Multi-leaf collimator and radiotherapy machine comprising the same
Patent Information
- Application Number
- CN202610222344.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-02-28
- Filing Date
- 2026-02-25
- Publication Date
- 2026-08-28
Smart Images
Figure CN122643604A_ABST
Abstract
Description
Technical Field
[0001] One or more example embodiments relate to a multileaf collimator (MLC) and a radiotherapy delivery machine including the multileaf collimator. Background Technology
[0002] Multi-leaf collimators (MLCs) are used in radiotherapy delivery machines to support radiotherapy such as intensity-modulated radiotherapy (IMRT). A typical MLC consists of a group of beam-blocking blades arranged in two opposing rows. In operation, each individual beam-blocking blade is positioned to block a portion of the radiation beam passing through the volume occupied by the blade. The combined positioning of all the beam-blocking blades defines one or more apertures through which the unblocked radiation beam passes, and the apertures define the shape of the radiation beam directed toward the isocentric treatment field. Summary of the Invention
[0003] The independent claims define the scope of protection sought for the various exemplary embodiments. Exemplary embodiments and / or features (if any) described in this specification that are not within the scope of the independent claims are to be interpreted as examples that aid in understanding the various embodiments.
[0004] In this patent application, nouns and pronouns referring to people generally do not specify a particular gender.
[0005] At least one illustrative embodiment provides a multi-leaf collimator for defining a treatment field of a radiotherapy machine, the multi-leaf collimator comprising: a first leaf box configured to move in a first direction and configured to receive a plurality of first beam-blocking leaflets arranged in a first row, wherein the plurality of first beam-blocking leaflets are configured to move relative to each other and relative to the first leaf box; a second leaf box arranged opposite to the first leaf box, the second leaf box configured to move in the first direction and configured to receive a plurality of second beam-blocking leaflets arranged in a second row, wherein the plurality of second beam-blocking leaflets are configured to move relative to each other, are configured to move relative to the plurality of first beam-blocking leaflets, and are configured to move relative to the second leaf box; and at least one first edge-defining leaflet extending between the first leaf box and the second leaf box, the first edge-defining leaflet being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining leaflet is fixed relative to the first leaf box and configured to move relative to the second leaf box.
[0006] At least one other example embodiment provides a radiotherapy machine including: a radiation source configured to emit a radiation beam; and a multi-leaf collimator for blocking portions of the radiation beam to define a treatment field of the radiotherapy machine, the multi-leaf collimator including: a first leaf box configured to move in a first direction and configured to receive a plurality of first beam-blocking leaflets arranged in a first row, wherein the plurality of first beam-blocking leaflets are configured to move relative to each other and relative to the first leaf box; a second leaf box arranged opposite to the first leaf box, the second leaf box configured to move in the first direction and configured to receive a plurality of second beam-blocking leaflets arranged in a second row, wherein the plurality of second beam-blocking leaflets are configured to move relative to each other, are configured to move relative to the plurality of first beam-blocking leaflets, and are configured to move relative to the second leaf box; and at least one first edge-defining leaflet extending between the first leaf box and the second leaf box, the first edge-defining leaflet being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining leaflet is fixed relative to the first leaf box and configured to move relative to the second leaf box.
[0007] According to one or more illustrative embodiments, the first edge-defining blade can define the edge of the treatment field.
[0008] The multi-leaf collimator may include a second edge-defining blade extending between a first blade box and a second blade box, the second edge-defining blade being disposed at a second end of a first row and a second end of a second row, wherein the second edge-defining blade is fixed relative to the second blade box and configured to move relative to the first blade box.
[0009] The first blade box can be configured to house a plurality of third beam-blocking blades arranged in a third row below a plurality of first beam-blocking blades, wherein the plurality of third beam-blocking blades can be configured to move relative to each other and relative to the first blade box. The second blade box can be configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below a plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades can be configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box. The multi-leaf collimator may further include a first scattering-blocking blade extending between the first and second blade boxes, the first scattering-blocking blade being arranged below a first edge-defining blade at a first end of the third row and a first end of the fourth row, wherein the first scattering-blocking blade is fixed relative to the first blade box and configured to move relative to the second blade box.
[0010] The multi-leaf collimator may further include a second scattering blocking blade extending between the first blade box and the second blade box, the second scattering blocking blade being disposed below the second edge defining blade at the second end of the third row and the second end of the fourth row, wherein the second scattering blocking blade is fixed relative to the second blade box and configured to move relative to the first blade box.
[0011] The first edge-defining leaf and the second edge-defining leaf can define the edge of the treatment field.
[0012] The first blade box can be configured to move a first edge-defined blade relative to the second blade box, and the second blade box can be configured to move a second edge-defined blade relative to the first blade box.
[0013] The first edge defining blade, the plurality of first beam blocking blades, and the plurality of second beam blocking blades can be configured to move relative to each other.
[0014] The first blade box is configured to move a first edge-defining blade relative to the second blade box, and the second blade box may include a guide member to hold the first edge-defining blade at the edge of the treatment field as the first edge-defining blade moves relative to the second blade box. Attached Figure Description
[0015] The exemplary embodiments will be more fully understood from the detailed description and accompanying drawings given below, wherein the same elements are indicated by the same reference numerals, which are given by way of illustration only and therefore do not limit this disclosure.
[0016] Figure 1 This is a side perspective view of a multi-leaf collimator (MLC) according to an example embodiment;
[0017] Figure 2A and Figure 2B yes Figure 1 The front perspective view of the MLC shown;
[0018] Figure 3 yes Figure 1 The side view of the MLC shown;
[0019] Figure 4 It shows Figure 1 The MLC shown has its blade box removed;
[0020] Figure 5 and Figure 6 yes Figure 1 A perspective view of the shielding elements and retaining mechanism of the MLC shown;
[0021] Figure 7 It shows Figure 5 and Figure 6A perspective view of the blade box and a portion of the MLC shown;
[0022] Figure 8 yes Figure 1 A perspective view of the blade box and outer shielding element of the MLC shown;
[0023] Figure 9 The outer shielding elements at the proximal and distal ends according to an example embodiment are shown;
[0024] Figure 10 This is a perspective view of the blade box according to an example embodiment;
[0025] Figure 11 It shows Figure 10 Another view of the blade box shown;
[0026] Figure 12 An example embodiment of a shielding element is shown. Figure 10 and Figure 11 The blade box shown;
[0027] Figure 13 This is a top view of an MLC according to other example embodiments;
[0028] Figure 14 An example of a radiotherapy machine according to an exemplary embodiment is shown; and
[0029] Figure 15 It is shown Figure 1 A block diagram of an example embodiment of the controller 220 shown.
[0030] It should be noted that these figures are intended to illustrate the general characteristics of the methods, structures, and / or materials used in certain exemplary embodiments and to supplement the written description provided below. However, these figures are not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any given embodiment, nor should they be construed as defining or limiting the range of values or properties included in the exemplary embodiments. The use of similar or identical reference numerals in the various figures is intended to indicate the presence of similar or identical elements or features. Detailed Implementation
[0031] Various exemplary embodiments will now be described more fully with reference to the accompanying drawings, some of which illustrate exemplary embodiments.
[0032] Detailed illustrative embodiments are disclosed herein. However, the specific structural and functional details disclosed herein are for the purpose of describing exemplary embodiments only. These exemplary embodiments may be embodied in many alternative forms and should not be construed as being limited to the embodiments described herein.
[0033] It should be understood that the exemplary embodiments are not intended to limit the specific forms disclosed. Rather, the exemplary embodiments will cover all modifications, equivalents, and alternatives falling within the scope of this disclosure. Throughout the description of the drawings, the same reference numerals refer to the same elements.
[0034] As described in this article, the terms “one or more” and “at least one” are used interchangeably.
[0035] It should be understood that multiple example embodiments can be used in combination.
[0036] While the operations in one or more diagrams may be presented as occurring in a series and in a specific order, the example embodiments are not limited to this. These operations may be performed in different orders and / or in parallel, or they may be performed iteratively.
[0037] Conventional radiotherapy equipment includes a primary collimation system located upstream of the multileaf collimator (MLC). The primary collimator is a fixed aperture that initially shapes the radiation beam exiting the linear accelerator to provide a basic level of beam shaping and limit the maximum field size.
[0038] Downstream of the primary collimator, movable x and y secondary collimators provide further refinement of the beam shape. These secondary collimators can be adjusted independently to create rectangular or square regions of different sizes.
[0039] For double-layer stacked MLCs, the secondary collimator can be omitted to save vertical space in the treatment head. However, with the reduction in pre-collimation before the MLC, field leakage to one side of the blade row is possible. Additional outer or side shielding blades or components can be used to mitigate and / or prevent this field leakage.
[0040] Furthermore, in conventional stacked MLCs with movable blade boxes, precise placement of the shielding components can be relatively difficult because the outer shielding components must be removed from the blade box when it is moved.
[0041] One or more example embodiments provide a multilayer MLC comprising outer shielding members (e.g., edge-defined blades and / or scattering-blocking blades) that span or extend across or into a matching guiding feature in an opposing blade box from a guiding feature (also referred to as a guiding groove or guiding member) in the radiotherapy field. Unlike paired beam-blocking blades that movably extend into the central portion of the radiotherapy field, each outer shielding member extends within the outer edge of one blade box into a corresponding outer edge of an opposing blade box in the treatment field.
[0042] By spanning two blade boxes, the placement of the outer shielding component can have the same or substantially the same tolerances as other beam-blocking blades in the MLC.
[0043] The outer shielding component may include edge-defining blades and / or scatter-blocking blades. Edge-defining blades define and shape the relative edges of the radiotherapy field for the patient during treatment. Scatter-blocking blades block or reduce scattered radiation reaching the patient's healthy tissues. The outer shielding component may also be referred to as an outer shielding element, boundary shielding element, or boundary shielding component.
[0044] As described herein, beam blocking blades, edge-defining blades, and / or scattering blocking blades may be more generally referred to as shielding elements or components. Shielding elements may be formed from one or more high-density materials, such as tungsten.
[0045] According to one or more example embodiments, the MLC is designed such that during a service event, a single blade box can be removed by retracting the blade box to its maximum limit, removing the retaining mechanism, and sliding the shielding component deeper into the blade box so that the shielding component slides out of the opposing blade box. At least in this respect, the outer shielding components do not always need to span two blade boxes, nor do they need to be removed simultaneously.
[0046] According to one or more illustrative embodiments, each outer shielding member may be fixed or stationary relative to the first blade box and configured to move relative to the opposing second blade box. In one example, the proximal and distal outer shielding members (e.g., edge defining blades and scattering blocking blades) on one side of the treatment field (or MLC) may move with the first blade box but relative to the opposing second blade box, while the proximal and distal outer shielding members on the opposite side of the treatment field (or MLC) may move with the second blade box but relative to the first blade box.
[0047] According to at least one other illustrative embodiment, each outer shielding component can be secured in place by a retaining bracket located at the middle portion of the respective outer shielding element. In this illustrative embodiment, each blade box is movable relative to the outer shielding element.
[0048] Now for reference Figures 1-13 A detailed description of example embodiments of MLCs and their components.
[0049] Figure 1 , Figure 2A , Figure 2B and Figure 3 Various views of the MLC according to an example embodiment are shown. Figure 4 It shows Figure 1 The MLC shown has the blade box removed. Figure 5 and Figure 6 yes Figure 1 A perspective view of the shielding elements and retaining mechanism of the MLC shown. Figure 7 It shows Figure 5 and Figure 6 A perspective view of the blade box and a portion of the MLC shown. Figure 8 yes Figure 1 A perspective view of the blade box and outer shielding element of the MLC shown.
[0050] refer to Figures 1-8 The MLC 120 includes a first blade box 3020 and a second blade box 3022 arranged opposite to each other. The first blade box 3020 is configured to move in a first direction (X direction). The second blade box 3022 is also configured to move in the first direction, such that the first blade box 3020 and the second blade box 3022 move linearly toward and away from each other. The first blade box 3020 and the second blade box 3022 can be moved by corresponding bracket motors (not shown). Since bracket motors are known, detailed discussion is omitted.
[0051] The first blade box 3020 includes a proximal section (discussed below). Figure 10 and Figure 11 The 30200U in the middle) and the remote part (discussed below) Figure 10 and Figure 11 (30200L in the example). In the proximal portion, the first blade box 3020 is configured to house a plurality of first proximal beam blocking blades 3040U (also referred to as upper beam blocking blades), which are arranged adjacent to each other (side by side) in a first linear array or row. Each first proximal beam blocking blade 3040U is configured to move independently relative to each other and relative to the first blade box 3020 in a first direction. Each of the plurality of first proximal beam blocking blades 3040U can be independently moved / driven by a drive assembly 3080U including one or more drive motors.
[0052] In the distal portion, the first blade box 3020 is configured to house a plurality of first distal beam blocking blades 3040L, which are arranged adjacent to each other (side-by-side) in a linear array or row below a plurality of first proximal beam blocking blades 3040U. Each first distal beam blocking blade 3040L is also configured to move independently relative to each other, relative to the first blade box 3020, and relative to the plurality of first proximal beam blocking blades 3040U in a first direction. The plurality of first distal beam blocking blades 3040L can be moved / driven independently by a drive assembly 3080L including one or more drive motors.
[0053] The second blade box 3022 also includes a proximal portion and a distal portion. In the proximal portion, the second blade box 3022 is configured to accommodate a plurality of second proximal beam blocking blades 3042U, which are arranged adjacent to each other (side-by-side) in a second linear array or row. Each second proximal beam blocking blade 3042U is configured to move independently relative to each other and relative to the second blade box 3022. The second proximal beam blocking blades 3042U can also be configured to move relative to a plurality of first proximal beam blocking blades 3040U. The plurality of second proximal beam blocking blades 3042U can be moved / driven independently by a drive assembly 3082U including one or more drive motors.
[0054] In the distal portion, the second blade box 3022 is configured to house a plurality of second distal beam blocking blades 3042L, which are arranged adjacent to each other (side-by-side) in a linear array or row below a plurality of second proximal beam blocking blades 3042U. Each second distal beam blocking blade 3042L is configured to move independently relative to each other, relative to the plurality of second proximal beam blocking blades 3042U, relative to the first blade box 3020 and the second blade box 3022, and relative to beam blocking blades 3040U and 3040L. The plurality of second distal beam blocking blades 3042L can be moved / driven independently by a drive assembly 3082L including one or more drive motors.
[0055] According to one or more illustrative embodiments, a first proximal beam blocking blade 3040U and a second proximal beam blocking blade 3042U are arranged in pairs (e.g., one first proximal beam blocking blade and one second proximal beam blocking blade), wherein each pair of proximal beam blocking blades can be moved independently (e.g., based on the radiotherapy plan) to block or allow the radiation beam to pass through the patient.
[0056] Similarly, the first distal beam blocking blade 3040L and the second distal beam blocking blade 3042L are arranged in pairs (e.g., one first distal beam blocking blade and one second distal beam blocking blade), wherein each pair of distal beam blocking blades can be moved independently (e.g., based on the radiotherapy plan) to block or allow the radiation beam to pass through the patient.
[0057] Still referencing Figures 1-8 The MLC 120 also includes edge-defining blades 3062U and 3064U extending between the proximal portions of the first blade box 3020 and the second blade box 3022.
[0058] Figure 9 An example embodiment of the edge-defined blade 3064U is shown. For example... Figure 9As shown, the edge-defining blade 3064U is a flat, rectangular beam-stopping material with notches 900 and 902 at opposite longitudinal edges. As discussed in more detail later, notches 900 and / or 902 allow the edge-defining blade 3064U to be stationary or fixed relative to the blade housing. Notches 900 and 902 can be formed in the material such that the beam-stopping blade can be positioned in multiple orientations. Washer and screw assemblies can engage with notches 900 or 902 and the corresponding blade housing, allowing the edge-defining blade 3064U to move together with the corresponding blade housing.
[0059] Back Figures 1-8 Edge-defining blades 3062U and 3064U are arranged at the corresponding ends of the rows of near-end beam-blocking blades 3040U and 3042U to define the corresponding edges of the radiotherapy field. Figures 1-8 In the illustrative embodiment shown, the movement of the edge-defining blade 3064U is fixed relative to the first blade housing 3020, such that the edge-defining blade 3064U moves linearly together with the first blade housing 3020 and moves relative to the second blade housing 3022 in the X direction. For example, the edge-defining blade 3064U slides into and out of the second blade housing 3022 guided by upper and lower proximal recesses. As discussed in more detail later, the movement of the edge-defining blade 3064U can be restricted and / or fixed by a screw and washer assembly fixed to the first blade housing 3020.
[0060] The movement of the edge-defining blade 3062U is fixed relative to the second blade housing 3022, such that the edge-defining blade 3062U moves linearly together with the second blade housing 3022 and moves relative to the first blade housing 3020 in the X direction. For example, the edge-defining blade 3062U slides into and out of the first blade housing 3020 guided by upper and lower proximal recesses. As discussed in more detail later, the movement of the edge-defining blade 3062U can be restricted and / or fixed by a screw and washer assembly fixed to the second blade housing 3022.
[0061] The MLC 120 also includes scattering blocking blades 3062L and 3064L extending between the distal portions of the first blade box 3020 and the second blade box 3022.
[0062] Figure 9 An example embodiment of the scattering blocking blade 3064L is also shown. For example... Figure 9As shown, the scattering blocking blade 3064L is a flat, rectangular beam-blocking material with notches 904 and 906 at opposite longitudinal edges. As discussed in more detail later, notches 904 and / or 906 allow the movement of the scattering blocking blade 3064L to be fixed relative to the blade housing, similar to an edge-defined blade. Notches 904 and 906 can be formed in the material such that the scattering blocking blade can be positioned in multiple orientations. A retaining bracket assembly can engage with notches 904 or 906 and the corresponding blade housing, allowing the scattering blocking blade 3064L to move together with the corresponding blade housing. Although not specifically described herein, it should be understood that the edge-defined blade 3062U and the scattering blocking blade 3062L can be respectively engaged with… Figure 9 The edge-limiting blade 3064U and the scattering-blocking blade 3064L shown are the same or substantially the same.
[0063] Back Figures 1-8 Scattering blocking blades 3062L and 3064L are arranged at the corresponding ends of the rows of far-end beam blocking blades 3040L and 3042L.
[0064] At least in this example, the movement of the scattering blocking blade 3064L is fixed relative to the first blade box 3020, such that the scattering blocking blade 3064L moves linearly in the X direction together with the first blade box 3020 and relative to the second blade box 3022. For example, the scattering blocking blade 3064L slides into and out of the second blade box 3022 guided by upper and lower distal recesses.
[0065] Similarly, the movement of the scattering blocking blade 3062L is fixed relative to the second blade box 3022, such that the scattering blocking blade 3062L moves linearly in the X direction together with the second blade box 3022 and relative to the first blade box 3020. For example, the scattering blocking blade 3062L slides into and out of the first blade box 3020 guided by the upper and lower distal recesses.
[0066] Figure 10 and Figure 11 Showing more details Figure 1 The first blade box 3020. Figure 12 The first blade box 3020 is shown, which includes edge-defining blades 3062U and 3064U, scattering-blocking blades 3062L and 3064L, a first near-end beam-blocking blade 3040U, a first far-end beam-blocking blade 3040L, and a radiation beam 125 (also shown). Figure 14(As shown in the figure). For the sake of brevity, only the first blade box 3020 will be described. However, it should be understood that the second blade box 3022 may be the same as or substantially the same as the first blade box 3020. When implemented in an MLC according to one or more example embodiments, the second blade box 3022 may be the same as the first blade box 3020, but rotated 180 degrees about the longitudinal axis.
[0067] refer to Figures 10-12 The first blade box 3020 includes a proximal portion 30200U and a distal portion 30200L.
[0068] The proximal portion 30200U includes a first upper proximal outer groove 30202U and a first lower proximal outer groove 30204U to hold the edge-defining blade 3062U at the edge of the radiotherapy field when the edge-defining blade 3062U moves relative to the first blade box 3020. In the Y direction, on the opposite side of the proximal portion 30200U, the proximal portion 30200U includes a second upper proximal outer groove 30222U and a second lower proximal outer groove 30224U to hold the edge-defining blade 3064U at the edge of the radiotherapy field when the edge-defining blade 3064U moves together with the first blade box 3020.
[0069] The proximal portion 30200U of the first blade box 3020 also includes a plurality of upper proximal inner grooves 30206U located between the upper proximal outer grooves 30202U and 30222U, and a plurality of lower proximal inner grooves 30208U located between the lower proximal outer grooves 30204U and 30224U.
[0070] Multiple upper proximal inner grooves 30206U and multiple lower proximal inner grooves 30208U maintain and guide multiple first proximal beam blocking blades 3040U during movement.
[0071] The distal portion 30200L includes a first upper distal outer groove 30202L and a first lower distal outer groove 30204L to hold the scattering blocking blade 3062L in place to block scattered radiation and to guide the scattering blocking blade 3062L when it moves relative to the first blade box 3020. On the opposite side in the Y direction, the distal portion 30200L includes a second upper distal outer groove 30222L and a second lower distal outer groove 30224L to hold the scattering blocking blade 3064L in place, thereby blocking scattered radiation when the scattering blocking blade 3064L moves together with the first blade box 3020.
[0072] The distal portion 30200L of the first blade box 3020 also includes a plurality of upper distal inner grooves 30206L located between the upper distal outer grooves 30202L and 30222L, and a plurality of lower distal inner grooves 30208L located between the lower distal outer grooves 30204L and 30224L.
[0073] Multiple upper distal inner grooves 30206L and multiple lower distal inner grooves 30208L maintain and guide multiple first distal beam blocking blades 3040L during movement.
[0074] The screw and washer assembly 3010 engages with the first blade box 3020 above the second upper proximal outer groove 30222U. (As follows) Figures 1-5 and Figure 12 As shown, for example, the washer portion of the screw and washer assembly 3010 engages with the recess 900 to restrict movement of the edge-defining blade 3064U relative to the first blade housing 3020 during operation. That is, for example, the screw and washer assembly 3010 engages with the first blade housing 3020 and the recess 900 (or 902, depending on the orientation) such that the edge-defining blade 3064U moves together with the first blade housing 3020. As described above, the edge-defining blade 3064U spans or extends between the first blade housing 3020 and the second blade housing 3022. At the second blade housing 3022, the edge-defining blade 3064U is allowed to slide and move relative to the second blade housing 3022 when the first blade housing 3020 moves in the X direction.
[0075] In one example, the screw portion of the screw and washer assembly 3010 may be an internal hex screw.
[0076] Still referencing Figures 10-12 The retaining bracket assembly 3012, secured by screws and washers 30122, has a protrusion 30120 extending in the Y direction and engaging with a notch 904 to restrict movement of the scattering blocking blade 3064L relative to the first blade box 3020 during operation. That is, for example, the retaining bracket assembly 3012 engages with the notch 904 (or 906, depending on the orientation) such that the scattering blocking blade 3064L moves with the first blade box 3020 in the same or substantially the same manner as the edge-defining blade 3064U. Similar to the edge-defining blade 3064U, at the second blade box 3022, the scattering blocking blade 3064L is allowed to slide and move relative to the second blade box 3022 as the first blade box 3020 moves.
[0077] In one example, the screw portion of the screw and washer assembly 30122 may be an internal hex screw.
[0078] According to at least one other illustrative embodiment, the edge-defining blades and the scattering-blocking blades can be secured in place by a retaining bracket or mechanism located at the middle portion of the respective outer shielding element. In this illustrative embodiment, each blade box is movable relative to the outer shielding element. Figure 13 The example embodiment is shown in the figure.
[0079] because Figure 13 The example embodiments shown are similar to the example embodiments described above, so only the differences will be described here.
[0080] In more detail, Figure 13 The illustrative embodiments shown are similar to those described above. Figures 1-12 The exemplary embodiments shown and described, except that each edge-defining blade 13060 and 13062 and the scattering-blocking blade are secured in place by corresponding retaining brackets in retaining brackets 13050 and 13052. (Regarding...) Figures 1-12 The example embodiments shown and described differ from those in which the respective blade boxes 13020 and 13022 move relative to the respective outer shielding elements.
[0081] Figure 14 A radiotherapy machine including an MLC 120 is shown according to an example embodiment.
[0082] refer to Figure 14 The radiotherapy machine 100 includes a patient bed 135 on which a patient 140 can be placed, such that the region of interest 130 is correctly located within the radiation beam 125. The treatment gantry 110 includes a radiation source 115 and an MLC 120. The radiation source 115 guides the radiation beam 125 through the MLC 120 and toward the region of interest (ROI) 130. The individual beam-blocking blades and outer shielding elements of the MLC 120 are arranged to block portions of the radiation beam 125 falling outside the region of interest 130, thereby defining the radiotherapy field.
[0083] In some example embodiments, the patient bed 135 includes multiple movable portions (not shown) to position the patient bed 135 below, beside, inside, or partially inside the treatment unit 105. Furthermore, in some example embodiments, the treatment gantry 110 may include movable portions that allow the treatment gantry 110 to rotate about the patient bed 135 or otherwise move relative to the region of interest 130. Movement of the treatment gantry 110 or the patient bed 135 may cause the region of interest 130 to move relative to the radiation source 115 and the MLC 120. Changes in the relative position of the region of interest 130 may cause changes in the shape and size of the region of interest, requiring movement of the individual beam-blocking blades of the MLC 120 to block different portions of the radiation beam 125 and modify the radiotherapy field.
[0084] The radiotherapy machine 100 communicates bidirectionally with the controller 220, which is configured for concurrent, simultaneous, individual, and separate control. Figure 14 The operation of one or more components of the radiotherapy machine shown.
[0085] Figure 15 It is shown Figure 14 A block diagram of an example embodiment of the controller 220 shown.
[0086] refer to Figure 15 The controller 220 includes at least one processor 225, at least one memory 230, and at least one communication interface 235. The at least one memory 230 can be configured to store instructions that can be executed by the at least one processor 225 to cause the radiotherapy machine 100 to perform one or more functions, such as performing a radiotherapy procedure, controlling the MLC 120, etc.
[0087] As will be understood, depending on the implementation of controller 220, controller 220 may include additional components. However, for the purpose of illustrating an exemplary embodiment, not all of these generally conventional components need to be shown. For illustrative purposes, controller 220 will be discussed with respect to processor 225. However, it should be understood that controller 220 may include one or more processors or other processing circuitry systems, such as one or more application-specific integrated circuits (ASICs).
[0088] Memory 230 may be a computer-readable storage medium, which typically includes random access memory (RAM), read-only memory (ROM), and / or permanent mass storage devices such as disk drives. Memory 230 may also store an operating system and any other routines / modules / applications to provide functionality to controller 220 to be executed by processor 225. These software components may also be loaded into memory 230 from a separate computer-readable storage medium using a drive mechanism (not shown). Such a separate computer-readable storage medium may include a disk, magnetic tape, DVD / CD-ROM drive, memory card, or other similar computer-readable media (not shown). In some example embodiments, software components may be loaded into memory 230 via one of various communication interfaces 235 instead of via a computer-readable storage medium.
[0089] Processor 225 or other processing circuitry can be configured to execute instructions of a computer program by performing arithmetic, logical, and input / output operations of the system. Instructions can be provided to processor 225 by memory 230.
[0090] Various communication interfaces 235 may be wired or wireless, and may include components for interfacing processor 225 with other input / output components and / or one or more communication networks. As will be understood, the various communication interfaces 235 and programs stored in memory 230 to articulate the dedicated functions of controller 220 may vary depending on the implementation of MLC 120 and / or radiotherapy machine 100.
[0091] The various communication interfaces 235 may also include one or more user input devices (such as keyboard, keypad, mouse, etc.) and user output devices (such as monitor, speaker, etc.).
[0092] Illustrative Example 1. A multi-leaf collimator for defining a treatment field of a radiotherapy machine, the multi-leaf collimator comprising: a first leaf box configured to move in a first direction and configured to receive a plurality of first beam-blocking leaflets arranged in a first row, wherein the plurality of first beam-blocking leaflets are configured to move relative to each other and relative to the first leaf box; a second leaf box arranged opposite to the first leaf box, the second leaf box being configured to move in the first direction and configured to receive a plurality of second beam-blocking leaflets arranged in a second row, wherein the plurality of second beam-blocking leaflets are configured to move relative to each other, are configured to move relative to the plurality of first beam-blocking leaflets, and are configured to move relative to the second leaf box; and at least one first edge-defining leaflet extending between the first leaf box and the second leaf box, the first edge-defining leaflet being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining leaflet is fixed relative to the first leaf box and configured to move relative to the second leaf box.
[0093] Illustrative Example 2. The multi-leaf collimator according to Illustrative Example 1, wherein the first edge-defining leaf defines the edge of the treatment field.
[0094] Illustrative Example 3. The multi-leaf collimator according to Illustrative Example 1 further includes: a second edge-defining blade extending between the first blade box and the second blade box, the second edge-defining blade being disposed at a second end of the first row and a second end of the second row, wherein the second edge-defining blade is fixed relative to the second blade box and configured to move relative to the first blade box.
[0095] Illustrative Example 4. According to the multi-leaf collimator of Illustrative Example 3, the first blade box is configured to house a plurality of third beam-blocking blades arranged in a third row below the plurality of first beam-blocking blades, wherein the plurality of third beam-blocking blades are configured to move relative to each other and relative to the first blade box; the second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box, and the multi-leaf collimator includes a first scattering-blocking blade extending between the first blade box and the second blade box, the first scattering-blocking blade being arranged at a first end of the third row and a first end of the fourth row below a first edge-defined blade, wherein the first scattering-blocking blade is fixed relative to the first blade box and is configured to move relative to the second blade box.
[0096] Illustrative Example 5. The multi-leaf collimator according to Illustrative Example 4 further includes: a second scattering blocking blade extending between the first blade box and the second blade box, the second scattering blocking blade being disposed below the second edge defining blade at the second end of the third row and the second end of the fourth row, wherein the second scattering blocking blade is fixed relative to the second blade box and configured to move relative to the first blade box.
[0097] Illustrative Example 6. A multi-leaf collimator according to any one of illustrative Examples 3 to 5, wherein the first edge-defining leaf and the second edge-defining leaf at least partially define the edge of the treatment field.
[0098] Illustrative Embodiment 7. A multi-leaf collimator according to any one of the foregoing illustrative embodiments, wherein the first blade box is configured to house a plurality of third beam-blocking blades arranged in a third row below the plurality of first beam-blocking blades, wherein the plurality of third beam-blocking blades are configured to move relative to each other and relative to the first blade box; the second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box, and the multi-leaf collimator includes a first scattering-blocking blade extending between the first blade box and the second blade box, the first scattering-blocking blade being arranged at a first end of the third row and a first end of the fourth row below a first edge-defined blade, wherein the first scattering-blocking blade is fixed relative to the first blade box and is configured to move relative to the second blade box.
[0099] Illustrative Embodiment 8. A multi-leaf collimator according to any one of Illustrative Embodiments 3 to 7, wherein the first blade box is configured to move the first edge-defining blade relative to the second blade box, and the second blade box is configured to move the second edge-defining blade relative to the first blade box.
[0100] Illustrative Embodiment 9. A multi-leaf collimator according to any one of the foregoing illustrative embodiments, wherein the first edge defining blade, the plurality of first beam blocking blades and the plurality of second beam blocking blades are configured to move relative to each other.
[0101] Illustrative Embodiment 10. A multi-leaf collimator according to any one of the foregoing illustrative embodiments, wherein the first leaf box is configured to move the first edge-defining leaf relative to the second leaf box, and the second leaf box includes a guide member to hold the first edge-defining leaf at the edge of the treatment field as the first edge-defining leaf moves relative to the second leaf box.
[0102] Illustrative Example 11. A radiotherapy machine includes: a radiation source configured to emit a radiation beam; and a multi-leaf collimator for blocking portions of the radiation beam to define a treatment field of the radiotherapy machine, the multi-leaf collimator including a first leaf box configured to move in a first direction and configured to receive a plurality of first beam-blocking leaflets arranged in a first row, wherein the plurality of first beam-blocking leaflets are configured to move relative to each other and relative to the first leaf box; a second leaf box arranged opposite to the first leaf box, the second leaf box being configured to move in the first direction and configured to receive a plurality of second beam-blocking leaflets arranged in a second row, wherein the plurality of second beam-blocking leaflets are configured to move relative to each other, are configured to move relative to the plurality of first beam-blocking leaflets, and are configured to move relative to the second leaf box; and at least one first edge-defining leaflet extending between the first leaf box and the second leaf box, the first edge-defining leaflet being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining leaflet is fixed relative to the first leaf box and configured to move relative to the second leaf box.
[0103] Illustrative Example 12. A radiotherapy machine according to Illustrative Example 11, wherein a first edge-defining blade defines the edge of the treatment field.
[0104] Illustrative Example 13. A radiotherapy machine according to Illustrative Example 11 or 12, wherein the multi-leaf collimator further includes: a second edge-defining blade extending between the first blade box and the second blade box, the second edge-defining blade being disposed at a second end of the first row and a second end of the second row, wherein the second edge-defining blade is fixed relative to the second blade box and configured to move relative to the first blade box.
[0105] Illustrative Example 14. A radiotherapy machine according to Illustrative Example 13, wherein the first blade box is configured to house a plurality of third beam-blocking blades arranged in a third row below the plurality of first beam-blocking blades, wherein the plurality of third beam-blocking blades are configured to move relative to each other and relative to the first blade box; the second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box, and the multi-leaf collimator includes a first scattering-blocking blade extending between the first blade box and the second blade box, the first scattering-blocking blade being arranged at a first end of the third row and a first end of the fourth row below a first edge-defining blade, wherein the first scattering-blocking blade is fixed relative to the first blade box and is configured to move relative to the second blade box.
[0106] Illustrative Example 15. The radiotherapy machine according to Illustrative Example 14, wherein the multi-leaf collimator further includes: a second scattering blocking leaf extending between the first leaf box and the second leaf box, the second scattering blocking leaf being disposed below the second edge defining leaf at the second end of the third row and the second end of the fourth row, wherein the second scattering blocking leaf is fixed relative to the second leaf box and configured to move relative to the first leaf box.
[0107] Illustrative Example 16. A radiotherapy machine according to any one of illustrative Examples 13 to 15, wherein the first edge-defining blade and the second edge-defining blade define the edge of the treatment field.
[0108] Illustrative Example 17. A radiotherapy machine according to any one of illustrative Examples 13 to 16, wherein the first blade box is configured to move the first edge-defined blade relative to the second blade box, and the second blade box is configured to move the second edge-defined blade relative to the first blade box.
[0109] Illustrative Example 18. A radiotherapy machine according to any one of illustrative Examples 11 to 17, wherein the first blade box is configured to house a plurality of third beam-blocking blades arranged in a third row below the plurality of first beam-blocking blades, wherein the plurality of third beam-blocking blades are configured to move relative to each other and relative to the first blade box; the second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box, and the multi-leaf collimator includes a first scattering-blocking blade extending between the first blade box and the second blade box, the first scattering-blocking blade being arranged at a first end of the third row and a first end of the fourth row below a first edge-defined blade, wherein the first scattering-blocking blade is fixed relative to the first blade box and is configured to move relative to the second blade box.
[0110] illustrative embodiment 19. A radiotherapy machine according to any one of illustrative embodiments 11 to 18, wherein the first edge defining blade, the plurality of first beam blocking blades and the plurality of second beam blocking blades are configured to move relative to each other.
[0111] Illustrative Example 20. A radiotherapy machine according to any one of illustrative Examples 11 to 19, wherein the first blade box is configured to move the first edge-defining blade relative to the second blade box, and the second blade box includes a guide member to hold the first edge-defining blade at the edge of the treatment field as the first edge-defining blade moves relative to the second blade box.
[0112] Although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.
[0113] When an element is described as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. In contrast, when an element is described as "directly connected" or "directly coupled" to another element, there are no intermediate elements. Other terms used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" and "directly between," "adjacent" and "next to"), etc.
[0114] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used herein also include the plural forms. It should also be understood that the terms “comprises,” “comprising,” “includes,” and / or “including”, when used herein, specify the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.
[0115] It should also be noted that in some alternative implementations, the above functions / actions may not occur in the order shown in the figures. For example, the two figures shown consecutively may actually be executed substantially simultaneously, or sometimes in reverse order, depending on the functions / actions involved.
[0116] Specific details are set forth in the following description to provide a thorough understanding of the exemplary embodiments. However, those skilled in the art will understand that the exemplary embodiments can be practiced without these specific details. For example, a system may be illustrated in block diagrams so as not to obscure the exemplary embodiments with unnecessary detail. In other instances, well-known processes, structures, and techniques may be shown without unnecessary detail to avoid obscuring the exemplary embodiments.
[0117] As described herein, example embodiments are described using action and symbolic representations of reference operations (e.g., in the form of flowcharts, diagrams, data flow graphs, structural diagrams, block diagrams, etc.). These operations can be implemented as program modules or functional processes (including routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types) and can be implemented using existing hardware, such as processing or control circuitry systems, including but not limited to one or more processors, one or more central processing units (CPUs), one or more controllers, one or more arithmetic logic units (ALUs), one or more digital signal processors (DSPs), one or more microcomputers, one or more field-programmable gate arrays (FPGAs), one or more system-on-a-chip (SoCs), one or more programmable logic units (PLUs), one or more microprocessors, one or more application-specific integrated circuits (ASICs), or any other device capable of responding to and executing instructions in a defined manner.
[0118] While flowcharts can describe operations as a sequential process, many operations can be executed in parallel, concurrently, or simultaneously. Furthermore, the order of operations can be rearranged. When a process completes its operations, it can be terminated, but there may also be additional steps not included in the diagram. A process can correspond to a method, function, procedure, subroutine, subroutine, etc. When a process corresponds to a function, its termination can correspond to the function returning to the calling function or the main function.
[0119] As disclosed herein, the terms “memory,” “storage medium,” “processor-readable medium,” “computer-readable storage medium,” or “non-transitory computer-readable storage medium” can refer to one or more devices for storing data, including read-only memory (ROM), random access memory (RAM), magnetic RAM, core memory, disk storage media, optical storage media, flash memory devices, and / or other tangible machine-readable media for storing information. The term “computer-readable medium” can include, but is not limited to, portable or fixed storage devices, optical storage devices, and various other media capable of storing, including, or carrying instructions and / or data.
[0120] Furthermore, the example embodiments can be implemented using hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, program code or code segments performing the necessary tasks can be stored in a machine or computer-readable medium, such as a computer-readable storage medium. When implemented in software, one or more processors will perform the necessary tasks. For example, as described above, according to one or more example embodiments, at least one memory may include or store computer program code, and at least one memory and computer program code may be configured, together with at least one processor, to cause a network element or network device to perform the necessary tasks. Furthermore, the processor, memory, and example algorithms encoded as computer program code serve as means to provide or cause the execution of the operations discussed herein.
[0121] The terms “include” and / or “have” as used herein are defined as including (i.e., open language). The term “coupled” as used herein is defined as a connection, although not necessarily direct or mechanical. Terms derived from the word “indicating” (e.g., “indicates” and “indication”) are intended to encompass all the various techniques that can be used to convey or reference the indicated object / information. Some (but not all) examples of techniques that can be used to convey or reference the indicated object / information include: conveying the indicated object / information, conveying an identifier of the indicated object / information, conveying information used to generate the indicated object / information, conveying a portion of the indicated object / information, conveying a derivative of the indicated object / information, and conveying a symbol representing the indicated object / information.
[0122] According to example embodiments, a medical system may be (or include) hardware, firmware, hardware executing software, or any combination thereof. Such hardware may include processing or control circuitry systems, such as, but not limited to, one or more processors, one or more CPUs, one or more controllers, one or more ALUs, one or more DSPs, one or more microcomputers, one or more FPGAs, one or more SoCs, one or more PLUs, one or more microprocessors, one or more ASICs, or any other device capable of responding to and executing instructions in a defined manner.
[0123] The benefits, other advantages, and solutions to problems have been described above with reference to specific embodiments. However, the benefits, advantages, solutions to problems, and any factors that may cause or result in such benefits, advantages, or solutions, or make such benefits, advantages, or solutions more apparent, should not be construed as key, essential, or fundamental features or elements of any or all claims.
Claims
1. A multi-leaf collimator for defining the treatment field of a radiotherapy machine, the multi-leaf collimator comprising: A first blade box is configured to move in a first direction and to accommodate a plurality of first beam blocking blades arranged in a first row, wherein the plurality of first beam blocking blades are configured to move relative to each other and relative to the first blade box. A second blade box is arranged opposite to the first blade box. The second blade box is configured to move in the first direction and is configured to accommodate a plurality of second beam blocking blades arranged in a second row, wherein the plurality of second beam blocking blades are configured to move relative to each other, are configured to move relative to the plurality of first beam blocking blades, and are configured to move relative to the second blade box. as well as At least one first edge-defining blade extends between the first blade box and the second blade box, the first edge-defining blade being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining blade is fixed relative to the first blade box and configured to move relative to the second blade box.
2. The multi-leaf collimator of claim 1, wherein the first edge-defining leaf defines the edge of the treatment field.
3. The multi-leaf collimator according to claim 1 further comprises: A second edge-defining blade extends between the first blade box and the second blade box, the second edge-defining blade being disposed at the second end of the first row and the second end of the second row, wherein the second edge-defining blade is fixed relative to the second blade box and configured to move relative to the first blade box.
4. The multi-leaf collimator according to claim 3, wherein The first blade box is configured to house a plurality of third beam blocking blades arranged in a third row below the plurality of first beam blocking blades, wherein the plurality of third beam blocking blades are configured to move relative to each other and relative to the first blade box. The second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box. The multi-leaf collimator includes a first scattering blocking blade extending between the first blade box and the second blade box, the first scattering blocking blade being disposed below the first edge defining blade at the first end of the third row and the first end of the fourth row, wherein the first scattering blocking blade is fixed relative to the first blade box and configured to move relative to the second blade box.
5. The multi-leaf collimator according to claim 4 further comprises: A second scattering blocking blade extends between the first blade box and the second blade box, the second scattering blocking blade being disposed below the second edge defining blade at the second end of the third row and the second end of the fourth row, wherein the second scattering blocking blade is fixed relative to the second blade box and configured to move relative to the first blade box.
6. The multi-leaf collimator of claim 3, wherein the first edge-defining leaf and the second edge-defining leaf at least partially define the edge of the treatment field.
7. The multi-leaf collimator according to claim 1, wherein... The first blade box is configured to house a plurality of third beam blocking blades arranged in a third row below the plurality of first beam blocking blades, wherein the plurality of third beam blocking blades are configured to move relative to each other and relative to the first blade box. The second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box. The multi-leaf collimator includes a first scattering blocking blade extending between the first blade box and the second blade box, the first scattering blocking blade being disposed below the first edge defining blade at the first end of the third row and the first end of the fourth row, wherein the first scattering blocking blade is fixed relative to the first blade box and configured to move relative to the second blade box.
8. The multi-leaf collimator according to claim 3, wherein... The first blade box is configured to move the first edge-defined blade relative to the second blade box, and The second blade box is configured to move the second edge-defined blade relative to the first blade box.
9. The multi-leaf collimator of claim 1, wherein the first edge defining blade, the plurality of first beam blocking blades, and the plurality of second beam blocking blades are configured to move relative to each other.
10. The multi-leaf collimator according to claim 1, wherein... The first blade box is configured to move the first edge-defined blade relative to the second blade box, and The second blade box includes a guide member to hold the first edge-defined blade at the edge of the treatment field as the first edge-defined blade moves relative to the second blade box.
11. A radiotherapy machine, comprising: The radiation source is configured to emit a radiation beam; as well as A multi-leaf collimator for blocking a portion of the radiation beam to define the treatment field of the radiotherapy machine, the multi-leaf collimator comprising: A first blade box is configured to move in a first direction and to house a plurality of first beam-blocking blades arranged in a first row, wherein the plurality of first beam-blocking blades are configured to move relative to each other and relative to the first blade box. A second blade box, arranged opposite to the first blade box, is configured to move in the first direction and to house a plurality of second beam-blocking blades arranged in a second row, wherein the plurality of second beam-blocking blades are configured to move relative to each other, to move relative to the plurality of first beam-blocking blades, and to move relative to the second blade box. At least one first edge-defining blade extends between the first blade box and the second blade box, the first edge-defining blade being disposed at a first end of the first row and a first end of the second row, wherein the first edge-defining blade is fixed relative to the first blade box and configured to move relative to the second blade box.
12. The radiotherapy machine of claim 11, wherein the first edge-defining blade defines the edge of the treatment field.
13. The radiotherapy machine according to claim 11, wherein the multi-leaf collimator further comprises: A second edge-defining blade extends between the first blade box and the second blade box, the second edge-defining blade being disposed at the second end of the first row and the second end of the second row, wherein the second edge-defining blade is fixed relative to the second blade box and configured to move relative to the first blade box.
14. The radiotherapy machine according to claim 13, wherein... The first blade box is configured to house a plurality of third beam blocking blades arranged in a third row below the plurality of first beam blocking blades, wherein the plurality of third beam blocking blades are configured to move relative to each other and relative to the first blade box. The second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box. The multi-leaf collimator includes a first scattering blocking blade extending between the first blade box and the second blade box, the first scattering blocking blade being disposed below the first edge defining blade at the first end of the third row and the first end of the fourth row, wherein the first scattering blocking blade is fixed relative to the first blade box and configured to move relative to the second blade box.
15. The radiotherapy machine according to claim 14, wherein the multi-leaf collimator further comprises: A second scattering blocking blade extends between the first blade box and the second blade box, the second scattering blocking blade being disposed below the second edge defining blade at the second end of the third row and the second end of the fourth row, wherein the second scattering blocking blade is fixed relative to the second blade box and configured to move relative to the first blade box.
16. The radiotherapy machine of claim 13, wherein the first edge-defining blade and the second edge-defining blade define the edge of the treatment field.
17. The radiotherapy machine according to claim 13, wherein... The first blade box is configured to move the first edge-defined blade relative to the second blade box, and The second blade box is configured to move the second edge-defined blade relative to the first blade box.
18. The radiotherapy machine according to claim 11, wherein... The first blade box is configured to house a plurality of third beam blocking blades arranged in a third row below the plurality of first beam blocking blades, wherein the plurality of third beam blocking blades are configured to move relative to each other and relative to the first blade box. The second blade box is configured to house a plurality of fourth beam-blocking blades arranged in a fourth row below the plurality of second beam-blocking blades, wherein the plurality of fourth beam-blocking blades are configured to move relative to each other, are configured to move relative to the plurality of third beam-blocking blades, and are configured to move relative to the second blade box. The multi-leaf collimator includes a first scattering blocking blade extending between the first blade box and the second blade box, the first scattering blocking blade being disposed below the first edge defining blade at the first end of the third row and the first end of the fourth row, wherein the first scattering blocking blade is fixed relative to the first blade box and configured to move relative to the second blade box.
19. The radiotherapy machine of claim 11, wherein the first edge-defining blade, the plurality of first beam-blocking blades, and the plurality of second beam-blocking blades are configured to move relative to each other.
20. The radiotherapy machine according to claim 11, wherein... The first blade box is configured to move the first edge-defined blade relative to the second blade box, and The second blade box includes a guide member to hold the first edge-defined blade at the edge of the treatment field as the first edge-defined blade moves relative to the second blade box.