemented in which the radiation irradiation method, such as the direction and amount of radiation to be irradiated, is determined by simulation, and then irradiation is carried out over several days. Because time passes between the time of treatment planning and irradiation, the structure inside the patient's body may change. Due to these structural changes, the dose to the target and surrounding organs may change from day to day, even if the same irradiation method is used. The treatment plan anticipates these changes in advance, evaluates the dose to the target and surrounding organs, and determines the irradiation method. Generally, the plan is to irradiate an area larger than the target itself, so that the desired dose can be irradiated to the target even if changes occur.

If it were possible to measure these changes in the patient just before irradiation and adjust the irradiation method to adapt to the changes, it would be possible to achieve a more concentrated dose on the target. This is called adaptive treatment. This type of adaptive treatment, in which the irradiation method is adjusted and irradiation is performed while the patient is lying on the treatment bed based on images taken on the day of irradiation, is called online adaptive treatment, and if this is realized, it will enable highly accurate treatment that adapts to daily structural changes.

To carry out this online adaptive treatment, it is necessary to grasp structural changes, revise plans, and verify them while the patient is lying down in the treatment bed. This requires software that can perform each of these tasks quickly, and a skilled operator who can quickly make the decisions that are required at each stage. For this online adaptive treatment to be accepted by a variety of hospitals, a system that supports rapid decision-making and operation during treatment is necessary.

A method for supporting decisions and operations during treatment is described in, for example, Patent Document 1. Patent Document 1 describes an automated workflow for adaptive radiation therapy, which includes a procedure for obtaining a set of instructions including information representing a planned treatment, a series of automated steps for generating a patient model stepwise using the set of instructions, and generating first and second treatment plans for the patient model, and a procedure for selecting a treatment plan suitable for the current treatment session.

US Patent Application Publication No. 2020/0121951

By using the automated workflow described in Patent Document 1, operations are performed automatically during treatment based on instructions created in advance, enabling rapid treatment. However, even when automatic operations are performed, expert knowledge is still required to determine whether the results created or selected using automatically set parameters are suitable for treatment and to decide whether to proceed to the next operation. Such judgments require expert knowledge and are difficult in hospitals that do not have experienced staff.

The present invention has been made in consideration of the above problems, and aims to provide a decision support system, a radiation therapy system, and a decision support method for the decision support system that can support decisions and operations during treatment, even in hospitals where staff have little experience with adaptive radiation therapy.

In order to solve the above problems, for example, the configurations described in the claims are adopted.
The present invention includes multiple means for solving the above-mentioned problems, and one example is as follows: the decision support system accepts input of decision support data consisting of a set of decision indices and judgment criterion values to be evaluated during treatment, accepts selective input of decision support data to be used for each target of radiation therapy, calculates the value of the judgment index for an image of a specified area captured by an imaging device that captures the specified area including the target on the day of treatment, and compares the value of the judgment index with the judgment criterion value and displays it.

The present invention makes it possible to support decisions and operations during treatment, even in hospitals where staff have little experience with adaptive radiation therapy.

1 is a diagram showing a schematic configuration of a radiation therapy system according to a first embodiment. FIG. 4 is a diagram showing an example of judgment support data for structural changes in the radiation therapy system according to the first embodiment; FIG. 11 is a diagram showing another example of judgment support data for structural changes in the radiation therapy system according to the first embodiment. FIG. 4 is a diagram showing an example of decision support data for replanning in the radiation therapy system according to the first embodiment; FIG. 4 is a diagram showing an example of decision support data for treatment plan evaluation in the radiation therapy system according to the first embodiment. 4 is a flowchart showing the operation of the radiation therapy system according to the first embodiment. 4 is a flowchart showing a positioning operation of the radiation therapy system according to the first embodiment. 10 is a flowchart showing an operation of determining whether or not contour creation is necessary in the radiation therapy system according to the first embodiment. 1 is a flowchart showing a contour creation and verification operation of the radiation therapy system according to Example 1. 4 is a flowchart showing a treatment plan selection operation of the radiation therapy system according to the first embodiment. 4 is a flowchart showing a treatment plan evaluation operation of the radiation therapy system according to the first embodiment. 4 is a flowchart showing a radiation irradiation operation of the radiation therapy system according to the first embodiment. 11 is a diagram showing an example of decision support data displayed in the contour creation necessity decision operation of the radiation therapy system according to Example 1. FIG. FIG. 11 is a diagram showing an example of decision support data displayed during the contour creation and verification operation of the radiation therapy system according to the first embodiment. 11 is a diagram showing an example of decision support data displayed in the treatment plan selection operation of the radiation therapy system according to Example 1. FIG. 11 is a diagram showing an example of decision support data displayed in the treatment plan evaluation operation of the radiation therapy system according to Example 1. FIG. 4 is a flowchart showing the operation of the radiation therapy system according to the first embodiment. FIG. 2 is a diagram showing a display example of a monitor in the radiation therapy system according to the first embodiment. 1 is a diagram showing a schematic configuration of a radiation therapy system according to a first embodiment. 4 is a flowchart showing the operation of the radiation therapy system according to the first embodiment.

The following describes an embodiment of the present invention with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some parts have been omitted or simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

In addition, in the figures explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanations are omitted.

The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

When there are multiple components with the same or similar functions, they may be described using the same reference numerals with different subscripts. However, when there is no need to distinguish between these multiple components, the subscripts may be omitted.

The first embodiment will be described with reference to Figures 1 to 18.

Figure 1 shows the schematic configuration of the radiation therapy system in Example 1.

The radiation therapy system of this embodiment includes a bed 2 that supports a subject (patient) 1, an imaging device 3 that images the subject 1 during treatment, and a therapeutic radiation irradiation device 4 that irradiates the subject with therapeutic radiation.

In normal radiation therapy, the subject 1 is fixed to a bed 2, and the internal structure of the body is photographed by an imaging device 3. The bed 2 is moved with reference to the image, and the subject 1 is moved to the planned position. After that, therapeutic radiation is irradiated from a therapeutic radiation irradiation device 4, and the radiation is applied to a target 5 inside the subject.

Here, a treatment plan for irradiating radiation, including the position of the subject 1, is created by an operator 11 on a treatment planning device 10 before the start of treatment. The operator 11 who operates the treatment planning device 10 may be a doctor who performs radiation therapy, or a radiologist, etc. The treatment planning device 10 uses images of the subject taken by the imaging device 3 or another imaging device in the hospital to grasp the internal structure of the body, and creates a treatment plan including a method for irradiating therapeutic radiation while evaluating the dose distribution to the target 5 and surrounding organs by simulation. Using the created treatment plan, the subject 1 is placed at the planned position and radiation is irradiated by the therapeutic radiation irradiation device 4, so that the target 5 is irradiated with the planned dose, and the dose to the surrounding organs can be kept to the planned dose.

In this series of steps, structural changes occur within the patient's body between the time the treatment plan is made and the final day of treatment, which spans multiple days. In conventional treatment plans, where the initial treatment plan is used from the first day to the final day, these structural changes are anticipated in advance, and the plan is made to irradiate an area larger than the target itself so that the desired dose is delivered to the target even if structural changes occur. This makes it possible to deliver the desired dose to the target even if irradiation is performed according to the initial treatment plan up until the final day of treatment.

On the other hand, if adaptive treatment is performed on the day of treatment, in which the structure inside the patient's body is re-identified and a treatment plan is revised or created accordingly, it becomes unnecessary to irradiate a wide area in anticipation of structural changes, and the dose to surrounding organs can be further reduced.

To realize adaptive treatment, it is necessary to quickly revise the plan on the day of treatment, so the work of revising the treatment plan is carried out in the treatment control room 13, which is adjacent to the treatment room 6 and controls the treatment equipment. Next, an overview of the work carried out in the treatment control room 13 will be explained. Note that hereafter, the revision or re-creation of the treatment plan may be referred to as re-planning.

First, the image captured by the imaging device 3 is sent to the patient structural change recognition device 14 via the network. The patient structural change recognition device 14 compares the just-captured subject image with the subject image at the time of treatment planning or at the time the plan is revised on a subsequent treatment day, recognizes structural changes in the subject, and generates the contours of each organ after the changes. This recognition of structural changes and the generation of the contours of each organ may be performed using a non-rigid registration method, a segmentation method, or a combination of these methods.

The structural change information and the generated contour information for each organ are displayed on the monitor 12 and visually confirmed by the operator 11. If the confirmed information is correct, approval is performed, and if it is incorrect, manual correction is performed. This approval process requires the operator 11 to have specialized knowledge, such as the degree of structural change that is acceptable. The approved structural change information, contour information for each organ, and captured image information are sent to the treatment planning device 10. Alternatively, if the software is on the same computer, the information is transmitted via a storage medium.

The treatment planning device 10 uses the newly obtained images, contour information, etc. to determine the dose distribution when irradiation is performed using the irradiation method defined in the plan. For the obtained dose distribution, the contour information is used to calculate the dose evaluation index for each organ. Indicators called maximum and minimum dose, dose flatness, and DVH (Dose Volume Histogram) are often used as dose indices. The operator 11 judges whether or not the irradiation needs to be modified based on these indices.

At this time, the criterion for judgment is whether the therapeutic effect envisaged in the treatment plan can be obtained, but a vast amount of knowledge and experience is required to predict the therapeutic effect from the dose evaluation index. If the judgment result shows that replanning is not necessary, the system proceeds directly to irradiation, and irradiation is performed by the therapeutic radiation irradiation device 4. On the other hand, if replanning is necessary, the irradiation method is re-optimized to meet the dose targets for each organ set during treatment planning.

Irradiation methods such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) in X-ray therapy, and scanning irradiation in particle beam therapy, are equipped with a function to automatically determine the irradiation method so as to meet the dose target as much as possible. At this time, it is good if all dose targets are met, but if they are not, advanced judgment similar to that during treatment planning is required to determine the priority order for meeting the dose targets and how to correct the dose distribution, and extensive experience is required to make such judgments in adaptive treatment, especially in online adaptive treatment, which requires speed. Once the necessary irradiation method modifications have been completed, the operator 11 performs an approval operation.

The approved treatment plan information is sent to the treatment plan verification device 15. The treatment plan verification device 15 verifies whether the dose distribution calculated by the treatment planning device 10 is valid. In normal treatment, this verification is performed by an irradiation test involving the actual irradiation of therapeutic radiation. However, in online adaptive treatment, irradiation tests cannot be performed because the treatment must be performed with the subject 1 present in the treatment room 6. Instead, a method called independent verification may be used in which the dose distribution is compared with one calculated using a different calculation method. In the case of independent verification, the dose distribution calculated using a different method is compared with the re-optimized distribution.

If the comparison shows a match, there is no problem, but if a mismatch occurs, it is necessary to determine on the spot whether it is within the range of treatable disease. What caused the difference and whether it is within the acceptable range varies from case to case, so a judgment based on extensive experience is required. If it is determined to be within the acceptable range, the operator 11 performs the approval process.

By following the above steps, approved replanned irradiation method data is created. From all these operations, a comprehensive decision is made as to whether to use the original planned data or the replanned data, and the operator 11 decides which data to use for irradiation, approves it, and finally moves to irradiation.

In this embodiment, the treatment planning device 10, the patient structural change recognition device 14, and the treatment plan verification device 15 are configured from devices capable of various information processing, for example, information processing devices such as computers. The information processing device has a processing element, a storage medium, and a communication interface, and further has an input unit such as a mouse and a keyboard, and a display unit such as a display, as necessary.

The computing element is, for example, a CPU (Central Processing Unit) or an FPGA (Field-Programmable Gate Array). The storage medium is, for example, a magnetic storage medium such as a HDD (Hard Disk Drive), a RAM (Random Access Memory), a ROM (Read Only Memory), or a SSD (Solid State Drive). In addition, a combination of an optical disk such as a DVD (Digital Versatile Disk) and an optical disk drive is also used as a storage medium. Other well-known storage media such as magnetic tape media are also used as storage media.

The storage medium stores programs such as firmware. When the treatment planning device 10 or the like starts to operate (e.g., when the power is turned on), the programs such as firmware are read from this storage medium and executed to perform overall control of the treatment planning device 10 or the like. In addition to the programs, the storage medium also stores data necessary for each process of the treatment planning device 10 or the like.

The treatment planning device 10 of this embodiment may be configured as a so-called cloud, in which the information processing device is configured to be able to communicate via a communication network.

In this embodiment, a decision support data input device 20 is provided to assist the operator 11 in making decisions at key points.

The decision support data input device 20 has the function of importing decision support data from outside the treatment facility into the treatment facility. This makes it possible to use decision support data created at other facilities with experienced staff within the treatment facility.

As will be described in detail later with reference to Figures 2 to 5, the decision support data is a set of decision support information classified by treatment area and treatment policy, and includes functional information of the treatment device required for the treatment method, contour judgment indices required for determining the success or failure of contour generation, dose evaluation index information for each area required for replanning, reference values and priorities for each index, and dose evaluation index information required for dose evaluation, reference values and priorities for each index.

The structural change judgment indexes during contour creation are the volume change rate and contour deformation rate for each part (target). The dose evaluation indexes required for replanning judgment are the dose in the low-dose region, the high-dose region, the average dose, the DVH index, etc. The DVH index is specified by a value such as the minimum dose irradiated to 95% or more of the volume, or the volume to which 20% or more of the prescribed dose is irradiated. The indexes used during evaluation of the treatment plan are, for example, the degree of distribution agreement during replanning, the change in the degree of prescription achievement for the DVH of the target, and the change in the degree of prescription achievement for the DVH of the surrounding organs. For example, an index called the gamma index can be used as the degree of distribution agreement, and the two dose distributions are divided into small pieces and evaluated based on the percentage of small pieces with a specified difference in dose within a specified amount of movement.

The decision support data is explained in more detail with reference to Figures 2 to 5.

The decision support data consists of decision indicators and decision criteria values. In addition, the necessity or priority of the indicator may be assigned to each decision indicator.

Decision support data is created and stored for each hospital, doctor, patient attribute (adult, child, obese, thin, male, female, etc.), tumor location (liver, pancreas, lung, etc.; it may be further subdivided according to the location of the tumor within the organ, such as dividing the lung into the right upper lobe, right middle lobe, etc.), and treatment plan, from which the operator 11 performing the treatment can select the most appropriate plan.

The judgment criteria are shown as XX% or XXmm, but the most appropriate display method can be selected for each doctor or hospital entering the data, and is not limited to these values as long as the judgment criteria are indicated.

An example of data supporting judgment of structural changes is shown in Figures 2 and 3.

As judgment indices for the structural change judgment support data, for example, the rate of change in shape of the target, the rate of change in shape of the surrounding organs, and the rate of change in depth from the body surface to the target are used. Of these, the rate of change in shape of the target and the rate of change in shape of the surrounding organs are required items. The rate of change here refers to the rate of change in shape of the target from when it was imaged when the treatment plan was created to when it was imaged during treatment (for example, the image taken in S15 in Figure 7 described below).

The rate of change in the target shape can be, for example, the rate of change in the target's volume or the degree of volumetric agreement of the target, as indicated by the Jaccard or Dice coefficient. If the target shape changes significantly, there is a high possibility that the radiation dose and distribution on the target will deviate from the original plan. Therefore, to irradiate according to the original plan, it is desirable that the rate of change in the target shape is equal to or less than a criterion value. In addition to the rate of change in the volume, the rate of change in the contour, such as the rate of change in the contour length, can also be used.

The rate of change in shape of the surrounding organs can be, for example, the rate of change in the volume of the surrounding organs or the degree of volume agreement of the surrounding organs as indicated by the Jaccard coefficient or Dice coefficient. If the change in shape of the surrounding organs is large, there is a possibility that the surrounding organs will be irradiated with more radiation than originally planned. Therefore, in order to irradiate according to the original plan, it is desirable that the rate of change in shape of the surrounding organs is equal to or less than a criterion value. In addition to the rate of change in volume, the rate of change in the contour, such as the rate of change in the length of the contour line, can also be used.

For example, the rate of change in depth from the body surface to the target is the rate of change in water equivalent thickness. When the irradiated radiation is a particle beam, the position in the depth direction at which the maximum dose is emitted varies depending on the energy of the irradiating beam. Therefore, if the distance in the depth direction to the target or the water equivalent thickness changes, there will be a deviation in the depth direction from the planned dose and distribution. Therefore, to irradiate according to the original plan, it is desirable that the rate of change in depth from the body surface to the target is equal to or less than a reference value.

In order to irradiate radiation according to the initial plan, the doctor's experience is a major factor in determining which index to use and to what extent it is acceptable, such as the rate of change in shape of the target, the rate of change in shape of surrounding organs, and the rate of change in depth from the body surface to the target. In this embodiment, these judgment indexes are acquired and displayed in advance, allowing for more appropriate and rapid judgment, and enabling highly accurate treatment in a short time.

An example of decision support data for replanning is shown in Figure 4.

As judgment indicators for the replanning judgment support data, for example, the dose in the low-dose region of the target 5, the dose in the high-dose region of the surrounding organs, the change in the distance between the surrounding organs and the end of the range, the change in the degree of achievement of the prescription for the DVH of the target 5, the change in the degree of achievement of the prescription for the DVH of the surrounding organs, etc. are used.

Ideally, the prescription dose specified for the target 5 before the replanning is created should be irradiated uniformly throughout the target. However, it is difficult to achieve perfect uniformity due to restrictions on the position of the organs at risk and the irradiation angle. However, it is desirable for the dose in the low-dose region within the target 5 to be equal to or greater than the prescribed dose reference value. Therefore, in this embodiment, for example, it is set to 90% or more of the prescribed dose.

It is necessary to concentrate the dose on the target 5 and suppress the dose irradiated to the normal surrounding organs. Therefore, it is desirable that the dose in the high-dose areas of the surrounding organs be below the reference value of the constraint dose. Therefore, in this embodiment, for example, the reference value is set to be 110% or less of the constraint dose.

When particle radiation is used as the radiation, a treatment plan is made to keep the distance between the surrounding organs and the end of the range at a specified distance or more in order to reduce the dose to the surrounding organs. This distance is checked to see if it has changed since planning and is too close.

For example, an index called D○○ is used to indicate the degree of achievement of the prescription for the DVH of target 5. This is the minimum dose that covers ○○% of the volume of target 5, and if D95 = 60 Gy, this indicates that a dose of 60 Gy or more is prescribed for 95% of the volume of target 5.

This D95 = 60 Gy is specified before the treatment plan is created, and the treatment plan is created to meet this indicator. In other words, since a sufficient amount of dose needs to be irradiated to the target, it is desirable that the change in achievement level when replanning is equal to or greater than the standard value. In other words, if D95 = 60 Gy at the time of planning and the standard value is 5% or less, the change in the dose prescribed for 95% of the volume of target 5 is within 5%, that is, D95 = 57-63 Gy, the standard is met.

For example, the average dose is used as the degree of achievement of the prescription for the DVH of surrounding organs. A constraint value for the average dose is specified before creating a treatment plan so that the average dose prescribed to surrounding organs, such as the pancreas, is 10 Gy or less, and the treatment plan is created to satisfy this indicator. Since it is desirable for the dose to surrounding organs to be low, it is desirable for the change in the degree of achievement when replanning to be less than the reference value.

An example of decision support data for treatment plan evaluation is shown in Figure 5.

As judgment indicators for decision support data in treatment plan evaluation, the degree of distribution consistency at the time of replanning, the dose in low-dose areas of the target, the dose in high-dose areas of surrounding organs, the change in the degree of prescription achievement for the DVH of the target, the change in the degree of prescription achievement for the DVH of surrounding organs, etc. are used. As an indicator of the degree of distribution consistency at the time of replanning, the pass rate of gamma analysis, etc. is used.

It is known that a general treatment planning device 10 introduces data from the outside to create a treatment plan. In addition, in this embodiment, a feature is that decision support data is introduced from the outside. More specifically, in the calculation of structural changes, it is known that a subject image that has just been captured and a subject image at the time of treatment planning or at the time the plan is revised on a subsequent treatment day are imported, but a feature is that a judgment index and a reference value are introduced to determine the extent of structural changes that can be tolerated. In addition, it is known that in replanning, the value of the DVH to be achieved is imported as data, and the treatment plan is revised or re-created. On the other hand, a feature is that a judgment index and a reference value are introduced for the replan, which is the treatment plan after re-creation, to determine whether the desired dose has been achieved to that extent. In addition, in the judgment of treatment plan evaluation, a feature is that a judgment index and a reference value are introduced for whether the desired dose has been achieved to that extent.

The decision support data imported into the facility is stored in the decision support database 21. When starting treatment, the operator 11 accesses this decision support database 21 and selects a set of decision support data that is suitable for the subject to be treated. The selected set of decision support data is sent to the patient structural change recognition device 14, the treatment planning device 10, and the treatment plan verification device 15.

Each device displays the type, priority, and standard value of the judgment index, calculates these values on the treatment day, and displays them on the monitor 12. As shown in FIG. 18, the display screen 40 of the monitor 12 displays the judgment index 41, judgment standard value 42, and calculated judgment 43, and displays the achievement level 44 by comparing the judgment standard value 42 and the judgment index value 43.

The operator 11 then makes a decision and performs approval operations. When making the decision, the items to be referenced and their priorities and standard values are displayed, making it possible to see whether the treatment date value meets the standard value, and if not, to see whether it meets the criteria, starting with the highest priority, making the decision easier.

The above system has been described as a system in which the patient structural change recognition device 14, the treatment planning device 10, and the treatment plan verification device 15 are implemented in separate hardware and linked via a network, but they may also be implemented as software on a common computer.

Next, the operation of the radiation therapy system of this embodiment will be explained with reference to the flowcharts in Figures 6 to 12.

Figure 6 is a flowchart showing the operation of the radiation therapy system according to the first embodiment, and more specifically, a flowchart showing the flow of online adaptive radiation therapy by the radiation therapy system of this embodiment.

First, in S0, the operator 11 selects decision support data suitable for the patient to be treated from the decision support database 21. Here, the decision support data for structural changes, decision support data for replanning, and decision support data for treatment plan evaluation may be selected all at once based on the hospital that created the decision support data, the characteristics of the patient, the location of the cancer, etc. Alternatively, the operator may select each of the decision support data for structural changes, decision support data for replanning, and decision support data for treatment plan evaluation individually.

Then, the decision support database 21 transmits the decision support data selected by the operator 11 to the patient structural change recognition device 14, the treatment planning device 10, and the treatment plan verification device 15.

Note that, although this S0 is executed at the start of the overall workflow shown in FIG. 6, the selection and/or transmission of decision support data may be performed at any time before the decision support data is displayed. In other words, the selection and transmission of decision support data for structural changes may be performed before S25 shown in FIG. 8, the selection and transmission of decision support data for replanning may be performed before S47 shown in FIG. 9, and the selection and transmission of decision support data for treatment plan evaluation may be performed before S67 shown in FIG. 10.

Next, in S1, patient 1 is fixed to bed 2, and bed 2 is moved to move patient 1 to the treatment position. In S2, a determination is made as to whether or not it is necessary to create the contours of each organ from the images captured on the day of patient 1's treatment.

In S3, if it is necessary to create an organ outline (S3 is Yes), proceed to S4. If it is not necessary to create an organ outline (S3 is No), proceed to S8.

In S4, the contours of each organ are created from the images captured on the day of treatment, and the created contours are verified. In S5, the treatment plan is re-planned using the contours created in S4. In S6, the treatment plan re-planned in S5 is evaluated, and a selection is made between the treatment plan created at the time of planning and the re-planned treatment plan. If the re-planned treatment plan is selected in this selection, S7 is executed, and if the treatment plan created at the time of planning is selected, S7 may be skipped and S8 executed. In S7, the treatment plan evaluated and selected in S6 is evaluated.

In S8, if the evaluation result in S7 is approved without any problems, radiation is irradiated from the therapeutic radiation irradiation device 4 to the patient 1 in accordance with the approved treatment plan. At this time, the irradiated radiation is stored as a log. In S9, the log output in S8 is evaluated, and the series of irradiations in the treatment room 6 controlled by the adaptive workflow is completed.

Figure 7 is a flowchart showing the positioning operation of the radiation therapy system according to Example 1, and is a flowchart showing details of S1 in Figure 6. The operation shown in the flowchart in Figure 7 is performed by a positioning device (not shown) provided in the therapeutic radiation irradiation device 4.

First, in S11, patient 1 is fixed to bed 2. After patient 1 is fixed, bed 2 is moved using a laser that indicates the isocenter position so that the center of radiation irradiation (isocenter) and the affected area are roughly aligned. Note that the imaging device 3 may capture images of the internal condition of patient 1 on the day of treatment before fixing patient 1 to bed 2. Also, after fixing patient 1, the imaging device 3 may capture images of the internal condition of patient 1 on the day of treatment before moving patient 1 to the isocenter, and then the patient may be moved to the isocenter position.

Next, in S13, in order to image the inside of the patient 1 who has been moved to the isocenter position, imaging parameters are set according to the position of the affected area and the body type of the patient 1. The imaging parameters may be set automatically from information about the patient 1, or may be set manually. Note that imaging may be performed by moving the imaging device 3 to the isocenter, or may be performed by a separate imaging device attached to the therapeutic radiation irradiation device 4. There is no set order for performing S11 and S13, and S13 may be performed first.

Next, in S15, the operator 11 gives instructions to take an image, and the imaging device 3 takes an image of the inside of the patient 1 body. In S17, the amount of movement required to align the affected area of the patient 1 with the isocenter is calculated from the images taken during treatment planning and the images taken in S15. In S19, when the operator 11 approves the movement, the bed 2 with the patient 1 on it moves, and the affected area of the patient 1 is precisely aligned with the isocenter.

Figure 8 is a flowchart showing the operation of determining whether or not contour creation is necessary in the radiation therapy system according to the first embodiment, and is a flowchart showing details of S2 in Figure 6. The operation shown in the flowchart in Figure 8 is executed by the patient structure change recognition device 14.

First, in S21, the water equivalent thickness (WET) is calculated from the image captured on the day of treatment. The water equivalent thickness obtained from the image at the time of treatment planning is compared with the water equivalent thickness from the image captured on the day of treatment, and the change in water equivalent thickness ΔWET is calculated. Note that while the calculation of WET has been described as an example here, other judgment indices may also be used. The judgment indices to be calculated may be determined by acquiring judgment support data for structural changes, identifying a judgment index contained in the acquired judgment support data for structural changes, and calculating the identified judgment index.

In S25, the results calculated in S21 and the judgment support data for structural changes are displayed. In S25, as shown in FIG. 13, the judgment index, judgment criterion value, and judgment index value are displayed. The judgment index and judgment criterion value are values obtained from the judgment support data, and the judgment index value is a value calculated on the day. To make it easier for the operator 11 to make a judgment, the priority of each index may also be displayed. The results of comparing the judgment criterion value and the judgment index value may be displayed. Also, it is possible to display only the judgment index and the comparison result without displaying the judgment criterion value and the judgment index value.

Then, in S27, the operator 11 refers to the decision support data and selects and inputs whether or not contour creation is required.

Figure 9 is a flowchart showing the contour creation and verification operation of the radiation therapy system according to the first embodiment, and is a flowchart showing the details of S4 in Figure 6. The operation shown in the flowchart in Figure 9 is executed by the patient structure change recognition device 14.

First, in S41 and S43, a recently captured subject image and a subject image at the time of treatment planning or at the time the plan is revised on a subsequent treatment day are set in the patient structure change recognition device 14. The patient structure change recognition device 14 compares the recently captured subject image with the subject image at the time of treatment planning or at the time the plan is revised on a subsequent treatment day, recognizes changes in the subject's structure, and generates contours of each organ after the changes.

To recognize this structural change and generate the contours of each organ (OAR (Organ at Risk), target, surrounding organs), a deformable image registration (DIR) technique may be used, a segmentation technique may be used, or a combination of these techniques may be used. Here, the volumes of the target and surrounding organs used for comparison in the structural change judgment support data are also calculated. Note that while the calculation of the volumes of the target and surrounding organs has been described as an example here, other judgment indices may also be used. The judgment indices to be calculated may be calculated by acquiring the structural change judgment support data, identifying a judgment index contained in the acquired structural change judgment support data, and calculating the identified judgment index.

Next, in S45, the data of the created contour is set in a contour verification device (program) to verify whether the contour has been created.

In S47 and S49, as shown in FIG. 14, the structural change information and the generated contour information of each organ are displayed on the monitor 12 and visually confirmed by the operator 11. If the confirmed information is correct, an approval operation is performed, and if it is incorrect, it is manually corrected. The approved structural change information, contour information of each organ, and captured image information are sent to the treatment planning device 10. Alternatively, if the software is on the same computer, the information is transmitted via a storage medium.

In the flowchart shown in FIG. 9, steps S41 to S43 and steps S45 to S49 may be executed by different devices.

Figure 10 is a flowchart showing the treatment plan selection operation of the radiation therapy system according to Example 1, and is a flowchart showing details of S6 in Figure 6. The operation shown in the flowchart in Figure 10 is executed by the treatment plan verification device 15.

First, in S61, the dose when radiation is irradiated according to the treatment plan created at the time of planning is calculated using the images captured on the day and the treatment plan created at the time of planning. For example, the dose distribution of the treatment plan created using the images at the time of planning is calculated by modifying it to match the images captured on the day. Next, in S63, a new treatment plan is created when radiation is irradiated using an irradiation method different from that at the time of planning, such as irradiation angle or irradiation energy, and the dose is calculated. There is no set order for executing S61 and S63, and S63 may be executed first. The dose calculations in S61 and S63 use the value of DVH to be achieved specified at the time of planning, or a new DVH to be achieved is specified and calculations are performed.

Furthermore, in S65, the dose evaluation index for each organ is calculated using the contour information for the doses obtained in S61 and S63. Indicators called maximum and minimum dose, dose flatness, and DVH (Dose Volume Histogram) are often used as dose indices. Items included in the decision support data selected in S0 may be obtained, and the obtained items may be calculated.

In S67, as shown in FIG. 15, the evaluation index and evaluation standard value contained in the judgment support data, and the evaluation index value calculated in S65 are displayed.

In S69, the operator 11 judges whether or not irradiation needs to be modified based on these indices. At this time, the criterion for judgment is whether or not the therapeutic effect envisaged in the treatment plan can be obtained, but a vast amount of knowledge and experience is required to predict the therapeutic effect from the dose evaluation indices. If the result of the judgment is that replanning is not necessary, the system proceeds directly to irradiation, and irradiation is performed by the therapeutic radiation irradiation device 4. On the other hand, if replanning is necessary, the irradiation method is reoptimized to meet the dose targets for each organ set during treatment planning.

Irradiation methods such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) in X-ray therapy, and scanning irradiation in particle beam therapy, are equipped with a function to automatically determine the irradiation method so as to meet the dose target as much as possible. At this time, it is good if all dose targets are met, but if they are not, advanced judgment similar to that during treatment planning is required to determine the priority order for meeting the dose targets and how to correct the dose distribution, and extensive experience is required to make such judgments when the speed of online adaptive treatment is required. Once the necessary irradiation method modifications have been completed, the operator 11 performs an approval operation.

In other words, the user selects whether to irradiate with the treatment plan created at the time of treatment planning, or with a newly created (replanned) treatment plan. If the treatment plan created at the time of treatment planning is selected, the process proceeds to S9 in FIG. 6. If the replanned data plan is selected, the process proceeds to S7 in FIG. 6, and the approved treatment plan information is sent to the treatment plan verification device 15.

Figure 11 is a flowchart showing the treatment plan evaluation operation of the radiation therapy system according to Example 1, and is a flowchart showing details of S7 in Figure 6. The operation shown in the flowchart in Figure 11 is executed by the treatment plan verification device 15.

The treatment plan verification device 15 verifies whether the dose distribution calculated by the treatment plan device 10 is valid. In normal treatment, this verification is performed by an irradiation test involving the irradiation of actual therapeutic radiation. However, in online adaptive treatment, the verification must be performed with the subject 1 in the treatment room 6, so an irradiation test cannot be performed. Instead, a method called independent verification, in which the dose distribution calculated by a different calculation method is compared, may be used. In the case of independent verification, the dose distribution calculated by a different method is compared with the re-optimized distribution. If the comparison shows a match, there is no problem, but if a mismatch occurs, it is necessary to immediately determine whether the difference is within the range in which treatment is possible. What causes the difference and whether it is within the acceptable range differs depending on the case, so a judgment based on extensive experience is required. If it is determined to be within the acceptable range, the operator 11 performs the approval work.

First, in S71, the dose is calculated independently using an algorithm different from the dose on the day calculated in S61 of FIG. 10, based on an image of the patient 1 at the time of treatment and the contours of each organ. Next, in S73, verification is performed as to whether the therapeutic radiation irradiation device 4 operates to irradiate radiation according to the treatment plan approved in S69 of FIG. 10. Note that S71 and S73 may operate independently, or the order may be reversed.

In S75, as shown in FIG. 16, the results calculated in S71 and the judgment support data for the treatment plan evaluation are displayed. As already shown in FIG. 10, the judgment index has already been calculated at this point. Then, in S77, the treatment plan approved by the operator 11 is transmitted to the therapeutic radiation irradiation device 4.

Figure 12 is a flowchart showing the radiation irradiation operation of the radiation therapy system according to Example 1, and is a flowchart showing the details of S8 and S9 in Figure 6. In the operation shown in the flowchart in Figure 12, S8 is executed by the therapeutic radiation irradiation device 4, and S9 is executed by the treatment plan verification device 15.

First, in S81, when the operator 11 issues an instruction to irradiate, the therapeutic radiation irradiation device 4 irradiates the patient 1 with radiation according to the treatment plan approved in S69 of FIG. 10. In S83, the therapeutic radiation irradiation device 4 generates a log of the position and dose of the irradiated radiation and the operation of the device. The generated log is sent to the treatment plan verification device 15.

In S91, the treatment plan verification device 15 compares the treatment plan with the log and evaluates the position and dose of radiation that was actually irradiated (actual dose evaluation). Then, in S93, the treatment plan verification device 15 verifies whether the operation of the device was accurate.

Figure 17 is a flowchart showing the operation of the radiation therapy system according to Example 1, and is a flowchart showing the main parts of the operation of this example.

First, in S102, before starting treatment, the operator 11 inputs decision support data using the decision support data input device 20. In the next step S103, the decision support data input device 20 stores the decision support data in the decision support database 21.

In the next step S104, the operator 11 selects decision support data suitable for the patient to be treated. In the next step S105, the decision support database 21 transmits the decision support data to the patient structural change recognition device 14, the treatment planning device 10, and the treatment plan verification device 15. These steps S104 and 105 correspond to S0 in FIG. 6.

In the next step S106, the patient structural change recognition device 14, the treatment planning device 10, and the treatment plan verification device 15 display the type, reference value, and achievement level of the judgment index based on the judgment support data. In the next step 107, the operator 11 checks the index and performs an approval operation. Once approval operations have been performed in all of the above steps, the therapeutic radiation irradiation device irradiates the treatment beam. These steps S106 and S107 correspond to steps S25 to S27 in FIG. 8, steps S47 to S49 in FIG. 9, and steps S67 to S69 in FIG. 10.

Therefore, according to the radiation therapy system of this embodiment, appropriate evaluation indices necessary for judgment during treatment, their success/failure criteria, and priorities are given, and judgments can be made while checking the degree of achievement of these, allowing even inexperienced operators to make appropriate judgments in a short time and enable adaptive treatment.

In other words, according to this embodiment, judgment indices and standard values that have been created in advance at a hospital with experienced staff can be incorporated into treatment at a hospital with inexperienced staff, making it possible to rapidly introduce new treatment methods that require judgments during treatment. In addition, by optimizing and speeding up judgments during treatment, highly accurate treatment can be performed in a short time.

In this embodiment, an example is shown in which decision support data is imported from outside the treatment facility using the decision support data input device 20, but decision support data created within the treatment facility may also be input. In addition, the decision support data may be corrected and updated using AI or the like based on past performance.

The radiation therapy system of Example 2 will be described with reference to Figures 19 and 20.

In contrast to the radiation therapy system described in Example 1, in the radiation therapy system of Example 2, the decision support data input device 20 is connected to the cloud server 30, and the decision support data input device 20 acquires data as appropriate, so that the data in the decision support database is always up to date, and newly developed treatment methods can be quickly introduced.

Here, the decision support data includes the requirements for the device to which it is suitable, and the decision support data input device 20 judges suitability and stores only decision support data suitable for the facility in the decision support database 21, making it possible to prevent irradiation using inappropriate data and to rapidly introduce treatment data. The criteria for judging suitability for a facility include the type and performance of the imaging device, the radiation irradiation accuracy of the therapeutic radiation irradiation device, the corresponding irradiation technique, etc. Editing of the introduced data that reflects the characteristics of the facility may also be accepted. Specifically, in cases where high precision is achieved by improving patient positioning using a characteristic method or by restricting patient movement in a characteristic way, the reference value of the judgment index can be changed to support high precision treatment.

Figure 20 is a flow diagram of the system of Example 2. Compared to the flow diagram of Example 1 (Figure 17), S102 and S103 have been changed to S201 and S202.

First, in S201, the decision support data input device 20 acquires decision support data from the cloud server 30. Next, in S202, only data in which the device information included in the decision support data acquired by the decision support data input device 20 is suitable for the facility is stored in the decision support database 21. The above data is classified by treatment target area and treatment method, and the suitability is judged for each data item before it is stored.

Therefore, the radiation therapy system of this embodiment can achieve the same effects as the radiation therapy system of embodiment 1.

The present invention is not limited to the above-mentioned examples, but includes various modified examples. The above-mentioned examples have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. It is also possible to replace part of the configuration of one example with the configuration of another example, and it is also possible to add the configuration of another example to the configuration of one example. It is also possible to add, delete, or replace part of the configuration of each example with other configurations.

Furthermore, the above-mentioned configurations, functions, processing units, processing means, etc. may be realized in hardware, in part or in whole, for example by designing them as integrated circuits. Furthermore, the above-mentioned configurations, functions, etc. may be realized in software, by a processor interpreting and executing a program that realizes each function. Information on the programs, tables, files, etc. that realize each function can be stored in a memory, a recording device such as a hard disk or SSD, or a recording medium such as an IC card, SD card, or DVD.

In addition, the control lines and information lines shown are those considered necessary for the explanation, and not all control lines and information lines on the product are necessarily shown. In reality, it can be assumed that almost all components are interconnected.

1: Subject 2: Bed 3: Imaging device 4: Therapeutic radiation irradiation device 5: Target 6: Treatment room 10: Treatment planning device 11: Operator 12: Monitor 13: Treatment control room 14: Patient structure change recognition device 15: Treatment plan verification device 20: Decision support data input device 21: Decision support database 30: Cloud server 40: Display screen 41: Decision index 42: Decision criterion value 43: Decision index value 44: Degree of achievement

Claims (11)

accepts input of decision support data consisting of a set of judgment indices and judgment criterion values to be evaluated during radiation irradiation therapy, accepts selective input of the decision support data corresponding to a target of the radiation irradiation therapy, calculates the value of the judgment index for an image of a specified area including the target captured on the treatment day by an imaging device that captures the specified area, and displays the value of the judgment index compared with the judgment criterion value ;
A judgment support system characterized in that the judgment index includes at least one of a shape change rate or amount of shape change of the target, a shape change rate or amount of shape change of an organ present in an image of the specified area captured by the imaging device, and a depth change rate or amount of depth change from the body surface to the target . The decision support system according to claim 1, further comprising a decision support database for storing the decision support data. The decision support system according to claim 1, characterized in that the calculation of the value of the decision index is performed during an operation to determine whether or not it is necessary to create a contour of an organ present in an image based on an image of the specified area captured by the imaging device. The decision support system according to claim 1, characterized in that the calculation of the value of the decision index is performed during the operation of creating a contour of an organ present in an image based on an image of the specified area captured by the imaging device. The decision support system according to claim 1, characterized in that the calculation of the value of the decision index is performed when evaluating the replanning of the radiation therapy. 6. The decision support system according to claim 5, wherein the decision index includes at least one of a dose in a low-dose region of the target, a dose in a high-dose region of an organ, a change in distance between the organ and a range end, a change in degree of prescription achievement for a dose volume histogram of the target, and a change in degree of prescription achievement for the dose volume histogram of the organ. The decision support system according to claim 1, characterized in that the calculation of the value of the decision index is performed when evaluating the treatment plan for the radiation irradiation therapy. The decision support system according to claim 7, characterized in that the decision index includes at least one of the following: the degree of distribution consistency when the radiation irradiation treatment is replanned, the dose in the low-dose region of the target, the dose in the high-dose region of the organ, the change in the degree of prescription achievement for the dose-volume histogram of the target, and the change in the degree of prescription achievement for the dose-volume histogram of the organ. The decision support system according to claim 2, characterized in that it accepts a selection input of the decision index, and accepts input of the decision support data from the decision support database based on the selected and input decision index. An imaging device that images a predetermined area including a target;
a radiation irradiation device for irradiating the target with radiation;
an irradiation control device that controls the radiation irradiation device;
Equipped with
the irradiation control device accepts input of decision support data consisting of a set of a judgment index and a judgment criterion value to be evaluated during treatment, accepts selective input of the decision support data corresponding to the target, calculates a value of the judgment index for the judgment index of the selectively input decision support data for the image of the predetermined region captured by the imaging device on the treatment day , and compares and displays the value of the judgment index and the judgment criterion value ;
A radiation therapy system characterized in that the judgment index includes at least one of a shape change rate or amount of shape change of the target, a shape change rate or amount of shape change of an organ present in an image of the specified area captured by the imaging device, and a depth change rate or amount of depth change from a body surface to the target . A decision support method in a decision support system, comprising:
the decision support system accepts input of decision support data consisting of a set of judgment indices to be evaluated during radiation irradiation therapy, accepts selective input of the decision support data corresponding to a target of the radiation irradiation therapy, calculates a value of the judgment index for an image of a specified area including the target captured on the treatment day by an imaging device that captures the specified area, and displays a comparison between the value of the judgment index and the judgment reference value ;
A judgment support method in a judgment support system, characterized in that the judgment index includes at least one of a shape change rate or amount of shape change of the target, a shape change rate or amount of shape change of an organ present in the image of the specified area captured by the imaging device, and a depth change rate or amount of depth change from a body surface to the target.