Treatment devices

Abstract

The present specification provides a treatment device (110, 110', 400, 400', 500, 500', 600, 600'). The treatment device (110, 110', 400, 400', 500, 500', 600, 600') may include a magnetic resonance imaging (MRI) device (310) for acquiring MRI data about a region of interest (ROI); and a radiotherapy device (300) for applying therapeutic radiation to at least a portion of the ROI. The MRI device (310) may include an annular cryostat (403, 503, 603, 700) having one or more chambers (403a, 403b, 503a, 503b, 603a, 603b), an annular structural device, and a groove (408, 508, 608) provided on the annular structural device. The radiotherapy apparatus (300) may include at least an accelerator (409, 509) and one or more collimation assemblies (412, 410, 512, 510, 612, 610).

Description

Technical Field

[0001] The present disclosure generally relates to a treatment apparatus for radiation therapy, and more particularly to a treatment apparatus that combines radiation therapy with magnetic resonance imaging technology. Background Art

[0002] Currently, it is difficult to track changes (e.g., movement) in lesions (e.g., tumors) during different treatment phases of radiotherapy. Today, various imaging technologies can be used to provide real-time images of tumors before or during each course of treatment. For example, a magnetic resonance imaging (MRI) device can be used in conjunction with a radiotherapy device to provide an MRI image of a tumor. A treatment device formed by combining an MRI device and a radiotherapy device may be difficult to arrange components of the MRI device (e.g., at least two main magnetic coils, at least two shielding magnetic coils) and components of the radiotherapy device (e.g., a linear accelerator) in a relatively compact space without causing interference. For example, when the radiation beam generated by the radiotherapy device passes through the cryostat of the MRI device, the radiation beam may be weakened due to severe scattering of the radiation beam, resulting in a poor radiotherapy effect. Therefore, it is desirable to provide a treatment device with high treatment quality and compact structure. Summary of the Invention

[0003] The first aspect of the present specification provides a therapeutic device. The therapeutic device may include a magnetic resonance imaging (MRI) device for acquiring MRI data about a region of interest (ROI); and a radiotherapy device for applying therapeutic radiation to at least a portion of the ROI. The MRI device may include an annular cryostat. The annular cryostat may include one or more chambers arranged along the axis of the annular cryostat, and an annular structure device surrounding the one or more chambers. The annular structure device may include a plurality of annular structures, and at least one of the plurality of annular structures may be made of a metal material and a reinforcing material. The radiotherapy device may include an accelerator for accelerating electrons in an electron beam to generate a photon beam of therapeutic radiation; and one or more collimation assemblies for shaping the photon beam. At least a portion of the accelerator is located in a groove of the annular cryostat.

[0004] In some embodiments, the annular cryostat may further include at least one groove disposed on the annular structure device, the groove having an opening formed on at least one outer surface of the annular structure device.

[0005] In some embodiments, the one or more chambers may include two chambers in fluid communication via a neck, and the groove may be formed by at least the two chambers and the neck.

[0006] In some embodiments, the two chambers may contain a cooling medium, and the neck is filled with the cooling medium.

[0007] In some embodiments, the annular structure device may include a first annular structure for providing a vacuum space enclosing one or more chambers; a second annular structure for reducing heat transfer from the first annular structure to the third annular structure; and a third annular structure for accommodating the cooling medium.

[0008] In some embodiments, the cooling medium may include liquid helium.

[0009] In some embodiments, the reinforcement material may have one or more properties of low density, high mechanical strength, radiation resistance, or heat resistance.

[0010] In some embodiments, the reinforcement material may include one or more of carbon fiber, glass fiber, aramid fiber, silicon carbide (SiC) fiber, asbestos fiber, whisker, graphene fiber, and graphene fiber.

[0011] In some embodiments, the annular cryostat may further include one or more sensors for detecting a liquid level of a cooling medium in each of the one or more chambers of the annular cryostat.

[0012] In some embodiments, at least a portion of the accelerator is surrounded by at least one shielding structure.

[0013] In some embodiments, the electron beam may be moved along an electron beam path parallel to an axis of the annular cryostat.The radiotherapy apparatus may further include a target and a beam deflection unit for deflecting electrons in the electron beam onto the target to generate a photon beam of therapeutic radiation.

[0014] A second aspect of the present disclosure provides a magnetic resonance imaging (MRI) apparatus. The MRI apparatus may include an annular cryostat. The annular cryostat may include one or more chambers arranged along an axis of the annular cryostat, and an annular structure device surrounding the one or more chambers. The annular structure device may include multiple annular structures, at least one of the multiple annular structures being made of a metal material and a reinforcing material.

[0015] In some embodiments, a groove may be provided on the annular structure device, wherein the groove has an opening formed on at least one outer surface of the annular structure device.

[0016] In some embodiments, the one or more chambers may include two chambers connected by a neck and in fluid communication through the neck, and the groove may be formed by at least the two chambers and the neck.

[0017] In some embodiments, the two chambers may contain a cooling medium and the neck may be filled with the cooling medium.

[0018] In some embodiments, the annular structure device may also include a first annular structure for providing a vacuum space enclosing the one or more chambers; a second annular structure for reducing heat transfer from the first annular structure to the third annular structure; and a third annular structure for accommodating the cooling medium.

[0019] In some embodiments, the reinforcement material may have one or more properties of low density, high mechanical strength, radiation resistance, and heat resistance.

[0020] In some embodiments, the reinforcement material may include one or more of carbon fiber, glass fiber, aramid fiber, silicon carbide (SiC) fiber, asbestos fiber, whisker, graphene fiber, and alloy material.

[0021] In some embodiments, the annular cryostat may further include one or more sensors for detecting a level of a cooling medium in each of the one or more chambers of the annular cryostat.

[0022] A third aspect of this specification provides a therapeutic device. The therapeutic device may include a magnetic resonance imaging (MRI) device for acquiring MRI data about a region of interest (ROI), wherein the MRI device includes an annular cryostat, and a radiotherapy device for applying therapeutic radiation to at least a portion of the ROI. The MRI device may include an annular cryostat. The annular cryostat may include one or more chambers arranged along the axis of the annular cryostat, and an annular structural device surrounding the one or more chambers. The annular structural device includes a plurality of annular structures and at least one groove provided on the annular structural device. At least one of the plurality of annular structures is made of a metal material and a reinforcing material. The groove has an opening formed on at least one outer surface of the annular structural device. The radiotherapy device includes an accelerator for accelerating electrons in an electron beam to generate a photon beam of the therapeutic radiation; a target; and a beam deflection unit for deflecting electrons in the electron beam onto the target to generate the photon beam of the therapeutic radiation. At least a portion of the accelerator is located within the groove of the annular cryostat.

[0023] Some additional features of this specification may be explained in the following description. Some additional features of this specification will be apparent to those skilled in the art through study of the following description and accompanying drawings, or through understanding the production or operation of the embodiments. The features of this specification may be realized and achieved through practice or use of the methods, means, and combinations of various aspects of the specific embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0025] Figure 1 is a block diagram of an exemplary radiation therapy system according to some embodiments of the present specification;

[0026] Figure 2 is a flow chart of an exemplary process of performing radiation therapy in a radiation therapy system according to some embodiments of the present specification;

[0027] Figure 3A is a schematic diagram of an exemplary therapeutic device according to some embodiments of the present specification;

[0028] Figure 3B is a schematic diagram of another exemplary therapeutic device according to some embodiments of the present specification;

[0029] Figure 4A is a cross-sectional view of the upper portion of an exemplary treatment device along the X direction according to some embodiments of the present specification;

[0030] Figure 4B is a cross-sectional view of the upper portion of another exemplary therapeutic device along the X direction according to some embodiments of the present specification;

[0031] Figure 4C is a cross-sectional view of an upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification;

[0032] Figure 5A is a cross-sectional view of the upper portion of an exemplary treatment device along the X direction according to some embodiments of the present specification;

[0033] Figure 5B is a cross-sectional view of the upper portion of another exemplary therapeutic device along the X direction according to some embodiments of the present specification;

[0034] Figure 5C is a cross-sectional view of an upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification;

[0035] Figure 6A is a cross-sectional view of the upper portion of an exemplary treatment device along the X direction according to some embodiments of the present specification;

[0036] Figure 6B is a cross-sectional view of the upper portion of another exemplary therapeutic device along the X direction according to some embodiments of the present specification;

[0037] Figure 6C is a cross-sectional view of an upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification;

[0038] Figure 7 FIG. 4 is a cross-sectional view of an exemplary cryostat according to some embodiments of the present specification, taken along the axial direction (ie, the Z direction) of the cryostat. DETAILED DESCRIPTION

[0039] The following description is intended to enable one of ordinary skill in the art to implement and utilize this specification, and is provided in the context of a specific application scenario and its requirements. It will be apparent to one of ordinary skill in the art that various modifications may be made to the disclosed embodiments, and that the general principles defined herein may be applied to other embodiments and application scenarios without departing from the principles and scope of this specification. Therefore, this specification is not limited to the described embodiments but should be accorded the broadest scope consistent with the claims.

[0040] The terms used in this specification are only used to describe specific exemplary embodiments and do not limit the scope of this specification. Unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" used herein do not specifically refer to the singular and may also include the plural. It is understood that the terms "including" and "comprising" used in this specification only indicate the features, integers, steps, operations, elements and / or parts that have been clearly identified, and do not exclude the presence and addition of one or more other features, integers, steps, operations, elements, parts and / or their combinations.

[0041] These and other features and characteristics of this specification, as well as the functions and methods of operation of the related structural elements, as well as the assembly of parts and manufacturing economies, will become more apparent from the following description of the accompanying drawings, which form a part of this specification. However, it should be understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of this specification. It should be understood that the drawings are not drawn to scale.

[0042] Figure 1FIG1 is a block diagram of an exemplary radiation therapy system 100 according to some embodiments of this specification. In some embodiments, the radiation therapy system 100 may be a multimodal imaging system, including, for example, a positron emission tomography-radiotherapy (PET-RT) system, a magnetic resonance imaging-radiotherapy (MRI-RT) system, and the like. For better understanding of this specification, an MRI-RT system will be used as an example of the radiation therapy system 100, and is not intended to limit the scope of this specification.

[0043] like Figure 1 As shown, the radiation therapy system 100 may include a treatment device 110, one or more processing devices 120, a network 130, a storage device 140, and one or more terminal devices 150. In some embodiments, the treatment device 110, the one or more processing devices 120, the storage device 140, and / or the terminal device 150 may be connected and / or communicate with each other via a wireless connection (e.g., a wireless connection provided by the network 130), a wired connection (e.g., a wired connection provided by the network 130), or any combination thereof.

[0044] The treatment device 110 may include a magnetic resonance imaging component (hereinafter referred to as an "MRI device"). The MRI device can generate image data related to a magnetic resonance imaging signal (hereinafter referred to as an "MRI signal") by scanning a subject or a portion of a subject. In some embodiments, the subject may include a human body, a substance, an object, etc., or any combination thereof. In some embodiments, the subject may include a specific part, a specific organ, or a specific tissue of the human body, such as the head, brain, neck, body, shoulder, arm, chest, heart, stomach, blood vessel, soft tissue, knee, foot, etc., or any combination thereof. In some embodiments, the treatment device 110 may send the image data to one or more processing devices 120, storage device 140, and / or terminal device 150 via the network 130 for further processing. For example, the image data may be sent to one or more processing devices 120 to generate an MRI image, or may be stored in the storage device 140.

[0045] The treatment device 110 may also include a radiotherapy component (hereinafter referred to as a "radiotherapy device"). The radiotherapy device can provide radiotherapy to a target area (e.g., a tumor). The radiation used here may include particle rays, photon rays, etc. Particle rays may include neutrons, protons, electrons, muons, heavy ions, alpha rays, etc., or any combination thereof. Photon rays may include X-rays, gamma rays, ultraviolet rays, lasers, etc., or any combination thereof. For illustrative purposes, a radiotherapy device related to X-rays is described as an example. In some embodiments, the treatment device 110 can generate a certain dose of X-rays with the assistance of image data provided by an MRI device to perform radiotherapy. For example, the image data can be processed to locate the tumor and / or determine the dose of the X-rays.

[0046] One or more processing devices 120 can process data and / or information obtained from the treatment device 110, the storage device 140 and / or the terminal device 150. For example, one or more processing devices 120 can process image data and reconstruct at least one MRI image based on the image data. For another example, one or more processing devices 120 can determine the position and radiation dose of the treatment area based on at least one MRI image. The benefits that MRI images can provide include, for example, superior soft tissue contrast, high resolution, and geometric accuracy, so that the treatment area can be accurately located. MRI images can be used to detect changes in the treatment area (for example, tumor regression or metastasis) during the determination of the treatment plan and during the implementation of the treatment, so that the original treatment plan can be adjusted accordingly. The original treatment plan can be determined before the start of treatment. For example, the original treatment plan can be determined at least one day, three days, one week, two weeks, or one month before the start of treatment.

[0047] In the original or adjusted treatment plan, the radiation dose can be determined based on, for example, the synthesized electron density information. In some embodiments, the synthesized electron density information can be generated based on MRI images.

[0048] In some embodiments, the one or more processing devices 120 may be a single processing device that communicates with the MRI device and the radiotherapy device of the treatment apparatus 110 and processes data. Alternatively, the one or more processing devices 120 may include at least two processing devices. One of the at least two processing devices may communicate with the MRI device of the treatment apparatus 110 and process data, and the other of the at least two processing devices may communicate with the radiotherapy device of the treatment apparatus 110 and process data. In some embodiments, the one or more processing devices 120 may include a treatment planning system. The at least two processing devices may communicate with each other.

[0049] In some embodiments, one or more processing devices 120 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, one or more processing devices 120 may be local or remote to the treatment device 110. For example, one or more processing devices 120 may access information and / or data from the treatment device 110, the storage device 140, and / or the terminal device 150 via the network 130. For another example, Figure 1 As shown by the dotted double arrows connecting the processing device 120 and the treatment device 110, one or more processing devices 120 can be directly connected to the treatment device 110; Figure 1As shown by the dashed bidirectional arrows connecting processing device 120 and terminal device 150, one or more processing devices 120 can be directly connected to terminal device 150 and / or storage device 140 to access information and / or data. In some embodiments, one or more processing devices 120 can be implemented on a cloud platform. Cloud platforms can include private clouds, public clouds, hybrid clouds, community clouds, distributed clouds, interconnected clouds, multiple clouds, or any combination thereof.

[0050] The network 130 may include any suitable network that can facilitate information and / or data exchange within the radiation therapy system 100. In some embodiments, one or more components of the radiation therapy system 100 (e.g., the treatment device 110, one or more processing devices 120, the storage device 140, or the terminal device 150) can communicate with one or more other components of the radiation therapy system 100 via the network 130 to obtain information and / or data. For example, one or more processing devices 120 can obtain image data from the treatment device 110 via the network 130. For another example, one or more processing devices 120 can obtain user instructions from the terminal device 150 via the network 130. The network 130 may include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN), a wide area network (WAN)), a wired network (e.g., an Ethernet network), a wireless network (e.g., an 802.11 network, a Wi-Fi network), a cellular network (e.g., a Long Term Evolution (LTE) network), a frame relay network, a virtual private network (“VPN”), a satellite network, a telephone network, a router, a hub, a switch, a server computer, the like, or any combination thereof. In some embodiments, the network 130 may include one or more network access points. For example, the network 130 may include wired and / or wireless network access points, such as base stations and / or Internet exchange points, through which one or more components of the radiation therapy system 100 may connect to the network 130 to exchange data and / or information.

[0051] The storage device 140 can store data, instructions, and / or any other information. In some embodiments, the storage device 140 can store data obtained from one or more processing devices 120 and / or terminal devices 150. In some embodiments, the storage device 140 can store data and / or instructions that can be executed or used by one or more processing devices 120 to perform the exemplary methods described in this specification. In some embodiments, the storage device 140 may include mass storage, removable storage, cloud-based storage, volatile read-write memory, read-only memory (ROM), etc., or any combination thereof. Exemplary mass storage may include magnetic disks, optical disks, solid-state disks, etc. Exemplary removable storage may include flash drives, floppy disks, optical disks, memory cards, compressed disks, magnetic tapes, etc. Exemplary volatile read-write memory may include random access memory (RAM). Exemplary RAM may include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), and zero-capacitance random access memory (Z-RAM). Exemplary read-only memories may include mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), compact disk read-only memory (CD-ROM), and digital versatile disk read-only memory, etc. In some embodiments, storage device 140 may be implemented on a cloud platform as described elsewhere in this specification.

[0052] In some embodiments, the storage device 140 can be connected to the network 130 to communicate with one or more other components of the radiation therapy system 100 (e.g., one or more processing devices 120 or terminal device 150). One or more components of the radiation therapy system 100 can access data or instructions stored in the storage device 140 via the network 130. In some embodiments, the storage device 140 can be part of one or more processing devices 120.

[0053] The terminal device 150 can be connected to the treatment device 110, one or more processing devices 120, and / or storage device 140, and / or communicate with the treatment device 110. For example, one or more processing devices 120 can obtain a scanning protocol from the terminal device 150. For another example, the terminal device 150 can obtain image data from the treatment device 110 and / or storage device 140. In some embodiments, the terminal device 150 may include a mobile device 151, a tablet computer 152, a laptop computer 153, or the like, or any combination thereof. For example, the mobile device 151 may include a mobile phone, a personal digital assistant (PDA), a gaming device, a navigation device, a point-of-sale (POS) device, a laptop computer, a tablet computer, a desktop computer, or the like, or any combination thereof. In some embodiments, the terminal device 150 may include input devices, output devices, and the like. Input devices may include alphanumeric and other keys that can be input via a keyboard, a touch screen (e.g., with tactile or haptic feedback), voice input, eye tracking input, a brain monitoring system, or any other similar input mechanism. Input information received via the input devices may be sent, for example, via a bus, to the one or more processing devices 120 for further processing. Other types of input devices may include cursor control devices, such as a mouse, trackball, or cursor direction keys. Output devices may include displays, speakers, printers, or any combination thereof. In some embodiments, terminal device 150 may be part of one or more processing devices 120.

[0054] This description is intended to illustrate, not to limit, the scope of this specification. Many alternatives, modifications, and variations will be apparent to those of ordinary skill in the art. The features, structures, methods, and characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and / or alternative exemplary embodiments. For example, the storage device 140 may be a data store comprising a cloud computing platform, such as a public cloud, a private cloud, a community cloud, a hybrid cloud, or the like. In some embodiments, one or more processing devices 120 may be integrated into the treatment device 110. However, such variations and modifications do not depart from the scope of this specification.

[0055] Figure 2 FIG. 2 is a flow chart of an exemplary process 200 for performing radiation therapy in a radiation therapy system according to some embodiments of the present disclosure. In some embodiments, Figure 2 One or more operations of process 200 shown in FIG. Figure 1 The radiation therapy system 100 shown in FIG. Figure 2 The process 200 shown in FIG. 1 may be stored in the form of instructions in the storage device 140 and executed by Figure 1For illustrative purposes, the process 200 is described by taking the implementation of the process 200 in one or more processing devices 120 as an example. It should be noted that the process 200 can also be similarly implemented in the terminal device 150.

[0056] In 202, one or more processing devices 120 may acquire magnetic resonance imaging (MRI) data regarding a region of interest (ROI) via an MRI apparatus. The MRI data may be MR signals from a subject received by an RF coil. A more detailed description of MR signals may be found elsewhere in this specification, such as FIG. 3 and its description.

[0057] In some embodiments, the ROI may refer to a treatment region associated with a tumor. The treatment region may be an area of a subject (e.g., a body, a substance, an object). In some embodiments, the ROI may be a specific part, organ, or tissue of the body, such as the head, brain, neck, body, shoulder, arm, chest, heart, stomach, blood vessels, soft tissue, knee, foot, or any combination thereof.

[0058] At 204, one or more processing devices 120 may reconstruct an MRI image associated with at least a portion of the ROI based on the MRI data. Based on the MRI data, the MR image may be reconstructed into a distribution of atomic nuclei within the subject. Various image reconstruction techniques may be employed during image reconstruction. Exemplary image reconstruction techniques may include Fourier reconstruction, constrained image reconstruction, and regularized image reconstruction in parallel MRI, or variations thereof, or any combination thereof.

[0059] MRI images can be used to determine radiation therapy for a tumor. For example, one or more processing devices 120 can determine the location of the tumor and the radiation dose based on the MRI images. In some embodiments, it may take at least several minutes to reconstruct an MRI image representing a larger imaging region. In some embodiments, to generate an MRI image in a relatively short time (e.g., per second), compared to an MRI image representing a larger imaging region, one or more processing devices 120 can reconstruct an initial image representing a smaller imaging region (e.g., at least a portion of the ROI) and then combine the initial image with the MRI image representing the larger imaging region. For example, one or more processing devices 120 can replace the portion of the MRI image representing the larger imaging region related to the ROI with the initial image. The MRI image representing the larger imaging region can include information about non-ROIs (e.g., healthy tissue) near the ROI and the ROI. In some embodiments, an MRI image representing the larger imaging region can be acquired and reconstructed prior to radiation therapy. For example, the MRI image representing the larger imaging region can be acquired less than one day, half a day, six hours, three hours, one hour, 45 minutes, 30 minutes, 20 minutes, 15 minutes, 10 minutes, five minutes, etc., before the radiation source begins emitting radiation beams for treatment. In some embodiments, an MRI image representing a larger imaging region may be retrieved from a storage device in the radiation therapy system 100 , such as the storage device 140 .

[0060] At 206, one or more processing devices 120 may determine a parameter related to the size of at least a portion of the ROI based on the MRI image. In some embodiments, the parameter related to the size of at least a portion of the ROI may include a characteristic cross-sectional dimension of the lesion (e.g., a tumor), the characteristic cross-sectional dimension being perpendicular to the direction of the radiation beam irradiating at least a portion of the ROI. As used herein, a characteristic cross-sectional dimension of a lesion may be the cross-sectional dimension of the lesion having the largest area among mutually parallel cross-sectional dimensions. In some embodiments, the ROI or a portion thereof may substantially conform to the characteristic cross-sectional dimension of the lesion. For example, for a circular ROI, the diameter of the ROI may be the same as or slightly larger (e.g., no more than 5%, 10%, 15%, 20%, 25%, 30%, 40%, or 50%) than the maximum dimension of the characteristic cross-sectional dimension of the lesion. For another example, for an elliptical or polygonal (e.g., square, rectangular, etc.) ROI, the area of the ROI may be the same as or slightly larger (e.g., no more than 5%, 10%, 15%, 20%, 25%, 30%, 40%, or 50%) than the area of the characteristic cross-sectional dimension of the lesion.

[0061] In some embodiments, a parameter related to the size of at least a portion of the ROI can represent a characteristic cross-sectional shape of the tumor. For example, a parameter related to the size of at least a portion of the ROI can represent whether the cross-sectional shape of the tumor is circular or nearly circular, and further represents a diameter of the circular or nearly circular shape. In some embodiments, to determine the parameter related to the size of at least a portion of the ROI, one or more processing devices 120 can extract texture information from the MRI image and determine a texture feature representing the ROI by identifying frequent texture patterns of the ROI in the extracted texture information. Then, one or more processing devices 120 can measure the size of the region in the MRI image that includes the texture feature and determine the parameter related to the size of the ROI.

[0062] At 208, one or more processing devices 120 may generate a control signal based on a parameter related to the size of at least a portion of the ROI. The control signal may be dynamically adjusted based on at least two MRI images taken at different time points (e.g., during a first radiation therapy session, during a second radiation therapy session, etc.). In some embodiments, the control signal may include parameters related to the radiation treatment of the tumor. For example, the control signal may include the dose of X-rays and the duration of the radiation beam. As another example, the control signal may include parameters of a multi-leaf collimator (MLC), which determines the shape of the radiation beam projected onto the subject. The MLC may include at least two separate leaves made of a high atomic number material (e.g., tungsten) that move in and out of the path of the radiation beam. The movement of some or all of the at least two leaves may be independent of each other. In some embodiments, the control signal may include parameters related to the movement of one or more components of the radiation therapy device. For example, the control signal may include parameters related to one or more positions of a radiation source of the radiation therapy device (e.g., the radiation therapy device in treatment apparatus 110, the radiation therapy device 300). For another example, the control signal may include parameters related to the height or position of the platform of the radiotherapy device (e.g., the position of the platform 308 of the treatment couch 330 along the axis of the magnet 302) to appropriately position the patient so that the patient's treatment area (e.g., a cancerous tumor) can appropriately receive the radiation beam from the radiotherapy device.

[0063] At 210, one or more processing devices 120 may send a control signal to the radiotherapy device to cause the radiotherapy device to apply therapeutic radiation. During radiotherapy, one or more components of the radiotherapy device may coordinate to emit therapeutic radiation. For example, the radiation source of the radiotherapy device (e.g., a linear accelerator) may rotate. Alternatively or additionally, the radiotherapy process may proceed based on parameters that vary over time. These parameters may include the dose of X-rays, the duration of the radiation beam from the radiation source, the shape of the MLC, and the position of the platform. In some embodiments, the radiation beam may only be emitted when the radiation source of the radiotherapy device is rotated to certain angles (e.g., 60 degrees, 120 degrees, 180 degrees, 240 degrees, 300 degrees, or 360 degrees). For example, intensity modulated radiation therapy (IMRT) may be applied. The radiation source may intermittently stop rotating. The radiation source may rotate to a desired position, pause at that position, emit a radiation beam, and then resume rotation. In some embodiments, the radiation source may rotate continuously and emit a radiation beam continuously or intermittently. In some embodiments, the radiation source may continuously emit a radiation beam while rotating.

[0064] In some embodiments, as described above, a treatment region (e.g., a region including a tumor) can be determined based on image data acquired from an MRI device. A radiation beam can then be generated by a radiation source of a radiotherapy device to perform radiation therapy on the treatment region. For example, the dose of the radiation beam and / or the location of the treatment region can be determined in real time with the assistance of the MRI device.

[0065] It should be noted that the above is provided for illustrative purposes only and is not intended to limit the scope of this specification. For those skilled in the art, various changes and modifications can be made based on the description of this specification. However, these changes and modifications will not deviate from the scope of this specification. For example, steps 202 and 204 can be performed simultaneously.

[0066] Figure 3A is a schematic diagram of an exemplary therapeutic device according to some embodiments of the present specification. Figure 3A As shown, treatment apparatus 110 may include an MRI scanner 310, a radiation therapy device 300, and a treatment couch 330. In some embodiments, MRI scanner 310 may generate MRI data as described in step 202, and radiation therapy device 300 may perform radiation therapy as described in step 210.

[0067] The MRI scanner 310 may include a bore 301, a magnet 302, one or more gradient coils (not shown), and one or more radio frequency (RF) coils (not shown). The MRI scanner 310 can be used to acquire image data from an imaging region. For example, the image data may be related to a treatment region associated with a tumor. In some embodiments, depending on the type of magnet 302, the MRI scanner 310 may be a permanent magnet MRI scanner, a superconducting electromagnetic MRI scanner, or a resistive electromagnetic MRI scanner. In some embodiments, depending on the strength of the magnetic field, the MRI scanner 310 may be a high-field MRI scanner, a medium-field MRI scanner, a low-field MRI scanner, or the like. In some embodiments, the MRI scanner 310 may be a closed-bore (cylindrical) type, an open-bore type, or the like.

[0068] The magnet 302 may be annular and may generate a static magnetic field B0 (or a main magnetic field B0). In some embodiments, the magnet 302 may be housed in a cryostat (e.g., a toroidal cryostat) containing a cooling medium (e.g., liquid helium). The magnet 302 may be of various types, including, for example, a permanent magnet, a superconducting electromagnet, a resistive electromagnet, and the like. A superconducting electromagnet may include one or more conductive coils made of a conductive material, such as niobium, vanadium, technetium alloy, and the like. For example, a superconducting electromagnet may be used to generate a large magnetic field required for the operation of the MRI scanner 310. In order to achieve superconductivity, the superconducting electromagnet may be maintained in a cryogenic environment with a temperature close to absolute zero. The MRI scanner 310 may use a cryostat containing a certain amount of cooling medium (e.g., liquid helium). The superconducting electromagnet consists of one or more conductive coils disposed in a cryostat. One or more conductive coils may be used to generate a main magnetic field B0 by circulating an electric current therein. The cryostat is not in Figure 3A Exemplary structures of cryostats can be found elsewhere in this specification (eg, cryostats 400, 400', 500, 500', 600, or 600' described below).

[0069] One or more gradient coils can generate magnetic field gradients to the main magnetic field B0 in the X, Y and / or Z directions (or axes). In some embodiments, one or more gradient coils may include an X-direction (or axis) coil, a Y-direction (or axis) coil, a Z-direction (or axis) coil, and the like. For example, the Z-direction coil can be designed based on a circular (Maxwell) coil, and the X-direction coil and the Y-direction coil can be designed based on a saddle (Golay) coil. As used herein, the X-direction may also be referred to as a readout (RO) direction (or frequency encoding direction), the Y-direction may also be referred to as a phase encoding (PE) direction, and the Z-direction may also be referred to as a slice selection encoding direction. In this specification, the readout direction and the frequency encoding direction may be used interchangeably.

[0070] By way of example only, the gradient magnetic field may include a slice selection gradient field corresponding to the Z direction, a phase encoding (PE) gradient field corresponding to the Y direction, and a readout (RO) gradient field corresponding to the X direction. Gradient magnetic fields in different directions can be used to encode spatial information in MR signals. In some embodiments, the gradient magnetic field may also be used to perform at least one of flow encoding, flow compensation, flow dephasing, or any combination thereof.

[0071] One or more RF coils can transmit RF pulses to a subject (e.g., a body, a substance, an object) under examination and / or receive MR signals therefrom. As used herein, RF pulses can include excitation RF pulses and refocusing RF pulses. In some embodiments, an excitation RF pulse (e.g., a 90-degree RF pulse) can deflect the magnetization vector from the direction of the main magnetic field B0. In some embodiments, a refocusing pulse (e.g., a 180-degree RF pulse) can rotate the dispersion spin isochromatic lines around an axis in the transverse plane, allowing the magnetization vector to later be rephased. In some embodiments, the RF coils can include an RF transmit coil and an RF receive coil. The RF transmit coil can transmit RF pulse signals that can excite nuclei in the subject to resonate at the Larmor frequency. The RF receive coil can receive MR signals transmitted from the subject. In some embodiments, the RF transmit coil and the RF receive coil can be integrated into a single coil, such as a transmit / receive coil. The RF coils can be of various types, including, for example, quotient-difference (QD) quadrature coils, phased array coils, and the like. In some embodiments, different RF coils 240 can be used to scan different parts of the body being examined, such as a head coil, a knee coil, a cervical spine coil, a thoracic spine coil, a temporomandibular joint (TMJ) coil, and the like. In some embodiments, RF coils can be categorized as volume coils and local coils based on their function and / or size. For example, volume coils may include birdcage coils, transverse electromagnetic coils, and surface coils. For another example, local coils may include solenoid coils, saddle coils, and flexible coils.

[0072] Radiation therapy device 300 may include a drum 312 and a base 307. Drum 312 may be annular. Drum 312 may be disposed around magnet 302 and intersect magnet 302 at the center of magnet 302 along axis 311 of bore 301. Drum 312 may house and support a radiation source for emitting a radiation beam toward a treatment area within bore 301. The radiation beam may be an X-ray beam, an electron beam, a gamma ray source, a proton beam, or the like. Drum 312 and the radiation source mounted thereon may rotate about axis 311 and / or a point known as the isocenter of bore 301. By way of example only, drum 312 and the radiation source mounted thereon may rotate about axis 311 at any angle, such as 90 degrees, 180 degrees, 360 degrees, 450 degrees, or 540 degrees. Drum 312 may be further supported by base 307.

[0073] It should be noted that the above is provided for illustrative purposes only and is not intended to limit the scope of this specification. A person skilled in the art would be able to make various changes or modifications based on the teachings of this specification. For example, the radiotherapy device 300 may further include a linear accelerator for accelerating electrons, ions, or protons, a dose detection device, a temperature control device (e.g., a cooling device), a multi-layer collimator, or any combination thereof. However, these changes and modifications do not deviate from the scope of this specification.

[0074] Treatment couch 330 may include a platform 308 and a base 309. In some embodiments, platform 308 may be movable in a horizontal direction and enter bore 301 of MRI scanner 310. In some embodiments, platform 308 may be movable in two, three, four, five, or six dimensions. In some embodiments, platform 308 may be movable based on changes (e.g., changes in position) of a tumor estimated, for example, from real-time MRI images acquired during treatment.

[0075] In some embodiments, the subject can be placed on platform 308 and brought into the MRI apparatus. In some embodiments, the subject can be a human patient. The human patient can lie on the platform 308 in a supine, prone, or side-lying position.

[0076] During treatment, the roller 312 can be arranged to rotate around the magnet 302. In some embodiments, the magnet 302 can include a groove (not shown) at its outer wall. The groove can be arranged around the entire circumference of the magnet 302. For example, the groove can have a ring shape around the magnet 302, thereby accommodating at least a portion of the roller 312. In some embodiments, the groove can be arranged around a portion of the circumference of the magnet 302. For example, the groove can have one or more arc shapes around the magnet 302.

[0077] In some embodiments, the radiation source can move along the entire rotation path within the groove. The radiation source can generate a radiation beam based on one or more parameters. Exemplary parameters may include parameters of the radiation beam, parameters of the radiation source, or parameters of the platform 308. For example, the parameters of the radiation beam may include irradiation intensity, irradiation angle, irradiation distance, irradiation area, irradiation time, intensity distribution, or the like, or any combination thereof. The parameters of the radiation source may include position, rotation angle, rotation speed, rotation direction, configuration of the radiation source, or the like, or any combination thereof. In some embodiments, the radiation source can generate a radiation beam taking into account energy loss of the radiation beam, because, for example, a magnet 302 located in the path of the radiation beam can absorb at least a portion of the radiation beam. For example, due to absorption by, for example, the magnet 302, the irradiation intensity of the radiation beam can be set to be greater than the irradiation intensity when there is no energy loss, thereby compensating for the energy loss so that a radiation beam of a specific intensity can be irradiated to the treatment area (e.g., a tumor).

[0078] Figure 3B is a schematic diagram of another exemplary therapeutic device according to some embodiments of the present specification. Figure 3A Compared to treatment device 110 in FIG. 1 , treatment device 110′ may utilize a gantry 306 instead of roller 312. Gantry 306 may be positioned on one side of magnet 302. Treatment head 304 may be mounted on gantry 306 via treatment arm 305. Treatment head 304 may house a radiation source (e.g., a linear accelerator). Gantry 306 may rotate treatment head 304 about axis 311 of aperture 301.

[0079] like Figure 3B As shown, groove 303 can be formed on the outer wall of magnet 302 and have an annular shape. Groove 303 can accommodate at least a portion of treatment tip 304 and provide a path for rotation of treatment tip 304. This arrangement can reduce the distance between treatment tip 304 and axis 311 of aperture 301 along the radial direction of magnet 302. In some embodiments, the reduced distance between treatment tip 304 and axis 311 of aperture 301 can increase the radiation dose reaching the treatment area (e.g., a tumor), thereby improving treatment efficiency. In some embodiments, the width of groove 303 along the Z direction (i.e., the axial direction of magnet 302) can be no less than the width of treatment tip 304 along the Z direction.

[0080] It should be noted that the above description of the treatment device 110 is provided for illustrative purposes only and is not intended to limit the scope of this specification. For those skilled in the art, various changes and modifications can be made based on the description of this specification. For example, the assembly and / or function of the treatment device 110 can be changed or altered according to the specific embodiment. In some embodiments, the magnet 302 of the MRI scanner 310 can also rotate relative to the treatment head 304. For example, the radiotherapy device 300 and the MRI scanner 310 can rotate synchronously or asynchronously around the same axis (e.g., axis 311). However, these changes and modifications do not deviate from the scope of this specification.

[0081] Figure 4A 4 is a cross-sectional view of an upper portion of an exemplary treatment device according to some embodiments of the present specification along the X direction. Treatment device 400 may include an MRI device (e.g., MRI scanner 310) for generating MRI data and a radiotherapy device (e.g., radiotherapy device 300) for applying therapeutic radiation. Figure 4A As shown, the MRI apparatus may include at least two main magnetic coils 401 , at least two shielding magnetic coils 402 and a cryostat 403 .

[0082] At least two main magnetic coils 401 and at least two shield magnetic coils 402 may be housed in a cryostat 403 and maintained in a superconducting state under certain conditions (eg, when the two coils are immersed in a cooling medium in the cryostat 403 ).

[0083] In some embodiments, the cryostat 403 may be arranged along an axis 405 (e.g., Figure 3A When the at least two main magnetic coils 401 carry current in a first direction, the at least two main magnetic coils 401 can be coaxially arranged along the axis 405 to generate a uniform magnetic field (e.g., a main magnetic field B0) in a specific area (e.g., an area within the hole 301).

[0084] The at least two shielding magnetic coils 402 may also be coaxially arranged along the axis 405 at a greater radius from the axis 405 than the at least two main magnetic coils 401. The at least two shielding magnetic coils 402 may carry current in a second direction opposite to the first direction. The at least two shielding magnetic coils 402 may be used to shield the magnetic field generated by the at least two main magnetic coils 401 in an external area of the MRI apparatus.

[0085] In some embodiments, the cryostat 403 may include one or more chambers surrounded by an annular structure arrangement. For example, the annular structure arrangement may include a plurality of annular structures, such as a first annular structure 421, a second annular structure 422, and a third annular structure 423. For illustration purposes only, Figure 4AAs shown, the cryostat 403 may include two chambers (e.g., a first chamber 403a and a second chamber 403b). The two chambers may be located on opposite sides of the cryostat 403 along the axial direction (i.e., the direction of the axis 405) and may be connected by a neck 430 between the two chambers. The radial dimension of the neck 430 may be smaller than the radial dimension of the two chambers. In some embodiments, each chamber may be annular with different outer walls. The outer wall may refer to the outer surface of the first annular structure 421 having an annular shape, for example Figure 7 The outer surface 721a of the first annular structure is shown. The two chambers and the neck can share the same inner wall, that is, the inner wall of the cryostat 403. In some embodiments, the inner wall can refer to the inner surface of the annular first annular structure 421, for example Figure 7 The inner surface 721b of the first annular structure shown. In some embodiments, the bore of the MRI device (e.g., the bore 301 of the MRI scanner 310) may include an area surrounded by the inner wall of the cryostat. In some embodiments, each chamber may accommodate at least one of at least two main magnetic coils 401 and at least one of at least two shielding magnetic coils 402. For example, at least one of the at least two main magnetic coils 401 may be arranged near the inner wall of the left chamber, and at least one of the at least two shielding magnetic coils 402 may be arranged near the outer wall of the left chamber. A gap 406 may be formed between the main magnetic coil arranged in the left chamber 403a and the main magnetic coil arranged in the right chamber 403b, thereby allowing the radiation beam generated by the radiotherapy device to pass through. The two chambers may be fluidically connected to each other via a neck therebetween. The cryostat 403 may contain a cooling medium in which the at least two main magnetic coils 401 and the at least two shielding magnetic coils 402 may be immersed to achieve a superconducting state. An exemplary cooling medium may be liquid helium. As Figure 4A As shown, at least two main magnetic coils 401 and at least two shielding magnetic coils 402 are immersed below the liquid surface 413 of liquid helium.

[0086] In some embodiments, the plurality of ring structures of the ring structure device can be arranged along the radial direction of the cryostat. Figure 7 , Figure 7 : is a cross-sectional view of an exemplary cryostat according to some embodiments of the present specification along the axial direction (i.e., Z direction) of the cryostat. It should be noted that the cryostat 700 can be the same as or similar to the cryostat described in the various embodiments of the present specification, such as the cryostat 403, 503, and 603. In some embodiments, the annular structure device can be considered as a tube-in-tube structure. For example, the first annular structure 421 surrounds the second annular structure 422, and the second annular structure 422 surrounds the third annular structure 423. Figure 7As shown, the outer and inner surfaces of the first, second, and third annular structures can be arranged radially along the cryostat. For example, the outer surface 721a of the first annular structure, the outer surface 722a of the second annular structure, the outer surface 723a of the third annular structure, the inner surface 723b of the third annular structure, the inner surface 722b of the second annular structure, and the inner surface 721b of the first annular structure are arranged from the outside of the cryostat to the inside. In some embodiments, the annular space surrounded by the inner surface 721b can extend along the axial direction 705 of the cryostat to form a bore for the MRI apparatus.

[0087] Return Reference Figure 4A , the first annular structure 421 may refer to a vacuum container for providing a vacuum space, which may surround one or more chambers (e.g., a left chamber and a right chamber). The second annular structure 422 may refer to a heat shield for reducing heat transfer from the first annular structure 421 to the third annular structure 423. The third annular structure 423 may refer to a cryogenic container for containing a cooling medium (e.g., liquid helium) for cooling at least two main magnetic coils 401 and at least two shielding magnetic coils 402. The heat shield may be disposed in the vacuum space between the cryogenic container and the vacuum container. In some embodiments, each of the multiple annular structures may be made of various materials to maintain the structural strength of the cryostat 403 and reduce radiation interference. More details about the materials from which the multiple annular structures are made can be found elsewhere in this specification (e.g., Figure 4C and its description).

[0088] In some embodiments, an annular structure device may be provided with an annular groove. Each annular structure may have a corresponding groove. Figure 4A As shown, a groove 408 may be provided at a radial position between the inner wall of the cryostat 403 (e.g., the inner surface of the first annular structure 421) and the outer walls of different chambers (e.g., two portions of the outer surface of the first annular structure 421 corresponding to the first and second chambers, respectively). The groove 408 may have an opening 407 formed between the outer surfaces of the first annular structure 421 corresponding to the first and second chambers. In some embodiments, in perspective view, the groove 408 may be annular. The annular ring may have the same or different widths (i.e., the axial dimension) at different radial positions or portions of the annular ring. The groove 408 may have a depth 440 (i.e., the thickness of the ring in the radial direction), which is defined as the distance in the radial direction from the opening 407 to the outermost surface of the neck of the cryostat 403.

[0089] In some embodiments, recess 408 may be used to accommodate one or more components of a radiotherapy device. Figure 4AAs shown, recess 408 can accommodate a radiation source, such as a linear accelerator, which includes an accelerator 409 , a magnetic shielding structure 411 , a primary collimator 412 , a target 404 , and a multi-leaf collimator (MLC) 410 .

[0090] The accelerator 409 can be used to accelerate charged subatomic particles or ions to high speeds. In some embodiments, the accelerator 409 can use microwave technology to accelerate electrons. For example, the accelerator 409 can use RF electromagnetic waves to accelerate electrons in an electron beam with energies between 4 MeV and 22 MeV.

[0091] The accelerator 409 may be mounted on a gantry or drum (e.g., gantry 306 or drum 312) that is rotatable about axis 405 and that enables the radiation beam to be emitted from any circumferential position. Figure 4A As shown, the gantry or drum can be rotated to a first position so that the accelerator 409 can be positioned above the axis 405. The accelerator 409 can include an accelerating waveguide (tube) whose axis is perpendicular to the axis 405. The accelerating waveguide (tube) can provide a linear path for accelerating electrons along an electron beam path perpendicular to the axis 405.

[0092] At least a portion of the accelerator 409 is surrounded by a shielding structure 411. In some embodiments, the shielding structure 411 can provide a cavity coaxial with the longitudinal axis of the accelerator 409 tube, with at least one end open to allow the radiation beam emitted by the accelerator 409 to pass through. In some embodiments, the accelerator 409 can be surrounded or substantially surrounded by the magnetic shielding structure 411. The magnetic shielding structure 411 can have any configuration. For example, the magnetic shielding structure 411 can include a first plate located on one side of the accelerator 409 along the circumference of the groove 408 and a second plate located on an opposite side of the accelerator 409 along the circumference of the groove 408. The first and second plates can be symmetrical with respect to the axis of the accelerator 409. The first and second plates can form an enclosure to surround and / or contain the accelerator 409. Each of the first and second plates can have a shape similar to an "I" character, providing a continuous path along the axial direction of the cryostat 803 for the magnetic field to pass through. Because the two plates of the magnetic shielding structure 411 are made of materials with high magnetic susceptibility and / or permeability, the magnetic field can be conducted through the two plates and away from the region formed between the two plates, thereby achieving magnetic shielding for the accelerator 409. It should be noted that the magnetic shielding structure 411 can be of any shape, as long as at least one end of the magnetic shielding structure 411 is open to allow the radiation beam emitted by the accelerator 409 to pass through. Further description of embodiments of the magnetic shielding structure can be found, for example, in International Application PCT / CN2018 / 115394.

[0093] In some embodiments, the magnetic shielding structure 411 may include at least two magnetic shielding layers. At least one of the at least two magnetic shielding layers may be used to reduce magnetic interference between one or more components of the MRI device and the radiotherapy device. For example, the magnetic shielding structure 411 may include a magnetic shielding layer for shielding the magnetic field generated by the MRI device (e.g., the main magnetic coil, the shielding magnetic coil, and the gradient coil) to prevent electrons from being affected by the magnetic field.

[0094] Additionally, at least one of the at least two magnetic shielding layers can be used to reduce RF and / or microwave interference between one or more components of the MRI device and the radiotherapy device. For example, the magnetic shielding structure 411 can include an electromagnetic shielding layer for shielding RF signals generated by the MRI device (e.g., an RF coil) and microwaves generated by the radiotherapy device.

[0095] The at least two magnetic shielding layers can be made of the same material and / or different materials. For example, both the electromagnetic shielding layer and the magnetic shielding layer can be made of a material with high magnetic susceptibility and permeability (e.g., non-oriented silicon steel), or one of the electromagnetic shielding layer and the magnetic shielding layer can be made of a material with high electrical conductivity and permeability. In some embodiments, the at least two magnetic shielding layers can be magnetically and / or electrically isolated from each other. In some embodiments, the at least two magnetic shielding layers can be made of a suitable dielectric material, such as air or plastic.

[0096] Alternatively or additionally, at least one of the at least two magnetic shielding layers can be used to protect one or more components of the MRI device from radiation generated by the accelerator 409. For example, one of the at least two magnetic shielding layers can be made of a material that can absorb radiation generated by the radiation beam of the accelerator 409. Exemplary materials that can absorb radiation may include materials for absorbing photon rays and / or materials for absorbing neutron rays. Materials that absorb photon rays may include steel, aluminum, lead, tungsten, etc. Materials that absorb neutron rays may include boron, graphite, etc. It should be noted that in some embodiments, the magnetic shielding structure 411 may be made only of radiation absorbing materials, without containing high magnetic susceptibility and permeability materials. In this way, the magnetic shielding structure 411 can provide radiation shielding only for one or more components of the MRI device.

[0097] Target 404 can be used to receive accelerated charged subatomic particles or ions (e.g., an electron beam) to generate a radiation beam for radiotherapy. For example, based on the bremsstrahlung effect, the electron beam can collide with target 404 to generate high-energy X-rays. In some embodiments, target 404 can be located near the exit window of accelerator 409 to receive the accelerated electron beam. In some embodiments, target 404 can be made of a material including aluminum, copper, silver, tungsten, etc., or any combination thereof. Alternatively, target 404 can be made of a composite material including tungsten and copper, tungsten and silver, tungsten and aluminum, etc., or any combination thereof.

[0098] The radiation beam from target 404 may pass through a primary collimator 412 to form a beam having a particular shape (eg, a cone beam).

[0099] The MLC 410 can be used to reshape the radiation beam. For example, the MLC 410 can adjust the irradiation shape, irradiation area, etc. of the radiation beam. The MLC 410 can be placed at any position along the path of the radiation beam. For example, Figure 4A As shown, the MLC 410 can be placed close to the accelerator 409. Therefore, after being reshaped by the MLC 410, the radiation beam can further pass through the neck of the cryostat 403 and the gap 406 between the at least two main magnetic coils to reach the treatment area. For another example, the MLC 410 can be placed at a relatively far distance from the accelerator (e.g., Figure 6A ), so that the MLC 410 can be closer to, for example, a patient to be irradiated.

[0100] The MLC 410 can be held stationary relative to the accelerator 409, thereby rotating with the accelerator 409 about the axis 405. The MLC 410 can include at least two separate blades of a high atomic number material (e.g., tungsten) that independently move in and out of the path of the radiation beam to block the radiation beam. As the at least two separate blades move in and out, the shape of the radiation beam can change, forming different slots that simulate a rotation from the axis of the radiation beam (i.e., Figure 4A 4 (shown as a vertical dashed line 416 in FIG). In some embodiments, MLC 410 may include one or more blades. For example, MLC 410 may have only one layer of blades, and the height of MLC 410 along the axis of the radiation beam may be between 7 and 10 centimeters. For another example, MLC 410 may have two layers, and the height of MLC 410 may be at least 15 centimeters.

[0101] Figure 4B FIG is a cross-sectional view of the upper portion of an exemplary treatment device 400' along the X direction according to some embodiments of the present specification. Figure 4A Compared to the treatment device 400 described in , at least a portion of the accelerator 409 of the treatment device 400' may be located outside the groove 408 in the radial direction of the cryostat 403. Figure 4B As shown, the accelerator 409 and a magnetic shielding structure 411 surrounding the accelerator 409 along the axis of the radiation beam can extend out of an opening 407 formed by the outer wall of the cryostat 403. In some embodiments, the accelerator 409 and the magnetic shielding structure 411 can be supported by or mounted to a frame or drum (e.g., frame 306 or drum 312) that is capable of rotating about the axis 405.

[0102] Figure 4C FIG. 1 is a cross-sectional view of the upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification. Figure 4A or Figure 4B As described above, the two chambers of the cryostat 403 can be formed by an annular structure assembly including a first annular structure 421, a second annular structure 422, and a third annular structure 423. In some embodiments, the first annular structure 421 can be a vacuum container, the second annular structure 422 can be a heat shield, and the third annular structure 423 can be a cryogenic container.

[0103] In radiotherapy using a radiotherapy device as described herein, before the radiation beam (e.g., high-energy X-rays) reaches the treatment area (e.g., lesions), the radiation beam may need to pass through multiple annular structures of the cryostat 403 and the cooling medium (e.g., liquid helium) therein. In the process of passing through the multiple annular structures, the radiation beam may be scattered, thereby affecting the dose rate of the radiotherapy. The degree of influence can be assessed by the degree of scattering of the radiation beam. For example, if the degree of scattering is large, a substantial drop in the intensity of the radiation beam may occur. Therefore, due to the weakening of the radiation energy compared to the plan, the lesion may not be effectively treated. The degree of scattering of the radiation beam can be reduced by designing the structure of the cryostat 403.

[0104] The degree of scattering can depend on the effective thickness of the cryostat and / or the depth of the cooling medium contained in one or more chambers of the cryostat. As used herein, effective thickness is defined as the product of the physical thickness (i.e., actual thickness) of an object and its density. In one aspect, the degree of scattering can be reduced by reducing the effective thickness of the cryostat compared to conventional cryostats. In another aspect, the degree of scattering can be reduced by controlling the depth of the cooling medium in one or more chambers.

[0105] The effective thickness of the cryostat may be related to the effective thickness of at least one of the plurality of annular structures of the cryostat, such as the first annular structure 421, the second annular structure 422, and the third annular structure 423. The effective thickness may be determined based on the physical thickness of the solid walls of the annular structure and the density of the material of each solid wall of the annular structure. For example, for an annular structure having two solid walls made of the same material, the effective thickness of the annular structure (L eff ) can be equal to the product of the physical thickness of the two solid walls (L) and the density of the solid wall material (D), that is, L eff = L × D. For another example, if the cryostat has multiple annular structures with a total of N solid walls, the physical thickness of each solid wall is L i And the density is D i If it is made of material, the effective thickness (L eff) can be equal to the physical thickness of the ith solid wall (L i ) and the material density of the i-th solid wall (D i ), that is, In some embodiments, under the condition of the structural strength of the cryostat, the effective thickness of at least one of the plurality of annular structures can be designed to be relatively small by using one or more suitable materials to form the annular structure. For example, at least one of the plurality of annular structures can be made of a metal material and a reinforcing material.

[0106] For most conventional cryostats, each of the multiple annular structures can be made of only the same or different metal materials. For example, the first annular structure 421 can be made of stainless steel, the second annular structure 422 can be made of aluminum, and the third annular structure 423 can be made of stainless steel. Due to the high density of the metal materials used, the effective thickness of each annular structure also becomes larger. In order to effectively reduce the effective thickness of the annular structure and maintain qualified structural strength, the annular structure can be made of different materials, including metal materials and reinforcing materials. The reinforcing material can be selected based on one or more properties of the material. The one or more properties may include low density, high mechanical strength, radiation resistance, heat resistance, etc. or any combination thereof. Exemplary reinforcing materials may include carbon fiber, glass fiber, aramid fiber, silicon carbide (SiC) fiber, asbestos fiber, whisker, graphene fiber, alloy material, etc.

[0107] For example, the first annular structure 421 can be made of stainless steel and carbon fiber. The effective thickness of the first annular structure 421 can be less than the effective thickness of a conventional first structure made only of stainless steel. For another example, the second annular structure 422 can be made of aluminum and carbon fiber. The effective thickness of the second annular structure 422 can be less than the effective thickness of a conventional second structure made only of aluminum. For another example, the third annular structure 423 can be made of stainless steel and carbon fiber. The effective thickness of the third annular structure 423 can be less than the effective thickness of a conventional third structure made only of stainless steel. As described above, the effective thickness of the cryostat can be designed to have a relatively small value compared to a conventional cryostat. In this way, the degree of scattering of the radiation beam passing through the cryostat can be reduced.

[0108] In some embodiments, the radiation beam is less scattered because the first annular structure 421 and the second annular structure 422 are relatively thinner than the third annular structure 423. In some embodiments, the first annular structure 421 and the second annular structure 422 can be made of corresponding conventional metal materials, while the third annular structure 423 can be made of a different material. Figure 4CAs shown in the enlarged structural diagram of a portion 420 of the annular structure of the medium and low temperature thermostat 403, the first annular structure 421 can be made of stainless steel 4211, the second annular structure 422 can be made of aluminum 4221, and the third annular structure 423 can be made of stainless steel 4231 and a reinforcing material 4232 (e.g., carbon fiber).

[0109] In some embodiments, when a radiation source (e.g., a linear accelerator) is rotated at a particular angle, the radiation beam may pass through an uneven portion of the cooling medium and be scattered. To address these and similar issues, one or more chambers of the cryostat may be designed so that the radiation beam always passes through a uniform cross-section of the cooling medium when the radiation source is rotated at various angles. Figure 4C As shown, the cryostat 403 may include a first chamber 403a and a second chamber 403b. The first chamber 403a and the second chamber 403b may be formed by a recessed neck portion of the cryostat (e.g., Figure 4A The two chambers of cryostat 403 can be equivalent to two sides of a connected container, that is, cryostat 403 can be equivalent to a connected container. According to the theory of connected containers, the liquid level in the left chamber and the liquid level in the right chamber can be at the same level. When the liquid level of the cooling medium in the two chambers (for example, liquid level 413) is higher than the height of the neck of cryostat 403, the neck can be filled with cooling medium; there is no portion of the neck that is not filled with cooling medium. The presence of a portion of the neck that is not filled with cooling medium may increase the degree of scattering of the radiation beam.

[0110] like Figure 4C As shown, reference numeral 440 represents the liquid level of the cooling medium, and reference numeral 430 represents the height (e.g., radial length) of the neck portion of the cryostat 403. If it is desired that the neck portion be filled with cooling medium, height 440 may always be greater than height 430. In this case, the radiation beam can pass through a uniform cooling medium when the radiation source is rotated at various angles. Therefore, the radiation beam passing through the cryostat 403 can be relatively uniform, and the quality of radiotherapy can be improved accordingly. When the neck portion is filled with cooling medium, the dose of the radiation beam passing through the cryostat can be guaranteed, regardless of the rotation angle of the radiation source.

[0111] In some embodiments, one or more liquid level sensors may be installed on the cryostat 403. The one or more liquid level sensors are used to detect the liquid level of the cooling medium in each chamber of the cryostat 403. For example, when the liquid level of the cooling medium is lower than the liquid level limit, the processing device 120 may generate an alarm to notify the user (e.g., operator) to open the cold head ( Figure 4C(not shown) injects cooling medium into cryostat 403. In some embodiments, the liquid level limit can be a value greater than height 430. In some embodiments, the one or more liquid level sensors can include a sight glass liquid level sensor, an ultrasonic sensor, a laser sensor, an infrared sensor, etc., or any combination thereof.

[0112] It should be noted that the above description of the treatment device 400 or 400' is provided for illustrative purposes only and is not intended to limit the scope of this specification. A person skilled in the art would be able to make various changes and modifications based on the description of this specification. For example, the primary collimator 412 and the MLC 410 could be integrated to form a single collimator. For another example, the neck shown in the cryostat 403 may not form a complete ring. Specifically, the neck may be a discrete arc connecting the left and right chambers of the cryostat 403. Thus, when the accelerator 409 rotates about the axis 405, the neck may intermittently appear in the path of the radiation beam to generate the radiation beam.

[0113] Figure 5A FIG is a cross-sectional view of the upper portion of an exemplary treatment device according to some embodiments of the present specification along the X direction. Figure 5A As shown, a treatment device 500 may include at least two main magnetic coils 501, at least two shielding magnetic coils 502, a cryostat 503 having an axis, a target 504, a gap 506, an opening 507, a groove 508, an accelerator 509, an MLC 510, a shielding structure 511, a primary collimator 512, and a deflection unit 513. The at least two main magnetic coils 501, the at least two shielding magnetic coils 502, the cryostat 503, the target 504, the axis 505, the gap 506, the opening 507, the groove 508, the MLC 510, and the primary collimator 512 may be similar to the at least two main magnetic coils 401, the at least two shielding magnetic coils 402, the cryostat 403, the target 404, the axis 405, the gap 406, the opening 407, the groove 408, the MLC 410, and the primary collimator 412, and a description thereof will not be repeated herein.

[0114] Unlike accelerator 409, the axis of the accelerating waveguide (tube) of accelerator 509 can be parallel to axis 505. Therefore, the accelerating waveguide (tube) can provide a linear path (also known as a "parallel beam path") for accelerating electrons along an electron beam path parallel to axis 505. At least two main magnetic coils 501 and at least two shielding magnetic coils 502 can generate a magnetic field parallel or substantially parallel to axis 505 (also known as a "parallel magnetic field"). It should be understood that the parallel magnetic field can have a minimal impact on the parallel beam path. Therefore, accelerator 509 can help reduce the impact of the magnetic field generated by the MRI device on electrons. Similarly, at least a portion of the accelerating waveguide (tube) of accelerator 509 can be surrounded by a magnetic shielding structure 511. The magnetic shielding structure 511 can be continuously distributed along the direction of axis 505. In some embodiments, the magnetic shielding structure 511 can extend along the axis to cover both ends of the accelerator, which means that the magnetic shielding structure 511 can have a larger dimension along the axis than the accelerator 509. The magnetic shielding structure 511 can be used to further reduce interference from the magnetic field generated by the MRI device. Further description of embodiments of magnetic shielding structures can be found, for example, in international application PCT / CN2018 / 115394.

[0115] The deflection unit 513 can be used to deflect accelerated electrons from the parallel beam path onto the target 504. In some embodiments, the deflected electrons can impact the target 504 perpendicularly, so the deflection angle of the electrons can be 90 or 270 degrees. In some embodiments, the deflection unit 513 can include one or more magnets for providing a deflection magnetic field to deflect the accelerated electrons.

[0116] like Figure 5A As shown, the accelerator 509 and the deflection unit 513 are both disposed within the recess 508. In some embodiments, there is no shielding magnetic coil that "covers" the accelerator 509 and / or the deflection unit 513 in the radial direction of the cryostat 503. That is, there is no overlap between the axial positions of the plurality of magnetic shielding magnetic coils 502 and the axial positions of the accelerator 509 and / or the deflection unit 513. In addition, the cryostat 503 may have a continuous body (i.e., a body that provides continuous fluid flow) in the radial direction of the cryostat 503, which accommodates at least two main magnetic coils 501 and at least two shielding magnetic coils 502.

[0117] The ring structure of the cryostat 503 can be configured as Figure 4A 、 Figure 4B or Figure 4C The cryostat 403 is the same or similar as shown. Figure 5A As shown, the first annular structure 521, the second annular structure 522 and the annular structure 523 may be arranged along the radial direction of the cryostat 503 (for example, referring to FIG. Figure 7In some embodiments, the first annular structure 521 may be a vacuum container, the second annular structure 522 may be a heat shield, and the third annular structure 523 may be a cryogenic container. Multiple annular structures may surround two chambers for containing cooling medium. More description of the multiple annular structures of the annular structure device can be found elsewhere in this specification (e.g., Figures 4A-4C and its description).

[0118] Figure 5B FIG is a cross-sectional view of the upper portion of another exemplary treatment device according to some embodiments of the present specification along the X direction. Figure 5A Compared to the treatment device 500 described in the foregoing, at least a portion of the accelerator 509 of the treatment device 500' may be located outside the groove 508 in the radial direction of the cryostat 503. Figure 5B As shown, the accelerator 509, the magnetic shield structure 511, and the deflection unit 513 can at least partially extend out of the opening 507 formed by the outer wall of the cryostat 503. In some embodiments, the accelerator 509 and the magnetic shield structure 511 can be supported by or mounted on a frame or drum (e.g., the frame 306 or the drum 312) that is capable of rotating about the axis 505.

[0119] Figure 5C FIG. 1 is a cross-sectional view of the upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification. Figure 4CCryostat 503 can be similar to cryostat 403. The first annular structure 521 can be made of stainless steel 5211, the second annular structure 522 can be made of aluminum 5221, and the third annular structure 523 can be made of stainless steel 5231 and a reinforcing material 5232 (e.g., carbon fiber). Compared to a conventional third annular structure made solely of stainless steel, the effective thickness of the third annular structure 523 can be reduced due to the low density of the reinforcing material (compared to stainless steel). Reducing the effective thickness of the third annular structure 523 can reduce the effective thickness of the cryostat 503. In this manner, the degree of scattering of the radiation beam passing through the cryostat 503 can be reduced. Furthermore, according to the container communication theory, the cryostat 503 can include a first chamber 503a and a second chamber 503b. The liquid levels of the first chamber 503a and the second chamber 503b can be at the same level. When the height 540 of the coolant (e.g., liquid helium) is higher than the height 530 of the neck of the cryostat 503, no portion of the neck is not filled with coolant. When the radiation beam passes through the cooling medium portion of the neck, the degree of scattering of the radiation beam can be reduced. Therefore, the radiation beam passing through the cryostat 503 can be relatively uniform. The quality of radiotherapy can be improved accordingly. In some cases, when the neck is filled with cooling medium, the dose of the radiation beam passing through the cryostat can be guaranteed without being affected by the rotation angle of the radiation source. More description of the structure of the cryostat 503 can be found in conjunction with Figure 4C The description is not repeated here.

[0120] In some embodiments, one or more liquid level sensors may be installed on the cryostat 503. One or more liquid level sensors may be used to detect the liquid level of the cooling medium in each chamber of the cryostat 503. For example, when the liquid level of the cooling medium is lower than the liquid level limit, the processing device 120 may generate an alarm to notify the user (e.g., operator) to remove the cooling medium through the cold head ( Figure 4C (not shown) injects cooling medium into cryostat 503. In some embodiments, the liquid level limit can be a value greater than height 530. In some embodiments, the one or more liquid level sensors can include a sight glass liquid level sensor, an ultrasonic sensor, a laser sensor, an infrared sensor, etc., or any combination thereof.

[0121] The above description of the treatment device 500 or 500' is provided for illustrative purposes only and is not intended to limit the scope of this specification. A person skilled in the art would readily appreciate that various changes and modifications may be made based on the description herein. For example, the primary collimator 512 and the MLC 510 may be integrated to form a single collimator. For another example, the neck shown in the cryostat 503 may not form a complete ring. Specifically, the neck may be a discrete arc connecting the left and right chambers of the cryostat 503. Thus, as the accelerator 509 rotates about the axis 505, the neck may intermittently appear in the path of the radiation beam to generate the radiation beam.

[0122] Figure 6A FIG is a cross-sectional view of the upper portion of an exemplary treatment device according to some embodiments of the present specification along the X direction. Figure 6A As shown, the treatment device 600 may include at least two main magnetic coils 601, at least two shielding magnetic coils 602, a cryostat 603 having an axis 605, a target 604, a first opening 607, a second opening 615, a groove 608, an accelerator 609, an MLC 610, a magnetic shielding structure 611, a primary collimator 612, and a deflection unit 613. The at least two main magnetic coils 601, the at least two shielding magnetic coils 602, the target 604, the axis 605, the first opening 607, the groove 608, the accelerator 609, the primary collimator 612, and the deflection unit 613 may be similar to the at least two main magnetic coils 501, the at least two shielding magnetic coils 502, the target 504, the axis 505, the opening 507, the groove 508, the accelerator 509, the primary collimator 512, and the deflection unit 513, and are not further described herein.

[0123] Compared to MLC 510 shown in FIG5 , MLC 610 can be radially farther from accelerator 609, allowing MLC 610 to be closer to, for example, a treatment area to be irradiated. It should be noted that the closer the MLC is to the treatment area, the more precisely the shape of the radiation beam irradiating the treatment area can be controlled by the MLC.

[0124] The inner wall of the cryostat 603 may have a recessed structure to accommodate the MLC 610. Similar to the recessed structure 608 having a first opening 607 formed between the outer walls of the two chambers of the cryostat 603, the recessed structure may have a second opening 615 formed between the inner walls of the two chambers of the cryostat 603. The recessed structure may be annular and coaxial with the recessed structure 608. The recessed structure and the recessed structure 608 may be separated by a neck of the cryostat 603. That is, the outermost surface of the neck forms the innermost boundary of the recessed structure, and the innermost surface of the neck forms the outermost boundary of the recessed structure. The recessed structure may have a depth along the radial direction of the cryostat 603 that is greater than the height of the MLC 610 along the radiation beam axis. In some embodiments, one or more of the at least two main magnetic coils 601 (e.g., 601a) may be arranged around the recessed structure along the axis 605. The main magnetic coil 601a and the remaining main magnetic coils can form a stepped structure in the left and right chambers of the cryostat 603. The main magnetic coil 601a can have a larger radius from the axis 605 than the remaining main magnetic coils. In addition, gaps 606 can be formed between the main magnetic coils 601a to allow the radiation beam to pass through. In some embodiments, the main magnetic coils may not be arranged around a recessed structure along the axis 605, so that all main magnetic coils 601 can be arranged around the inner wall of the cryostat 603 and have the same radius from the axis 605.

[0125] Figure 6B FIG is a cross-sectional view of the upper portion of another exemplary treatment device according to some embodiments of the present specification along the X direction. Figure 6A Compared to the treatment device 600 described in the foregoing, at least a portion of the accelerator 609 of the treatment device 600' can be located outside the groove 608 along the radial direction of the cryostat 603. Figure 6B As shown, the accelerator 609, the shield structure 611, and the deflection unit 613 can at least partially extend out of the opening 607 formed by the outer wall of the cryostat 603. In some embodiments, the accelerator 609, the shield structure 611, and the deflection unit 613 can be supported by or mounted to a frame or roller (e.g., the frame 306 or the roller 312) that is capable of rotating about the axis 605.

[0126] Figure 6C FIG. 1 is a cross-sectional view of the upper portion of another exemplary cryostat along the X direction according to some embodiments of the present specification. Figure 4CAs described in Figure 5C, in the cryostat 603, the first annular structure 621 can be made of stainless steel 6211, the second annular structure 622 can be made of aluminum 6221, and the third annular structure 623 can be made of stainless steel 6231 and a reinforcing material 6232 (e.g., carbon fiber). Compared to a conventional third annular structure 623 made solely of stainless steel, the effective thickness of the third annular structure 623 can be reduced due to the low density of the reinforcing material (compared to stainless steel). By reducing the effective thickness of the third annular structure 623, the effective thickness of the cryostat 603 can be reduced. In this case, the degree of scattering of the radiation beam passing through the cryostat 603 can be reduced. Furthermore, based on the theory of container communication, the cryostat 603 can include a first chamber 603a and a second chamber 603b. The liquid levels in the first chamber 603a and the second chamber 603b can be at the same level. When the height 640 of the coolant (e.g., liquid helium) is higher than the height 630 of the cryostat neck, there is no portion of the neck that is not filled with coolant. When the radiation beam passes through the uniform cooling medium in the neck, the degree of scattering of the radiation beam can be reduced. Therefore, the radiation beam passing through the cryostat 603 can be relatively uniform. The radiotherapy effect can be improved accordingly. In some cases, when the neck is filled with cooling medium, the dose of the radiation beam passing through the cryostat can be guaranteed without being affected by the rotation angle of the radiation source. More description of the structure of the cryostat 603 can be found in conjunction with Figure 4C or Figure 5C , I will not go into details here.

[0127] In some embodiments, one or more liquid level sensors may be installed on the cryostat 603. One or more liquid level sensors may be used to detect the liquid level of the cooling medium in each chamber of the cryostat 503. For example, when the liquid level of the cooling medium is lower than the liquid level limit, the processing device 120 may generate an alarm to notify the user (e.g., operator) to remove the cooling medium through the cold head ( Figure 4C (not shown) injects cooling medium into the cryostat 603. In some embodiments, the liquid level limit can be a value greater than the height 630. In some embodiments, the one or more liquid level sensors can include a sight glass liquid level sensor, an ultrasonic sensor, a laser sensor, an infrared sensor, etc., or any combination thereof.

[0128] It should be noted that the above description of treatment device 600 or 600' is provided for illustrative purposes only and is not intended to limit the scope of this specification. Numerous variations and modifications are possible within the scope of this specification, as will be apparent to those skilled in the art. For example, the neck portion shown in cryostat 603 may not form a complete ring. Specifically, the neck portion may be a discrete arc connecting the left and right chambers of cryostat 603. Thus, as accelerator 609 rotates about axis 605, the neck portion may intermittently appear in the path of the radiation beam to generate the radiation beam.

[0129] The basic concepts have been described above. It will be apparent to those skilled in the art after reading this application that the above disclosures are provided for illustrative purposes only and do not constitute limitations on this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and revisions to this specification. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0130] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that the mention of "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification does not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0131] In addition, it will be understood by those skilled in the art that various aspects of this specification may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvement thereof. Accordingly, various aspects of this specification may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as a "unit," "module," or "system." In addition, various aspects of this specification may take the form of a computer program product embodied in one or more computer-readable media, wherein computer-readable program code is contained therein.

[0132] In addition, unless expressly stated in the claims, the order of the processing elements and sequences described in this specification, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the implementation of the various components described above can be embodied in a hardware device, it can also be implemented as a software-only solution, for example, installation on an existing server or mobile device.

[0133] Similarly, it should be noted that, in order to simplify the presentation of this specification and thereby facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this approach should not be interpreted as reflecting an intention that the claimed subject matter requires more features than expressly recited in each claim. Rather, the subject matter of the invention may have fewer features than the single embodiment described above.

[0134] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values are as accurate as possible within the feasible range.

[0135] All patents, patent applications, patent application publications, and other materials (such as articles, books, specifications, publications, records, things, and / or the like) referred to herein are hereby incorporated by reference in their entirety for all purposes, except any prosecution record related to such documents, any such documents that are inconsistent or conflicting with this document, or any such documents that limit the broad scope of the claims that may or may not be related to this document. For example, if there is any inconsistency or conflict between the descriptions, definitions, and / or terminology used in this document and any of the incorporated materials, the descriptions, definitions, and / or terminology used in this document shall prevail.

[0136] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A therapeutic device, characterized in that: include: A magnetic resonance imaging (MRI) apparatus for acquiring MRI data about a region of interest (ROI), wherein the MRI apparatus comprises an annular cryostat comprising: one or more chambers arranged along an axis of the annular cryostat; an annular structure arrangement surrounding the one or more chambers, wherein the annular structure arrangement comprises a plurality of annular structures through which the radiation beam passes, at least one of the plurality of annular structures being made of a metal material and a reinforcing material to reduce scattering of the radiation beam passing through the annular cryostat; and a radiotherapy apparatus for applying therapeutic radiation to at least a portion of the ROI, the radiotherapy apparatus comprising: an accelerator for accelerating electrons in an electron beam to generate said radiation beam of said therapeutic radiation; and One or more collimating components for shaping the radiation beam.

2. The treatment device according to claim 1, characterized in that The annular cryostat further includes at least one groove disposed on the annular structural device, the groove having an opening formed on at least one outer surface of the annular structural device.

3. The therapeutic device according to claim 2, characterized in that The one or more chambers include two chambers connected through a neck, and the groove is formed by at least the two chambers and the neck.

4. The treatment device according to claim 3, characterized in that The two chambers contain a cooling medium, and the neck is filled with the cooling medium.

5. The treatment device according to claim 4, characterized in that The annular structure device comprises: a first annular structure for providing a vacuum space enclosing the one or more chambers; a second annular structure for reducing heat transfer from the first annular structure to the third annular structure; and The third annular structure is used to accommodate the cooling medium.

6. The treatment device according to claim 4, characterized in that The cooling medium includes liquid helium.

7. The therapeutic device according to claim 1, characterized in that The reinforcing material has one or more properties of low density, high mechanical strength, radiation resistance or heat resistance.

8. The therapeutic device according to claim 1, characterized in that The reinforcing material includes one or more of carbon fiber, glass fiber, aramid fiber, silicon carbide (SiC) fiber, asbestos fiber, whisker, graphene fiber, and alloy material.

9. The treatment device according to claim 4, characterized in that The annular cryostat further includes one or more sensors for detecting a level of a cooling medium in each of the one or more chambers of the annular cryostat.

10. The treatment device according to claim 1, characterized in that At least a portion of the accelerator is surrounded by at least one shielding structure.

11. The treatment device according to claim 1, characterized in that The electron beam moves along an electron beam path parallel to an axis of the annular cryostat, the radiotherapy apparatus further comprising: target; and A beam deflecting unit is used to deflect electrons in the electron beam onto the target to generate the radiation beam of the therapeutic radiation.

12. A magnetic resonance imaging (MRI) apparatus comprising a ring-shaped cryostat, characterized in that: The annular cryostat comprises: one or more chambers arranged along an axis of the annular cryostat; An annular structure device surrounding the one or more chambers, wherein the annular structure device includes a plurality of annular structures, the radiation beam passes through the plurality of annular structures, and at least one of the plurality of annular structures is made of a metal material and a reinforcing material to reduce the degree of scattering of the radiation beam passing through the annular cryostat.

13. The MRI apparatus according to claim 12, wherein: The annular cryostat further comprises: At least one groove is provided on the annular structure device, wherein the groove has an opening formed on at least one outer surface of the annular structure device.

14. The MRI apparatus according to claim 13, wherein: The one or more chambers include two chambers connected through a neck, and the groove is formed by at least the two chambers and the neck.

15. The MRI apparatus according to claim 14, wherein: The two chambers contain a cooling medium, and the neck is filled with the cooling medium.

16. The MRI apparatus according to claim 12, wherein: The annular structure device comprises: a first annular structure for providing a vacuum space enclosing the one or more chambers; a second annular structure for reducing heat transfer from the first annular structure to the third annular structure; and The third annular structure is used to accommodate the cooling medium.

17. The MRI apparatus according to claim 12, wherein: The reinforcing material has one or more properties of low density, high mechanical strength, radiation resistance or heat resistance.

18. The MRI apparatus according to claim 12, wherein: The reinforcing material includes one or more of carbon fiber, glass fiber, aramid fiber, silicon carbide (SiC) fiber, asbestos fiber, whisker, graphene fiber, and alloy material.

19. The MRI apparatus according to claim 15, wherein The annular cryostat further includes one or more sensors for detecting a level of a cooling medium in each of the one or more chambers of the annular cryostat.

20. A therapeutic device, characterized in that include: A magnetic resonance imaging (MRI) apparatus for acquiring MRI data about a region of interest (ROI), wherein the MRI apparatus comprises an annular cryostat comprising: one or more chambers arranged along an axis of the annular cryostat; an annular structure device surrounding the one or more chambers, wherein the annular structure device includes a plurality of annular structures through which the radiation beam passes, and at least one of the plurality of annular structures is made of a metal material and a reinforcing material to reduce the degree of scattering of the radiation beam passing through the annular cryostat; at least one groove provided on the annular structure device, the groove having an opening formed on at least one outer surface of the annular structure device; and a radiotherapy apparatus for applying therapeutic radiation to at least a portion of the ROI, the radiotherapy apparatus comprising: an accelerator for accelerating electrons in the electron beam along an electron beam path parallel to the axis; target; and A beam deflecting unit is used to deflect electrons in the electron beam onto the target to generate the radiation beam of the therapeutic radiation.

Images