A simulation phantom

Abstract

The present invention discloses a simulation phantom, which relates to the technical field of radiotherapy and can solve the problems of increased cost, inconvenient storage and arrangement in the related art due to the fact that the simulation phantom can only be imaged on one imaging device alone. The simulation phantom includes a simulated target area and simulated normal tissues covering the simulated target area. Among them, the area of the simulated target area and the simulated normal tissues that is adjacent to the simulated target area has a first characteristic for imaging the simulation phantom on a first imaging device, and the area of the simulated target area and the simulated normal tissues that is adjacent to the simulated target area also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device. The present invention is used to replace a patient for simulation before the patient's treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of radiotherapy, and in particular, to a simulation phantom. Background Art

[0002] Radiotherapy, abbreviated as RT, is a treatment method that uses high-energy rays (such as X-rays, γ-rays) or high-energy particles (such as protons, heavy ions) to irradiate tumors, thereby killing cancer cells. In order to ensure the accuracy of radiotherapy, it is necessary to use a phantom to replace the patient to simulate the entire radiotherapy process before the patient's treatment, so as to verify the accuracy of the treatment plan or radiotherapy equipment.

[0003] During this simulation process, it is necessary to image the simulation phantom. However, the simulation phantom in the related art can only be imaged on one imaging device alone. In order to meet different requirements, it is necessary to separately prepare multiple phantoms for imaging on different imaging devices. In this way, on the one hand, the cost increases, and on the other hand, it is not convenient for storage and arrangement. Summary of the Invention

[0004] Embodiments of the present invention provide a simulation phantom, which can solve the problems of increased cost, inconvenient storage and arrangement caused by the simulation phantom in the related art that can only be imaged on one imaging device alone.

[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0006] A simulation phantom, the simulation phantom includes a simulated target area and a simulated normal tissue covering the simulated target area. Among them, the area of the simulated target area and the simulated normal tissue that is in contact with the simulated target area has a first characteristic for imaging the simulation phantom on a first imaging device, and the area of the simulated target area and the simulated normal tissue that is in contact with the simulated target area also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device.

[0007] The simulation phantom provided by the embodiments of the present invention, because the area of the simulated target area and the simulated normal tissue that is in contact with the simulated target area has a first characteristic for imaging the simulation phantom on a first imaging device, and the area of the simulated target area and the simulated normal tissue that is in contact with the simulated target area also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device, that is, the simulation phantom can be imaged on at least two different imaging devices, so the number of simulation phantoms to be prepared can be reduced, thereby reducing the cost on the one hand and facilitating storage and arrangement on the other hand. Brief Description of the Drawings

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0009] Figure 1 Schematic diagram when the first body and the second body of the simulation phantom in the embodiment of the present invention are disassembled;

[0010] Figure 2 Schematic diagram when the box of the simulation phantom in the embodiment of the present invention is opened;

[0011] Figure 3 Schematic diagram when the first body and the second body of the simulation phantom in the embodiment of the present invention are disassembled and the box is taken out;

[0012] Figure 4 Overall schematic diagram of the simulation phantom in the embodiment of the present invention;

[0013] Figure 5 Another angle of the overall schematic diagram of the simulation phantom in the embodiment of the present invention;

[0014] Figure 6 Schematic diagram of the marking points in the simulation phantom in the embodiment of the present invention;

[0015] Figure 7 Schematic diagram of the specific position of the box in the simulation phantom in the embodiment of the present invention;

[0016] Figure 8 Schematic diagram of the position to be avoided by the box in the simulation phantom in the embodiment of the present invention. Detailed implementation manner

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0018] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0019] The terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0020] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Figures 1 to 3 This is a specific embodiment of the simulation phantom of the embodiment of the present invention. The simulation phantom in this embodiment includes a simulated target area 3 and a simulated normal tissue 100 covering the simulated target area 3. Among them, the simulated normal tissue 100 can be soft tissue, can be bone, or can be soft tissue and bone. The area of the simulated target area 3 and the simulated normal tissue 100 that is in contact with the simulated target area 3 has a first characteristic for imaging the simulation phantom on a first imaging device. The area of the simulated target area 3 and the simulated normal tissue 100 that is in contact with the simulated target area 3 also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device.

[0022] For the simulation phantom provided by the embodiment of the present invention, since the area of the simulated target area 3 and the simulated normal tissue 100 that is in contact with the simulated target area 3 has a first characteristic for imaging the simulation phantom on a first imaging device, and the area of the simulated target area 3 and the simulated normal tissue 100 that is in contact with the simulated target area 3 also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device, that is, the simulation phantom can be imaged on at least two different imaging devices. Therefore, the number of simulation phantoms to be prepared can be reduced, thereby reducing the cost on the one hand and facilitating storage and arrangement on the other hand.

[0023] Any of the above first imaging device and second imaging device can be a CT imaging device, a nuclear magnetic imaging device, an ultrasonic imaging device or any other imaging device, as long as the first imaging device and the second imaging device are different. For example, the first characteristic can be different CT values, that is, the regions of the simulated target area 3 and the simulated normal tissue 100 adjacent to the simulated target area 3 have different CT values. At this time, the simulation phantom can be imaged on a CT imaging device, that is, the first imaging device is a CT imaging device; the second characteristic can be different hydrogen densities, that is, the regions of the simulated target area 3 and the simulated normal tissue 100 adjacent to the simulated target area 3 have different hydrogen densities (at this time, the regions of the simulated target area 3 and the simulated normal tissue 100 adjacent to the simulated target area 3 need to be made of hydrogen-containing materials, such as polymethyl methacrylate, acrylic acid, agarose gel, etc.). At this time, the simulation phantom can be imaged on a nuclear magnetic imaging device, that is, the second imaging device is a nuclear magnetic imaging device; the second characteristic can also be different acoustic impedance and acoustic attenuation characteristics, that is, the regions of the simulated target area 3 and the simulated normal tissue 100 adjacent to the simulated target area 3 have different acoustic impedance and acoustic attenuation characteristics. At this time, the simulation phantom can be imaged on an ultrasonic imaging device, that is, the second imaging device is an ultrasonic imaging device. Of course, the simulation phantom can also be imaged on other imaging devices other than the first imaging device and the second imaging device, for example, it can also be imaged on a third imaging device.

[0024] Further, the simulation phantom further includes a box body 5 for accommodating the simulated target area 3. A box body groove 6 is further provided at a position corresponding to the box body 5 in the simulated normal tissue 100. The box body 5 is fitted and installed in the box body groove 6 and is detachably connected to the box body groove 6. The simulated target area 3 and the box body 5 have the first characteristic and the second characteristic. Thus, a plurality of box bodies 5 with different shapes of simulated target areas 3 can be prepared. When it is necessary to replace the simulated target area 3 with a different shape, the corresponding box body 5 can be selected and installed in the box body groove 6 as needed.

[0025] In order to facilitate the installation of the box body 5 into the box body groove 6 or the removal of the box body 5 from the box body groove 6, in this embodiment, the simulated normal tissue 100 includes a first body 11 and a second body 12 that are detachably connected. By disassembling the first body 11 and the second body 12, the box body 5 can be conveniently placed into the box body groove 6 or removed from the box body groove 6, and then the first body 11 and the second body 12 are connected to make the simulation phantom into an integral structure.

[0026] Preferably, the simulated target area 3 is a sphere, so that it is easier to outline the spherical target area and determine the center of the sphere when making a treatment plan to facilitate the setting of the target point.

[0027] To measure the cumulative error of the radiotherapy device (i.e., to measure the comprehensive positioning accuracy), after imaging the above-mentioned simulation phantom on the first imaging device or the second imaging device and formulating a treatment plan, before performing "radiotherapy" on the simulation phantom, the simulation phantom needs to be positioned. For this purpose, in this embodiment, a plurality of fine marking points 10 are provided on the outer surface of the simulated normal tissue 100. When using a laser lamp for positioning, the treatment couch is controlled to move so that the fine marking points 10 on the outer surface of the simulated normal tissue 100 coincide with the crosshair projected by the laser lamp, and the preliminary positioning of the simulation phantom can be completed.

[0028] Referring to Figures 1 to 5 , the simulation phantom is a head simulation phantom, and the fine marking points 10 include: a first fine marking point 101, a second fine marking point 102, and a third fine marking point 103. The first fine marking point 101 is located on the forehead of the head simulation phantom, and the second fine marking point 102 and the third fine marking point 103 are respectively located at relative positions on both sides of the forehead of the head simulation phantom, and the intersection of the line connecting the second fine marking point 102 and the third fine marking point 103 and the perpendicular line from the first fine marking point 101 to the line coincides with the center of the simulated target area 3; in this embodiment, the use of three fine marking points 10 coinciding with the laser projection crosshair can achieve the positioning of the head simulation phantom. Compared with using more fine marking points 10, the structure of this embodiment is simpler while ensuring the positioning function.

[0029] After the preliminary positioning of the simulation phantom using the laser lamp, the image formed by the imaging device (such as CBCT) can be further registered (i.e., image-guided) with the image formed by the first imaging device or the second imaging device, and the position of the simulation phantom can be adjusted according to the registration result to achieve the precise positioning of the simulation phantom.

[0030] To improve the registration accuracy, as Figure 6 shown, in this embodiment, a plurality of marking points 13 are further provided in the simulated normal tissue 100. The plurality of marking points 13 and the parts in contact with themselves have the first characteristic and / or the second characteristic, so that the plurality of marking points 13 can be imaged on the first imaging device or the second imaging device, and the images formed by the plurality of marking points 13 can be distinguished from the parts in contact with themselves. During the registration process, the plurality of marking points 13 can be combined for registration. Of course, the plurality of marking points 13 can also assist in verifying the accuracy of the registration.

[0031] It should be noted here that the fine marking points 10 and the outer surface of the simulated normal tissue 100 have the first characteristic and / or the second characteristic, so that the images formed by the fine marking points 10 and the outer surface of the simulation phantom on the first imaging device and the second imaging device can be distinguished, and can also assist in verifying the accuracy of the registration.

[0032] The simulation phantom is a head simulation phantom, referring to Figure 6, multiple fiducial points 13 are located within the simulated soft tissue 2 on the forehead of the head phantom. On the one hand, this ensures that the accuracy of registration can be assisted and verified. On the other hand, it avoids having too many fiducial points 13, thus simplifying the structure.

[0033] Furthermore, the multiple fiducial points 13 can be made of rigid materials, such as being made of a material similar to the simulated skull, and the multiple fiducial points 13 can be spheres of different sizes.

[0034] Refer to Figures 1 to 3 , in this embodiment, a film accommodating groove D for accommodating the film is further provided in the box body 5. The deviation between the focal spot formed by the beam on the film and the preset point can be used to verify whether the actual beam of the irradiation device can accurately irradiate the target point, and the comprehensive positioning accuracy can be reflected by the deviation.

[0035] To avoid affecting the positioning accuracy due to inserting the film, the film can be placed in the film accommodating groove D in the box body 5 before positioning.

[0036] More specifically, after being verified by image guidance and the registration result meets the preset conditions, the treatment plan is started to irradiate the target area in the simulated target area. Exemplarily, the film is in the XOY plane, the central axis of the beam is perpendicular to the plane XOY where the film is located. After irradiation, the film is taken out and the position between the focal spot formed on the film and the preset point is analyzed to obtain the deviation between the center of the focal spot and the preset point in the X and Y directions; similarly, when the film is in the YOZ plane and the central axis of the beam is perpendicular to the plane YOZ where the film is located, the deviation between the center of the focal spot and the preset point in the Y and Z directions is obtained; finally, based on the two deviations, the deviation between the center of the focal spot and the preset point in the X, Y, and Z directions can be obtained, so as to verify whether the actual beam can accurately irradiate the target point, and further reflect the cumulative error of the radiotherapy device (i.e., measure the comprehensive positioning accuracy).

[0037] It should be noted here that the preset point is used to indicate the center point of the simulated target area, and after positioning is completed, the preset point coincides with the mechanical center point, etc.

[0038] It should also be noted that the above example of first placing one film in the XOY plane and then placing another film in the YOZ plane is just an example. It is also possible to first place one film in the YOZ plane and then place another film in the XOY plane.

[0039] Refer to Figure 2, the cassette body 5 includes a first cassette body 51 and a second cassette body 52 which are oppositely arranged and detachably connected. A film accommodation groove D is formed between the opposite surfaces (A, B) of the first cassette body 51 and the second cassette body 52, that is, the opposite surfaces (A, B) of the first cassette body 51 and the second cassette body 52 are used to clamp the film. Thus, when verifying whether the actual beam can accurately irradiate the target point, first place a film between the opposite surfaces (A, B) of the first cassette body 51 and the second cassette body 52, and emit the beam for irradiation. After the irradiation is completed, place another film between the opposite surfaces (A, B) of the first cassette body 51 and the second cassette body 52, and rotate the cassette body 5 so that the direction of the second film is different from that of the previous film, and then emit the beam for irradiation; compared with the cassette body 5 of other structures, the space around the film is larger after the cassette body 5 of this embodiment is opened, which is more convenient for the insertion and removal of the film, and the structure of the cassette body 5 is relatively simple and more convenient to process.

[0040] There are various ways to detachably connect the above-mentioned first cassette body 51 and the second cassette body 52. In this embodiment, as an example, the first cassette body 51 and the second cassette body 52 are detachably connected by a positioning pin 7 and a positioning hole 8 that cooperate with each other; referring to Figure 2 , a positioning pin 7 is provided at each corner of the surface A of the first cassette body 51 opposite to the second cassette body 52, and a positioning hole 8 is provided at each corner of the surface B of the second cassette body 52 opposite to the first cassette body 51. The multiple positioning pins 7 and the multiple positioning holes 8 are in one-to-one correspondence and cooperation, so that the first cassette body 51 and the second cassette body 52 can be joined. Compared with other detachable connection methods, the structure of this embodiment is simple and convenient to disassemble; in addition, the distance between one positioning pin 71 and the edge of the first cassette body 51 is different from the distance between other positioning pins 72 and the edge of the first cassette body 51 to facilitate the determination of the film direction.

[0041] In order to more conveniently determine whether the center of the focal spot deviates from the preset point, in this embodiment, a spherical hollow 9 is provided at the center of the simulated target area 3, and the center of the spherical hollow 9 coincides with the center of the simulated target area 3. Thus, after the irradiation is completed, the first cassette body 51 and the second cassette body 52 are disassembled, and whether the center of the focal spot deviates from the center of the spherical hollow 9 can be clearly observed with the film attached to the first cassette body 51 or the second cassette body 52, so as to more conveniently determine whether the center of the focal spot deviates from the preset point.

[0042] Referring to Figure 7 and Figure 8 , the simulation phantom is a head simulation phantom. The cassette body 5 is preferably located at the position between the back of the head and the face of the head simulation phantom, so that less bone information from the orbit to the spine part (as marked by C) can be covered, making the CT image and the MRI image more comprehensive.

[0043] The cassette body 5 is preferably a cuboid or a cube. At this time, the cassette groove 6 in the simulated normal tissue 100 is correspondingly a cuboid or a cube. When the cassette body 5 is rotated to another angle to irradiate the second film, the inner surface of the cassette groove 6 can limit the cassette body 5 at the rotated another angle. Compared with cassette bodies 5 of other shapes (such as cylinders, spheres, etc.), in this embodiment, there is no need to provide a limiting structure for limiting the cassette body 5, thus making the processing of the simulation phantom more convenient.

[0044] Specifically, the simulation phantom can be a head simulation phantom, a head and neck simulation phantom or a body simulation phantom, and the present invention does not limit this.

[0045] In the case where the simulation phantom is a head simulation phantom or a head and neck simulation phantom, the simulated normal tissue 100 includes a simulated skull 1, simulated soft tissue 2 filled in the simulated skull 1, and simulated skin 4 located outside the simulated skull 1. The simulated target area 3 is arranged in the simulated soft tissue 2. The simulated skull 1, the simulated soft tissue 2 and the simulated skin 4 have the first characteristic and / or the second characteristic, so that the images formed by the simulated skull 1, the simulated soft tissue 2 and the simulated skin 4 on the first imaging device and the second imaging device can all be distinguished; different structures in the simulated soft tissue 2 also have the first characteristic and / or the second characteristic, so that the images formed by different structures in the simulated soft tissue 2 on the first imaging device and the second imaging device can all be distinguished. By way of example, different structures in the simulated soft tissue 2 include the brain, the cerebellum, the diencephalon, the brainstem, etc.

[0046] In the case where the simulation phantom is a body simulation phantom, the simulated normal tissue 100 includes the thoracic cavity and the abdominal cavity. Organs such as the heart and lungs are arranged in the thoracic cavity, and organs such as the stomach, liver, gallbladder, spleen, pancreas, and kidneys are arranged in the abdominal cavity.

[0047] In order to simulate the patient more realistically, in this embodiment, the simulation phantom further includes a simulated target area driving device for driving the simulated target area to move along a preset trajectory at a preset frequency. Thus, this simulation phantom can simulate the situation where the tumor target area is located in the patient's lungs, thereby making the simulation of the patient more real.

[0048] Furthermore, in this embodiment, a simulated cavity for simulating the internal cavity of the human body is also arranged in the simulated normal tissue, so that the image formed by the simulation phantom is closer to the real image of the human body. In the case where the simulation phantom is a head simulation phantom or a head and neck simulation phantom, the simulated cavity includes the nasal cavity, the maxillary sinus and the respiratory tract.

[0049] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A simulation phantom, characterized in that, The simulation phantom includes a simulated target area and simulated normal tissues covering the simulated target area. Among them, the area of the simulated normal tissues adjacent to the simulated target area has a first characteristic for imaging the simulation phantom on a first imaging device, and the area of the simulated normal tissues adjacent to the simulated target area also has a second characteristic for imaging the simulation phantom on a second imaging device different from the first imaging device. Among them, the first imaging device is a CT imaging device, and correspondingly, the first characteristic is different CT values; the second imaging device is a nuclear magnetic imaging device, and correspondingly, the second characteristic is different hydrogen densities. The simulation phantom further includes: a box body for accommodating the simulated target area. A box body groove is also provided at a position corresponding to the box body in the simulated normal tissues. The box body is fitted and installed in the box body groove and is detachably connected to the box body groove. The simulated target area and the box body have the first characteristic and the second characteristic. A film accommodating groove is further provided in the box body for accommodating a film. The film is placed in the film accommodating groove of the box body before positioning, and the film is used to verify whether the actual beam of the irradiation device can accurately irradiate the target point through the deviation between the focal spot formed by the beam on the film and the center point of the simulated target area. A spherical hollow is provided at the center of the simulated target area, and the center of the spherical hollow coincides with the center of the simulated target area.

2. The simulation phantom according to claim 1, wherein The simulated normal tissues include a first body and a second body that are detachably connected. By disassembling or connecting the first body and the second body, the box body can be placed in the box body groove or taken out of the box body groove.

3. The simulation phantom according to claim 1, wherein, The simulated target area is a sphere.

4. The simulated phantom according to claim 1, wherein, A plurality of fiducial points are provided on the outer surface of the simulated normal tissues for positioning the simulation phantom.

5. The simulation phantom according to claim 4, wherein, In the case where the simulation phantom is a head simulation phantom, the fiducial points include: a first fiducial point, a second fiducial point, and a third fiducial point. Among them, the first fiducial point is located on the forehead of the head simulation phantom, and the second fiducial point and the third fiducial point are respectively located at opposite positions on both sides of the forehead of the head simulation phantom, and the intersection of the line connecting the second fiducial point and the third fiducial point and the perpendicular line from the first fiducial point to the line coincides with the center of the simulated target area.

6. The simulation phantom according to claim 4, wherein The fiducial points and the outer surface of the simulated normal tissues have the first characteristic and / or the second characteristic.

7. The simulation phantom according to claim 1, wherein A plurality of marker points are further provided in the simulated normal tissues. The marker points and the parts in contact with themselves have the first characteristic and / or the second characteristic.

8. The simulated phantom according to claim 7, wherein In the case where the simulation phantom is a head simulation phantom, a plurality of the marker points are located in the simulated soft tissues of the forehead of the head simulation phantom.

9. The simulation phantom according to claim 8, wherein The box body includes a first box body and a second box body that are oppositely arranged and detachably connected. A film accommodating groove is formed between the opposite surfaces of the first box body and the second box body.

10. The simulation phantom according to claim 9, wherein The first box body and the second box body are detachably connected through a positioning pin and a positioning hole that cooperate with each other.

11. The simulation phantom according to claim 1, wherein When the simulation phantom is a head simulation phantom, the box body is located at a position between the back of the head and the face of the head simulation phantom.

12. The simulation phantom according to claim 1, characterized in that, The box body is a cuboid or a cube.

13. The simulation phantom according to claim 1, wherein The simulation phantom is a head simulation phantom, a head and neck simulation phantom or a body simulation phantom.

14. The simulation phantom according to claim 13, wherein, When the simulation phantom is a head simulation phantom or a head and neck simulation phantom, the simulated normal tissues include a simulated skull, simulated soft tissues filled in the simulated skull, and simulated skin located outside the simulated skull. The simulated target area is arranged in the simulated soft tissues, and the simulated skull, the simulated soft tissues and the simulated skin have the first property and / or the second property.

15. The simulation phantom according to claim 1, wherein The simulation phantom further includes a simulated target area driving device for driving the simulated target area to move along a preset trajectory at a preset frequency.

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