Alignment of medical radiation systems

Abstract

Provided herein is technology relating to medical radiation systems, particularly, but not exclusively, to apparatus, methods, and systems for aligning a radiation source with a patient positioning and / or patient rotation system used in medical diagnostic imaging and / or radiation therapy.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 399,862, filed August 22, 2022, which is incorporated herein by reference in its entirety.

[0002] Provided herein is technology relating to medical radiation systems, particularly, but not exclusively, to apparatus, methods, and systems for aligning a radiation source with a patient positioning and / or patient rotation system used in medical diagnostic imaging and / or radiation therapy. [Background technology]

[0003] Medical radiation systems use radiation sources for imaging and treatment purposes (e.g., for computed tomography imaging and in radiation therapy). Medical treatment and imaging procedures typically involve immobilizing a patient in a bed or chair and moving a radiation source around the patient to target relevant areas of the patient's body. The technology used for such procedures often involves complex mechanisms to provide stability for the medical radiation system and extensive shielding for the moving radiation source. Therefore, conventional medical radiation systems are typically expensive to install and maintain.

[0004] U.S. Patent Application Publication No. 20200268327 and U.S. Patent Application No. 63 / 237,513 (each incorporated herein by reference) describe a patient positioning assembly and system for orienting a patient relative to a stationary radiation source and moving, positioning, and / or rotating the patient's body as needed for imaging or treatment. Aligning the patient positioning assembly and system with the radiation source can improve patient treatment and imaging. Therefore, the use of medical radiation systems would benefit from techniques related to aligning the medical radiation system with the patient positioning assembly and system.

Prior technical literature

Charter Documents

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0268327

Non-licensed literature

[0006]

Non-patent document 1

Non-patent document 2

Non-patent document 3

Non-patent document 4

[0007] Provided herein is technology relating to medical radiation systems, particularly, but not exclusively, to apparatus, methods, and systems for aligning a radiation source with a patient positioning and / or patient rotation system used in medical diagnostic imaging and / or radiation therapy.

[0008] In particular, the techniques provided herein relate to medical diagnostic (e.g., imaging) and / or therapeutic radiation techniques in which a patient support assembly (e.g., including a patient) rotates about an axis, as described herein. The techniques adjust the axis of rotation of the patient support assembly (e.g., including the patient) to align the imaging beam and / or treatment beam with respect to any point within the patient by calculating compensatory translations of the patient support assembly and / or the patient along one or more of three translation axes. Furthermore, in some embodiments, the techniques adjust the axis of rotation of the patient support assembly (e.g., including the patient) to align the imaging and / or treatment beam with respect to any point within the patient by calculating compensatory translations of the patient along one or more translation axes. In particular, embodiments provide methods in which a first step includes calculating compensatory translations along one or more axes; and a second step includes vectorially adding the independent translations. [Means for solving the problem]

[0009] Thus, in some embodiments, the present technology provides a method for aligning a medical radiation system including a patient rotation system and a radiation source. For example, in some embodiments, the method includes rotating the patient rotation system about an axis of rotation, detecting a radiation beam from the radiation source to produce an image of a reference target located on a patient support assembly of the patient rotation system, analyzing the image to determine a displacement of the patient support assembly relative to the axis of rotation, and adjusting the patient support assembly to align the patient support assembly relative to the axis of rotation. In some embodiments, the displacement is determined by comparing a location and orientation of the reference target relative to the axis of rotation. In some embodiments, adjusting the patient support assembly includes aligning a center of rotation of the reference target with the axis of rotation. In some embodiments, the method further includes analyzing the image to locate a central axis of the radiation beam relative to the axis of rotation, and adjusting the radiation source so that the central axis of the radiation beam intersects the axis of rotation. In some embodiments, the patient rotation system includes a base configured to rotate. In some embodiments, the base supports the patient support assembly. In some embodiments, the patient support assembly is configured for movement with six degrees of freedom relative to the base. In some embodiments, adjusting the patient support assembly includes performing a translational movement of the patient support assembly relative to the base. In some embodiments, adjusting the patient support assembly includes performing a rotational movement of the patient support assembly relative to the base. In some embodiments, rotating the patient rotation system includes rotating the base, wherein the axis of rotation is an axis of the base. In some embodiments, the axis of rotation is an axis of symmetry of the base. In some embodiments, the medical radiation system further includes an imaging device for detecting the radiation beam and producing an image of the reference target. In some embodiments, the imaging device is located on an opposite side of the radiation source relative to the patient support assembly. In some embodiments, the image of the reference target includes at least two images of the reference target produced for different angles of rotation of the patient rotation system.

[0010] In some embodiments, the reference target comprises a body and one or more markers affixed to the body in a pre-arranged configuration. In some embodiments, the one or more markers are affixed to the body in a pre-arranged configuration such that each marker is at least partially exposed to the radiation beam at each angle of rotation of the patient rotation system. In some embodiments, the one or more markers are disposed on an imaginary plane within the body, the imaginary plane being tilted relative to the axis of rotation when the reference target is positioned on the patient support assembly. In some embodiments, the reference target comprises a central marker disposed within the body at a center of rotation of the reference target. In some embodiments, the body is transparent to the radiation beam (e.g., radiolucent). In some embodiments, the one or more markers are opaque to the radiation beam (e.g., radiopaque). In some embodiments, the radiation source is an imaging radiation source or a therapeutic radiation source.

[0011] In some embodiments, the radiation source is a first radiation source (e.g., producing a first radiation beam), and the medical radiation system further comprises a second radiation source (e.g., producing a second radiation beam). In some embodiments, the method further includes detecting a second radiation beam from the second radiation source to produce an additional image of the reference target, analyzing the additional image to locate a central axis of the second radiation beam relative to the rotation axis, and adjusting the second radiation source so that the central axis of the second radiation beam intersects the rotation axis. In some embodiments, the method further includes adjusting at least one of the first radiation source and / or the second radiation source so that the central axis of the second radiation beam intersects the central axis of the first radiation beam.

[0012] In some embodiments, the method further includes mounting a reference target to the patient support assembly, hi some embodiments, the patient support assembly comprises an interface for mounting the reference target at a fixed position on the patient support assembly.

[0013] In some embodiments, the present technology provides a system. For example, in some embodiments, the system includes a medical radiation system and a reference target comprising a body and one or more markers affixed to the body in a pre-arranged configuration. In some embodiments, the system includes a detector. In some embodiments, the system includes a patient support assembly. In some embodiments, the patient support assembly includes an interface structured to accept the reference target. In some embodiments, the system is structured to rotate the reference target about an axis orthogonal to an axis between the source and the detector. In some embodiments, the medical radiation system includes a stationary radiation source. In some embodiments, the system includes software components including instructions for rotating a patient rotation system about an axis of rotation; controlling a radiation beam; receiving signals and / or data from a detector to produce an image; analyzing the image to determine a displacement of the patient support assembly relative to the axis of rotation; analyzing the image to locate an isocenter of the radiation beam relative to the axis of rotation; and / or determining a displacement of a central axis of the radiation beam relative to the axis of rotation. In some embodiments, the system includes a component structured to adjust the patient support assembly to align the patient support assembly with respect to the axis of rotation of the patient support assembly. In some embodiments, the system comprises a component structured to adjust the position of the radiation source and / or the position of the beam produced by said radiation source.

[0014] Some portions of this description describe embodiments of the technology in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are commonly used by those skilled in the data processing arts to effectively convey the substance of their work to others skilled in the art. These operations, while described functionally, computationally, or logically, will be understood to be implemented by computer programs or equivalent electrical circuits, microcode, or the like. Further, it has proven convenient at times to refer to these arrangements of operations as modules, without loss of generality. The described operations and their associated modules may be embodied in software, firmware, hardware, or any combination thereof.

[0015] Certain steps, operations, or processes described herein may be performed or implemented in one or more hardware or software modules, alone or in combination with other devices. In some embodiments, software modules are implemented in a computer program product that includes a computer-readable medium containing computer program code. The computer program may be executed by a computer processor to perform any or all of the described steps, operations, or processes.

[0016] In some embodiments, the system comprises a computer and / or data storage that is virtually provided (e.g., as a cloud computing resource). In particular embodiments, the present technology involves the use of cloud computing to provide a virtual computer system that comprises computer components and / or performs functions as described herein. Thus, in some embodiments, cloud computing provides infrastructure, applications, and software as described herein through a network and / or via the Internet. In some embodiments, computing resources (e.g., data analysis, calculations, data storage, application programs, file storage, etc.) are provided remotely via a network (e.g., the Internet and / or a cellular network).

[0017] Embodiments of the present technology also relate to apparatus for performing the operations herein. The apparatus may be specially structured for the required purposes and / or may include a general-purpose computing device selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored on a non-transitory, tangible, computer-readable storage medium that can be coupled to a computer system bus or any type of medium suitable for storing electronic instructions. Furthermore, the computing systems referred to herein may include a single processor or may be architectures employing multiple processor designs to increase computing power.

[0018] Additional embodiments will be apparent to those skilled in the art based on the teachings contained herein.

[0019] These and other features, aspects, and advantages of the present technology will be better understood with regard to the following drawings. [Brief explanation of the drawings]

[0020] [Figure 1A] 1 is a schematic diagram illustrating a perspective view of an exemplary medical radiation system. [Figure 1B] 1 is a schematic diagram showing a top view of a medical radiology system. [Figure 1C] 1 is a schematic diagram showing a top view of a medical radiation system with a patient positioned in the path of the beam. [Figure 1D] 1 is a schematic diagram showing a top view of a medical radiation system with two radiation sources, with a patient positioned in the path of the beam produced by one of the two radiation sources. [Figure 1E] 1 is a schematic diagram showing a top view of a medical radiation system with two radiation sources, with a patient positioned in the path of the beam produced by one of the two radiation sources. [Figure 1F] 1 is a schematic diagram showing a top view of a medical radiation system with a reference target positioned in the path of the beam; [Figure 2] FIG. 1 is a block diagram of an exemplary method for aligning a medical radiation system. [Figure 3] FIG. 3 shows a perspective view of an exemplary reference target for use in the method of FIG. 2. [Figure 4] FIG. 4 is a top view of the reference target of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0021] It should be understood that the figures are not necessarily drawn to scale, and that objects in the figures are not necessarily drawn to scale relative to each other. The figures are representations intended to provide clarity and understanding to various embodiments of the devices, systems, and methods disclosed herein. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts. It should also be understood that the drawings are not intended to limit the scope of the present teachings in any way.

[0022] Provided herein is technology related to medical radiation systems, particularly, but not exclusively, to devices, methods, and systems for aligning a radiation source with a patient positioning system and / or patient rotation system used in medical diagnostic imaging and / or radiation therapy. In some embodiments, the technology provides an embodiment of a method for aligning a medical radiation system including a patient rotation system and a radiation source. In some embodiments, the method includes rotating the patient rotation system about an axis of rotation, detecting a radiation beam from the radiation source, and creating an image of a reference target located on a patient support assembly of the patient rotation system. In some embodiments, the method further includes analyzing the image to determine a displacement of the patient support assembly relative to the axis of rotation and adjusting the patient support assembly to align the patient support assembly relative to the axis of rotation. In some embodiments, the method further includes analyzing the image to determine a displacement of a central axis of the radiation beam relative to the axis of rotation and adjusting the radiation source so that the central axis of the radiation beam intersects the axis of rotation.

[0023] In this detailed description of various embodiments, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, those skilled in the art will recognize that the various embodiments may be practiced without these specific details. In other instances, structures and devices are shown in block diagram form. Furthermore, those skilled in the art will readily appreciate that the specific order in which the methods are presented and performed is illustrative, and it is contemplated that the order can be changed and still remain within the spirit and scope of the various embodiments disclosed herein.

[0024] All literature and similar materials cited in this application, including but not limited to patents, patent applications, papers, books, articles, and Internet web pages, are expressly incorporated by reference in their entirety for any purpose. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments described herein belong. When definitions of terms in incorporated references appear to differ from definitions provided in the present teachings, the definitions provided in the present teachings shall control. The section headings used herein are for organizational purposes only and should not be construed in any way as limiting the subject matter described.

[0025] definition To facilitate understanding of the present technology, several terms and phrases are defined below. Additional definitions are set forth throughout the detailed description.

[0026] Throughout the specification and claims, the following terms take the meanings expressly associated therewith unless the context clearly dictates otherwise. As used herein, the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may. Further, as used herein, the phrase "in another embodiment" does not necessarily refer to different embodiments, although it may. Thus, as described below, various embodiments of the invention can be readily combined without departing from the scope or spirit of the invention.

[0027] Also, as used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or" unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for based on additional unexplained factors unless the context clearly dictates otherwise. Also, throughout the specification, the meanings of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0028] As used herein, the terms "about," "approximately," "substantially," and "significantly" will be understood by those of ordinary skill in the art and will vary to some extent depending on the context in which they are used. If there are uses of these terms that are not clear to persons of ordinary skill in the art given the context in which they are used, "about" and "approximately" mean plus or minus 10% or less of the particular term, and "substantially" and "significantly" mean plus or minus more than 10% of the particular term.

[0029] As used herein, the disclosure of a range includes the disclosure of all values ​​within the entire range and further divided ranges, including the endpoints and subranges given therein. As used herein, the disclosure of a numerical range includes, to the same degree of precision, the endpoints and each intermediate number therebetween. For example, for the range 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are expressly contemplated.

[0030] As used herein, the suffix "-free" refers to an embodiment of a technology that omits features of the base stem of the word to which "-free" is added. That is, the term "X-free" as used herein means "without X," where X is the feature of the technology omitted in the "X-free" technology. For example, a "calcium-free" composition does not contain calcium, a "blending-free" method does not include a blending step, etc.

[0031] As used herein, terms such as "first," "second," "third," and the like may be used to describe various steps, elements, compositions, components, regions, layers, and / or sections; however, these steps, elements, compositions, components, regions, layers, and / or sections should not be limited by these terms unless otherwise specified. These terms are used to distinguish one step, element, composition, component, region, layer, and / or section from another step, element, composition, component, region, layer, and / or section. As used herein, terms such as "first," "second," and other numerical terms do not imply an order or ranking unless clearly indicated by context. Thus, a first step, element, composition, component, region, layer, or section discussed herein could be referred to as a second step, element, composition, component, region, layer, or section without departing from the art.

[0032] As used herein, the words "presence" or "absence" (or "present" or "absence") are used in a relative sense to describe the amount or level of a particular entity (e.g., a component, action, element). For example, when an entity is said to be "present," this means that the level or amount of the entity is above a predetermined threshold. Conversely, when an entity is said to be "absent," this means that the level or amount of the entity is below a predetermined threshold. The predetermined threshold may be a detectability threshold associated with a particular test used to detect the entity, or any other threshold. If an entity is "detected," it is "present," and if an entity is "not detected," it is "absent."

[0033] As used herein, "increase" or "decrease" refers to a detectable (e.g., measured) positive or negative change in the value of a variable relative to a previously measured value, relative to a pre-established value, and / or relative to a standard control value, respectively. An increase is preferably at least a 10%, more preferably a 50%, even more preferably a 2-fold, even more preferably at least a 5-fold, and most preferably at least a 10-fold positive change relative to a previously measured value, pre-established value, and / or standard control value. Similarly, a decrease is preferably at least a 10%, more preferably a 50%, even more preferably at least an 80%, and most preferably at least a 90% negative change relative to a previously measured value, pre-established value, and / or standard control value. Other terms indicating quantitative changes or differences, such as "more" or "less," are used herein in the same manner as above.

[0034] As used herein, a "system" refers to multiple actual and / or abstract components that work together for a common purpose. In some embodiments, a "system" is an integrated collection of hardware and / or software components. In some embodiments, each component of a system interacts with and / or is related to one or more other components. In some embodiments, a system refers to a combination of components and software for controlling and directing a method. For example, a "system" or a "subsystem" may include one or more of the following, or a combination thereof: mechanical devices, hardware, hardware components, circuits, circuit configurations, logical designs, logical components, software, software modules, components of software or software modules, software procedures, software instructions, software routines, software objects, software functions, software classes, software programs, files containing software, and the like, for performing the functions of the system or subsystem. Thus, the methods and apparatus of the embodiments, or certain aspects or portions thereof, may take the form of program code (e.g., instructions) embodied in a tangible medium, such as a floppy disk, a CD-ROM, a hard drive, a flash memory, or any other machine-readable storage medium. When program code is loaded and executed on a machine, such as a computer, the machine becomes an apparatus for practicing the embodiments. In the case of program code running on a programmable computer, the computing device generally includes a processor, a processor-readable storage medium (e.g., volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. One or more programs may implement or utilize the processes described in connection with the embodiments, for example, through the use of application programming interfaces (APIs), reusable controls, etc. Such programs are preferably implemented in a high-level procedural or object-oriented programming language to communicate with a computer system.However, the programs can also be implemented in assembly or machine language, if desired. In either case, the language may be a compiled or interpreted language, and combined with hardware implementations.

[0035] As used herein, the term "computed tomography" is abbreviated as "CT" and refers to both tomographic and non-tomographic radiography. For example, the term "CT" refers to many forms of CT, including, but not limited to, X-ray CT, positron emission tomography (PET), single-photon emission computed tomography (SPECT), and photon-counting computed tomography. Generally, computed tomography (CT) involves the use of an X-ray source and a detector that rotates around the patient and subsequent reconstruction of images into different planes. In the CT embodiments described herein (e.g., devices, apparatus, and methods provided for CT), the X-ray source is stationary and the patient rotates relative to the stationary source. The X-ray current used in CT describes the flow of current from the cathode to the anode and is typically measured in milliamperes (mA).

[0036] As used herein, the term "structured to [verb]" means that the specified element or assembly has a structure that is shaped, sized, arranged, coupled, and / or configured to perform the specified verb. For example, a member "structured to move" is movably coupled to another element and includes an element that causes the member to move, or the member is configured to move in response to another element or assembly. Thus, as used herein, "structured to [verb]" recites structure, not function. Furthermore, as used herein, "structured to [verb]" means that the specified element or assembly is intended to and designed to perform the specified verb.

[0037] As used herein, the term "associated" means that elements are part of the same assembly and / or work or interact together in some way. For example, a car has four tires and four hubcaps. It is understood that all elements are joined together as part of the car, but each hubcap is "associated" with a particular tire.

[0038] As used herein, the term "coupled" refers to two or more components that are secured together by any suitable means. Thus, in some embodiments, a statement that two or more parts or components are "coupled" means that the parts are joined or operate together directly or indirectly (e.g., through one or more intermediate parts or components). As used herein, "directly coupled" means that the two elements are in direct contact with each other. As used herein, "fixedly coupled" or "fixed" means that the two components are coupled so that they move as a single component while maintaining a constant orientation relative to each other. Thus, when two elements are coupled, all portions of the elements are coupled. However, a statement that a particular portion of a first element is coupled to a second element (e.g., a first end of an axle is coupled to a first wheel) means that the particular portion of the first element is disposed closer to the second element than the other portions. Furthermore, an object resting on another object held in place only by gravity is not "coupled" to the lower object unless the upper object is otherwise substantially maintained in place. That is, for example, a book on a table is not coupled to the table, but a book glued to the table is coupled to the table.

[0039] As used herein, the terms "removably coupled" or "temporarily coupled" mean that one component is coupled to another component in an essentially temporary manner. That is, the two components are coupled in a manner that allows for easy joining or separation of the components without damaging the components. Thus, "removably coupled" components can be easily uncoupled and recoupled without damaging the components.

[0040] As used herein, the term "operably coupled" means that several elements or assemblies, each movable between a first position and a second position or configuration, are coupled such that movement of the first element from one position / configuration to another position / configuration causes the second element to also move between positions / configurations. Note that a first element is "operably coupled" to another element, not vice versa.

[0041] As used herein, the term "rotatably coupled" refers to two or more components coupled such that at least one of the components is rotatable relative to the other component.

[0042] As used herein, the term "translatably coupled" refers to two or more components coupled such that at least one of the components is translatable relative to the other component.

[0043] As used herein, the term "temporarily disposed" means that a first element or assembly is placed on a second element or assembly such that the first element / assembly can be moved without uncoupling or otherwise manipulating the first element. For example, a book that simply rests on a table (e.g., the book is not glued or secured to the table) is "temporarily disposed" on the table.

[0044] As used herein, the term "corresponding" indicates that two structural components are sized and shaped similarly to one another and bond with minimal friction. Thus, an opening that "corresponds" to a member is sized slightly larger than the member so that the member can pass through the opening with minimal friction. This definition is modified when two components fit "closely." In that situation, the difference in size of the components is even smaller, increasing the amount of friction. If the elements defining the opening and / or the components inserted into the opening are made from deformable or compressible materials, the opening may even be slightly smaller than the components inserted into the opening. With respect to surfaces, shapes, and lines, two or more "corresponding" surfaces, shapes, or lines generally have the same size, shape, and contour.

[0045] As used herein, a "path of travel" or "path," when used in connection with a moving element, includes the space through which the element travels during movement. Thus, any element that moves inherently has a "path of travel" or "path."

[0046] As used herein, the statement that two or more parts or components "engage" one another means that the elements exert a force or bias on one another, either directly or through one or more intermediate elements or components. Additionally, when used herein with respect to a moving part, the moving part may "engage" another element while moving from one position to another and / or may "engage" another element once it is in the described position. Thus, the statements "element A engages element B when element A moves to element A's first position" and "element A engages element B when element A is in element A's first position" are understood to be equivalent statements and mean that element A engages element B when moving to element A's first position and / or that element A engages element B when element A is in element A's first position.

[0047] As used herein, the term "operably engage" means "engage and move." That is, when used with respect to a first component structured to move a second, movable or rotatable component, "operably engage" means that the first component applies a force sufficient to move the second component. For example, a screwdriver is placed in contact with a screw. When no force is applied to the screwdriver, the screwdriver is simply "coupled" to the screw. When an axial force is applied to the screwdriver, the screwdriver presses against the screw and "engages" it. However, when a rotational force is applied to the screwdriver, the screwdriver "operably engages" the screw and turns it. Furthermore, with respect to electronic components, "operably coupled" means that one component controls another component via a control signal or current.

[0048] As used herein, the term "number" means one or an integer greater than one (eg, multiple).

[0049] As used herein, in the phrase "[x] moves between its first and second positions," or "[y] is structured to move [x] between its first and second positions," "[x]" is the name of an element or assembly. Furthermore, when [x] is an element or assembly that moves between positions, the pronoun "the" refers to "[x]," i.e., the named element or assembly that precedes the pronoun "the."

[0050] As used herein, the "radial sides / surfaces" of a circular or cylindrical body are those sides / surfaces that extend around or surround its center or a height line passing through its center. As used herein, the "axial sides / surfaces" of a circular or cylindrical body are those sides that extend in a plane that extends generally perpendicular to a height line passing through its center. That is, generally, for a cylindrical soup can, the "radial sides / surfaces" are the generally circular sidewalls and the "axial sides / surfaces" are the top and bottom of the soup can.

[0051] As used herein, a "diagnostic" test includes detecting or identifying a disease state or condition in a subject, determining the likelihood that a subject will suffer from a particular disease or condition, determining the likelihood that a subject with a disease or condition will respond to treatment, determining the prognosis (or likelihood of progression or regression) of a subject with a disease or condition, and determining the effectiveness of a treatment for a subject with a disease or condition. For example, diagnostics can be used to detect the presence or likelihood that a subject has cancer, or the likelihood that such a subject will respond successfully to a compound (e.g., an agent, e.g., a drug) or other treatment.

[0052] As used herein, the term "symptom" generally refers to an illness, disease, injury, event, or change in health status.

[0053] As used herein, the term "treating" or "treatment," with respect to a condition, refers to preventing the condition, reducing the onset or incidence of the condition, reducing the risk of developing the condition, preventing or delaying the onset of symptoms associated with the condition, alleviating or terminating symptoms associated with the condition, causing complete or partial regression of the condition, or some combination thereof. In some embodiments, "treatment" includes exposing the patient or a portion thereof (e.g., a tissue, organ, site, or other localized region of the patient's body) to radiation (e.g., electromagnetic radiation, ionizing radiation).

[0054] As used herein, the term "beam" refers to a stream of radiation (e.g., electromagnetic waves and / or particle radiation). In some embodiments, the beam is produced by a line source and is confined to a small solid angle. In some embodiments, the beam is collimated. In some embodiments, the beam is a generally unidirectional beam. In some embodiments, the beam is a diverging beam.

[0055] As used herein, the term "patient" or "subject" refers to a mammalian animal identified and / or selected for imaging and / or treatment with radiation. Thus, in some embodiments, the patient or subject is contacted with a beam of radiation, e.g., a primary beam produced by a radiation source. In some embodiments, the patient or subject is a human. In some embodiments, the patient or subject is a veterinary or livestock animal, a domestic animal or pet, or an animal used in clinical research. In some embodiments, the subject or patient has cancer and / or is recognized to have or be at risk for cancer.

[0056] As used herein, the term "treatment volume" or "imaging volume" refers to a volume (e.g., tissue) of a patient selected for imaging and / or treatment with radiation. For example, in some embodiments, a "treatment volume" or "imaging volume" includes a tumor in a cancer patient. As used herein, the term "healthy tissue" refers to a volume (e.g., tissue) of a patient that is not and / or does not include the treatment volume. In some embodiments, the imaging volume is larger than the treatment volume and includes the treatment volume.

[0057] As used herein, the term "radiation source" or "ray source" refers to a device that produces radiation (e.g., ionizing radiation) in the form of photons (e.g., described as particles or waves). In some embodiments, the radiation source is a linear accelerator ("linac") that produces x-rays or electrons to treat cancer patients by contacting tumors with the x-ray or electron beam. In some embodiments, the radiation source produces particles (e.g., photons, electrons, neutrons, hadrons, ions (e.g., protons, carbon ions, other heavy ions)). In some embodiments, the radiation source produces electromagnetic waves (e.g., x-rays and gamma rays having wavelengths ranging from about 1 pm to about 1 nm). It is understood that radiation can be described as having both wave-like and particle-like aspects, although it is sometimes convenient to refer to radiation in terms of waves and sometimes in terms of particles. Thus, without limiting the art, both descriptions are used throughout, with the understanding that the laws of quantum mechanics provide that all particles or quantum entities can be described as particles or waves.

[0058] As used herein, the term "stationary source" refers to a source that does not orbit around a patient during use for imaging or therapy. In particular, a "stationary source" remains fixed with respect to an axis that passes through the patient while the patient is being imaged or treated. To create a relative motion between the stationary source and the rotating patient equivalent to the relative motion of the source orbiting around the stationary patient, the patient can rotate about said axis; however, the stationary source does not move with respect to a third object, frame of reference (e.g., the treatment room in which the patient is positioned), or patient axis of rotation during imaging or treatment, while the patient rotates with respect to the third object, frame of reference (e.g., the treatment room in which the patient is positioned), or patient axis of rotation that passes through the patient during imaging or treatment. Thus, a stationary source is mounted on a mobile platform, and therefore, as the mobile platform moves to transport the stationary source, the stationary source may move with respect to the Earth and fixed objects on the Earth. Thus, the term "stationary source" can refer to a mobile "stationary source." However, this moving "stationary source" does not orbit around an axis of rotation through the patient during patient imaging or treatment. Furthermore, the stationary source may translate and / or orbit around the patient to position the stationary source before or after patient imaging or treatment. Thus, the term "stationary source" may refer to a source that translates or orbits around the patient in non-imaging and non-treatment uses, for example, to position the source relative to the patient when the patient is not being imaged and / or treated. In some embodiments, the "stationary source" is a photon source and is therefore referred to as a "stationary photon source."

[0059] As used herein, the term "detector" refers to a sensor for detecting, for example, photons produced by a radiation source (e.g., a stationary radiation source). Accordingly, embodiments provide detectors for imaging and / or patient support alignment. In some embodiments, the detector is an electromagnetic radiation detector, an X-ray detector, a photon detector, and / or a gamma ray detector. Accordingly, in some embodiments, the detector is capable of detecting photons of visible light. Embodiments provide detectors for CT, PET, SPECT, photon-counting computed tomography, and / or portal imaging.

[0060] A detector may include multiple "detection elements," each of which includes an array of pixels. As used herein, the term "pixel," when referring to a detector, refers to the smallest discrete element of photon sensing by a photon detector element and, therefore, by the detector. In some embodiments, a pixel has an area of ​​approximately 1 mm x 1 mm. The detector element includes components for detecting photons at each pixel and for outputting an electrical signal (e.g., current or voltage) for each pixel corresponding to the photons detected by each pixel of the detection element. Integrating ("indirect") detector elements include a scintillator and a photodiode (e.g., semiconductor). Photons striking the scintillator produce a number of visible photons that are absorbed by the photodiode. The photodiode measures the amount of light produced by the scintillator and generates an electrical signal (e.g., current or voltage) proportional to the total energy deposited during the measurement interval. Photon-counting ("direct") detector elements include a photodiode (e.g., semiconductor) that produces a current or voltage for each photon detected by the photodiode (photon-counting detector elements do not include a scintillator). Photons absorbed in a semiconductor create pairs of positive and negative charges that move away from each other due to a voltage applied to the semiconductor. The moving charges generate an electrical signal that is fed to an electronic readout circuit. For example, a photon-counting detector element can include a multi-channel analyzer that identifies photons based on their photon energy and sorts the photons into energy channels based on their photon energy. Thus, the photon-counting detector element can be used to create a photon energy spectrum.

[0061] As used herein, the terms "module" or "detector module" refer to a discrete component of a detector that includes multiple detector elements. Thus, multiple detector modules can be assembled to provide a detector having a desired design and a desired number of detector elements (e.g., in some embodiments, arranged in multiple rows and multiple columns).

[0062] Thus, a detector may comprise multiple detector modules, a detector module may include multiple detector elements, and a detector element may comprise multiple pixels.

[0063] As used herein, the term "Z" refers to the atomic number (e.g., of an element and / or a substance that includes an element). As used herein, the "Z" of a substance refers to the atomic number of one or more elements from which the substance is made.

[0064] As used herein, "effective atomic number" or "Z eff The term "" refers to the effective or average atomic number of a compound or mixture of substances (e.g., an alloy). effis determined experimentally or by Murty (1965) "Effective Atomic Numbers of Heterogeneous Materials" Nature 207(4995):398-99, Taylor (2008) "The effective atomic number of dosimetric gels" Australasian Physics&Engineering Sciences in Medicine 31(2):131-38, Taylor (2009) "Electron Interaction with Gel Dosimeters: Effective Atomic Numbers for Collisional,Radiative and Total Interaction Processes” Radiation Research 171(1):123-26, Taylor (2011) “Robust determination of effective atomic numbers for electron interactions with TLD-100 and TLD-100H thermoluminescent dosimeters” Nuclear Instruments and Methods in Physics Research Section B:Beam Interactions with Materials and Atoms 269(8):770-73, and Taylor (2012) “Robust calculation of effective atomic numbers: The Auto-Z eff "Auto-Z software" by Taylor, "Medical Physics 39(4):1769-78, each of which is incorporated herein by reference. eff The software calculates the Z of a compound or mixture of substances. eff is freely available to calculate

[0065] As used herein, the term "attenuation coefficient" or "linear attenuation coefficient" refers to a measure of the degree to which the radiative flux of a beam is reduced when passing through a particular material, for example, as a result of absorption and / or scattering. The "mass attenuation coefficient" of a material may be used, in which the attenuation coefficient is normalized per unit density of the material, thus providing a constant value for a given element or compound.

[0066] Embodiments of the technology described herein involve translation along and / or rotation about an axis. In some embodiments, a coordinate system is used that includes X, Y, and Z axes defined relative to the patient support and / or patient. See FIG. 1A. As shown in FIG. 1A, embodiments use a coordinate system in which the X and Y axes together lie in and / or define a horizontal plane, and the Z axis is a vertical axis and / or defines a vertical axis. With respect to a patient positioned on a patient support (e.g., a patient positioning device), the X axis is the left-right, horizontal, or frontal axis, the Y axis is the anterior-posterior, dorso-ventral, or sagittal axis, and the Z axis is the sagittal or longitudinal axis. The X and Y axes together lie in and / or define a horizontal, transverse, and / or axial plane. The Y and Z axes together lie in and / or define a sagittal or longitudinal plane. The X and Z axes together lie in and / or define a frontal or coronal plane.

[0067] Thus, in some embodiments, descriptions of moving "forward" or "backward" are descriptions of movement along the Y-axis, descriptions of moving "left" or "right" are descriptions of movement along the X-axis, and descriptions of moving "up" and "down" are descriptions of movement along the Z-axis. Furthermore, rotations described as "roll" are rotations about the Y-axis, rotations described as "pitch" are rotations about the X-axis, and rotations described as "yaw" are rotations about the Z-axis. Thus, in some embodiments, technology is described as having six degrees of freedom, e.g., translation along one or more of the X, Y, and / or Z axes, and / or rotations about one or more of the X, Y, and / or Z axes.

[0068] Medical Radiation Systems In some embodiments, the technology relates to aligning components of a medical radiation system. In some embodiments, the technology relates to a medical radiation system 100, for example, as shown in FIGS. 1A through 1F. In some embodiments, the medical radiation system 100 comprises a patient rotation system 110 structured to rotate about an axis of rotation. In some embodiments, the patient rotation system 110 comprises a patient positioning system (e.g., comprising a patient positioning device or a configurable patient support assembly 120) mounted to a base 130. The base 130 is structured to rotate about an axis 131 of the base 130. In some embodiments, the base 130 is structured to rotate about a vertical axis of symmetry of the base 130. In some embodiments, the patient positioning system, the patient positioning device, and / or the configurable patient support 120 are described in U.S. Patent Application Publication No. 20200268327 and U.S. Patent Application No. 63 / 237,513, each of which is incorporated herein by reference.

[0069] The patient support assembly 120 is structured to support the patient 140 in an upright (e.g., standing, sitting, perched) position during radiation treatment or imaging. Thus, in embodiments, the configurable patient support assembly 120 is adjustable to support the patient 140 in an upright (e.g., standing, sitting, perched) position or any other position in which the torso of the patient 140 is in a generally vertical or upright position (e.g., semi-upright position, crouched position). In some embodiments, the patient support assembly 120 comprises support members such as a seat, backrest, headrest, armrests, shin rest, foot braces (e.g., heel stops), and / or footrests to help support and / or stabilize the patient 140 in a given position. In some embodiments, the configurable patient support assembly 120 comprises one or more configurable and movable components, such as a backrest (e.g., a configurable and movable backrest), a headrest (e.g., a configurable and movable headrest), an armrest (e.g., a configurable and movable armrest), a seat member (e.g., a configurable and movable seat member), a thin rest (e.g., a configurable and movable thin rest), and / or a foot brace (e.g., a configurable and movable foot brace), as described, for example, in U.S. Patent Application No. 63 / 237,513 (incorporated herein by reference). In some embodiments, one or more configurable, movable components of the configurable patient support comprise one or more powered components, such as a powered backrest (e.g., a backrest operably engaged with a backrest motor), a powered headrest (e.g., a headrest operably engaged with a headrest motor), a powered armrest (e.g., an armrest operably engaged with an armrest motor), a powered seat member (e.g., a seat member operably engaged with a seat member motor), a powered thinrest (e.g., a thinrest operably engaged with a thinrest motor), and / or a powered foot brace (e.g., a foot brace operably engaged with a foot brace motor).In some embodiments, the backrest motor is structured to move (e.g., translate and / or rotate) the backrest, the headrest motor is structured to move (e.g., translate and / or rotate) the headrest, the armrest motor is structured to move (e.g., translate and / or rotate) the armrest, the seat member motor is structured to move (e.g., translate and / or rotate) the seam member, the thinrest motor is structured to move (e.g., translate and / or rotate) the thinrest, and / or the foot brace motor is structured to move (e.g., translate and / or rotate) the foot brace. In some embodiments, the present technology provides a configurable patient support 120 configured in a static configuration. In some embodiments, the present technology provides a configurable patient support 120 configured in a dynamic configuration (e.g., a configuration that moves to assist with patient movement, such as patient ingress and / or patient egress). See U.S. Patent Application No. 63 / 237,513, which is incorporated herein by reference.

[0070] In some embodiments, the patient support assembly 120 is operably coupled to the base 130 such that the patient support assembly 120 rotates therewith (e.g., about axis 131). However, the patient support assembly 120 may be adjustably mounted to the base 130 to adjust the position and / or orientation of the patient support assembly 120 relative to the base 130. In some embodiments, the patient support assembly 120 is configured for movement with six degrees of freedom, allowing translation along three perpendicular axes (e.g., two axes in the horizontal plane and a vertical axis; see FIG. 1A ) and rotation about three perpendicular axes (e.g., yaw, pitch, and roll; see FIG. 1A ). See U.S. Patent Application No. 63 / 237,513, which is incorporated herein by reference. In some embodiments, the patient support assembly 120 is movable with fewer than six degrees of freedom.

[0071] In some embodiments, the medical radiation system 100 comprises a first radiation source 150 configured to generate a beam 151 of electromagnetic radiation. In some embodiments, the first radiation source 150 is a kilovoltage (kV) or megavoltage (MV) X-ray radiation source. The first radiation source 150 can be a therapeutic radiation source or an imaging radiation source. In some embodiments, the medical radiation system further comprises a second radiation source 152 structured to generate a second beam 153 of electromagnetic radiation. Thus, in some embodiments, the medical radiation system 100 comprises two radiation sources, e.g., the first radiation source is a therapeutic radiation source and the second radiation source is an imaging radiation source. In some embodiments, the radiation source 150 is a stationary source, e.g., a source that cannot move during normal operation (e.g., during radiation therapy). Thus, the radiation source 150 may translate, orbit, and / or rotate during a calibration or alignment procedure. In some embodiments, first radiation source 150 is a stationary source and / or second radiation source 152 is a stationary source. Thus, first radiation source 150 and / or second radiation source 152 may translate, orbit, and / or rotate during a calibration or alignment procedure.

[0072] Furthermore, in embodiments, the radiation beam 151 from the first radiation source 150 is perpendicular to the rotation axis 131 of the base 130 (e.g., after an alignment procedure) and / or the radiation beam 153 from the second radiation source 152 is perpendicular to the rotation axis 131 of the base 130 (e.g., after an alignment procedure). In some embodiments, the radiation source 150 is oriented such that the radiation beam 151 intersects the rotation axis 131. In some embodiments, the isocenter of the radiation beam intersects the rotation axis 131.

[0073] In some embodiments, the radiation source 150 is structured to direct the radiation beam 151 towards the patient support assembly 120. Thus, when the patient 140 is positioned on the patient support assembly 120, the radiation source 150 is structured to direct the radiation beam 151 towards the patient 140. In some embodiments, the medical radiation system 100 includes a detector 160 (e.g., a detection panel) disposed opposite the radiation source 150 to detect the radiation beam 151 traversing the patient 140. In some embodiments, the detector 160 is an imaging device that produces signals and / or data for generating an image produced by the radiation beam 151. In some embodiments, an additional (e.g., second) detector 162 is associated with the second radiation source 152 of the medical radiation system 100. In some embodiments, for example, as described further herein, a reference target 170 (e.g., a reference target 170 comprising a body and a plurality of markers affixed to the body (e.g., as shown in FIGS. 3 and 4)) is placed between the radiation source 150 and the detector 160 (e.g., a detection panel). In some embodiments, for example, as described further herein, a reference target 170 (e.g., a reference target 170 comprising a body and a plurality of markers affixed to the body (e.g., as shown in FIGS. 3 and 4)) is placed between the second radiation source 152 and the second detector 162 (e.g., a detection panel). In some embodiments, the present technology provides a system comprising the medical radiation system 100 and the reference target 170 (e.g., a reference target 170 comprising a body and a plurality of markers affixed to the body (e.g., as shown in FIGS. 3 and 4)).

[0074] method In some embodiments, for example, as shown in FIG. 2 , the present technology provides a method 200 for aligning a medical radiation system. For example, the medical radiation system includes a patient rotation system and a radiation source (shown in FIGS. 1A-1F ). In some embodiments, the method 200 includes rotating (210) the patient rotation system about an axis of rotation. In some embodiments, the method 200 includes detecting a radiation beam from the radiation source to create (220) an image of a reference target located on a patient support assembly of the patient rotation system. In some embodiments, the reference target is an embodiment of the reference target 300 described herein (see, e.g., FIGS. 3 and 4 ). In some embodiments, the method 200 includes analyzing (230) the image to determine a displacement or offset of the patient support assembly relative to the axis of rotation. In some embodiments, the method 200 includes adjusting (240) the patient support assembly to align the patient support assembly relative to the axis of rotation.

[0075] In some embodiments, the method 200 is used in aligning a medical radiation system, for example, the medical radiation system 100 as shown in Figure 1. However, the technique is not limited to aligning the medical radiation system 100 shown in Figure 1. Thus, the technique may be used in aligning any other medical radiation system, such as a radiation therapy system or a medical imaging system.

[0076] In some embodiments, the patient rotation system includes a base structured to rotate. In some embodiments, the base is structured to rotate about an axis of the base, such as a vertical axis of symmetry of the base. In some embodiments, the base supports a patient support assembly. In some embodiments, the patient support assembly is adjustably mounted to the base. In some embodiments, adjusting the patient support assembly includes translating and / or rotating one or more of a backrest (e.g., a configurable, movable backrest), a headrest (e.g., a configurable, movable headrest), an armrest (e.g., a configurable, movable armrest), a seat member (e.g., a configurable, movable seat member), a thinrest (e.g., a configurable, movable thinrest), and / or a foot brace (e.g., a configurable, movable foot brace).

[0077] In some embodiments, the base is fixed to a location (e.g., a healthcare provider's floor). For example, the axis of the base is at a fixed location (e.g., a healthcare provider's floor) and the base is structured to rotate relative to the axis and / or floor. Thus, in embodiments, the base comprises an axis, which further defines an axis of rotation of the system about which components of the medical radiation system (e.g., the patient support assembly and the radiation source) are adjusted for alignment. In some embodiments, components mounted on the patient rotation system (e.g., the patient positioning system, the patient positioner, and / or the patient support assembly) are aligned (e.g., centered or zeroed) about a fixed axis of rotation. For example, in some embodiments, horizontal displacement of the patient support assembly about the axis of rotation may cause the center of the patient support assembly to move in a precessing motion about the axis of rotation rather than rotating on the axis of rotation (e.g., the axis of rotation of the patient support assembly is misaligned such that the axis of rotation of the patient support assembly rotates about a second axis and the patient support assembly moves in a precessing motion about the second axis). Thus, in an embodiment, the central axis of the radiation beam is adjusted to align with and point towards the isocenter of the patient rotation system.

[0078] In some embodiments, for example, analyzing the image to determine 230 the displacement or offset of the patient support assembly relative to the axis of rotation includes comparing a location and / or orientation of a reference target relative to the axis of rotation, and in some embodiments, adjusting 240 the patient support assembly to align the patient support assembly relative to the axis of rotation includes aligning a center of rotation (or center of symmetry) of the reference target with the axis of rotation.

[0079] In some embodiments, method 200 further includes analyzing the image to locate a central axis or isocenter of the radiation beam relative to the axis of rotation. In some embodiments, analyzing the image to locate a central axis or isocenter of the radiation beam relative to the axis of rotation includes analyzing the image to determine a displacement of the central axis of the radiation beam relative to the axis of rotation (e.g., a displacement between the central axis of the radiation beam and the axis of rotation). In some embodiments, method 200 further includes adjusting the radiation source so that the central axis or isocenter of the radiation beam intersects the axis of rotation. In some embodiments, adjusting the radiation source so that the central axis or isocenter of the radiation beam intersects the axis of rotation includes performing a translational and / or rotational movement of the radiation source. In some embodiments, adjusting the radiation source further includes adjusting or changing an operating characteristic of the radiation source to change the direction of the radiation beam.

[0080] In some embodiments, the medical radiation system includes a second radiation source. For example, in some embodiments, the medical radiation system includes a first radiation source that is an imaging radiation source for producing images of the patient during treatment, and a second radiation source that is a therapeutic or treatment radiation source for treating the patient. In some embodiments, the first radiation source and / or the second radiation source are stationary (e.g., after adjustment). In some embodiments, the first radiation source and / or the second radiation source are fixed in place during normal operation to prevent displacement.

[0081] In some embodiments, method 200 further includes detecting a second radiation beam from a second radiation source to create an additional image, for example, of a reference target. In some embodiments, method 200 further includes analyzing the additional image to determine a displacement of the patient support assembly relative to the axis of rotation. In some embodiments, method 200 further includes analyzing the additional image to locate a central axis of the second radiation beam relative to the axis of rotation or to determine a displacement of the central axis of the second radiation beam relative to the axis of rotation; and adjusting the radiation source so that the central axis of the second radiation beam intersects the axis of rotation.

[0082] In some embodiments, the method 200 further includes adjusting the first radiation source and / or the second radiation source such that a central axis of the second radiation beam intersects a central axis of the first radiation beam. In some embodiments, the two radiation beams intersect at an axis of rotation of the patient rotation system.

[0083] In some embodiments, the medical radiation system further comprises an imaging device (e.g., a detector) for detecting the radiation beam and creating an image of the reference target. In some embodiments, the medical radiation system comprises multiple imaging devices, each associated with a different radiation source. In some embodiments, each imaging device is located opposite, or effectively or substantially opposite, its associated radiation source with respect to the patient support assembly. Thus, in embodiments, during method 200, a reference target on the patient support assembly is located between the radiation source and its associated imaging device such that the radiation beam from the radiation source passes through the reference target and is received by the imaging device to create an image of the reference target.

[0084] In some embodiments, the images of the reference target include at least two images (e.g., at least a first image and a second image) of the reference target produced for different angles of rotation of the patient rotation system. In some embodiments, the images of the reference target include at least four images (e.g., at least a first image, a second image, a third image, and a fourth image) of the reference target produced at orthogonal angles of rotation of the patient rotation system. In some embodiments, analyzing 230 the images to determine the displacement or offset of the patient support assembly relative to the axis of rotation includes producing multiple images of the reference target to provide a location of the reference target in three-dimensional space. Thus, in some embodiments, method 200 includes providing a location of the reference target in three-dimensional space. In some embodiments, the images of the reference target produced by each radiation source are analyzed independently to locate the reference target relative to the axis of rotation. In some embodiments, the images of the reference target produced by each radiation source are analyzed in combination to locate the reference target relative to the axis of rotation.

[0085] In some embodiments, the reference target provides one or more reference points for determining the position of the patient support assembly or the radiation beam relative to the axis of rotation or any other fixed axis, point, or location. In some embodiments, the reference target is a point or surface on the patient support assembly. In some embodiments, the reference target is a target of known dimensions, composition (e.g., known material, known Z, and / or known Z) that is attached to the patient support assembly and rotated by a patient rotation system. eff ), and a separate device with a marker of the configuration.

[0086] In some embodiments, the reference target is attached to a fixed location on the patient support assembly (and / or the patient rotation system) prior to rotating 210 the patient rotation system about the axis of rotation. In some embodiments, the reference target is attached to the center of the patient support assembly. In some embodiments, the patient support assembly is adjusted such that the center of the patient support assembly is moved to align with the axis of rotation of the patient rotation system during adjusting the patient support assembly to align 240 the patient support assembly with respect to the axis of rotation.

[0087] In some embodiments, the reference target is attached to the patient support assembly using a quality assurance (QA) interface, index, belt, strap, or other fastening component provided on the patient support assembly.

[0088] In some embodiments, the reference target is attached to the patient support assembly through an interface. In some embodiments, the interface provides fixed positioning of the reference target relative to the patient support assembly (and / or relative to the patient rotation system). For example, in some embodiments, the interface reliably positions the target at the center of the patient support assembly, thus allowing the position and / or orientation of the patient support assembly to be determined by using the reference target. In some embodiments, the placement of the interface on the patient support assembly is used to calibrate and / or define the zero position of the patient support assembly (and / or is used to calibrate and / or define the zero position of the patient rotation system). An offset or poor repeatability in the placement of the reference target on the patient support assembly may result in a variation in the apparent zero position after performance of method 200. Therefore, in some embodiments, method 200 further includes attaching or mounting the reference target to the patient support assembly. In some embodiments, the patient support assembly includes an interface for attaching or mounting the reference target to a fixed position on the patient support assembly.

[0089] In some embodiments, method 200 provides a way to minimize the radiation isocenter of a treatment beam and / or an imaging beam (e.g., by orienting the central axis of the radiation beam to intersect the axis of rotation). In some embodiments, method 200 provides a way to align the treatment beam using features in an image of the edge of the beam shaping system. In some embodiments, the medical radiation system includes a beam shaping system that attenuates the treatment beam to shape its intensity profile, e.g., to match the profile of a tumor. In some embodiments, the method includes aligning the beam shaping system with the central axis of the treatment beam, e.g., to ensure that the shape of the radiation field is symmetric about the central axis of the beam and / or to optimize the shape of collimator leaves, which are adjustable components of the beam shaping system.

[0090] Reference Target In some embodiments, the technique is associated with a reference target 300 (also known as a "reference phantom"), as shown, for example, in Figures 3 and 4. In some embodiments, the reference target 300 is used in embodiments of the method 200 described herein.

[0091] In some embodiments, the reference target 300 comprises a body 310 and a plurality of markers 320 affixed to the body. In some embodiments, the plurality of markers 320 are affixed to the body in a pre-arranged configuration. In some embodiments, the body 310 is made from a material having a low attenuation coefficient (e.g., a radiotransparent or "radiolucent" material). In some embodiments, the body 310 comprises a homogenous material having a low attenuation coefficient (e.g., a radiotransparent or "radiolucent" material). In some embodiments, the material having a low attenuation coefficient is, for example, poly(methyl methacrylate), which is also known as acrylic glass and is commercially available under the name PERSPEX. In some embodiments, the body 310 comprises ridges.

[0092] In some embodiments, the markers 320 are made from a material having a high attenuation coefficient (e.g., a “radiopaque” material). In some embodiments, the material having a high attenuation coefficient is, for example, tungsten. Thus, when the reference target 300 is imaged using a radiation source, the contrast between the body 310 and the markers 320 allows the body 310 to be distinguished from the markers 320. In some embodiments, a first marker of the plurality of markers 320 is made from a first material having a high attenuation coefficient, and a second marker of the plurality of markers 320 is made from a second material having a high attenuation coefficient. In some embodiments, the first material is a different material from the second material. Thus, in embodiments, when the reference target 300 is imaged using a radiation source, the first marker of the plurality of markers 320 can be distinguished from the second marker of the plurality of markers 320. In further embodiments, the third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, ..., and / or nth markers are made of a third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, ..., and / or nth material having a high attenuation coefficient, such that when the reference target 300 is imaged using a radiation source, one or more of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, ..., and / or nth markers are distinguishable from one or more other markers of the plurality of markers 320.

[0093] Radiolucent materials such as air have a Hounsfield number of approximately −1000, and radiolucent materials such as water have a Hounsfield number of 0 (zero). Body tissues have Hounsfield numbers ranging from, for example, −900 to −750 (e.g., for lung), −100 to −50 (e.g., for fat), and 500 to 3000 (e.g., for bone) (trabecular bone is less dense (e.g., lower Hounsfield number) and cortical bone is more dense (e.g., higher Hounsfield number)). Radiopaque markers typically have Hounsfield numbers in the same range as bone (e.g., 500 to 3000 (e.g., 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550) , 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2550, 2600, 2650, 2700, 2750, 2800, 2850, 2900, 2950, ​​3000).

[0094] In some embodiments, one or more of the markers 320 have a shape to facilitate identification and / or recognition, for example, in a radiological image. In some embodiments, one or more of the markers 320 have a shape that is a sphere, an ellipsoid, a prism, a pyramid, an elongated rod, or a torus. In some embodiments, one or more of the markers 320 have a shape that is a circle, a square, a rectangle, a polygon, or a line when projected onto a two-dimensional plane.

[0095] In some embodiments, the body 310 has a shape with rotational symmetry (e.g., a cylinder or a sphere). In some embodiments, the body 310 has a shape that allows it to be attached (or secured) to a patient support assembly on which a patient rests (e.g., patient support assembly 120 as shown in FIG. 1).

[0096] 3, the markers 320 are arranged in a rotationally asymmetric arrangement, i.e., an arrangement that does not repeat itself during one rotation of the body 310. In this way, each marker is visible at each stage of the rotation process to contribute to each image of the reference phantom 300. In some embodiments, the markers 320 are fixed to the body 310 in a configuration such that at each angle (or most angles) of rotation of the patient rotation system, each marker is at least partially exposed to, or visible along a straight line of sight with, the radiation beam. In some embodiments, the markers 320 are arranged in a symmetric arrangement.

[0097] In some embodiments, the markers 320 are positioned to lie on a plane 330. In some embodiments, the markers 320 are positioned to lie on a plane 330 that is tilted or at an angle relative to the center of rotation 340 of the reference target 300. Thus, in some embodiments, the center of rotation 340 is not perpendicular or orthogonal to the plane 330.

[0098] In some embodiments, the reference target comprises a central marker 322. In some embodiments, the central marker 322 is aligned with the center of the patient support assembly (and center of rotation 340) when the reference target 300 is attached to the patient support assembly. Thus, in embodiments, a non-center, or offset, marker 320 can be used to determine the tilt of the reference phantom 300. In some embodiments, the tilted placement of the markers 320 can avoid overlap between markers, for example, at angles where it may be difficult to detect the location of two overlapping markers.

[0099] In some embodiments, the present technology provides a method for, for example, measuring the tilt of the reference target 300 at one or more angles. In some embodiments, the present technology provides a method for correcting isocenter size (e.g., an isocenter that is too large due to beam misalignment) by measuring the tilt of the reference target 300 at one or more angles. For example, when the radiation beam is misaligned and the patient support assembly is aligned with the rotation axis, the tilt of the reference target 300 does not change (e.g., does not change substantially, does not change effectively, and / or does not change detectably) as the patient support assembly is rotated, but the center marker 322 appears to move during rotation (e.g., the center marker 322 may appear to the left of the radiation isocenter at a first rotation angle and the center marker 322 may appear to the right of the radiation isocenter at a second rotation angle different from the first rotation angle. A maximum range of movement may be detected between the first and second rotation angles that are 180 degrees apart). Conversely, when the radiation beam is aligned and the patient support assembly is misaligned with the rotation axis, the location of the central marker 322 does not change (e.g., does not change substantially, does not change effectively, and / or does not change detectably), but the tilt of the non-central markers changes with the rotation angle (e.g., the non-central marker may appear to be tilted to the left at a first rotation angle, while the non-central marker may appear to be tilted to the right at a second rotation angle different from the first rotation angle; a range of maximum tilt difference may be detected between the first and second rotation angles that are 180° apart).

[0100] In some embodiments, the reference target 300 is used in determining the displacement of a radiation beam with respect to a physical device, such as a patient rotation system or another quality assurance device. In some embodiments, the reference target 300 is used in determining the displacement of a radiation beam with respect to a rotating physical device. In some embodiments, the reference target 300 is used in determining the displacement of the isocenter of a radiation beam (e.g., a treatment beam or an imaging beam) with respect to a patient rotation system and / or a quality assurance device. In some embodiments, the reference target 300 is used in verifying that the isocenter size and / or isocenter coincidence (MV & kV) meets a given specification. In some embodiments, the reference target 300 is used in measuring the isocenter size. In some embodiments, the reference target 300 is used in measuring the isocenter difference and / or coincidence (MV & kV).

[0101] In some embodiments, the reference target 300 is located at a fixed position on a patient rotation system, and measurements of the marker locations are used to align the patient rotation system (or equipment mounted on the patient rotation system) with a reference point (e.g., isocenter). In some embodiments, methods involving measuring the locations of markers on a reference target 300 located at a fixed position on a patient rotation system are used during initial installation and setup of a radiation system, patient positioning system, patient positioning device, patient rotation system, and / or radiation source. In some embodiments, methods involving measuring the locations of markers on a reference target 300 located at a fixed position on a patient rotation system are used for maintenance and / or quality assurance of a radiation system, patient positioning system, patient positioning device, patient rotation system, and / or radiation source.

[0102] In some embodiments, the reference target 300 is used in determining the displacement of the patient support assembly relative to the axis of rotation. For example, in some embodiments, determining the displacement of the patient support assembly relative to the axis of rotation is used to “zero” a location for one or more of its x, y, and z axis positions relative to the axis of rotation. In some embodiments, determining the displacement of the patient support assembly relative to the axis of rotation is used to “zero” a rotation about one or more of the pitch, roll, and yaw axes of rotation. In some embodiments, the technique determines the displacement of the patient support assembly relative to the axis of rotation; “zeroes” a location for one or more of its x, y, and z axis positions relative to the axis of rotation; and / or “zeroes” a rotation about one or more of the pitch, roll, and yaw axes of rotation for all planes of motion using one image set, for example, because the placement of the markers 320 ensures that at least one marker is always visible and the center marker 320 identifies the center of the reference target 300 and the patient support assembly. In some embodiments, the reference target can align the central axes of both the imaging and treatment radiation sources so that they intersect the isocenter (e.g., axis of rotation) of the patient rotation system. Thus, the reference target 300 is used in aligning one or more of the central axis of the treatment beam, the central axis of the imaging beam, the axis of rotation, and / or the "zero" position of the patient support assembly.

[0103] In some embodiments, the placement of the markers 320 on the reference target 300 allows various quantities to be calculated using the same set of images of the reference target 300. For example, an image set acquired for one revolution of the reference target 300 allows for the calculation of: the location of the rotation axis (or isocenter) of the patient rotation system; the distance between the central axis of the treatment beam and the rotation axis; the distance between the central axis of the imaging beam and the rotation axis; the distance between the central axis of the imaging beam and the central axis of the treatment beam; and the distance between a fixed location on the patient rotation system (identified by a marker through an interface that mounts the reference target 300 to the patient support assembly) and a current reading of the patient rotation system's location (e.g., x, y, z axes; pitch, yaw, and roll). In some embodiments, measuring the distance between a fixed location on the patient rotation system (identified by a marker through an interface that mounts the reference target 300 to the patient support assembly) and a current reading of the patient rotation system's location (e.g., x, y, z axes; pitch, yaw, and roll) includes providing an interface that allows for mounting the reference target 300 to a fixed, reproducible location on the patient support assembly (or patient rotation system).

[0104] system In some embodiments, the present technology provides a system including a reference target, e.g., a system including a medical radiation system and a reference target (e.g., as shown in FIGS. 1A-1F). In some embodiments, the present technology provides a system including a medical radiation system 100 and a reference target 170 (e.g., a reference target 170 including a body and a plurality of markers affixed to the body). For example, in some embodiments, the reference target is an embodiment of the reference target 300 described herein (see, e.g., FIGS. 3 and 4).

[0105] In some embodiments, the patient rotation system 110 comprises a patient positioning system (e.g., comprising a patient positioning device or a configurable patient support assembly 120) mounted to a base 130. The base 130 is structured to rotate about an axis 131 of the base 130. In some embodiments, the base 130 is structured to rotate about a vertical axis of symmetry of the base 130. In some embodiments, the patient positioning system, the patient positioning device, and / or the configurable patient support 120 are described in U.S. Patent Application Publication No. 20200268327 and U.S. Patent Application No. 63 / 237,513, each of which is incorporated herein by reference.

[0106] In some embodiments, the patient support assembly 120 is operably coupled to the base 130 such that the patient support assembly 120 rotates therewith (e.g., about an axis 131). In some embodiments, the system comprises a radiation source. For example, some embodiments of the system include a first radiation source 150 structured to produce a beam 151 of electromagnetic radiation. In some embodiments, the first radiation source 150 is a kilovoltage (kV) or megavoltage (MV) X-ray radiation source. The first radiation source 150 can be a therapeutic radiation source or an imaging radiation source. In some embodiments, the system further comprises a second radiation source 152 structured to produce a second beam 153 of electromagnetic radiation. Thus, in some embodiments, the system comprises two radiation sources, e.g., the first radiation source is a therapeutic radiation source and the second radiation source is an imaging radiation source. In some embodiments, the radiation source 150 is a stationary source, e.g., a source that cannot move during normal operation (e.g., during radiation therapy). Thus, radiation source 150 may translate, orbit, and / or rotate during a calibration or alignment procedure. In some embodiments, first radiation source 150 is a stationary source and / or second radiation source 152 is a stationary source. Thus, first radiation source 150 and / or second radiation source 152 may translate, orbit, and / or rotate during a calibration or alignment procedure.

[0107] Furthermore, in embodiments, the radiation beam 151 from the first radiation source 150 is perpendicular to the rotation axis 131 of the base 130 (e.g., after an alignment procedure) and / or the radiation beam 153 from the second radiation source 152 is perpendicular to the rotation axis 131 of the base 130 (e.g., after an alignment procedure). In some embodiments, the radiation source 150 is oriented such that the radiation beam 151 intersects the rotation axis 131. In some embodiments, the isocenter of the radiation beam intersects the rotation axis 131.

[0108] In some embodiments, the radiation source 150 is structured to direct the radiation beam 151 toward the patient support assembly 120. Thus, when the reference target 170 is positioned on the patient support assembly 120, the radiation source 150 is structured to direct the radiation beam 151 toward the reference target 170. In some embodiments, the system includes a detector 160 (e.g., a detection panel) disposed opposite the radiation source 150 to detect the radiation beam 151 traversing the reference target 170. In some embodiments, the detector 160 is an imaging device that produces signals and / or data for generating an image produced by the radiation beam 151. In some embodiments, an additional (e.g., second) detector 162 is associated with the second radiation source 152.

[0109] Embodiments of the system are used in aligning a medical radiation system, such as a medical radiation system including a patient rotation system and a radiation source (e.g., as shown in FIGS. 1A-1F). In some embodiments, the system is structured to rotate the patient rotation system about an axis of rotation. In some embodiments, the system includes a radiation source structured to produce a radiation beam used to produce an image of a reference target located on a patient support assembly of the patient rotation system.

[0110] As described herein, in some embodiments, the system includes a patient rotation system. In some embodiments, the patient rotation system includes a base structured to rotate. In some embodiments, the base is structured to rotate about an axis of the base, such as a vertical axis of symmetry of the base. In some embodiments, the base supports a patient support assembly. In some embodiments, the patient support assembly is adjustably mounted to the base. In some embodiments, the system is structured to adjust the patient support assembly by effecting translational and / or rotational movement of the patient support assembly relative to the base. In some embodiments, the system is structured to adjust the patient support assembly by translating and / or rotating one or more of a backrest (e.g., a configurable, movable backrest), a headrest (e.g., a configurable, movable headrest), an armrest (e.g., a configurable, movable armrest), a seat member (e.g., a configurable, movable seat member), a thinrest (e.g., a configurable, movable thinrest), and / or a foot brace (e.g., a configurable, movable foot brace).

[0111] In some embodiments, the base is fixed to a location (e.g., a healthcare provider's floor). For example, the axis of the base is at a fixed location (e.g., a healthcare provider's floor) and the base is structured to rotate relative to the axis and / or floor. Thus, in embodiments, the base comprises an axis, which further defines an axis of rotation of the system about which components of the medical radiation system (e.g., the patient support assembly and the radiation source) are adjusted for alignment (e.g., with the beam). In some embodiments, components mounted on the patient rotation system (e.g., the patient positioning system, the patient positioner, and / or the patient support assembly) are aligned (e.g., centered or zeroed) about a fixed axis of rotation. For example, in some embodiments, horizontal displacement of the patient support assembly about the axis of rotation may cause the center of the patient support assembly to move in a precessing motion about the axis of rotation rather than rotating on the axis of rotation (e.g., the axis of rotation of the patient support assembly is misaligned such that the axis of rotation of the patient support assembly rotates about a second axis and the patient support assembly moves in a precessing motion about the second axis). Thus, in an embodiment, the central axis of the radiation beam is adjusted to align with and point towards the isocenter of the patient rotation system.

[0112] In some embodiments, the system comprises a software component including instructions for rotating the patient rotation system about the axis of rotation. In some embodiments, the system comprises a software component including instructions for controlling the radiation beam. In some embodiments, the system comprises a software component including instructions for receiving signals and / or data from a detector to produce an image, e.g., an image of a reference target. In some embodiments, the system comprises a software component including instructions for analyzing the image to determine a displacement or offset of the patient support assembly relative to the axis of rotation. In some embodiments, the system is configured to adjust the patient support assembly to align the patient support assembly relative to the axis of rotation. For example, in some embodiments, the system comprises components (e.g., motors, linear actuators, adjustment screws, etc.) used to adjust the patient support assembly to align the patient support assembly relative to the axis of rotation. In some embodiments, for example, the software component including instructions for analyzing the image to determine a displacement or offset of the patient support assembly relative to the axis of rotation includes instructions for comparing the location and / or orientation of the reference target relative to the axis of rotation. In some embodiments, the system is configured to adjust the patient support assembly to align the patient support assembly relative to the axis of rotation. For example, in some embodiments, the system includes components (e.g., motors, linear actuators, adjustment screws, etc.) used to align the center of rotation (or center of symmetry) of the reference target with the axis of rotation.

[0113] In some embodiments, the system comprises a software component including instructions for analyzing the image to locate a central axis, or isocenter, of the radiation beam relative to the axis of rotation. In some embodiments, analyzing the image to locate the central axis, or isocenter, of the radiation beam relative to the axis of rotation includes analyzing the image to determine a displacement of the central axis of the radiation beam relative to the axis of rotation (e.g., a displacement between the central axis of the radiation beam and the axis of rotation). In some embodiments, the system is configured to adjust the radiation source so that the central axis, or isocenter, of the radiation beam intersects the axis of rotation. In some embodiments, the system is configured to adjust the radiation source so that the central axis, or isocenter, of the radiation beam intersects the axis of rotation by performing translational and / or rotational movements of the radiation source. In some embodiments, the system is configured to adjust the radiation source by adjusting or changing operating characteristics of the radiation source to change the direction of the radiation beam.

[0114] In some embodiments, the system includes a second radiation source. For example, in some embodiments, the system includes a first radiation source that is an imaging radiation source for producing images of the patient during treatment, and a second radiation source that is a therapeutic or treatment radiation source for treating the patient. In some embodiments, the first radiation source and / or the second radiation source are stationary (e.g., after adjustment). In some embodiments, the first radiation source and / or the second radiation source are fixed in position during normal operation to prevent displacement.

[0115] In some embodiments, the system comprises a software component including instructions for controlling the second radiation beam. In some embodiments, the system comprises a software component including instructions for receiving signals and / or data from a second detector to produce an additional image, e.g., an additional image of a reference target. In some embodiments, the system comprises a software component including instructions for analyzing the additional image to determine a displacement of the patient support assembly relative to the axis of rotation. In some embodiments, the system comprises a software component including instructions for analyzing the additional image to locate a central axis of the second radiation beam relative to the axis of rotation or to determine a displacement of the central axis of the second radiation beam relative to the axis of rotation; and the system is configured to adjust the radiation source so that the central axis of the second radiation beam intersects the axis of rotation.

[0116] In some embodiments, the system includes a component (e.g., a motor, a linear actuator, an adjustment screw, etc.) structured to adjust the first radiation source and / or the second radiation source so that a central axis of the second radiation beam intersects a central axis of the first radiation beam. In some embodiments, the two radiation beams intersect at the axis of rotation of the patient rotation system.

[0117] In some embodiments, the system includes an imaging device (e.g., a detector) for detecting the radiation beam and creating an image of the reference target. In some embodiments, the system includes multiple imaging devices, each associated with a different radiation source. In some embodiments, each imaging device is located opposite, or virtually or substantially opposite, its associated radiation source relative to the patient support assembly. Thus, in some embodiments, the system includes a reference target located on the patient support assembly between the radiation source and its associated imaging device such that the radiation beam from the radiation source passes through the reference target and is received by the imaging device, which then sends data and / or signals to a software component to create an image of the reference target.

[0118] In some embodiments, the system includes an image of the reference target. In some embodiments, the system includes a memory component containing the image of the reference target in digital form. In some embodiments, the image of the reference target includes at least two images (e.g., at least a first image and a second image) of the reference target generated for different angles of rotation of the patient rotation system. In some embodiments, the image of the reference target includes at least four images (e.g., at least a first image, a second image, a third image, and a fourth image) of the reference target generated at orthogonal angles of rotation of the patient rotation system.

[0119] In some embodiments, the system comprises a software component including instructions for determining the displacement or offset of the patient support assembly relative to the axis of rotation by producing multiple images of the reference target that identify the location of the reference target in three-dimensional space. Accordingly, in some embodiments, the system comprises a software component including instructions for determining the location of the reference target in three-dimensional space. In some embodiments, the images of the reference target produced by each radiation source are analyzed independently by the software component to locate the reference target relative to the axis of rotation. In some embodiments, the images of the reference target produced by each radiation source are analyzed in combination by the software component to locate the reference target relative to the axis of rotation.

[0120] In some embodiments, the system comprises a reference target located to provide one or more reference points for determining the position of the patient support assembly or the radiation beam relative to the axis of rotation or any other fixed axis, point, or location. In some embodiments, the reference target is a point or surface on the patient support assembly. In some embodiments, the reference target is a target of known size, composition (e.g., known material, known Z, and / or known Z) that is attached to the patient support assembly and rotated by a patient rotation system. eff ), and a separate device with a marker of the configuration.

[0121] In some embodiments, the system includes a reference target mounted at a fixed location on the patient support assembly (and / or the patient rotation system). In some embodiments, the reference target is mounted at the center of the patient support assembly. In some embodiments, the patient support assembly is structured such that during adjustment of the patient support assembly to align the patient support assembly with the axis of rotation, the center of the patient support assembly is adjusted to be moved into alignment with the axis of rotation of the patient rotation system.

[0122] In some embodiments, the patient support assembly includes a quality assurance (QA) interface, index, belt, strap, or other fastening component. In some embodiments, the system includes a reference target attached to the patient support assembly using a quality assurance (QA) interface, index, belt, strap, or other fastening component provided on the patient support assembly.

[0123] In some embodiments, the patient support assembly comprises an interface. In some embodiments, a reference target is attached to the patient support assembly using the interface. In some embodiments, the interface provides fixed positioning of the reference target relative to the patient support assembly (and / or relative to the patient rotation system). For example, in some embodiments, the interface securely positions the reference target at the center of the patient support assembly, thus allowing the position and / or orientation of the patient support assembly to be determined (e.g., by the system) using the reference target. In some embodiments, placement of the interface on the patient support assembly is used to calibrate and / or define a zero position of the patient support assembly (and / or is used to calibrate and / or define a zero position of the patient rotation system). Thus, in some embodiments, the system comprises a reference target attached or mounted to the patient support assembly. In some embodiments, the patient support assembly comprises an interface that is in a fixed position on the patient support assembly, and the reference target is mounted to the interface.

[0124] In some embodiments, the system comprises a software component including instructions for minimizing the radiation isocenter of the treatment beam and / or the imaging beam (e.g., by orienting the central axis of the radiation beam to intersect the axis of rotation). In some embodiments, the system comprises a software component including instructions for aligning the treatment beam using features in an image of the edge of the beam shaping system. In some embodiments, the system comprises a beam shaping system that attenuates the treatment beam to shape its intensity profile, e.g., to match the profile of the tumor. In some embodiments, the system is structured to align the beam shaping system with the central axis of the treatment beam, e.g., to ensure that the shape of the radiation field is symmetric about the central axis of the beam and / or to optimize the shape of the collimator leaves, which are adjustable components of the beam shaping system.

[0125] Although the disclosure herein refers to certain illustrated embodiments, it should be understood that these embodiments are presented by way of example and not by way of limitation.

[0126] All publications and patents mentioned in the above specification are incorporated herein by reference in their entirety for all purposes. Various modifications and variations of the composition, method, and use of the described technology will be apparent to those skilled in the art without departing from the scope and spirit of the described technology. Although the technology has been described in connection with specific exemplary embodiments, it should be understood that the claimed invention should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims

1. 1. A method for aligning a medical radiation system comprising a patient rotation system and a radiation source, the method comprising: rotating the patient rotation system about an axis of rotation; detecting a radiation beam from the radiation source to produce an image of a reference target located on a patient support assembly of a patient rotation system; analyzing the images to determine a displacement of the patient support assembly relative to the axis of rotation; adjusting the patient support assembly to align the patient support assembly with respect to the axis of rotation; A method comprising:

2. The method of claim 1 , wherein the displacement is determined by comparing the location and orientation of a reference target relative to the axis of rotation.

3. The method of claim 1 or 2, wherein adjusting the patient support assembly comprises aligning a center of rotation of a reference target with the axis of rotation.

4. analyzing the image to locate a central axis of the radiation beam relative to the axis of rotation; adjusting the radiation source so that the central axis of the radiation beam intersects with the rotation axis; The method of claim 1 , further comprising:

5. The method of claim 1 , wherein the patient rotation system comprises a base configured to rotate, the base supporting the patient support assembly.

6. The method of claim 1 , wherein the patient support assembly is configured for movement with six degrees of freedom relative to the base.

7. The method of claim 5 or 6, wherein adjusting the patient support assembly comprises effecting translational movement of the patient support assembly relative to the base.

8. The method of claim 5 , wherein adjusting the patient support assembly comprises performing a rotational movement of the patient support assembly relative to the base.

9. 9. The method of claim 5, wherein rotating the patient rotation system comprises rotating a base, and the axis of rotation is an axis of the base.

10. 10. The method of claim 9, wherein the axis of rotation is the axis of symmetry of the base.

11. 11. The method of claim 1, wherein the medical radiation system further comprises an imaging device for detecting the radiation beam and producing an image of the reference target, the imaging device being located on an opposite side of the radiation source relative to the patient support assembly.

12. 12. The method of claim 1, wherein the images of the reference target include at least two images of the reference target produced for different angles of rotation of the patient rotation system.

13. The method of claim 1 , wherein the reference target comprises a body and one or more markers fixed to the body in a pre-arranged configuration.

14. 14. The method of claim 13, wherein the one or more markers are secured to the body in a pre-arranged configuration such that each marker is at least partially exposed to the radiation beam at each angle of rotation of the patient rotation system.

15. 15. The method of claim 13 or 14, wherein the one or more markers are disposed on an imaginary plane within the body, the imaginary plane being tilted relative to the axis of rotation when the reference target is located on the patient support assembly.

16. 16. The method of any one of claims 13 to 15, wherein the reference target comprises a central marker disposed within the body at the center of rotation of the reference target.

17. 17. A method according to any one of claims 13 to 16, wherein the body is substantially radiotransparent to the radiation beam.

18. 18. The method of any one of claims 13 to 17, wherein the one or more markers are opaque to the radiation beam.

19. 19. The method of any one of claims 1 to 18, wherein the radiation source is one of an imaging radiation source or a therapeutic radiation source.

20. 20. The method of any one of claims 1 to 19, wherein the medical radiation system further comprises a second radiation source.

21. detecting a second radiation beam from a second radiation source to produce an additional image of the reference target; analyzing the additional image to locate a central axis of the second radiation beam relative to the axis of rotation; adjusting the second radiation source so that the central axis of the second radiation beam intersects the axis of rotation; 21. The method of claim 20, further comprising:

22. 22. The method of claim 21, further comprising adjusting at least one of the radiation source and the second radiation source so that a central axis of the second radiation beam intersects the central axis of the radiation beam.

23. 23. The method of any one of claims 1 to 22, further comprising mounting a reference target on a patient support assembly.

24. 24. The method of claim 23, wherein the patient support assembly comprises an interface for mounting a reference target at a fixed location on the patient support assembly.

25. a medical radiation system; a reference target comprising a body and one or more markers fixed to the body in a pre-arranged configuration; A system comprising:

26. 26. The system of claim 25, further comprising a detector.

27. 26. The system of claim 25, further comprising a patient support assembly.

28. 28. The system of claim 27, wherein the patient support assembly comprises an interface structured to receive the reference target.

29. 26. The system of claim 25, wherein the system is structured to rotate the reference target about an axis orthogonal to an axis between a source and a detector.

30. 26. The system of claim 25, wherein the medical radiation system comprises a stationary source.

31. Rotating the patient rotation system about the axis of rotation; controlling the radiation beam; 26. The system of claim 25, further comprising a software component including instructions for receiving signals and / or data from the detector to create an image, analyzing the image to determine a displacement of the patient support assembly relative to the axis of rotation, analyzing the image to locate an isocenter of the radiation beam relative to the axis of rotation, and / or determining a displacement of a central axis of the radiation beam relative to the axis of rotation.

32. 26. The system of claim 25, further comprising a component structured to adjust the patient support assembly to align the patient support assembly with respect to an axis of rotation of the patient support assembly.

33. 26. The system of claim 25, further comprising a component structured to adjust the position of the radiation source and / or the position of the beam produced by the radiation source.

Images