JP5276575B2 - Radiotherapy interference check device and radiotherapy interference check method - Google Patents

Description

  The present invention relates to a radiotherapy apparatus and a particle beam therapy apparatus for cancer treatment, and more particularly to a radiotherapy interference check apparatus for confirming interference between therapy apparatuses or between a therapy apparatus and a patient.

  In conventional radiotherapy and particle beam therapy, prediction of interference between treatment apparatuses or between a treatment apparatus and a patient is performed based on past reference data and empirical rules at the time of treatment planning. Therefore, in some cases, interference may be found at the time of treatment. In that case, treatment was interrupted and the treatment plan was re-executed. For this reason, there is a problem that the start of treatment for the patient is delayed, rework of the treatment plan work occurs, and further, the compensation filter created for each treatment plan is wasted.

Patent Document 1 discloses an irradiation planning apparatus that checks in advance physical interference between a radiation therapy apparatus, a treatment bed, and a patient at the time of irradiation planning, regardless of past reference data and empirical rules. It has been proposed that this irradiation planning apparatus simulates the presence or absence of interference using CT (Computed Tomography) images taken for treatment planning or patient contour information obtained using other radiation sources.

JP 2006-174485 A

  This prior art is effective when the treatment radiation source device is relatively small and the presence or absence of interference can be sufficiently determined within the range of the contour image obtained from a CT image taken for treatment planning or other radiation sources. I can expect. However, when the therapeutic radiation source device is large, such as a particle beam therapy device, there is a possibility that it interferes with the patient and the treatment device outside the range taken by the CT image for treatment planning and other radiation sources. The accuracy of the check simulation is not sufficient. In addition, it is not preferable to take a patient image with a CT apparatus or other radiation source in a wide enough range necessary for the presence / absence of interference because it increases the exposure dose to the patient. Not right.

  An object of the present invention is to improve the accuracy of an interference check simulation.

  Based on a patient 3D model imaging unit that generates a patient 3D model in which an optical image obtained by imaging a patient with an optical stereo camera and a CT image used for a radiation therapy treatment plan are associated with each other, and the patient 3D model and the 3D model of the treatment apparatus And an interference check simulation unit for checking the presence or absence of physical interference.

  The radiotherapy interference check apparatus according to the present invention generates a patient 3D (three-dimensional) model associated with a CT image used for a treatment plan from an optical image, and therefore performs interference simulation using the patient 3D model with high accuracy. Can do.

It is a block diagram of the radiotherapy interference check apparatus of this invention. It is a screen image figure of the radiotherapy interference check apparatus of FIG. It is a figure explaining the patient 3D model imaging | photography part of FIG. It is a front view explaining the imaging | photography method of the patient 3D model imaging | photography part of FIG. It is a top view explaining the imaging | photography method of the patient 3D model imaging | photography part of FIG. It is a figure which shows the interference check flow of Embodiment 1 of this invention. It is a figure explaining the function of the radiotherapy interference check apparatus in Embodiment 2 of this invention. 10 is a 3D view screen of the radiotherapy interference check apparatus according to the second embodiment. It is a figure explaining the function of the radiotherapy interference check apparatus in Embodiment 3 of this invention. It is a figure explaining the function of the radiotherapy interference check apparatus in Embodiment 4 of this invention. It is a figure explaining the function of the radiotherapy interference check apparatus in Embodiment 5 of this invention.

Embodiment 1 FIG.
FIG. 1 is a block diagram of a radiotherapy interference check apparatus according to Embodiment 1 of the present invention. The radiotherapy interference check device 1 includes an interference check simulation unit 2, a treatment device 3D model database 3, a patient 3D model database 4, and a patient 3D model imaging unit 5. The interference check simulation unit 2 includes a computer and software. The treatment device 3D model database 3 stores a treatment device 3D model that is a 3D model of all treatment devices necessary for the interference check for each treatment room. The patient 3D model database 4 stores a patient 3D model that is a 3D model of the patient. The patient 3D model imaging unit 5 has a function of imaging the patient 3D model, and stores the patient 3D model in the patient 3D model database 4 after imaging of the patient and creation of the patient 3D model. The treatment planning apparatus 10 devises several treatment plans such as irradiation conditions based on the three-dimensional data of the affected area that is an irradiation target, and simulates particle beam treatment. Based on the treatment plan generated by the treatment planning device 10, the interference check simulation unit 2 performs a treatment device 3D model stored in the treatment device 3D model database 3 and a patient 3D model stored in the patient 3D model database 4. Simulate interference check.

  FIG. 2 is a screen image diagram of the radiotherapy interference check apparatus. The screen of the radiotherapy interference check apparatus 1 includes a 3D model display unit 20, an operation menu unit 18, and a position setting unit 19. The 3D model display unit 20 includes a rotating gantry 11 of the treatment apparatus 3D model, an irradiation nozzle 12, a treatment table top plate 13, and a treatment table lower part 14, and a patient 3D model 15 on the treatment table top plate 13. Is placed.

  The rotating gantry 11 can be rotated 360 degrees to change the irradiation angle. The irradiation nozzle 12 emits a particle beam from the lowermost part during treatment. The treatment table lower part 14 supports the treatment table top plate 13. An arrow 16 represents the shortest distance between the irradiation nozzle 12, the treatment table top plate 13, the treatment table lower part 14, and the patient 3D model 15. A dotted line 17 is an air gap, and represents a distance between the lowermost center of the irradiation nozzle 12 and the body surface of the patient 3D model 15 on a straight line from the lowermost center of the irradiation nozzle 12 toward the center of the rotating gantry 11. The operation menu unit 18 displays the execution control of the interference check simulation and the shortest distance and the air gap as the execution result. The position setting unit 19 is an input unit that sets the position of the patient model, and inputs the treatment isocenter coordinates calculated by the treatment planning apparatus and the patient direction, so that the treatment position where the patient 3D model 15 is planned by the treatment planning apparatus 10 is input. Set to.

  FIG. 3 is a diagram illustrating a patient 3D model imaging unit of the radiotherapy interference check apparatus. The patient 3D model photographing unit 5 photographs an optical image of the patient 24 fixed to the CT bed 25 in the CT room by the optical stereo camera 23. The CT origin 22 is the center of the CT gantry 21. The CT image origin 26 is a point where the patient 24 enters the CT gantry 21 and becomes the CT image origin at the time of CT imaging. The model reference coordinate point 27 is a reference coordinate point of the imaging region 28 captured by the optical stereo camera 23, and is a reference point of the captured patient 3D model 15.

  The optical stereo camera 23 performs calibration according to the coordinate system of the CT apparatus (CT gantry 21). The variable distance L1 represents the difference between the CT origin 22 and the CT image origin 26. The fixed distance L0 represents the difference between the CT origin 22 and the model reference coordinate point 27. The variable distance L2 represents a reference point between the CT image origin 26 and the model reference coordinate point 27. Here, the coordinates of the CT origin 22, the CT image origin 26, and the model reference coordinate point 27 are the same for the X coordinate and the Z coordinate, and only the Y coordinate is different.

  FIG. 4 is a front view for explaining a photographing method of the patient 3D model photographing unit, and FIG. 5 is a top view for explaining a photographing method of the patient 3D model photographing unit. In the optical stereo camera 23, two lenses are incorporated in one housing, and the two lenses are in a predetermined fixed distance, so that a three-dimensional measurement of an object to be photographed is possible by the principle of triangulation. It will be. Since a single camera has many blind spots, a configuration in which two optical stereo cameras 23a and 23b (four lenses) are used to photograph from the upper left and right of the patient 24 fixed to the CT bed 25 is suitable. . Thereby, blind spots can be reduced and sufficient images can be taken. In order to secure the field of view of the optical stereo camera 23, the distance between the optical stereo camera 23 and the patient 24 is about 2 m. As a result, a range of about 1000 mm (height direction of patient, Y direction) can be photographed. The angle θ between the CT bed normal 60 and the camera normal 61a of the optical stereo camera 23a and the angle θ between the CT bed normal 60 and the camera normal 61b of the optical stereo camera 23b are about 35 degrees. A random dot pattern is projected onto the object to be photographed in order to increase the photographing accuracy. It is appropriate to use visible light or infrared light as the light source. In the case of a patient who feels dazzling with visible light, taking an infrared image is an effective option.

  FIG. 6 is a diagram showing an interference check flow using the radiotherapy interference check apparatus. Step S001 is a patient 3D model creation phase by the patient 3D model photographing unit 5, and includes steps S002 to S006. Step S011 is a treatment planning process by the treatment planning apparatus 10, and includes steps S012 to S014. Step S021 is a phase of the interference check simulation by the interference check simulation unit 2, and includes steps S022 to S027. The operation will be described below.

  Before performing the radiotherapy apparatus or particle beam therapy treatment planning operation step S011, a CT image used for the therapy planning is taken. When this CT image is captured, the patient 3D model imaging unit 5 captures the patient and creates a patient 3D model 15. The procedure is as follows. After the treatment planning CT imaging, the patient is placed on the CT bed 25 and moved to the imaging range of the optical stereo camera 23 to be fixed (step S002). Since it is assumed that the treatment isocenter that will bring the treatment radiation source device close to each other during the treatment is near the CT image origin 26, the position that becomes the CT image origin 26 is moved to the vicinity of the center of the imaging range of the optical stereo camera. Since the position that becomes the CT image origin 26 differs for each patient, the moving distance at this time is the variable distance L1.

Next, the patient 24 on the CT bed 25 is imaged using the optical stereo camera 23 (step S003). Photographing is performed by the photographing method shown in FIGS. The CT bed movement amount of the CT bed 25 and the patient direction of the patient 24, which are information at the time of imaging, are input as attribute information of the captured image (step S004).

  A patient 3D model is generated with the reference coordinate point 27 of the imaging region 28 imaged by the optical stereo camera 23 as the initial origin (step S005). Here, the fixed distance L0 is a fixed distance depending on the installation relationship between the optical stereo camera 23 and the CT gantry 21, and the variable distance L1 can be measured by the CT apparatus when the CT bed 25 moves, so that the variable distance L2 is L0−. L1 can be calculated. By performing the process of moving the origin position by the variable distance L2 from the initial origin 27 of the patient model, the patient 3D model 15 having the CT image origin 26 as the origin can be obtained. A detailed description of the patient 3D model 15 will be described later. The patient direction is also stored as a photographing attribute when the patient 3D model is stored. In the interference check simulation described later, it is necessary to install the patient 24 in the simulation space in accordance with the treatment plan calculated by the treatment planning device 10. The coordinate calculation in the treatment planning apparatus 10 is based on the coordinate system of the CT image. Since the patient 3D model 15 can have the CT image origin information by the method described above, the patient is photographed by the optical stereo camera 23 that does not have a direct coordinate relationship with the CT apparatus, and the patient 3D model 15 is created from the photographed optical image. The patient 3D model 15 can be used for interference check simulation. The patient 3D model 15 created in step S005 is stored in the patient 3D model database 4 (step S006).

  Here, the patient 3D model 15 will be described. The patient 3D model 15 has a set of polygon data representing the body surface and attribute information. Only the body surface information of the patient 3D model 15 is sufficient for interference check purposes. Specifically, the polygon data of the patient 3D model 15 uses a format called STL (Standard Triangulated Language), and each polygon (triangle) is represented by vertex coordinates (X, Y, Z) and its normal vector. The patient 3D model 15 includes, as attribute information, patient ID, patient name, photographing date and time, comments at the time of photographing, positional relationship between the CT bed 25 and the patient 24 at the time of photographing, CT bed position at the time of photographing (position in the CT room), and the like. Have.

  The polygon data of the patient 3D model 15 is generated as follows. First, an image is captured by the optical stereo camera 23 to obtain point cloud information of the object to be imaged (patient 24). At this time, the object to be imaged is a set of many points (X, Y, Z). Polygon data is generated by applying a polygon (triangle) to the set of points. Thus, the body surface information of the patient 24 is configured in the patient 3D model 15. The operator inputs the patient ID, patient name, photographing date / time, and photographing comment in the attribute information of the patient 3D model 15 while viewing the operation screen. The positional relationship between the CT bed 25 and the patient 24 at the time of imaging and the CT bed position (position in the CT room) at the time of imaging can be measured and input by the operator, but can also be measured by the CT apparatus as described above. It is.

  Next, the treatment plan shown in step S011 is performed. In step S012, a treatment plan is started. In step S013, treatment isocenter coordinates and patient directions are calculated. In step S013, the irradiation angle and the air gap are calculated.

  Next, an interference check simulation by the interference check simulation unit 2 shown in step S021 is performed. In the particle beam therapy interference check device, the interference check simulation unit (function) 2 is activated, and steps S022 to S027 are performed. When the interference check simulation unit (function) 2 is activated, by specifying the treatment room and patient ID, for the treatment room, all the treatment device 3D models corresponding to the treatment room designated from the treatment device 3D model database 3 are selected. Take out and place in interference check simulation space. Similarly, for the patient 3D model 15, the model of the designated patient ID is extracted from the patient 3D model database 4 and placed in the interference check simulation space.

  Next, among the data calculated in the treatment plan, the coordinates of the treatment isocenter and the patient direction are input to the position setting unit 19 of the radiotherapy interference check apparatus 1 (step S022). Since the coordinates of the treatment isocenter are calculated as the distance from the CT image origin 26 by the treatment planning apparatus 10, the patient 3D is moved in the simulation space by moving the distance from the origin of the patient 3D model 15 that is the CT image origin 26. The treatment isocenter of the model 15 can be made to coincide with the space center of the treatment room as the particle beam irradiation position. Similarly, the patient direction is set in the simulation space using the patient direction information stored when the patient 3D model imaging unit (function) 5 captures the image.

  Next, it inputs into the operation menu part 18 of the radiotherapy interference check apparatus 1 as an interference check condition (step S023). The input condition is a value that specifies the position of each 3D model, such as a gantry angle, a nozzle distance, and a rotation of a treatment table. After inputting the conditions, each 3D model moves to the designated position.

  Next, the operation menu unit 18 of the radiotherapy interference check apparatus 1 is operated to execute an interference check (step S024). In the simulation space of the radiotherapy interference check apparatus 1, the irradiation nozzle 12 gradually extends toward the patient 3D model 15 of the patient 24. At that time, the shortest distance 16 and the air gap 17 between the irradiation nozzle 12, the patient 3D model 15 and the treatment table (treatment table top plate 13, treatment table lower part 14) are highlighted in real time (see FIG. 2). At the same time, the air gap and the shortest distance are displayed as numerical values in the upper part of the operation menu section 18 on the right side of the screen. When the nozzle distance specified by the condition input is extended, the irradiation nozzle 12 stops. If interference occurs until the nozzle distance is reached, the irradiation nozzle 12 stops at that point, and the occurrence of interference is displayed in the result display column of the operation menu section 18.

  In step S025, it is determined whether interference has occurred, and when it is found that interference occurs when the irradiation nozzle 12 is extended by the nozzle distance designed in the treatment plan, the interference is displayed in the result display column of the operation menu unit 18. The air gap at the time of interference occurrence is confirmed (step S026), and the treatment plan is corrected by returning to step S014 with reference to the air gap at the time of interference occurrence.

  In step S025, it is determined whether interference has occurred. If it is found that interference does not occur when the irradiation nozzle 12 is extended by the nozzle distance established in the treatment plan, it is determined whether the air gap is an appropriate air gap. (Step S027) If appropriate, the interference check simulation is terminated. In this case, there is no revision of the treatment plan. On the other hand, if it is determined that the condition is not appropriate, condition input is performed again using the operation menu unit 18, and an appropriate air gap is confirmed by simulation (step S026). Then, the process returns to step S014 to correct the treatment plan. .

  Since the radiotherapy interference check apparatus 1 according to the first embodiment generates a wide range of patient 3D models 15 associated with CT images used for treatment planning from optical images, interference simulation using the patient 3D model 15 can be performed with high accuracy. It can be carried out.

  The radiotherapy interference check apparatus 1 according to the first embodiment can obtain an accurate patient 3D model 15 in a necessary and sufficient range to be used for the interference check simulation. Whether or not interference occurs when treatment is performed in the room can be accurately confirmed by 3D simulation. Further, the positional relationship between the treatment apparatus and the patient 24 in which interference does not occur can be fed back to the treatment plan as necessary, and the completeness of the treatment plan can be increased. Since these can be determined at the time of preparation of a treatment plan before actual treatment is started, treatment of the patient 24 can be started as planned as compared to the case where interference occurs at the time of treatment. There are effects that rework to be performed can be reduced and that the compensation filter created based on the treatment plan is not wasted.

  As described above, according to the radiotherapy interference check apparatus 1 of the first embodiment, the patient 3D model 15 in which the optical image obtained by imaging the patient 24 with the optical stereo camera 23 and the CT image used for the radiotherapy treatment plan are associated with each other. The patient 3D model photographing unit 5 for generating the signal and the interference check simulation unit 2 for checking the presence or absence of physical interference based on the patient 3D model 15 and the 3D model of the treatment apparatus are used. Therefore, the patient 3D model 15 is used. Interference simulation can be performed with high accuracy.

Embodiment 2. FIG.
FIG. 7 is a diagram illustrating the function of the radiotherapy interference check apparatus according to the second embodiment of the present invention. This embodiment is different from the first embodiment in that a “noise removal function (function unit)” is added to the interference check simulation unit (function) 2 of the radiotherapy interference check apparatus 1. By adding the “noise removal function (function unit)”, it is possible to remove noise included in the patient 3D model, thereby further improving the accuracy of the interference check. This will be described below.

  FIG. 7A is a diagram illustrating a state where noise is generated in the patient 3D model generated from the optical image, and FIG. 7B is a diagram illustrating the patient 3D model after noise removal. Reference numeral 31 denotes a patient 3D model before noise removal, and reference numeral 35 denotes a patient 3D model after noise removal. The noise 32 is noise near the abdominal side where the vertex is shared with the polygon on the body surface of the patient 3D model 31, and the noise 33 is noise near the abdominal side where the vertex is not shared with the polygon on the body surface of the patient 3D model 31. . Noises 32 and 33 are noises included in the point cloud data when the optical stereo camera 23 is used for photographing. Noise that has been included when the point cloud data is acquired is subjected to a certain degree of noise removal before surface processing (polygonization). However, if the noise cannot be completely removed, the surface is treated near the surface of the body, and some unevenness and protrusions may occur near the body surface. .

  When performing an interference check simulation in which the irradiation nozzle 12 is brought close to the vicinity of the noises 32 and 33, the interference check accuracy decreases due to the influence of noise included in the patient 3D model 31. Therefore, as shown in FIG. 7A, the designated noise is deleted by designating the noise range designation 34. In the case of the noise 32 having the vertex shared by the polygon set, as shown in FIG. 8, the 3D view screen 41 of the radiotherapy interference check apparatus 1 is opened and the 3D view screen 41 is used for manual deletion. The noise range designation 36 is designated and deleted. FIG. 8 is a diagram showing a 3D view screen of the radiotherapy interference check apparatus. The noise range designation 36 is designated by, for example, the designated vertex P and the lengths m1, m2, and m3 in the three orthogonal directions from the designated vertex P. The noise removal function is performed before the check execution (see FIG. 2) of the operation menu unit 18 is operated as a step S024.

  If the noise to be deleted is data separated from the patient 3D model 31, that is, noise 33 that does not share a vertex in a polygon set, it can be automatically deleted using that condition.

  The noise removal function in the interference check simulation unit (function) 2 according to the second embodiment uses the 3D view screen 41 of the interference check simulation unit (function) 2 for noise that could not be automatically removed during imaging of the patient 3D model. Thus, the accurate range of the patient 3D model 35 can be obtained by manually or automatically deleting the range determined as noise. Since an accurate patient 3D model 35 can be obtained, the accuracy of the interference check simulation is further improved.

Embodiment 3 FIG.
FIG. 9 is a diagram for explaining the function of the radiotherapy interference check apparatus according to the third embodiment of the present invention. The difference from Embodiments 1 and 2 is that a “body surface complementing function (function unit)” is added to the interference check simulation unit (function) 2 of the radiotherapy interference check apparatus 1. By adding the “body surface complementing function (functional unit)”, the missing body surface included in the patient 3D model can be complemented, so that the interference check accuracy can be further improved. This will be described below.

  FIG. 9A is a diagram illustrating a state in which a missing portion is generated in the patient 3D model generated from the optical image, and FIG. 9B is a diagram illustrating the patient 3D model after complementing the missing portion. 42 is an example of a patient 3D model in which a missing body surface (missing part) 43 is present on the side of the abdomen, and 44 is an example of a patient 3D model after complementing the missing part. As a drawback of imaging the patient 24 with an optical camera including the optical stereo camera 23, there are cases where point cloud data cannot be acquired depending on imaging conditions. It is a part that specularly reflects and a part that strongly absorbs light. For example, when specular reflection occurs in a part of the fixture that fixes the patient 24, strong light returns in one direction, and therefore the lens flare phenomenon occurs in the optical stereo camera 23. The body surface may be lost due to failure. On the contrary, when light is strongly absorbed, most of the light does not return to the optical stereo camera 23, so that the three-dimensional measurement cannot be performed at that portion, and the body surface may be lost.

  The body surface complementation function is performed before the check execution (see FIG. 2) of the operation menu unit 18 is operated as the process of step S024. By manually selecting the missing portion 43 on the 3D view screen 41 shown in the second embodiment, a patient 3D model 44 to which a body surface 45 that complements the missing portion 43 is added can be obtained.

Embodiment 4 FIG.
FIG. 10 is a diagram illustrating the function of the radiotherapy interference check apparatus according to Embodiment 3 of the present invention. This embodiment is different from the first to third embodiments in that an interference check simulation is executed with a patient 3D model corrected by contour information of a CT image. It has an image fusion function (function unit) for image fusion that corrects the patient 3D model based on the contour information of the CT image. The patient 3D model corrected by the contour information of the CT image can obtain an optical image and a contour image of the CT image by image fusion. By correcting the patient 3D model based on the contour information of the CT image, a patient 3D model with improved accuracy can be obtained, and as a result, the accuracy of the interference check simulation can be further improved. This will be described below.

  FIG. 10A is a diagram showing an imaging range of a CT image of the patient 24, and FIG. 10B is a diagram showing an outline of image fusion. An imaging range 46 of the CT image is between an upper cut surface 47 including the upper limit contour information 49 of the CT image and a lower cut surface 48 including the lower limit contour information 50 of the CT image. The contour 52 (patient 3D model 63) of the optical image photographed by the optical stereo camera 23 and the contour 53 of the CT image corresponding to the contour 52 portion of the optical image are overlapped to obtain a double contour 55. The contour 52 of the optical image is converged so as to approach the contour 53 of the CT image to obtain the contour 54 (patient 3D model 62) of the optical image after image fusion. By performing image fusion on the imaging range 46 of the CT image, it is possible to obtain the patient 3D model 62 that has been corrected by the contour information of the CT image.

  The contour information of the CT image is considered to be more accurate than the contour information of the optical image. The body surface shape (contour) photographed by the optical stereo camera 23 is corrected in accordance with the contour information of the CT image. While maintaining the body surface shape (contour) photographed by the optical stereo camera 23 to some extent, a process for converging so that the body surface shape (contour) is closest to the contour of the CT image as a whole is performed. Specifically, convergence processing is performed by changing each vertex information of STL data (polygon data).

Image fusion is performed before operating the check execution (see FIG. 2) of the operation menu unit 18 as a step S024. The image fusion screen on which the contour 52 of the optical image and the contour 53 of the CT image in FIG. 10A and FIG. 10B are displayed is opened, and image fusion is executed. When the image fusion screen opens, the patient's CT image is read from the CT image database. Since the patient 3D model is based on the coordinate system of the CT image, by performing an image fusion operation, the radiotherapy interference check apparatus 1 causes the patient's height direction of the upper limit contour information 49 and the lower limit contour information 50 of the CT image. The imaging range 46 of the CT image is set from the Y coordinate in the (Y direction), each vertex information of the STL data (polygon data) of the patient 3D model 63 is changed, and a convergence process is performed.

  The radiotherapy interference check apparatus 1 according to the fourth embodiment can obtain the patient 3D model 62 with improved accuracy by correcting the patient 3D model 63 based on the contour information of the CT image using image fusion. The accuracy of the interference check simulation can be further improved.

Embodiment 5 FIG.
FIG. 11 is a diagram for explaining the function of the radiotherapy interference check apparatus according to the fifth embodiment of the present invention. The patient 3D model 15 is different from the first to fourth embodiments in that it has a positional relationship between the CT image origin 26 and the CT bed 25 as attribute information. The positional relationship between the patient 3D model 15 and the treatment table 13 (see FIG. 2) at the time of the interference check simulation can be accurately reproduced as the relationship between the patient 24 and the CT bed 25 at the time of optical image capturing. Since the relationship between the patient 24 and the CT bed 25 is accurately reproduced in the interference check simulation, the interference simulation for performing treatment with this positional relationship can be performed with higher accuracy.

  In the interference check simulation, the initial position of the patient 3D model 15 is set based on the positional relationship between the CT bed 25 and the patient 24 at the time of imaging, which is the attribute information of the patient 3D model 15, and the CT bed position (position in the CT room) at the time of imaging. . As shown in FIG. 11, when the CT image origin 26 of the patient 24 is laterally displaced from the center line 57 of the CT bed 25, the positional relationship between the CT image origin 26 and the CT bed 25 is determined based on both ends of the CT bed. The distance from the markers 58 and 59 is automatically measured by the optical stereo camera 23. Since the CT image origin 26 is on the center line 56 of the CT gantry 21, the coordinates of the CT image origin 26 and the markers 58 and 59 are obtained by obtaining the coordinates of the markers 58 and 59 in the short direction (X direction) of the CT bed. You can get a relationship. Since the optical stereo camera 23 performs calibration in accordance with the coordinate system of the CT apparatus (CT gantry 21), the markers 58 and 59 are measured three-dimensionally, so that the CT 58 of the markers 58 and 59 in the short direction (X direction) of the CT bed. Coordinates can be obtained. The patient 3D model 15 has a positional relationship between the CT image origin 26 and the CT bed 25 as attribute information.

  The radiotherapy interference check apparatus according to the present invention can suitably perform interference confirmation between therapy apparatuses or between a therapy apparatus and a patient when using a radiotherapy apparatus or a particle beam therapy apparatus.

DESCRIPTION OF SYMBOLS 1 Radiotherapy interference check apparatus 2 Interference check simulation part 5 Patient 3D model imaging | photography part 15 Patient 3D model 23 Optical stereo camera 23a Optical stereo camera 23b Optical stereo camera 24 Patient 25 CT bed 26 CT image origin 34 Noise range designation 35 Patient 3D model (After noise removal)
36 Noise range specification 44 Patient 3D model (after missing part compensation) 62 Patient 3D model (after image fusion)

Claims (10)

A radiotherapy interference check device for checking the presence or absence of physical interference between a treatment device and a patient or other treatment device by a simulation before radiation treatment,
A patient 3D model imaging unit for generating a patient 3D model in which an optical image obtained by imaging the patient with an optical stereo camera and a CT image used for the radiation therapy treatment plan are associated; and the patient 3D model and the 3D of the treatment apparatus A radiotherapy interference check apparatus comprising: an interference check simulation unit that checks the presence or absence of physical interference based on a model.   The radiotherapy interference check apparatus according to claim 1, wherein the origin of the patient 3D model is the CT image origin of the CT image.   The radiotherapy interference check apparatus according to claim 1, wherein the optical image in the patient 3D model is obtained by photographing the patient from a plurality of directions by the optical stereo camera.   The said interference check simulation part has a noise removal function part which removes the noise of the body surface vicinity in the patient 3D model produced | generated by the said patient 3D model imaging | photography part, The Claim 1 thru | or 3 characterized by the above-mentioned. The radiotherapy interference check apparatus as described.   The radiotherapy interference check apparatus according to claim 4, wherein the noise removal function unit deletes the noise designated by a noise range designated on a screen.   The said interference check simulation part has a body surface complementation function part which complements the missing body surface in the patient 3D model produced | generated by the said patient 3D model imaging | photography part, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The radiotherapy interference check apparatus as described.   The radiotherapy interference check apparatus according to claim 6, wherein the body surface complementation function unit complements the missing body surface with a complementation range designated on a screen.   The said interference check simulation part has an image fusion function part which corrects the patient 3D model produced | generated by the said patient 3D model imaging | photography part based on the outline information of the said CT image, The one of Claims 1 thru | or 7 characterized by the above-mentioned. The radiotherapy interference check apparatus according to item 1.   9. The patient 3D model according to claim 1, wherein the patient 3D model has a positional relationship between a CT image origin of the CT image and a table on which the patient is fixed when the optical image is captured. The radiotherapy interference check apparatus as described. A radiotherapy interference check method for checking the presence or absence of physical interference between a treatment device and a patient or other treatment device before radiation treatment,
A procedure for generating an optical image by photographing the patient with an optical stereo camera, generating a patient 3D model in which the optical image is associated with a CT image used for the treatment plan of the radiation therapy, the patient 3D model, and the A radiotherapy interference check method comprising: checking for the presence of physical interference based on a 3D model of the treatment device.

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