CN111228658A

CN111228658A - Magnetic resonance image guided radiotherapy system

Info

Publication number: CN111228658A
Application number: CN202010103170.8A
Authority: CN
Inventors: 倪成; 余兴恩; 汪鹏
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2020-02-19
Filing date: 2020-02-19
Publication date: 2020-06-05

Abstract

The embodiment of the application discloses a magnetic resonance image guided radiation therapy system. The magnetic resonance image guided radiation therapy system comprises: a radiotherapy apparatus comprising a treatment head; the magnetic resonance imaging equipment comprises a main body, wherein a superconducting magnet adopting a liquid helium-free conduction cooling technology and a through hole for communicating the inner wall and the outer wall of the main body are arranged on the main body; the treatment head is at least partially disposed within the through-hole for emitting a radiation beam toward the interior cavity of the body for radiation treatment.

Description

Magnetic resonance image guided radiotherapy system

Technical Field

The present application relates to the field of radiation therapy systems, and in particular, to a magnetic resonance image guided radiation therapy system.

Background

Radiation Therapy (RT) is an important local treatment for malignancies. Approximately 70% of cancer patients require radiation therapy in the course of cancer treatment. The role and position of radiation therapy in tumor therapy is increasingly highlighted. Radiation therapy has become one of the primary means of treating malignant tumors. The medical linear accelerator is a large medical equipment for cancer radiotherapy, and can directly irradiate the tumor in the body of a patient by generating X-rays and electronic rays, thereby achieving the purpose of eliminating or reducing the tumor. At present, most of medical linear accelerators can not image a treatment part in real time during treatment, but the medical linear accelerators need to be firstly photographed and positioned on a focus part in other imaging equipment (such as magnetic resonance imaging equipment) and then can be used for treating on the linear accelerators. The defect is that the treatment can not be accurately performed on the parts of the lung, the chest and the like which move along with the breathing.

Disclosure of Invention

The present application provides a magnetic resonance image guided radiation therapy system. The magnetic resonance image guided radiation therapy system comprises: a radiotherapy apparatus comprising a treatment head; the magnetic resonance imaging equipment comprises a main body, wherein a superconducting magnet adopting a liquid helium-free conduction cooling technology and a through hole for communicating the inner wall and the outer wall of the main body are arranged on the main body; the treatment head is at least partially disposed within the through-hole for emitting a radiation beam toward the interior cavity of the body for radiation treatment.

Drawings

The present application will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a schematic block diagram of an exemplary image-guided radiation therapy system according to some embodiments of the present application;

FIG. 2 is a state diagram of use of an exemplary image-guided radiation therapy system according to some embodiments of the present application;

FIG. 3 is another state diagram of use of an exemplary image-guided radiation therapy system according to some embodiments of the present application;

FIG. 4 is a cross-sectional view of an exemplary image-guided radiation therapy system according to some embodiments of the present application;

figure 5 is a cross-sectional view of an exemplary magnetic resonance imaging apparatus shown in accordance with some embodiments of the present application;

FIG. 6 is a schematic view of an exemplary radiation therapy device shown in accordance with some embodiments of the present application;

figure 7 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application;

figure 8 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application;

figure 9 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application.

In the figure, 100 is a treatment system, 110 is a radiotherapy apparatus, 120 is a magnetic resonance imaging apparatus, 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 hole, 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 magnetic thermal shield, 126 is a magnetic vacuum layer, 127 is a main coil, 127a is a first main coil, 127B is a second main coil, 128 is a shielding coil, 128a is a first shielding coil, 128B is a second shielding coil, 129a is a first bobbin, 129B is a second bobbin, 129c is a third bobbin, 129d is a fourth bobbin, 1210 is a conductive cooling conductor, 1211 is a refrigerator, 1212 is a vacuum pumping port, 1213 is an X-ray, 131 is a base, 132 is a base, 200 is a sectional view of the treatment system, a is an a hole, and B is a hole B.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

The present application relates to a magnetic resonance image guided radiation therapy system. The magnetic resonance image guided radiation therapy system includes a radiation therapy device and a magnetic resonance imaging device (MRI). By the combined arrangement of the treatment head of the radiotherapy device and the magnetic resonance imaging device, the magnetic resonance imaging device can acquire images while the radiotherapy device performs radiotherapy. In some embodiments, the radiotherapy apparatus and the magnetic resonance imaging apparatus may be used separately, sequentially or simultaneously.

FIG. 1 is a schematic block diagram of an exemplary image-guided radiation therapy system according to some embodiments of the present application; FIG. 2 is a state diagram of use of an exemplary image-guided radiation therapy system according to some embodiments of the present application; FIG. 3 is another state diagram of use of an exemplary image-guided radiation therapy system according to some embodiments of the present application; FIG. 4 is a cross-sectional view of an exemplary image-guided radiation therapy system according to some embodiments of the present application; figure 5 is a cross-sectional view of an exemplary magnetic resonance imaging apparatus shown in accordance with some embodiments of the present application; FIG. 6 is a schematic view of an exemplary radiation therapy device shown in accordance with some embodiments of the present application; figure 7 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application; figure 8 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application; figure 9 is another cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application. A magnetic resonance image guided radiation therapy system 100 according to an embodiment of the present application will be described in detail below with reference to fig. 1 to 9. It should be noted that the following examples are only for explaining the present application and do not constitute a limitation to the present application.

As shown in fig. 1-9, the image guided radiation therapy system 100 may include a radiation therapy device 110, a magnetic resonance imaging device 120, and a treatment couch 130.

In some embodiments, the radiation therapy device 110 may include a linear accelerator (LINAC) for accelerating electrons, ions, or protons. The radiation therapy device 110 can include a gantry 111, a treatment head 112, a base 113, a treatment arm 114, and an aperture 115. Treatment head 112 may be mounted to gantry 111 by treatment arm 114. The frame 111 may be supported by a base 113. Treatment head 112 may be configured to emit a radiation beam. In particular, treatment head 112 may include a radiation source that emits a radiation beam. The radiation beam may be an X-ray beam, an electron beam, a gamma ray source, a proton ray source, or the like. For example, the radiation beam may be an X-ray 1213 as in FIGS. 8-9.

The magnetic resonance imaging device 120 may comprise a body. The body may be understood as a housing for enclosing and/or carrying components of the magnetic resonance imaging apparatus 120, such as the superconducting magnet 121 and the like. In particular, the body may be provided with a superconducting magnet 121, one or more gradient coils, and one or more Radio Frequency (RF) coils. The superconducting magnet 121 may be used to generate a static magnetic field during an MRI process. In some embodiments, the superconducting magnet 121 may be a superconducting magnet 121 employing liquid helium free conduction cooling techniques. By using the superconducting magnet 121 without the liquid helium conduction cooling technology, the risk of quench of the magnet with liquid helium during rotation can be avoided. The superconducting magnet 121 may include a main coil 127 and a shield coil 128. The primary coil 127 may include a first primary coil 127a and a second primary coil 127 b. The shield coils 128 may include a first shield coil 128a and a second shield coil 128 b. Both ends of the body may be provided with a main coil 127 and a shield coil 128. The main coil 127 and the shield coil 128 may be separated from each other or may be connected to each other. For example, the main coils at both ends of the main body may be a whole body (e.g., the first main coil 127a and the second main coil 127b are a whole body, and the first main coil 127a and the second main coil 127b are electrically connected). For another example, the shielding coils at the two ends of the main body may be a single body (e.g., the first shielding coil 128a and the second shielding coil 128b are a single body, and the first shielding coil 128a and the second shielding coil 128b are electrically connected). In the present embodiment, the magnetic resonance imaging device 120 is preferably a monolithic imaging device. The components of the magnetic resonance imaging apparatus 120 (such as the superconducting magnet 121) may rotate integrally with the main body.

In some embodiments, one or more cryocoolers 1211 and conductive cooling conductor 1210 are also provided on the body. Conductive cooling conductors 1210 may be used to connect one or more cryocoolers 1211 with the superconducting magnet 121. In some embodiments, as shown in fig. 8, two cryocoolers 1211 may be disposed on the main body, and each cryocooler 1211 is connected to the main coil 127 and the shield coil 128 disposed at one end of the main body through a conductive cooling conductor 1210. By providing two cryocoolers 1211, the cryocoolers can be closer to the superconducting magnet 121 at both ends of the main body, and the cooling effect is better. In some embodiments, as shown in fig. 9, a refrigerator 1211 may be disposed on the main body, and the refrigerator 1211 is connected to the main coil 127 and the shield coil 128 disposed at both ends of the main body through a conductive cooling conductor 1210. By providing one refrigerator, the cost of the apparatus can be effectively reduced, and the cooling effect of the superconducting magnets 121 provided at both ends of the main body can be made more uniform. In some embodiments, chiller 1211 may be a GM chiller. In some embodiments, conductive cooling conductor 1210 may be two separate conductors (e.g., when two cryocoolers are provided on the body) or may be a unitary body (e.g., when one cryocooler or two cryocoolers are provided on the body). In some embodiments, the conduction cooling conductor 1210 may be disposed in a non-radiation-irradiated region to avoid affecting the conduction effect due to radiation irradiation. In some embodiments, the conductive cooling conductor 1210 may be comprised of a metallic material. The metallic material may comprise one or more metals, alloy materials. Specifically, the metal material may be a metal material having a thermal conductivity greater than a certain threshold. For example, the metal material may be, but is not limited to, gold, silver, copper, and the like.

In some embodiments, the body may further include a through hole 122 communicating the inner and outer walls of the body. The through hole 122 may be provided at a substantially middle position in the body axis direction. For example, the through hole 122 may be provided at an intermediate position in the axial direction of the main body. The through hole 122 may be a stepped hole. As shown in fig. 4, the through-holes 122 may include a-holes and B-holes, the a-holes having a larger diameter than the B-holes; the hole A is close to the outer wall of the main body, and the hole B is close to the inner wall of the main body. In some embodiments, the treatment head 112 may be disposed in a through-hole 122 on the magnetic resonance imaging device 120 for emitting a radiation beam to an internal cavity 123 of the magnetic resonance imaging device 120 for radiation treatment. For example, treatment head 112 may be inserted into the a-hole and emit a radiation beam through the B-hole toward the internal cavity of the body. In some embodiments, a vacuum port 1212 is also provided in the body for evacuating the body.

In some embodiments, the axes of the radiotherapy device 110 and the magnetic resonance imaging device 120 may coincide (i.e., axis 116 in fig. 3 or 4). The treatment head 112 and the body of the magnetic resonance imaging apparatus 120 are simultaneously rotatable about the common axis 116 of the radiotherapy apparatus 110 and the magnetic resonance imaging apparatus 120. In some embodiments, as shown in fig. 1 to 3, the main body of the magnetic resonance imaging apparatus 120 may be fixed to one side of the gantry 111 of the radiotherapy apparatus 110, and the treatment head 112 of the radiotherapy apparatus 110 extends into the through hole 122 of the main body, so that the treatment head 112 and the main body of the magnetic resonance imaging apparatus 120 can rotate coaxially with the gantry 111. In some embodiments, the magnetic resonance imaging device 120 may further include a gantry supporting its body. In some embodiments, the bodies of the radiotherapy apparatus 110 and the magnetic resonance imaging apparatus 120 may also be of unitary construction. For example, the main body of the magnetic resonance imaging apparatus 120 and the gantry 111 of the radiotherapy apparatus 110 may be an integrally molded structure.

In some embodiments, the image guided radiation therapy system 100 may include a processor that may be used to control the simultaneous rotation of the treatment head 112 and the body of the magnetic resonance imaging device 120. The processor may also control the treatment head 112 to perform radiation treatment and the magnetic resonance imaging device 120 to perform image acquisition. For example, under control of the processor, the magnetic resonance imaging device 120 may acquire images while the radiotherapy device is delivering radiotherapy. In some embodiments, the processor may also direct the treatment head 112 to deliver radiation therapy based on images acquired by the magnetic resonance imaging device 120. For example, the processor may control treatment parameters of the radiotherapy apparatus based on image data acquired by the magnetic resonance imaging apparatus, which may include, but is not limited to, radiation dose, treatment head rotation angle, and the like.

In some embodiments, the treatment couch 130 may include a couch top 131 and a base 132 for supporting a patient. In some embodiments, treatment couch 130 may also include a patient positioning system for adjusting the position of the patient to ensure that the patient treatment area (e.g., a tumor) may receive treatment radiation from radiation treatment device 110.

Figure 4 is a cross-sectional view of an exemplary magnetic resonance image guided radiation therapy system, shown in accordance with some embodiments of the present application. As shown in FIG. 4, by positioning treatment head 112 within throughbore 122, the distance between treatment head 112 and axis 116 of internal cavity 123 may be reduced (e.g., a conventional treatment distance of a radiation treatment system may be achieved), thereby increasing the accuracy and efficiency of treatment by treatment head 112.

Figure 5 is a cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application. As shown in fig. 5, the magnetic resonance imaging device 120 may include one or more main coils (e.g., a first main coil 127a and a second main coil 127b), one or more shield coils (e.g., a first shield coil 128a and a second shield coil 128b), one or more heat exchange plates (e.g., the heat exchange plate 124), one or more magnet heat shields (e.g., the magnet heat shield 125), and one or more magnet outer vacuum layers (e.g., the magnet outer vacuum layer 126) configured to generate a main magnetic field.

In some embodiments, the first and second shield coils 128a and 128b may be symmetrically distributed at both ends of the body (or the magnet 121). In some embodiments, one or more primary coils (e.g., the first primary coil 127a and the second primary coil 127b) may be connected to each other by, for example, wires. In some embodiments, the

primary 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 maintained at a suitable temperature). The direction of current flow in the shield coils 128a and 128b may be opposite to the direction of current flow in the

primary coils

127a and 127 b. The inner diameter of the shielding coils 128a and 128b may be larger than the outer diameter of the

main coils

127a and 127b so as to shield the

main coils

127a and 127b from magnetic fields generated by electrons. In some embodiments, the

primary coils

127a and 127b may be integrated into one primary coil. In some embodiments, the

primary coils

127a and 127b may be wound on the first bobbin 129a and the second bobbin 129b, respectively. When current is passed through

main coils

127a and 127b, a magnetic field is generated in internal cavity 123 and is oriented parallel to axis 116. In some embodiments, the primary coil 127a and the primary coil 127b may be connected by a wire. The strength of the magnetic field generated by the

primary coils

127a and 127b may be related to the number of turns of the coils. The shield coils 128a and 128b may be wound on the third bobbin 129c and the fourth bobbin 129d, respectively.

In some embodiments, the heat exchange plate 124 is a high efficiency heat exchanger formed by stacking a series of corrugated metal sheets, with thin rectangular channels formed between the sheets through which heat is exchanged. The heat exchange plate has the characteristics of high heat exchange efficiency, small heat loss, compact and light structure, small occupied area, wide application, long service life and the like. Under the condition of the same pressure loss, the heat transfer coefficient of the heat exchanger is 3-5 times higher than that of the tubular heat exchanger, the occupied area of the heat exchanger is one third of that of the tubular heat exchanger, and the heat recovery rate can reach more than 90 percent. The heat exchanger plates may be used to quickly transfer heat from the magnet heat shield to achieve a desired degree of uniformity and/or stability in the temperature of the

primary coils

127a and 127 b.

In some embodiments, the magnet thermal shield 125 may be used to rapidly conduct the heat generated by the main coil to achieve a desired degree of uniformity and/or stability in the temperature of the

main coils

127a and 127 b. For example, the

main coils

127a and 127b may be uniform to the extent that the difference between the maximum temperature and the minimum temperature in the coils at a certain time point is lower than 20 ℃, 15 ℃, 10 ℃, 8 ℃, 5 ℃, 2 ℃ or 1 ℃ or the like. As used herein, a desired degree of stabilization of the temperature of the

primary coils

127a and 127b may be a rate or value of change of the temperature of the

primary coils

127a and 127b (e.g., as compared to a standard temperature suitable for normal operation of the primary coils) below a respective threshold. For example, a desirable degree of stabilization of the temperature of the

primary coils

127a and 127b may be a rate of temperature change within the coils of less than 20 deg.C/minute, 15 deg.C/minute, 10 deg.C/minute, 8 deg.C/minute, 5 deg.C/minute, 2 deg.C/minute, or 1 deg.C/minute, etc. For another example, the desired degree of stabilization of the temperature of the

main coils

127a and 127b may also be a value of temperature change (e.g., deviation from a standard temperature) in any portion of the main coils during one operation that is less than 20 ℃, 15 ℃, 10 ℃, 8 ℃, 5 ℃, 2 ℃, or 1 ℃, etc. As another example, a desired degree of stabilization of the temperature of the

primary coils

127a and 127b may be when the rate and value of temperature change of the

primary coils

127a and 127b (e.g., as compared to a standard temperature suitable for normal operation of the primary coils) is below a respective threshold.

In some embodiments, the magnet outer vacuum layer 126 integrates different portions of the vacuum layer fluid communication. The transfer of heat from the patient positioned within the internal cavity 123 to the primary coil can be blocked to achieve a desired degree of uniformity and/or stability in the temperature of the

primary coils

127a and 127 b.

Figure 7 is a cross-sectional view of an exemplary magnetic resonance imaging apparatus, shown in accordance with some embodiments of the present application. As shown in fig. 7, by replacing the conventional liquid helium cooled magnet with a superconducting magnet using a conduction technique without liquid helium cooling, the risk of quench by the superconducting magnet can be reduced.

It should be noted that the above description is for illustrative purposes and does not limit the scope of applicability of the present application. It is obvious that various modifications and changes can be made thereto by those skilled in the art under the guidance of the present application. However, such modifications and changes are still within the scope of the present application. For example, the size, shape, and distribution of the through holes 122 may be appropriately adjusted according to the situation. Similar variations are within the scope of the present application.

The beneficial effects that may be brought by the embodiments of the present application include, but are not limited to: (1) the magnetic resonance imaging equipment adopts a superconducting magnet without a liquid helium conduction cooling technology, so that the risk of quenching of the magnet with liquid helium in the rotating process is avoided; (2) the radiotherapy equipment is combined with the magnetic resonance imaging equipment, so that the real-time imaging can be realized while the radiotherapy is carried out on a patient, the focus can be more accurately positioned, and the treatment condition of the focus part can be observed in real time; (3) the radiation beam of the radiotherapy equipment can directly reach a patient through the through hole, so that the attenuation of rays is avoided; (4) the treatment head can extend into the through hole, so that the loss of rays is avoided; (5) the whole size of the system is small, and the cost is low; (6) the therapeutic head and the main body of the medical imaging device (such as a magnetic resonance imaging device) can rotate around a common axis, so that various therapeutic modes such as dynamic, intensity-modulated and arc-drawing can be realized, and the patient can be effectively treated. It is to be noted that different embodiments may produce different advantages, and in different embodiments, any one or combination of the above advantages may be produced, or any other advantages may be obtained.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be considered merely illustrative and not restrictive of the broad application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present application. Other variations are also possible within the scope of the present application. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present application can be viewed as being consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A magnetic resonance image guided radiation therapy system, comprising:

a radiotherapy apparatus comprising a treatment head;

the magnetic resonance imaging equipment comprises a main body, wherein a superconducting magnet adopting a liquid helium-free conduction cooling technology and a through hole for communicating the inner wall and the outer wall of the main body are arranged on the main body;

the treatment head is at least partially disposed within the through-hole for emitting a radiation beam toward the interior cavity of the body for radiation treatment.

2. The radiation therapy system of claim 1, wherein said body further includes a refrigerator and a conductive cooling conductor for connecting said refrigerator to said superconducting magnet.

3. The radiation therapy system of claim 2, wherein said conductive cooling conductor is comprised of a metallic material.

4. The radiation therapy system of claim 2, wherein the superconducting magnet includes main coils and a shield coil, the conductive cooling conductor further for connecting the main coils and the shield coil.

5. The radiation therapy system of claim 4, wherein said through hole is provided at a substantially middle position in an axial direction of said main body; the main coil and the shielding coil are arranged at two ends of the main body.

6. The radiation therapy system of claim 5, wherein said body has a cryocooler coupled thereto via said conductive cooling conductor to a primary coil and a shield coil disposed at opposite ends of said body.

7. The radiation therapy system of claim 5, wherein two cryocoolers are disposed on said body, each cryocooler being connected by a conductive cooling conductor to a primary coil and a shielding coil disposed at one end of said body.

8. The radiation therapy system of claim 1, wherein said main body and said treatment head are simultaneously rotatable about a common axis of said radiation therapy device and said magnetic resonance imaging device.

9. The radiation therapy system of claim 1, wherein said through-hole is a stepped hole.

10. The radiation therapy system of claim 1, wherein said magnetic resonance imaging device is monolithic.