A magnetic resonance image guided radiotherapy system

Abstract

The embodiment of the present application discloses a magnetic resonance image guided radiotherapy system. The magnetic resonance image guided radiotherapy system comprises a radiotherapy device, the radiotherapy device comprises a treatment head; a magnetic resonance imaging device, the magnetic resonance imaging device comprises a main body, the main body is provided with a superconducting magnet adopting a liquid-helium-free conduction cooling technology and a through hole communicating the inner wall and the outer wall of the main body; the treatment head is at least partially arranged in the through hole and is used for emitting a radiation beam to the internal cavity of the main body to perform radiotherapy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radiotherapy systems, and in particular, to a magnetic resonance image guided radiotherapy system. BACKGROUND

[0002] Radiotherapy (RT) is an important local treatment method for malignant tumors. Nearly 70% of cancer patients need radiotherapy in the process of treating cancer. The role and position of radiotherapy in tumor treatment are increasingly prominent. Radiotherapy has become one of the main means for treating malignant tumors. A medical linear accelerator is a large medical device for cancer radiotherapy, which generates X-rays and electron beams to directly irradiate tumors in the body of a patient, so as to eliminate or reduce the tumors. At present, most medical linear accelerators cannot image the treatment site in real time during treatment, but need to take pictures in other imaging devices (such as magnetic resonance imaging devices) to position the lesion site first, and then the linear accelerator can be used for treatment. The disadvantage is that for lung and chest parts that move with breathing, accurate treatment cannot be achieved. SUMMARY

[0003] The present application provides a magnetic resonance image guided radiotherapy system. The magnetic resonance image guided radiotherapy system comprises: a radiotherapy device, the radiotherapy device comprising a treatment head; a magnetic resonance imaging device, the magnetic resonance imaging device comprising a main body, the main body being provided with a superconducting magnet adopting a liquid-helium-free conduction cooling technology and a through hole communicating an inner wall and an outer wall of the main body; the treatment head being at least partially arranged in the through hole and used for emitting a radiation beam to an inner cavity of the main body to perform radiotherapy. BRIEF DESCRIPTION OF DRAWINGS

[0004] The present application will be further described in the manner of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, wherein:

[0005] Figure 1 is a structural schematic diagram of an exemplary image guided radiotherapy system according to some embodiments of the present application;

[0006] Figure 2 is a use state diagram of an exemplary image guided radiotherapy system according to some embodiments of the present application;

[0007] Figure 3 is another use state diagram of an exemplary image guided radiotherapy system according to some embodiments of the present application;

[0008] Figure 4 is a sectional view of an exemplary image guided radiotherapy system according to some embodiments of the present application;

[0009] Figure 5 is a cross-sectional view of an exemplary magnetic resonance imaging device shown in accordance with some embodiments of the present application;

[0010] Figure 6 is a schematic view of an exemplary radiotherapy device shown in accordance with some embodiments of the present application;

[0011] Figure 7 is another cross-sectional view of an exemplary magnetic resonance imaging device shown in accordance with some embodiments of the present application;

[0012] Figure 8 is another cross-sectional view of an exemplary magnetic resonance imaging device shown in accordance with some embodiments of the present application;

[0013] Figure 9 is another cross-sectional view of an exemplary magnetic resonance imaging device shown in accordance with some embodiments of the present application.

[0014] In the drawings: 100 is a treatment system, 110 is a radiotherapy device, 120 is a magnetic resonance imaging device, 130 is a treatment couch, 111 is a gantry, 112 is a treatment head, 113 is a base, 114 is a treatment arm, 115 is a bore, 116 is an axis, 121 is a superconducting magnet, 122 is a through hole, 123 is an internal cavity, 124 is a heat exchange plate, 125 is a magnet thermal shield, 126 is a magnet vacuum layer, 127 is a main coil, 127a is a first main coil, 127b is a second main coil, 128 is a shield coil, 128a is a first shield coil, 128b is a second shield coil, 129a is a first bobbin, 129b is a second bobbin, 129c is a third bobbin, 129d is a fourth bobbin, 1210 is a conduction cooling conductor, 1211 is a refrigerator, 1212 is a vacuum extraction port, 1213 is an X-ray, 131 is a couch board, 132 is a base, 200 is a treatment system cross-sectional view, A is an A bore, B is a B bore. DETAILED DESCRIPTION

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those skilled in the art, the present application can also be applied to other similar scenarios without creative labor. Unless it is obvious from the language environment or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0016] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0017] This application relates to a magnetic resonance imaging (MRI) guided radiotherapy system. The MRI system includes a radiotherapy device and a magnetic resonance imaging (MRI) device. By combining the treatment head of the radiotherapy device and the MRI device, the MRI device can acquire images while the radiotherapy device is performing radiotherapy. In some embodiments, the radiotherapy device and the MRI device can be used individually, sequentially, or simultaneously.

[0018] Figure 1 This is a schematic diagram of the structure of an exemplary image-guided radiotherapy system according to some embodiments of this application; Figure 2 These are usage diagrams of an exemplary image-guided radiotherapy system according to some embodiments of this application; Figure 3 This is another usage diagram of an exemplary image-guided radiotherapy system according to some embodiments of this application; Figure 4 This is a cross-sectional view of an exemplary image-guided radiotherapy system according to some embodiments of this application; Figure 5 This is a cross-sectional view of an exemplary magnetic resonance imaging apparatus according to some embodiments of this application; Figure 6 These are schematic diagrams of exemplary radiotherapy devices according to some embodiments of this application; Figure 7 This is another cross-sectional view of an exemplary magnetic resonance imaging apparatus shown in some embodiments of this application; Figure 8 This is another cross-sectional view of an exemplary magnetic resonance imaging apparatus shown in some embodiments of this application; Figure 9 This is another cross-sectional view of an exemplary magnetic resonance imaging apparatus shown according to some embodiments of this application. The following will be combined with... Figures 1-9 The magnetic resonance imaging-guided radiotherapy system 100 according to the embodiments of this application will be described in detail. It should be noted that the following embodiments are only used to explain this application and do not constitute a limitation on this application.

[0019] like Figures 1-9 As shown, the image-guided radiotherapy system 100 may include a radiotherapy device 110, a magnetic resonance imaging device 120, and a treatment bed 130.

[0020] In some embodiments, the radiotherapy device 110 can include a linear accelerator (LINAC) for accelerating electrons, ions or protons. The radiotherapy device 110 can include a gantry 111, a treatment head 112, a base 113, a treatment arm 114 and a bore 115. The treatment head 112 can be mounted on the gantry 111 by the treatment arm 114. The gantry 111 can be supported by the base 113. The treatment head 112 can be configured to emit a radiation beam. Specifically, the treatment head 112 can include a radiation source that emits a radiation beam. The radiation beam can be an X-ray beam, an electron beam, a gamma ray source, a proton ray source, etc. For example, the radiation beam can be an X-ray 1213 as shown in FIG. 1B. Figures 8-9

[0021] The MRI device 120 can include a main body. The main body can be understood as a housing for wrapping and / or carrying components (such as the superconducting magnet 121, etc.) of the MRI device 120. Specifically, the main body can be provided with the superconducting magnet 121, one or more gradient coils, and one or more radio frequency (RF) coils. The superconducting magnet 121 can be used to generate a static magnetic field during MRI processing. In some embodiments, the superconducting magnet 121 can be a superconducting magnet 121 employing a liquid-helium-free conduction cooling technology. By employing the superconducting magnet 121 with the liquid-helium-free conduction cooling technology, the risk of quenching of the magnet with liquid helium during rotation can be avoided. The superconducting magnet 121 can include a main coil 127 and a shield coil 128. The main coil 127 can include a first main coil 127a and a second main coil 127b. The shield coil 128 can include a first shield coil 128a and a second shield coil 128b. The main coil 127 and the shield coil 128 can be provided at both ends of the main body. The main coil 127 and the shield coil 128 can be separate or connected to each other. For example, the main coils at both ends of the main body can be an integral whole (e.g., the first main coil 127a and the second main coil 127b are an integral whole, and the first main coil 127a and the second main coil 127b are electrically connected to each other). For another example, the shield coils at both ends of the main body can be an integral whole (e.g., the first shield coil 128a and the second shield coil 128b are an integral whole, and the first shield coil 128a and the second shield coil 128b are electrically connected to each other). In the embodiments of the present application, the MRI device 120 is preferably a whole-body imaging device. The components (such as the superconducting magnet 121, etc.) of the MRI device 120 can rotate as a whole with the main body.

[0022] In some embodiments, one or more refrigerators 1211 and a conduction cooling conductor 1210 are further provided on the main body. The conduction cooling conductor 1210 can be used to connect the one or more refrigerators 1211 to the superconducting magnet 121. In some embodiments, the conduction cooling conductor 1210 can be a copper rod, a copper braid, a copper wire, etc. Figure 8 ​As shown, the main body can be equipped with two coolers 1211. Each cooler 1211 is connected to a main coil 127 and a shielding coil 128 located at one end of the main body via a conductive cooling conductor 1210. By providing two coolers 1211, the conduction distance between the coolers and the superconducting magnets 121 at both ends of the main body can be shortened, resulting in a better cooling effect. In some embodiments, such as Figure 9 As shown, a chiller 1211 can be provided on the main body. The chiller 1211 is connected to the main coil 127 and the shielding coil 128 located at both ends of the main body via a conductive cooling conductor 1210. By providing a chiller, the equipment cost can be effectively reduced, and the cooling effect of the superconducting magnets 121 located at both ends of the main body can be more consistent. In some embodiments, the chiller 1211 can be a GM chiller. In some embodiments, the conductive cooling conductor 1210 can be two independent conductors (e.g., when two chillers are provided on the main body), or it can be a whole (e.g., when one or two chillers are provided on the main body). In some embodiments, the conductive cooling conductor 1210 can be located in a non-radiation irradiation area to avoid affecting the conduction effect due to radiation irradiation. In some embodiments, the conductive cooling conductor 1210 can be made of a metallic material. The metallic material can include one or more metals or alloys. Specifically, the metallic material can be a metallic material with a thermal conductivity greater than a certain threshold. For example, the metallic material can be, but is not limited to, gold, silver, copper, etc.

[0023] In some embodiments, the body may further include a through hole 122 communicating with the inner wall and the outer wall of the body. The through hole 122 may be located approximately at the center of the body along its axial direction. For example, the through hole 122 may be located at the center of the body along its axial direction. The through hole 122 may be a stepped hole. Figure 4 As shown, the through-hole 122 may include hole A and hole B, with hole A having a larger diameter than hole B; hole A is located near the outer wall of the main body, and hole B is located near the inner wall of the main body. In some embodiments, the treatment head 112 may be disposed within the through-hole 122 on the magnetic resonance imaging device 120 for emitting a radiation beam into the internal cavity 123 of the magnetic resonance imaging device 120 for radiotherapy. For example, the treatment head 112 may be embedded in hole A and emit a radiation beam into the internal cavity of the main body through hole B. In some embodiments, the main body is also provided with a vacuum port 1212 for evacuating the main body.

[0024] In some embodiments, the axes of the radiotherapy device 110 and the magnetic resonance imaging device 120 may coincide (i.e., Figure 3 Or axis 116 in 4). The treatment head 112 and the main body of the magnetic resonance imaging device 120 are capable of rotating simultaneously about the common axis 116 of the radiotherapy device 110 and the magnetic resonance imaging device 120. In some embodiments, such as Figures 1-3As shown, the main body of the magnetic resonance imaging device 120 can be fixed on one side of the gantry 111 of the radiation therapy device 110, and the treatment head 112 of the radiation therapy device 110 can extend into the through hole 122 on the main body, so that the treatment head 112 and the main body of the magnetic resonance imaging device 120 can rotate coaxially with the gantry 111. In some embodiments, the magnetic resonance imaging device 120 can also include a gantry supporting the main body thereof. In some embodiments, the main body of the magnetic resonance imaging device 120 and the gantry 111 of the radiation therapy device 110 can be integrally formed.

[0025] In some embodiments, the image-guided radiation therapy system 100 can include a processor, which can be configured to control the treatment head 112 and the main body of the magnetic resonance imaging device 120 to rotate simultaneously. The processor can also control the treatment head 112 to perform radiation therapy and control the magnetic resonance imaging device 120 to perform image acquisition. For example, under the control of the processor, the magnetic resonance imaging device 120 can acquire images while the radiation therapy device performs radiation therapy. In some embodiments, the processor can also guide the treatment head 112 to perform radiation therapy according to the images acquired by the magnetic resonance imaging device 120. For example, the processor can control the treatment parameters of the radiation therapy device according to the image data acquired by the magnetic resonance imaging device, and the treatment parameters can include but are not limited to radiation dose, treatment head rotation angle, etc.

[0026] In some embodiments, the treatment bed 130 can include a bed plate 131 and a base 132 for supporting a patient. In some embodiments, the treatment bed 130 can also include a patient positioning system for adjusting the position of the patient, so as to ensure that the treatment region (e.g., tumor) of the patient can receive treatment rays from the radiation therapy device 110.

[0027] Figure 4 is a cross-sectional view of an exemplary magnetic resonance image-guided radiation therapy system according to some embodiments of the present application. As shown, by arranging the treatment head 112 in the through hole 122, the distance between the treatment head 112 and the axis 116 of the internal cavity 123 can be reduced (e.g., to a conventional treatment distance of a radiation therapy system), so that the accuracy and efficiency of the treatment by the treatment head 112 can be improved. Figure 4

[0028] Figure 5 is a cross-sectional view of an exemplary magnetic resonance imaging device according to some embodiments of the present application. As shown, the main body of the magnetic resonance imaging device 120 can be fixed on one side of the gantry 111 of the radiation therapy device 110, and the treatment head 112 of the radiation therapy device 110 can extend into the through hole 122 on the main body, so that the treatment head 112 and the main body of the magnetic resonance imaging device 120 can rotate coaxially with the gantry 111. In some embodiments, the magnetic resonance imaging device 120 can also include a gantry supporting the main body thereof. In some embodiments, the main body of the magnetic resonance imaging device 120 and the gantry 111 of the radiation therapy device 110 can be integrally formed. Figure 5 ​As shown, the magnetic resonance imaging device 120 can include one or more main coils (e.g., first main coil 127a and second main coil 127b) configured to generate a main magnetic field, one or more shield coils (e.g., first shield coil 128a and second shield coil 128b), one or more heat exchanger plates (e.g., heat exchanger plate 124), one or more magnet heat shields (e.g., magnet heat shield 125), and one or more outer vacuum layers (e.g., outer vacuum layer 126).

[0029] In some embodiments, the first shield coil 128a and the second shield coil 128b can be symmetrically distributed at both ends of the main body (or the magnet 121). In some embodiments, the one or more main coils (e.g., the first main coil 127a and the second main coil 127b) can be connected to each other by, for example, a wire. In some embodiments, the main coils 127a and 127b and / or the shield coils 128a and 128b are superconducting at least under certain conditions (e.g., when the coils are kept at an appropriate temperature). The direction of the current in the shield coils 128a and 128b can be opposite to the direction of the current in the main coils 127a and 127b. The inner diameter of the shield coils 128a and 128b can be greater than the outer diameter of the main coils 127a and 127b, so as to shield the magnetic field generated by the escaping electrons of the main coils 127a and 127b. In some embodiments, the main coils 127a and 127b can be integrated into one main coil. In some embodiments, the main coils 127a and 127b can be wound on the first bobbin 129a and the second bobbin 129b, respectively. When the current passes through the main coils 127a and 127b, a magnetic field is generated in the inner cavity 123, and the direction of the magnetic field is parallel to the axis 116. In some embodiments, the main coil 127a can be connected to the main coil 127b by a wire. The strength of the magnetic field generated by the main coils 127a and 127b can be related to the number of turns of the coils. The shield coils 128a and 128b can be wound on the third bobbin 129c and the fourth bobbin 129d, respectively.

[0030] In some embodiments, the heat exchanger plate 124 refers to a high-efficiency heat exchanger made of a series of metal sheets with a certain corrugated shape. Thin rectangular channels are formed between the various plates, and heat exchange is carried out through the plates. The heat exchanger plate has the characteristics of high heat exchange efficiency, small heat loss, compact and light structure, small floor area, wide application, long service life, etc. Under the same pressure loss condition, the heat transfer coefficient is 3-5 times higher than that of the tube type heat exchanger, the floor area is one third of that of the tube type heat exchanger, and the heat recovery rate can be as high as 90% or more. The heat exchanger plate can be used to quickly transfer the heat on the magnet heat shield layer to achieve the ideal uniformity and / or stability of the temperature of the main coils 127a and 127b.

[0031] In some embodiments, the magnet thermal shield layer 125 can be used to quickly conduct the heat generated by the main coils to achieve a desired uniformity and / or stability of the temperature of the main coils 127a and 127b. For example, a desired uniformity of the main coils 127a and 127b can be a difference between the highest temperature and the lowest temperature within the coils at a certain point in time, which can be less than 20°C, 15°C, 10°C, 8°C, 5°C, 2°C, or 1°C, etc. As used herein, a desired stability of the temperature of the main coils 127a and 127b can be a rate or a value of the temperature change of the main coils 127a and 127b (e.g., compared to a standard temperature suitable for normal operation of the main coils) that is below a respective threshold. For example, a desired stability of the temperature of the main coils 127a and 127b can be a rate of the temperature change within the coils that is less than 20°C / minute, 15°C / minute, 10°C / minute, 8°C / minute, 5°C / minute, 2°C / minute, or 1°C / minute, etc. For another example, a desired stability of the temperature of the main coils 127a and 127b can also be a value of the temperature change (e.g., a deviation from a standard temperature) in any portion of the main coils during an operation that is less than 20°C, 15°C, 10°C, 8°C, 5°C, 2°C, or 1°C, etc. For yet another example, a desired stability of the temperature of the main coils 127a and 127b can be a rate and a value of the temperature change of the main coils 127a and 127b (e.g., compared to a standard temperature suitable for normal operation of the main coils) that is below a respective threshold.

[0032] In some embodiments, the magnet outer vacuum layer 126 integrates different portions of the vacuum layer in fluid communication. This can block the heat from the patient inside the internal cavity 123 from being transferred to the main coils to achieve a desired uniformity and / or stability of the temperature of the main coils 127a and 127b.

[0033] Figure 7 is a cross-sectional view of an exemplary magnetic resonance imaging device according to some embodiments of the present application. As shown, by replacing the conventional liquid helium-cooled magnet with a superconducting magnet employing a liquid-helium-free cooling conduction technique, the risk of quenching caused by the superconducting magnet can be reduced. Figure 7

[0034] It should be noted that the above description is for illustrative purposes only and does not limit the scope of the present application. Obviously, those skilled in the art can make various modifications and changes to the present application under the guidance of the present application. However, these modifications and changes are still within the scope of protection of the present application. For example, the size, shape, and distribution of the through holes 122 can be appropriately adjusted according to the situation. Similar changes are still within the scope of protection of the present application.

[0035] ​The beneficial effects brought by the embodiments of the present application may include but are not limited to: (1) the magnetic resonance imaging device adopts a superconducting magnet of the liquid-helium-free conduction cooling technology, thereby avoiding the risk of quenching of the magnet with liquid helium during rotation; (2) the combination of the radiotherapy device and the magnetic resonance imaging device can realize real-time imaging while performing radiotherapy on the patient, thereby more accurately positioning the lesion and observing the treatment condition of the lesion part in real time; (3) the radiation beam of the radiotherapy device can directly pass through the through hole to reach the patient, thereby avoiding attenuation of the rays; (4) the treatment head can extend into the through hole, thereby avoiding loss of the rays; (5) the overall size of the system is small, and the cost is low; (6) the treatment head and the main body of the medical imaging device (such as the magnetic resonance imaging device) can rotate around the common axis, and various treatment modes such as dynamic, intensity modulation, and arc pulling can be realized to effectively treat the patient. It should be noted that the beneficial effects of different embodiments may be different, and in different embodiments, the beneficial effects that may be produced can be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0036] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of specific terminology. As such, the description herein is not intended to limit the application to the specific embodiments described. It is to be understood that modifications, improvements, and / or changes can be suggested by those skilled in the art and are to be incorporated into the spirit and scope of the application. Accordingly, it is expressly intended that the right to use, and license others to use, the application as set forth in the claims, including any priority documents, is retained, notwithstanding any element described in the prior art.

[0037] Also, the present application has used specific words in describing the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" means some feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "one alternative embodiment" mentioned in different places in the description is not necessarily the same embodiment. In addition, some features, structures, or characteristics in one or more embodiments of the present application can be properly combined.

[0038] Similarly, it should be noted that, in order to simplify the description of the present application and to help understand one or more embodiments of the present application, sometimes multiple features are combined into one embodiment, figure, or description thereof. However, this method of disclosure does not mean that the features required by the present application are more than the features mentioned in the claims. In fact, the features of the embodiment are less than all the features of the disclosed single embodiment.

[0039] Finally, it should be understood that the embodiments described herein are merely exemplary of the principles of the application. Other embodiments can fall within the scope of the application. Thus, although the application has been described with respect to example embodiments, it will be recognized that the scope of the application encompasses alternatives and modifications thereof. Accordingly, the embodiments of the application are not limited to the examples described above, but rather are limited only by the claims.

Claims

1. A magnetic resonance imaging-guided radiotherapy system, characterized in that, include: A radiotherapy device, the radiotherapy device including a treatment head; A magnetic resonance imaging (MRI) device includes a main body, on which a superconducting magnet employing liquid helium-free conductive cooling technology and a through hole connecting the inner and outer walls of the main body are provided; the superconducting magnet can rotate with the main body; the main body also has a conductive cooling conductor for connecting a refrigerator and the superconducting magnet; The treatment head is at least partially disposed within the through-hole for emitting a radiation beam into the internal cavity of the main body for radiotherapy.

2. The radiotherapy system as described in claim 1, characterized in that, The refrigeration unit is mounted on the main body.

3. The radiotherapy system as described in claim 1, characterized in that, The conductive cooling conductor is made of metallic material.

4. The radiotherapy system as described in claim 1, characterized in that, The superconducting magnet includes a main coil and a shielding coil, and the conductive cooling conductor is also used to connect the main coil and the shielding coil.

5. The radiotherapy system as described in claim 4, characterized in that, The through hole is located at the middle position along the axis of the main body; the main coil and the shielding coil are provided at both ends of the main body.

6. The radiotherapy system as described in claim 5, characterized in that, The main body is equipped with a refrigeration unit, which is connected to the main coil and shielding coil located at both ends of the main body through the conductive cooling conductor.

7. The radiotherapy system as described in claim 5, characterized in that, The main body is equipped with two refrigeration units, each of which is connected to the main coil and the shielding coil located at one end of the main body via a conductive cooling conductor.

8. The radiotherapy system as claimed in claim 1, characterized in that, The main body and the treatment head can rotate simultaneously around the common axis of the radiotherapy device and the magnetic resonance imaging device.

9. The radiotherapy system as claimed in claim 1, characterized in that, The through hole is a stepped hole.

10. The radiotherapy system as claimed in claim 1, characterized in that, The magnetic resonance imaging device is an integrated unit.

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