JP6440312B2 - Radiotherapy system and radiotherapy program - Google Patents

Description

  The present invention relates to a radiotherapy system and a radiotherapy program used for radiotherapy, and in particular, radiotherapy capable of improving irradiation accuracy by evaluating a patient's respiratory phase from movement of a marker embedded in a patient's body. The system and radiation therapy program.

  Conventionally, in radiotherapy, it has been required to irradiate an affected area such as a cancer that moves with the patient's breathing while minimizing exposure of a normal site to a minimum. For this reason, the respiratory phase is grasped from the motion of the patient's body surface, and respiratory synchronized radiotherapy (Patent Document 1) that irradiates the affected part with radiation only in a specific respiratory phase, or a marker placed in the vicinity of the affected part in the body in real time. The moving body pursuit radiotherapy which monitors by (1) and irradiates with radiation according to a respiratory phase etc. is performed (patent document 2).

JP-T-2002-528194 JP 2006-230673 A

  However, in the conventional respiratory synchronization radiotherapy including the invention described in Patent Document 1, the movement outside the body and the movement inside the body do not completely match. May be accompanied. Further, Patent Document 1 grasps the respiratory phase based only on the movement in one axis direction, such as the vertical movement of the abdomen. For this reason, in reality, a change in respiratory phase (so-called baseline shift) constituted by complicated three-dimensional motion cannot be detected, and there is a possibility that radiation is irradiated to a normal part.

  In addition, in the conventional moving body tracking radiotherapy including the invention described in Patent Document 2, when starting the treatment, the patient is placed so that the marker in the body seen through X-rays comes to the planned position determined in the treatment plan. Need to be aligned. For this reason, conventionally, the operator carefully observed the movement of the marker, manually stopped the fluoroscopic image at a timing that seems to be the respiratory phase (generally the expiratory phase) similar to the treatment plan, and displayed the X-ray image of the marker. Have acquired. For this reason, the patient positioning operation largely depends on the judgment and experience of the operator, and there is a problem that the reproducibility is low.

  Furthermore, in the conventional moving body tracking radiotherapy, as shown in FIG. 15A, an ambulation area is registered within a predetermined allowable range from the planned position of the marker, and radiation is irradiated every time the marker enters the ambulation area. doing. At this time, as shown in FIG. 15B, if the respiratory phase when the marker enters the ambush region matches the respiratory phase at the time of treatment planning, normal irradiation is performed.

  However, it is known that the positional relationship between the marker and the affected part (target) is different in different respiratory phases (exhalation phase and inspiration phase, etc.). Therefore, as shown in FIG. 15C, even if the marker is in the ambush area, the position of the affected part may be shifted if the respiratory phase at that time is different from the respiratory phase at the time of treatment planning. There is sex. Therefore, there is also a problem that irradiation accuracy and treatment accuracy are not sufficient when radiation is irradiated based only on the position of the marker, regardless of the respiratory phase of the patient as in the past.

  The present invention has been made to solve such problems, and by evaluating the respiratory phase directly from the three-dimensional motion of the marker implanted in the body of the patient, An object of the present invention is to provide a radiotherapy control apparatus and a radiotherapy program that can improve reproducibility and treatment accuracy by radiation, and can automatically detect the occurrence of a baseline shift.

  The radiotherapy system according to the present invention includes a marker position calculation unit that calculates a three-dimensional position of the marker based on a fluoroscopic image obtained by imaging a marker embedded in the body of the patient, and the marker in the respiratory cycle of the patient. The three-dimensional position of the marker that is farthest from the average position is associated with the inspiratory phase, and the three-dimensional position of the marker when moved by a predetermined distance from the previous inspiratory phase is changed from the previous inspiratory phase to the current inspiratory phase. A respiratory phase evaluation unit that evaluates the respiratory phase of the patient by associating it with a respiratory phase corresponding to a ratio of the predetermined distance to a moving distance that the marker has moved, and a three-dimensional position of the marker and the patient And a therapeutic radiation irradiation determining unit that determines whether or not the therapeutic radiation may be irradiated based on the respiratory phase. The radiotherapy program according to the present invention causes a computer to function as each component described above.

  Further, as one aspect of the radiation therapy system and the radiation therapy program according to the present invention, the therapeutic radiation irradiation determination unit is configured such that the three-dimensional position of the marker calculated by the marker position calculation unit is predetermined from the planned position of the marker. The respiratory phase evaluated by the respiratory phase evaluation unit is changed to an ambush respiratory phase set within a predetermined allowable range from the respiratory phase at the time of treatment planning. When entering, it may be determined that therapeutic radiation may be applied.

  Furthermore, as one aspect of the radiotherapy system according to the present invention, among the respiratory phases evaluated by the respiratory phase evaluation unit, a position for aligning the patient with a fluoroscopic image in the same respiratory phase as the patient's treatment plan An image acquisition unit for alignment acquired as an image for alignment, and a patient position that corrects the position of the bed on which the patient is placed so that the marker in the image for alignment matches the planned position determined in the treatment plan And a mating portion. Moreover, you may make a computer function as each said structure part as one aspect | mode of the radiotherapy program concerning this invention.

  As one aspect of the radiotherapy system according to the present invention, when the predetermined respiratory phase evaluated by the respiratory phase evaluation unit does not coincide with the ambush respiratory phase continuously for a predetermined number of times, a change occurs in the respiratory phase. It may have a baseline shift detection unit that detects that the above has occurred. Moreover, you may make a computer function as said baseline shift detection part as one aspect | mode of the radiotherapy program which concerns on this invention.

  Furthermore, as one aspect of the radiation therapy system and the radiation therapy program according to the present invention, the baseline shift detection unit is configured to be able to change a coordinate axis serving as a reference for monitoring temporal changes in the three-dimensional position of the marker. May be.

  Moreover, you may have the treatment plan preparation apparatus which produces the said patient's treatment plan based on the respiratory phase evaluated by the said respiratory phase evaluation part as one aspect | mode of the radiotherapy system which concerns on this invention. Moreover, you may make a computer function as said treatment plan preparation apparatus as one aspect | mode of the radiotherapy program which concerns on this invention.

  Furthermore, as one aspect of the radiation therapy system and the radiation therapy program according to the present invention, the respiratory phase evaluation unit is configured to move to a half of the moving distance that the marker has moved from the previous inspiration phase to the current inspiration phase. The three-dimensional position of the marker may be associated with the expiratory phase.

  Further, as one aspect of the radiation therapy system according to the present invention, in each of the real-time irradiation device capable of controlling the irradiation field of the therapeutic radiation in real time and the plurality of respiratory phases evaluated by the respiratory phase evaluation unit, The therapeutic radiation irradiation determining unit determines that the therapeutic radiation may be irradiated, and the irradiation field of the real-time irradiation device is set within a predetermined allowable range from the irradiation field at the time of treatment planning. An irradiation control / monitor device that outputs an irradiation instruction signal instructing the real-time irradiation device to irradiate the therapeutic radiation may be provided only during the ambush irradiation region. Further, as one aspect of the radiotherapy program according to the present invention, a computer may function as the real-time irradiation apparatus and the irradiation control / monitor apparatus.

  Furthermore, as one aspect of the radiation treatment system and the radiation treatment program according to the present invention, when the irradiation time in each respiratory phase becomes equal to or shorter than a predetermined time or zero, the irradiation control / monitor device indicates that the irradiation instruction signal is maximum. The movement of the irradiation field may be adjusted so that the respiratory phase evaluation unit may reevaluate the respiratory phase of the patient.

  According to the present invention, it is possible to improve the reproducibility of patient alignment and treatment accuracy by radiation by directly evaluating the respiratory phase from the three-dimensional movement of the marker embedded in the body of the patient, and to shift the baseline. Can be automatically detected.

1 is a block diagram showing a first embodiment of a radiation therapy system according to the present invention. It is a block diagram which shows the radiotherapy control apparatus of this 1st Embodiment. It is a figure explaining the evaluation method of the respiration phase by the respiration phase evaluation part of this 1st embodiment. In the first embodiment, (a) an example of a marker table, and (b) a diagram showing a marker trajectory. In this 1st Embodiment, it is a figure which shows the time change of the three-dimensional position (x-axis, y-axis, z-axis) of a marker. It is a flowchart which shows the radiotherapy method performed by the radiotherapy system and radiotherapy program of this 1st Embodiment. It is a flowchart which shows the process in the prior preparation stage of this 1st Embodiment. It is a flowchart which shows the process in the patient alignment stage of this 1st Embodiment. It is a flowchart which shows the process in the respiratory phase evaluation step of this 1st Embodiment. It is a flowchart which shows the process in the radiotherapy stage of this 1st Embodiment. It is a block diagram which shows 2nd Embodiment of the radiotherapy system which concerns on this invention. It is a block diagram which shows the radiotherapy control apparatus of this 2nd Embodiment. In the second embodiment, showing an example of a signal chart in the case of irradiating in two regions of the respiratory phases P ₀ and P _50. It is a flowchart which shows the process in the radiotherapy stage of this 2nd Embodiment. In conventional moving body tracking radiotherapy, (a) a diagram showing an ambush area based on a treatment plan, (b) a diagram showing a state where normal irradiation is performed, and (c) a state where an affected part is displaced from an irradiation field. FIG.

  Hereinafter, a first embodiment of a radiation therapy system 1A and a radiation therapy program 1a according to the present invention will be described with reference to the drawings. In the present invention, radiation is a concept including all electromagnetic waves such as X-rays and γ-rays and particle beams such as proton beams and heavy particle beams.

  The radiotherapy system 1A of the first embodiment is a system suitable for performing moving body tracking radiotherapy, and as shown in FIG. 1, mainly, a treatment plan creation device 11, a fluoroscopic imaging device 12, The apparatus includes a patient bed driving device 13, a therapeutic radiation gate control device 14, an irradiation control / monitor device 15, a therapeutic radiation irradiation device 16, and a radiotherapy control device 17. Hereinafter, each device will be described in detail.

  The treatment plan creation device 11 is a device that creates a treatment plan in advance for a patient undergoing radiation therapy. The treatment plan creation device 11 is composed of a personal computer or the like, and has a treatment plan data storage unit 11a that stores treatment plan data related to the treatment plan. In the first embodiment, the treatment plan data includes a plan position that is a three-dimensional position of a marker at the time of treatment planning, a plan breathing phase that is a breathing phase at the time of treatment planning, and an irradiation sequence (irradiation dose and irradiation posture) at the plan position. The prescription dose of the therapeutic radiation to be administered to the patient at the planned position, the dose distribution formed in the patient's body by the irradiation of the therapeutic radiation, and the like are calculated and stored.

  The planned position is calculated based on a CT (Computer Tomography) image of a patient taken at the time of treatment planning before starting treatment, and is transmitted to the radiotherapy control device 17 together with the planned respiratory phase. . On the other hand, the irradiation sequence (irradiation dose, irradiation posture), prescription dose, and dose distribution are transmitted to the irradiation control / monitor device 15.

  In the first embodiment, since the moving body tracking radiotherapy for irradiating the therapeutic radiation in synchronization with the so-called expiratory phase (the state where the breath has been exhaled) is performed, the CT image taken at the time of the treatment plan is the expiratory phase. It is obtained. That is, the expiratory phase is used as the planned respiratory phase. However, in the present invention, the planned respiratory phase is not limited to the expiratory phase, and any respiratory phase can be used. For example, in the case of irradiating therapeutic radiation in synchronization with the inspiration phase (the state in which inspiration is taken), the inspiration phase is used as the planned respiratory phase.

  The marker to be implanted in the patient's body is preferably formed of a material that is less harmful to the human body, such as gold, platinum, or iridium, and that absorbs much radiation, but is not particularly limited. In addition, the shape of the marker is preferably a columnar shape or a spherical shape, but may be other shapes.

  The fluoroscopic image capturing device 12 captures a fluoroscopic image with radiographic radiation. As shown in FIG. 1, two sets of X-ray generators 12a and 12a and an X-ray detector 12b set in two different directions are used. , 12b. The X-ray generator 12 a generates X-rays according to the imaging trigger transmitted from the radiation therapy control device 17. On the other hand, the X-ray detector 12b outputs a fluoroscopic patient's fluoroscopic image to the radiotherapy control device 17 in accordance with the synchronization signal transmitted in synchronization with the imaging trigger. Here, the angle formed by the first fluoroscopic direction and the second fluoroscopic direction by the X-ray generators 12a and 12a and the X-ray detectors 12b and 12b is preferably close to 90 °.

  In the first embodiment, as described above, the fluoroscopic images from two directions are acquired using the two sets of fluoroscopic image capturing devices 12, but the present invention is not limited to this configuration. For example, as proposed by the inventors of the present invention in Japanese Patent Laid-Open No. 2013-192702, in order to reduce the exposure dose due to the radiation for photographing, the fluoroscopy from one direction photographed by a pair of fluoroscopic image photographing devices It is possible to calculate the three-dimensional position of the marker from only the image. Conversely, it is possible to obtain the three-dimensional coordinates of the marker with high accuracy by acquiring fluoroscopic images from two or more directions, but it is necessary to consider the balance with the amount of exposure. In the first embodiment, X-rays are used as imaging radiation, but other radiation may be used.

  The patient bed driving device 13 drives the bed 13a on which the patient is placed, and performs alignment when irradiating therapeutic radiation. Specifically, as shown in FIG. 1, the patient bed driving device 13 is provided on the bed 13a, and the bed 13a is driven in accordance with a position correction signal from the radiotherapy control device 17 to correct the position. It has become.

  The therapeutic radiation gate controller 14 controls a gate signal indicating whether or not to apply therapeutic radiation. In the first embodiment, the therapeutic radiation gate control device 14 is configured so that the radiation treatment control device 17 can be configured to irradiate therapeutic radiation. Specifically, when it is determined that the radiation therapy control device 17 may irradiate, the gate signal is turned on. On the other hand, when it is determined that irradiation should not be performed, the gate signal is turned off. Then, as shown in FIG. 1, the therapeutic radiation gate control device 14 outputs the gate signal to the irradiation control / monitor device 15.

  The irradiation control / monitor device 15 controls the irradiation of therapeutic radiation by the therapeutic radiation irradiation device 16 and monitors the cumulative dose to the patient. In the first embodiment, the irradiation control / monitor device 15 acquires and stores an irradiation sequence (irradiation dose, irradiation posture), prescription dose, dose distribution, and the like from the treatment plan creation device 11. If the gate signal received from the therapeutic radiation gate control device 14 is on, an irradiation instruction signal for irradiating the radiation specified in the irradiation sequence is output to the therapeutic radiation irradiation device 16. .

  Further, the irradiation control / monitoring device 15 has a function of monitoring the cumulative dose of therapeutic radiation while performing radiotherapy. Specifically, the irradiation control / monitor device 15 accumulates the dose administered to the patient, and compares the accumulated dose with the prescription dose acquired from the treatment plan creation device 11 as needed. Then, radiotherapy is continued unless the cumulative dose reaches the prescription dose. On the other hand, when the cumulative dose reaches the prescription dose, the operator is notified that one of the radiotherapy or the treatment procedure has been completed.

  In the first embodiment, the therapeutic radiation gate control device 14 is interposed between the radiation therapy control device 17 and the irradiation control / monitor device 15, but the present invention is not limited to this configuration. For example, when the irradiation control / monitor device 15 has the function of the therapeutic radiation gate control device 14, it is not necessary to separately provide the therapeutic radiation gate control device 14.

  The therapeutic radiation irradiation device 16 irradiates therapeutic radiation toward the affected area of the patient. Specifically, when receiving the irradiation instruction signal from the irradiation control / monitor apparatus 15, the therapeutic radiation irradiation device 16 irradiates the therapeutic radiation toward the affected area of the patient according to the irradiation sequence specified by the irradiation instruction signal. It is supposed to be. In the first embodiment, X-rays are used as therapeutic radiation, but other radiation may be used. Further, the affected part of the patient may be other necessary parts as well as the affected part requiring radiotherapy such as cancer and malignant tumor.

  The radiotherapy control device 17 controls moving body tracking radiotherapy using the radiotherapy system 1A of the first embodiment. In the first embodiment, the radiotherapy control device 17 is characterized in that the respiratory phase of the patient is evaluated from the temporal change of the three-dimensional position of the marker implanted in the body, that is, the three-dimensional movement of the marker. Hereinafter, the radiation therapy control device 17 of the first embodiment will be described in detail.

  In the first embodiment, the radiotherapy control device 17 is configured by a computer such as a personal computer. As shown in FIG. 2, the radiotherapy control device 17 mainly includes the radiotherapy program 1a of the first embodiment and various data. It comprises a storage means 2 for storing, and an arithmetic processing means 3 for acquiring various data and performing arithmetic processing.

  The storage unit 2 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), a flash memory, and the like. The storage unit 2 stores various data and the arithmetic processing unit 3 performs arithmetic processing. It functions as a working area when performing. In the first embodiment, as shown in FIG. 2, the storage unit 2 includes a program storage unit 21, a plan data storage unit 22, an ambush data storage unit 23, a template image storage unit 24, and a transformation matrix storage unit. 25, a marker position storage unit 26, and a respiratory phase storage unit 27. Hereinafter, each component will be described in more detail.

  The program storage unit 21 is installed with the radiation therapy program 1a of the first embodiment. The radiotherapy program 1a is executed by the arithmetic processing means 3 so that the computer functions as each component described later. In the present invention, not only programs installed in the radiation therapy control device 17 but also programs installed in the treatment plan creation device 11, the irradiation control / monitor device 15, the treatment radiation irradiation device 16 and the like are collectively referred to as The radiation treatment program 1a is assumed.

  Moreover, the utilization form of the radiation therapy program 1a is not restricted to the said structure. For example, the radiation therapy program 1a may be stored in a computer-readable recording medium, such as a CD-ROM or DVD-ROM, and read directly from the recording medium and executed. Further, an ASP (Application Service Provider) method or a cloud computing method may be used from an external server or the like.

  The plan data storage unit 22 stores a plan position that is a three-dimensional position of the marker at the time of treatment planning and a plan breathing phase that is a breathing phase at the time of treatment planning. In the first embodiment, the plan data storage unit 22 stores a plan position and a plan breathing phase acquired by the plan data acquisition unit 31 described later from the treatment plan creation device 11 in association with a patient performing radiation therapy. It has become.

  The ambush data storage unit 23 stores an ambush area set within a predetermined allowable range from the planned position of the marker, and an ambush respiratory phase set within a predetermined allowable range from the respiratory phase at the time of treatment planning. . In the first embodiment, the ambush area is set by a cube having a side of several millimeters around a planned position or a sphere having a diameter of several millimeters. The ambush respiratory phase is set with a phase difference of several percent before and after the planned respiratory phase. That is, a range in which the deviation between the respiratory phase at the time of ambush irradiation obtained during radiotherapy and the planned respiratory phase is within several percent is set as the ambush respiratory phase.

  Note that the ambush respiratory phase may be set based on the deviation between the position of the marker corresponding to the planned respiratory phase obtained during radiotherapy and the planned position. That is, if the marker corresponding to the planned respiratory phase is within a range set by a cube having a side of several millimeters around the planned position or a sphere having a diameter of several millimeters, it is determined that the marker is within the ambush respiratory phase. Also good.

  The template image storage unit 24 stores a template image for specifying the projected position of the marker in the fluoroscopic image. This template image is an image used as a template when calculating a similarity with a predetermined region in the fluoroscopic image in a template pattern matching process described later. Specifically, in the template image storage unit 24, an image of a marker embedded in the patient's body is stored in advance as a template image. When the marker to be used has a shape other than a spherical shape, a plurality of images obtained by projecting the marker from various angles may be stored as template images.

  The conversion matrix storage unit 25 stores a conversion matrix for calculating an equation of a projection line that connects the projected position of the marker in the fluoroscopic image and the focal position of the fluoroscopic image capturing device 12. In the first embodiment, the calibration operation of the fluoroscopic imaging device 12 is performed in advance in each of the two fluoroscopic directions. Then, the two transformation matrices in the respective fluoroscopic directions obtained by the calibration work are stored in the transformation matrix storage unit 25.

  The marker position storage unit 26 stores the three-dimensional position of the marker in time series. The marker position storage unit 26 stores the three-dimensional position of the marker calculated in real time by a marker position calculation unit 34 described later in time series. The three-dimensional motion of the marker is reconstructed from the time-series data of the three-dimensional position, and the respiratory motion of the patient is grasped.

  The respiratory phase storage unit 27 stores the relationship between the respiratory phase evaluated by the respiratory phase evaluation unit 35 described later and the three-dimensional position of the marker. In the first embodiment, the respiratory phase storage unit 27 stores the three-dimensional position of the marker and the movement time from the reference respiratory phase for each of the expiration phase and the inspiration phase. However, the present invention is not limited to this configuration, and the relationship of the three-dimensional position of the marker with respect to an arbitrary respiratory phase can be stored.

  Next, the arithmetic processing means 3 is comprised from CPU (Central Processing Unit) etc., By executing the radiotherapy program 1a installed in the memory | storage means 2, a computer is made to the radiotherapy control of this 1st Embodiment. The device 17 is mounted.

  Specifically, as shown in FIG. 2, the radiation therapy program 1a executed by the arithmetic processing unit 3 includes a plan data acquisition unit 31, an ambush data setting unit 32, a fluoroscopic image acquisition unit 33, and a marker position calculation. The computer functions as the unit 34, the respiratory phase evaluation unit 35, the alignment image acquisition unit 36, the patient alignment unit 37, the therapeutic radiation irradiation determination unit 38, and the baseline shift detection unit 39. Hereinafter, each component will be described in more detail.

  The plan data acquisition unit 31 acquires a plan position that is a three-dimensional position of a marker at the time of treatment planning and a plan breathing phase that is a breathing phase at the time of treatment planning. In the first embodiment, the plan data acquisition unit 31 acquires the planned position and the planned respiratory phase of the marker embedded in the patient on whom radiation therapy is to be performed, from the treatment plan data storage unit 11a of the treatment plan creation device 11. . Then, the planned position and the planned respiratory phase are stored in the planned data storage unit 22.

  The ambush data setting unit 32 sets an ambush area set within a predetermined allowable range from the planned position, and an ambush respiratory phase set within a predetermined allowable range from the planned respiratory phase. In the first embodiment, the ambush data setting unit 32 sets the ambush area by a cube having a side of several millimeters centered on the planned position or a sphere having a diameter of several millimeters in response to an instruction input from the operator. To do. In addition, the ambush data setting unit 32 sets the ambush breathing phase with a phase difference of several percent before and after the planned breathing phase in response to an instruction input from the operator.

  The fluoroscopic image acquisition unit 33 acquires a fluoroscopic image from the fluoroscopic image capturing device 12 when aligning the patient before the start of radiotherapy and during actual radiotherapy. In the first embodiment, the fluoroscopic image acquisition unit 33 outputs an imaging trigger to each X-ray generator 12a at predetermined time intervals (for example, about 30 times per second), and at the same time, each X-ray A synchronization signal is output to the detector 12b. Thereby, the fluoroscopic image which image | photographed the marker embedded in the patient's body from two different directions is acquired from the fluoroscopic image imaging device 12.

  In the first embodiment, the fluoroscopic image acquisition unit 33 acquires a fluoroscopic image directly from the fluoroscopic image capturing device 12, but the configuration is not limited to this configuration, and the fluoroscopic image acquisition unit 33 is not limited to this configuration, and the fluoroscopic image acquisition unit 33 is not limited to this configuration. A fluoroscopic image photographed by the image photographing device 12 may be acquired. Further, in the first embodiment, the fluoroscopic image acquisition unit 33 acquires the fluoroscopic image by a plurality of still images, but may acquire it by a moving image.

  The marker position calculation unit 34 calculates the three-dimensional position of the marker based on a fluoroscopic image obtained by photographing the marker embedded in the patient's body. In the first embodiment, the marker position calculation unit 34 first reads a template image from the template image storage unit 24, and performs template pattern matching processing based on the normalized cross-correlation for each perspective image acquired by the perspective image acquisition unit 33. Apply. Thereby, the projection position (two-dimensional coordinate) of the marker on each fluoroscopic image is specified every predetermined time interval.

  In the first embodiment, the marker position calculation unit 34 specifies the projected position of the marker by the template pattern matching process based on the normalized cross-correlation. However, the present invention is not limited to this processing method. As long as the projected position of the marker can be specified, it may be specified by the mutual information amount, or another image recognition technique may be adopted.

  Subsequently, the marker position calculation unit 34 calculates an equation of a projection line that connects the projected position of the marker in each fluoroscopic image and the focal position of the fluoroscopic image capturing device 12. Specifically, the marker position calculation unit 34 acquires the transformation matrix in each perspective direction from the transformation matrix storage unit 25, and uses the transformation matrix to coordinate corresponding points in the three-dimensional space of each projection position. Calculate the group (linear equation). Then, the marker position calculation unit 34 calculates the calculated intersection of the equations as the three-dimensional position of the marker.

  The respiratory phase evaluation unit 35 evaluates the respiratory phase of the patient based on the temporal change (three-dimensional movement) of the three-dimensional position of the marker. Specifically, as shown in FIG. 3, the respiratory phase evaluation unit 35 corresponds to the respiratory phase in the immediately preceding respiratory cycle for each preset respiratory cycle of the patient according to the following steps (1) to (5). Evaluate 3D position. In the first embodiment, the respiratory cycle is set to 4 seconds corresponding to one breath of the patient, but can be appropriately set according to the respiratory cycle of the patient.

(1) The average position of markers (average of three-dimensional positions) in a predetermined respiratory cycle is calculated.
(2) The distance from the calculated average position to the marker is calculated.
(3) The three-dimensional position of the marker when the calculated distance is the largest is associated with the inspiratory phase.
(4) The moving distance from the previous intake phase to the current intake phase is calculated.
(5) Associating the three-dimensional position of the marker when moved by a predetermined distance from the previous inspiratory phase with the respiratory phase corresponding to the ratio of the predetermined distance to the moving distance.

  That is, the respiratory phase evaluation unit 35 associates the three-dimensional position of the marker when it is farthest from the average position of the marker in the patient's respiratory cycle with the inspiratory phase. In addition, the respiratory phase evaluation unit 35 determines the three-dimensional position of the marker when it has moved by a predetermined distance from the previous inspiratory phase as to the predetermined distance with respect to the moving distance that the marker has moved from the previous inspiratory phase to the current inspiratory phase. Correspond to the respiratory phase according to the proportion of distance. In FIG. 3, the three-dimensional position of the marker when moving to half (50%) of the moving distance is associated with the expiratory phase.

  In the first embodiment, the respiratory phase evaluation unit 35 creates a marker table in which the three-dimensional position of the marker and the movement time of the marker are associated with each respiratory phase, as shown in FIG. It is stored in the respiratory phase storage unit 27.

For example, when the movement distance from the previous inspiratory phase (P ₀ ) evaluated by the respiratory phase evaluating unit 35 to the current inspiratory phase (P ₁₀₀ ) is L, as shown in FIG. three-dimensional position _{M 10} when the marker from the three-dimensional position _{M 0} of the intake phase _{P 0} by L / 10 has moved is associated with respiratory phase _{P 10.} Since the ratio of the predetermined distance to the travel distance (L) (L / 10) is 10%, because associated with the respiratory phase P ₁₀ which corresponds to 10% of the phase in one cycle of breath in response to the ratio.

Respiratory phase evaluation unit 35, together with the correspondence of the three-dimensional position _{M 10} in respiratory phase _{P 10,} calculates a travel time _{t 10} to the three-dimensional position _{M 10.} Similarly, each time the marker further by L / 10 from that point is moved, the three-dimensional position _{M 20, M 30, M 40} , ... M 100 respiratory phase _{P 20, P 30, P 40} , ... to _{P 100} Set and register the travel times t ₂₀ , t ₃₀ , t ₄₀ ,... T ₁₀₀ .

  The alignment image acquisition unit 36 acquires an alignment image for aligning the patient at a desired position when starting radiotherapy. Specifically, the alignment image acquisition unit 36 acquires a fluoroscopic image in the same respiratory phase as the patient's treatment plan among the respiratory phases evaluated by the respiratory phase evaluation unit 35 as an alignment image. ing. In the first embodiment, the expiratory phase is adopted as the respiratory phase at the time of treatment planning, but any respiratory phase may be used.

  The patient alignment unit 37 aligns the patient to an appropriate position when irradiating therapeutic radiation. In the first embodiment, when performing radiotherapy, a CT image taken in the expiratory phase at the time of treatment planning is used. For this reason, the patient alignment unit 37 allows the three-dimensional position of the marker in the alignment image acquired by the alignment image acquisition unit 36 to match the planned position determined in the treatment plan. A position correction amount is calculated. Then, the position correction amount is output as a position correction signal to the patient bed driving device 13 to correct the position of the bed 13a on which the patient is placed.

  The therapeutic radiation irradiation determination unit 38 determines whether or not the therapeutic radiation may be irradiated based on the three-dimensional position of the marker and the respiratory phase of the patient. Specifically, the therapeutic radiation irradiation determination unit 38 reads the ambush area and the ambush breathing phase registered in the ambush data storage unit 23. The therapeutic radiation irradiation determination unit 38 has the three-dimensional position of the marker calculated by the marker position calculation unit 34 in the ambush area, and the respiratory phase evaluated by the respiratory phase evaluation unit 35 is the ambush respiratory phase. When it is in, it is determined that therapeutic radiation may be applied.

  On the other hand, if the marker is not within the ambush area, or if the respiratory phase is not within the ambush respiratory phase, it is determined that therapeutic radiation should not be applied. On / off of the gate signal in the therapeutic radiation gate control device 14 is set based on the determination result.

  The baseline shift detection unit 39 detects a baseline shift indicating a change in respiratory phase. Specifically, the baseline shift detection unit 39 generates a change in the respiratory phase (baseline shift) when the expiratory phase evaluated by the respiratory phase evaluation unit 35 does not match the ambush respiratory phase continuously a predetermined number of times. It is detected that The respiratory phase used for detection is not limited to the expiratory phase, and a predetermined respiratory phase may be used as long as it is a respiratory phase corresponding to the ambush respiratory phase, that is, a respiratory phase at the time of treatment planning.

  Further, in the first embodiment, the baseline shift detection unit 39 is configured to be able to change the coordinate axis serving as a reference for monitoring temporal changes in the three-dimensional position of the marker during the detection process. For example, as shown in FIG. 5, there is a case where vibrations with a large amplitude are easily observed with respect to the y axis even if the x axis and z axis are difficult to observe because the amplitude of the marker accompanying respiration is small. Therefore, the baseline shift detection unit 39 correctly grasps the patient's respiratory motion by changing the reference coordinate axis.

  Next, the operation of the radiation therapy system 1A and the radiation therapy method executed by the radiation therapy program 1a of the first embodiment will be described.

  As shown in FIG. 6, the radiotherapy method of the first embodiment is roughly divided into a preparatory stage (step S1) in which a treatment plan and ambush data necessary for radiotherapy are prepared in advance, and a desired patient. It includes a patient positioning stage (step S2) for positioning to a position and a radiotherapy stage (step S3) in which radiation treatment is actually performed by irradiating the affected part of the patient with the therapeutic radiation.

  First, the ambush data preparation stage is a stage in which a treatment plan and ambush data necessary for radiation therapy are prepared in advance (step S1). Specifically, as shown in FIG. 7, first, in step S11, the treatment plan creation device 11 uses a predetermined CT system to obtain a planned position, an irradiation sequence (irradiation dose). , Irradiation posture), prescription dose, dose distribution, and other treatment plan data are created and stored in advance in the treatment plan data storage unit 11a.

  In radiation therapy, it is most desirable to irradiate radiation in the same state as at the time of treatment planning. Therefore, in the first embodiment, the treatment plan creation device 11 creates a treatment plan for the patient based on the respiratory phase evaluated by the respiratory phase evaluation unit 35. Thereby, the consistency between the time of treatment planning and the time of radiotherapy is increased, and more accurate treatment is possible. In order to create a treatment plan based on the evaluation respiratory phase, 4D-CT (4-D) capable of continuously acquiring a stereoscopic image by four dimensions obtained by adding time (one dimension) to space (three dimensions). It is preferable to use Dimensional Computed Tomography).

  Next, in step S12, the plan data acquisition unit 31 acquires the planned position of the marker and the respiratory phase at the time of the treatment plan (planned respiratory phase) from the treatment plan data storage unit 11a of the treatment plan creation device 11, and these plan positions. The planned respiratory phase is stored in the planned data storage unit 22. In this step S12, the treatment plan creation apparatus 11 separately irradiates and controls irradiation sequence (irradiation dose, irradiation posture), prescription dose, dose distribution, and other data stored in the treatment plan data storage unit 11a. The data is transmitted to the device 15.

  Subsequently, in step S13, the ambush data setting unit 32 determines the ambush region and the plan based on the plan position and the plan breathing phase stored in the plan data storage unit 22 and the allowable range value input by the operator. Set ambush breathing phase. Thereby, preparation of data required for the radiation therapy of the first embodiment is completed.

  Next, the patient alignment step is a step of aligning the patient at a desired position before starting radiotherapy (step S2). Specifically, as shown in FIG. 8, first, in step S21, the fluoroscopic image acquisition unit 33 captures fluoroscopic images obtained by photographing markers embedded in the patient's body from two different directions at predetermined time intervals. Obtained from the fluoroscopic image capturing device 12.

  Next, in step S22, the marker position calculation unit 34 calculates the three-dimensional position of the marker for each time interval based on the fluoroscopic images from two directions acquired by the fluoroscopic image acquisition unit 33 for each predetermined time interval. calculate. Thereby, since the three-dimensional position of the marker is obtained in time series, the three-dimensional movement of the marker is reconstructed and the respiratory movement of the patient is grasped.

  Subsequently, in step S23, the respiratory phase evaluation unit 35 evaluates the patient's respiratory phase based on the three-dimensional movement of the marker calculated by the marker position calculation unit 34. Specifically, as shown in FIGS. 3 and 9, the respiratory phase evaluation unit 35 waits until a predetermined respiratory cycle has elapsed (step S231), and then calculates the average position of the markers in the respiratory cycle ( Step S232). The respiratory phase evaluation unit 35 calculates the distance from the average position to the marker (step S233), and associates the three-dimensional position of the marker when the distance is the largest with the inspiratory phase (step S234). Further, the respiratory phase evaluation unit 35 calculates a moving distance from the previous inspiratory phase to the current inspiratory phase (step S235), and moves the three-dimensional position of the marker when moving by a predetermined distance from the previous inspiratory phase. Corresponding to the respiratory phase according to the ratio of the predetermined distance to the distance (step S236). In the first embodiment, the three-dimensional position of the marker when moved to half the moving distance is associated with the expiratory phase.

  Through the above processing, the respiratory phase (expiratory phase or inspiratory phase) of the patient is quantitatively evaluated based on the three-dimensional movement of the marker embedded in the patient's body.

  Subsequently, in step S24, the alignment image acquisition unit 36 performs the same breathing phase as the patient's treatment plan among the breathing phases evaluated by the breathing phase evaluation unit 35, that is, fluoroscopy in the expiratory phase in the first embodiment. An image is acquired as an alignment image. Thereby, the image for alignment which was conventionally performed by the operator's manual operation is acquired automatically. For this reason, the reproducibility of the patient positioning operation is improved without intervention by the operator.

  In step S25, the patient alignment unit 37 causes the three-dimensional position of the marker in the alignment image acquired by the alignment image acquisition unit 36 to coincide with the planned position determined in the treatment plan. The patient bed driving device 13 is driven to correct the position of the bed 13a. Thereby, the three-dimensional position in the treatment room coordinate space of the marker embedded in the patient is matched with the plan position at the time of creating the treatment plan, and preparations for executing radiation treatment are completed.

  In the case where a CT image of a patient is separately taken immediately before the start of the radiotherapy stage (step S3) described in detail below, and the marker position obtained from the CT image is within a predetermined allowable range from the planned position. May omit steps S21 to S25 described above.

  The radiation treatment stage is a stage where radiation treatment is actually performed by irradiating the affected area of the patient with therapeutic radiation (step S3). Specifically, as shown in FIG. 10, in steps S31 to S33, the same processes as in steps S21 to S23 in the patient alignment stage of FIG. 8 are performed. That is, in step S31, the fluoroscopic image acquisition unit 33 acquires, from the fluoroscopic image imaging device 12, fluoroscopic images obtained by imaging the marker embedded in the patient's body from two different directions at predetermined time intervals.

  Next, in step S <b> 32, the marker position calculation unit 34 calculates the three-dimensional position of the marker at each time interval based on the fluoroscopic images from the two directions acquired at predetermined time intervals by the fluoroscopic image acquisition unit 33. calculate. In step S33, the respiratory phase evaluation unit 35 evaluates the respiratory phase of the patient based on the three-dimensional movement of the marker calculated by the marker position calculation unit 34.

  Next, in step S34, the therapeutic radiation irradiation determination unit 38 compares the ambush area set in step S13 with the three-dimensional position of the marker calculated in step S22. Further, the therapeutic radiation irradiation determination unit 38 compares the ambush respiratory phase set in step S13 with the respiratory phase evaluated in step S33 (in the first embodiment, the expiratory phase).

  As a result of the comparison, only when the marker is in the ambush area and the respiratory phase is in the ambush respiratory phase (step S34: YES), the therapeutic radiation irradiation determination unit 38 irradiates the therapeutic radiation. The gate signal in the therapeutic radiation gate control device 14 is set to ON (step S35). Then, while the gate signal is set to ON in the therapeutic radiation gate control device 14, the irradiation control / monitor device 15 outputs an irradiation instruction signal to the therapeutic radiation irradiation device 16 according to the irradiation sequence acquired in step S12. Then, the therapeutic radiation is irradiated (step S36).

  On the other hand, when the marker is not within the ambush region or when the respiratory phase is not within the ambush respiratory phase (step S34: NO), the therapeutic radiation irradiation determination unit 38 should not irradiate therapeutic radiation. And the gate signal in the therapeutic radiation gate control device 14 is set to OFF (step S37).

  As described above, not only that the marker is in the ambush area, but also that the respiratory phase at that time is in the ambush respiratory phase, and to allow radiation irradiation, It is unlikely that the affected area is misaligned. Therefore, irradiation accuracy and treatment accuracy are improved and erroneous irradiation to normal sites is reduced compared to the case where radiation is irradiated based only on the marker position, regardless of the respiratory phase of the patient as in the past. To do.

  If the gate signal remains off, in step S38, the base line shift detector 39 detects whether or not a base line shift has occurred. If the occurrence of a baseline shift is detected as a result of the detection (step S38: YES), the process returns to the patient alignment step of step S2, and the alignment operation is performed again. As a result, the occurrence of the baseline shift is automatically detected, and the patient's re-alignment work is appropriately performed, so that radiation to a normal site is prevented.

  Finally, after irradiation of therapeutic radiation (step S36) or if no occurrence of baseline shift is detected (step S38: NO), the irradiation control / monitor device 15 is acquired in step S12 in step S39. Compare the prescription dose with the cumulative dose administered to the patient. Then, unless the cumulative dose reaches the prescription dose (step S39: NO), the process returns to step S31 and the radiation therapy is continued. On the other hand, when the cumulative dose reaches the prescription dose (step S39: YES), the radiotherapy is terminated.

According to the radiotherapy system 1A and the radiotherapy program 1a of the first embodiment as described above, the following operational effects can be obtained.
1. The respiratory phase can be evaluated directly from the three-dimensional motion of the marker implanted in the patient's body.
2. An alignment image can be automatically acquired based on the evaluated respiratory phase, and the reproducibility of patient alignment can be improved.
3. By monitoring not only the three-dimensional position of the marker but also the respiratory phase of the patient, the treatment accuracy by radiation can be improved.
4). It is possible to automatically detect the occurrence of the baseline shift and reduce the erroneous irradiation to the normal part.
5. The coordinate axis used as a reference for monitoring the three-dimensional movement of the marker can be changed, and the respiratory movement of the patient can be correctly grasped.
6). By creating a treatment plan for a patient based on the evaluated respiratory phase, consistency between the treatment plan and the radiation treatment can be improved, and treatment accuracy can be improved.

  Next, a second embodiment of the radiation therapy system 1B and the radiation therapy program 1b according to the present invention will be described. Note that, in the second embodiment, the same or equivalent configurations and steps as those of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  The feature of the second embodiment is that the irradiation efficiency and the treatment efficiency are improved by enabling a plurality of times of irradiation in one respiratory cycle, the treatment time is shortened, and the burden on the patient is reduced. There is in point to do.

  In the second embodiment, as shown in FIG. 11, a real-time irradiation device 18 capable of controlling the irradiation field of therapeutic radiation in real time is used instead of the therapeutic radiation irradiation device 16 in the first embodiment. And in order to irradiate radiation in each of a plurality of respiration phases in one respiration cycle, treatment plan creation device 11 creates a treatment plan in each respiration phase. A planned irradiation field that is an irradiation field for each respiratory phase is also added to the treatment plan.

  Further, as shown in FIG. 12, the radiotherapy control device 17 has a control signal transmission unit 40 as compared with the first embodiment. The control signal transmission unit 40 transmits, to the real-time irradiation device 18, an irradiation field control signal for controlling the direction of the irradiation field toward the affected part in each respiratory phase based on the treatment plan for each of the plurality of respiratory phases. . Further, in the second embodiment, the ambush data setting unit 32 acquires a planned irradiation field from the treatment plan creation device 11 and sets a predetermined allowable range from the irradiation field at the time of treatment planning for each respiratory phase. Set the ambush field.

  The real-time irradiation device 18 sets the irradiation field in the direction specified by the irradiation field control signal, and when the irradiation field is in the ambush irradiation region, emits a position signal indicating whether or not the position setting is properly completed. It has a function of transmitting to the control / monitor device 15.

  In the second embodiment, the irradiation control / monitoring device 15 indicates that the therapeutic radiation irradiation determination unit 38 may irradiate therapeutic radiation in each of a plurality of respiratory phases evaluated by the respiratory phase evaluation unit 35. Only when the irradiation field of the real-time irradiation device 18 is in the ambush irradiation region, the irradiation instruction signal for instructing the real-time irradiation device 18 to irradiate therapeutic radiation is output. Yes.

Here, FIG. 13 is an example of a signal chart when irradiation is performed in two regions of the respiratory phase P ₀ (expiratory phase) and P ₅₀ (inspiratory phase). As shown in FIG. 13, in each respiratory phase P ₀ and P _50, while entering the marker ambush region, a gate signal corresponding to each respiratory phase P ₀ and P ₅₀ are set to ON. Further, in each of the respiratory phases P ₀ and P ₅₀ , the position signal corresponding to each of the respiratory phases P ₀ and P ₅₀ is set to ON while the irradiation field is in the ambush irradiation region. In each of the respiratory phases P ₀ and P ₅₀ , the irradiation instruction signal is set to ON only while both the gate signal and the position signal are ON.

  In other words, if there is no time for both the gate signal and the position signal to be on, the irradiation instruction signal is not set to on. Therefore, in the second embodiment, the irradiation control / monitoring device 15 adjusts the movement of the irradiation field so that the irradiation instruction signal becomes maximum when the irradiation time in each respiratory phase is equal to or shorter than a predetermined time or zero. .

  Specifically, the irradiation control / monitoring device 15 detects the gate signal when the ratio of the time during which the irradiation instruction signal is on to the time during which the gate signal is on falls below a predetermined set value. A shift amount that maximizes the overlap between ON and the position signal is calculated, and the movement of the irradiation field is adjusted according to the shift amount. That is, the irradiation control / monitoring device 15 shifts the movement of the irradiation field in FIG. 13 in the time axis direction to maximize the time during which the irradiation instruction signal is turned on.

  In the second embodiment, the above-described shift amount is adjusted by adjusting the movement of the irradiation field, but the present invention is not limited to this configuration. For example, the patient's respiratory phase may be reevaluated by the respiratory phase evaluation unit 35 and the marker table shown in FIG. 4A may be updated. Thereby, since the respiratory phase is reevaluated based on the latest respiratory motion, the movement of the marker in FIG. 13 is corrected in the time axis direction, and the time during which the irradiation instruction signal is turned on increases.

  Next, the operation of the radiation therapy system 1B and the radiation therapy method executed by the radiation therapy program 1b of the second embodiment will be described.

  As in the first embodiment, the radiation treatment stage (step S3) is performed after the preliminary preparation stage (step S1) and the patient positioning stage (step S2). Specifically, as shown in FIG. 14, the respiratory phase is evaluated by the processing from step S31 to step S33. At this time, in the second embodiment, the respiratory phase evaluation unit 35 calculates the three-dimensional position and movement time of the marker for each of a plurality of respiratory phases in one respiratory cycle.

  Next, in step S41, the control signal transmission unit 40 transmits an irradiation field control signal to the real-time irradiation device 18 for each of a plurality of respiratory phases to be irradiated. Thereby, the real-time irradiation device 18 sets the irradiation field in the direction specified by the irradiation field control signal, and when the irradiation field is in the ambush irradiation region, the position indicating whether or not the position setting is properly completed. The signal is transmitted to the irradiation control / monitor device 15.

  Subsequently, in step S34, the therapeutic radiation irradiation determination unit 38 turns on the gate signal only when the marker is in the ambush area and the respiratory phase is in the ambush respiratory phase (step S34: YES). (Step S35). Next, in step S42, the irradiation control / monitoring device 15 determines whether or not the position signal is on. If the position signal is on (step S42: YES), the irradiation instruction signal is set on (step S36). As a result, since radiation is emitted in a plurality of respiratory phases even in one respiratory cycle, an increase in treatment time is prevented and the burden on the patient is reduced.

  However, when the position signal is not turned on and the irradiation time is zero (step S42: NO), or when the irradiation time in each respiratory phase is equal to or shorter than the predetermined time (step S43: YES), in step S44, irradiation control / The monitor device 15 adjusts the movement of the irradiation field in the time axis direction so that the output time of the irradiation instruction signal is maximized, and maximizes the time during which the irradiation instruction signal is turned on. Thereby, an appropriate irradiation time is automatically secured.

According to the radiation therapy system 1B and the radiation therapy program 1b of the second embodiment as described above, the following effects are obtained in addition to the effects of the first embodiment described above.
1. Irradiation can be performed with a plurality of respiratory phases in one respiratory cycle, and irradiation efficiency can be improved.
2. An increase in treatment time can be prevented and the burden on the patient can be reduced.
3. It is possible to prevent the irradiation time in each respiratory phase from being shortened and to automatically maintain an appropriate irradiation time.

  In addition, the radiotherapy system and radiotherapy program which concern on this invention are not limited to each embodiment mentioned above, It can change suitably.

  For example, in the radiotherapy system of each of the embodiments described above, a fluoroscopic image is acquired using X-rays, but a fluoroscopic image may be acquired by a method for acquiring a fluoroscopic image other than X-rays such as ultrasound. . In each embodiment, X-rays are used as therapeutic radiation, but proton beams other than X-rays, heavy particle beams, and the like may be used.

DESCRIPTION OF SYMBOLS 1A, 1B Radiation therapy system 1a, 1b Radiation therapy program 2 Memory | storage means 3 Arithmetic processing means 11 Treatment plan creation apparatus 11a Treatment plan data storage part 12 Fluoroscopic imaging apparatus 12a X-ray generator 12b X-ray detector 13 Patient bed drive apparatus 13a Bed 14 Treatment Radiation Gate Control Device 15 Irradiation Control / Monitor Device 16 Treatment Radiation Irradiation Device 17 Radiation Treatment Control Device 18 Real Time Irradiation Device 21 Program Storage Unit 22 Plan Data Storage Unit 23 Ambush Data Storage Unit 24 Template Image Storage Unit 25 Transformation matrix storage unit 26 Marker position storage unit 27 Respiration phase storage unit 31 Plan data acquisition unit 32 Ambush data setting unit 33 Perspective image acquisition unit 34 Marker position calculation unit 35 Respiration phase evaluation unit 36 Image acquisition unit for alignment 37 Patient alignment Part 38 therapeutic radiation irradiation determination section 39 baseline shift detection unit 40 a control signal transmission unit

Claims (18)

A marker position calculation unit that calculates a three-dimensional position of the marker based on a fluoroscopic image obtained by imaging a marker embedded in the body of a patient;
The three-dimensional position of the marker when the furthest away from the average position of the marker in the respiratory cycle of the patient is associated with the inspiration phase, and the three-dimensional position of the marker when moved by a predetermined distance from the previous inspiration phase A respiratory phase evaluation unit that evaluates the respiratory phase of the patient by associating with the respiratory phase according to the ratio of the predetermined distance to the moving distance the marker has moved from the previous inspiration phase to the current inspiration phase;
A radiotherapy system comprising: a therapeutic radiation irradiation determination unit that determines whether or not therapeutic radiation may be irradiated based on a three-dimensional position of the marker and a respiratory phase of the patient.   The therapeutic radiation irradiation determination unit is in an ambush area where the three-dimensional position of the marker calculated by the marker position calculation unit is set within a predetermined allowable range from the planned position of the marker, and When the respiratory phase evaluated by the respiratory phase evaluation unit is in an ambush respiratory phase set within a predetermined allowable range from the respiratory phase at the time of treatment planning, it is determined that the therapeutic radiation may be irradiated. The radiation therapy system according to claim 1. An alignment image acquisition unit that acquires a fluoroscopic image in the same respiratory phase as the treatment plan of the patient among the respiratory phases evaluated by the respiratory phase evaluation unit, as an alignment image for aligning the patient;
The patient alignment part which correct | amends the position of the bed which put the patient so that the marker in the said image for an alignment may correspond with the plan position defined by the said treatment plan. The radiation therapy system described.   When the predetermined respiratory phase evaluated by the respiratory phase evaluation unit does not coincide with the ambush respiratory phase continuously for a predetermined number of times, a baseline shift detection unit that detects that a change has occurred in the respiratory phase is provided. The radiation therapy system according to claim 2.   The radiotherapy system according to claim 4, wherein the baseline shift detection unit is configured to be able to change a coordinate axis serving as a reference for monitoring a temporal change in the three-dimensional position of the marker.   The radiotherapy system according to claim 1, further comprising a treatment plan creation device that creates a treatment plan for the patient based on the respiratory phase evaluated by the respiratory phase evaluation unit.   The respiratory phase evaluation unit associates a three-dimensional position of the marker with the expiratory phase when the marker moves to half of the moving distance that the marker has moved from the previous inspiration phase to the current inspiration phase. The radiation therapy system in any one of 6. A real-time irradiation device capable of controlling the irradiation field of the therapeutic radiation in real time;
In each of a plurality of respiratory phases evaluated by the respiratory phase evaluation unit, the therapeutic radiation irradiation determination unit determines that the therapeutic radiation may be irradiated, and the irradiation of the real-time irradiation device An irradiation instruction signal for instructing the real-time irradiation apparatus to irradiate the therapeutic radiation is output only while the field is in the ambush irradiation area set within a predetermined allowable range from the irradiation field at the time of treatment planning. The radiation treatment system according to claim 1, further comprising: an irradiation control / monitoring device.   When the irradiation time in each respiratory phase is less than or equal to a predetermined time or zero, the irradiation control / monitor device adjusts the movement of the irradiation field so that the output time of the irradiation instruction signal is maximized, or The radiation therapy system according to claim 8, wherein the respiratory phase evaluation unit reevaluates the respiratory phase of the patient. A marker position calculation unit that calculates a three-dimensional position of the marker based on a fluoroscopic image obtained by imaging a marker embedded in the body of a patient;
The three-dimensional position of the marker when the furthest away from the average position of the marker in the respiratory cycle of the patient is associated with the inspiration phase, and the three-dimensional position of the marker when moved by a predetermined distance from the previous inspiration phase A respiratory phase evaluation unit that evaluates the respiratory phase of the patient by associating with the respiratory phase according to the ratio of the predetermined distance to the moving distance the marker has moved from the previous inspiration phase to the current inspiration phase;
A radiotherapy control program that causes a computer to function as a therapeutic radiation irradiation determination unit that determines whether or not therapeutic radiation may be irradiated based on a three-dimensional position of the marker and a respiratory phase of the patient.   The therapeutic radiation irradiation determination unit is in an ambush area where the three-dimensional position of the marker calculated by the marker position calculation unit is set within a predetermined allowable range from the planned position of the marker, and When the respiratory phase evaluated by the respiratory phase evaluation unit is in an ambush respiratory phase set within a predetermined allowable range from the respiratory phase at the time of treatment planning, it is determined that the therapeutic radiation may be irradiated. The radiotherapy control program according to claim 10. An alignment image acquisition unit that acquires a fluoroscopic image in the same respiratory phase as the treatment plan of the patient among the respiratory phases evaluated by the respiratory phase evaluation unit, as an alignment image for aligning the patient;
The computer functions as a patient alignment unit that corrects the position of the bed on which the patient is placed so that the marker in the alignment image matches the planned position determined in the treatment plan. The radiotherapy control program according to claim 11.   If the predetermined respiratory phase evaluated by the respiratory phase evaluation unit does not coincide with the ambush respiratory phase continuously for a predetermined number of times, the computer functions as a baseline shift detection unit that detects that the respiratory phase has changed. The radiotherapy control program according to claim 11.   The radiotherapy control program according to claim 13, wherein the baseline shift detection unit is configured to be able to change a coordinate axis serving as a reference for monitoring a temporal change in a three-dimensional position of the marker.   The radiotherapy control program according to any one of claims 10 to 14, which causes a computer to function as a treatment plan creation device that creates a treatment plan for the patient based on the respiratory phase evaluated by the respiratory phase evaluation unit. .   The respiration phase evaluation unit associates the three-dimensional position of the marker with the expiratory phase when the marker moves to half of the movement distance from which the marker moved from the previous inspiration phase to the current inspiration phase. The radiotherapy control program according to any one of 15. A real-time irradiation device capable of controlling the irradiation field of the therapeutic radiation in real time;
In each of a plurality of respiratory phases evaluated by the respiratory phase evaluation unit, the therapeutic radiation irradiation determination unit determines that the therapeutic radiation may be irradiated, and the irradiation of the real-time irradiation device Only when the field is in the ambush irradiation area specified in the treatment plan, the computer is used as an irradiation control / monitoring device that outputs an irradiation instruction signal instructing the real-time irradiation device to emit the therapeutic radiation. The radiotherapy control program according to any one of claims 10 to 16, which is caused to function.   When the irradiation time in each respiratory phase is less than or equal to a predetermined time or zero, the irradiation control / monitor device adjusts the movement of the irradiation field so that the output time of the irradiation instruction signal is maximized, or The radiotherapy control program according to claim 17, wherein the respiratory phase evaluation unit reevaluates the respiratory phase of the patient.

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