Delivery via a high-speed multi-leaf collimator through a fast sliding window

Abstract

A system for delivering radiation dose includes: a gantry for moving around a target to be irradiated; and a radiation source mounted to the gantry and guided inward toward the target. The system further includes: a collimator mounted to the gantry and in front of the radiation source, the collimator being used to shape the radiation beam guided to the target, wherein the collimator is used to modulate the sub-beam intensity of the radiation beam on a plurality of sub-beams for subdividing the flux field into a two-dimensional (2D) grid, and to deliver a plurality of independent two-dimensional (2D) sub-beam intensity patterns from multiple gantry angles while the gantry is continuously moved.

Description

[0001] Related applications

[0002] Pursuant to 35 § 119(e) of the United States Code, this application claims the benefit of U.S. Patent Application 16 / 055,507, filed August 6, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to rapid sliding window delivery via a high-speed multi-leaf collimator (MLC) in a radiation treatment system. Background Technology

[0004] In radiotherapy, a radiation dose delivered via a radiotherapy beam from a source outside the patient's body is delivered to a target region within the body to destroy tumor cells. Care must be taken to maximize the radiation dose delivered to the intended treatment area while minimizing the radiation dose delivered to untreated areas. In radiotherapy, the radiotherapy beam aperture shapes the radiotherapy beam to conform as closely as possible to the intended target region. The radiotherapy beam aperture is typically defined by an MLC (Medium-to-Large Array). Attached Figure Description

[0005] The invention will be more fully understood from the following detailed description and the accompanying drawings of various implementations thereof.

[0006] Figure 1A A helical radiation delivery system according to an embodiment described herein is shown.

[0007] Figure 1B A robotic radiation treatment system that can be used according to the embodiments described herein is shown.

[0008] Figure 1C A radiation treatment system based on a C-arm gantry is shown according to an embodiment described herein.

[0009] Figure 2A A multileaf MLC is shown according to an embodiment described herein for delivering a radiation treatment dose to a target area.

[0010] Figure 2B A bottom view of a multileaf MLC according to an embodiment described herein is shown.

[0011] Figure 2C A perspective view of a multi-leaf high-speed MLC according to an embodiment described herein is shown.

[0012] Figure 2D A top view of the leaves of a multi-leaf high-speed MLC according to an embodiment described herein is shown.

[0013] Figure 2E A typical leaf arrangement used in a multi-leaf high-speed MLC according to the embodiments described herein is shown.

[0014] Figure 3A ~C shows a typical leaf opening time profile according to the embodiments described herein.

[0015] Figure 3D ~F shows a typical optimized leaf opening time profile according to the embodiments described herein.

[0016] Figure 3G A typical leaf opening time profile with maximum incorporation speed is shown according to the embodiments described herein.

[0017] Figure 4A ~C illustrates various typical leaf arrangements conforming to the target region according to the embodiments described herein.

[0018] Figure 5A This is a flowchart illustrating a method used for a fast sliding window with high-speed MLC according to an embodiment described herein.

[0019] Figure 5B This is a flowchart illustrating a method for delivering binary MLCs with a field width per leaf according to an embodiment.

[0020] Figure 6 Examples of different systems that can be used in the event of a radiation treatment, according to embodiments described herein. Detailed Implementation

[0021] This document describes embodiments of a method and apparatus for rapid sliding window delivery via a high-speed MLC in a radiotreatment system. In the radiotreatment system, two opposing rows of blades of an MLC can be used to create one or more patterns that shape the radiotreatment beam to conform to a target region.

[0022] For target regions with non-uniform shapes, IMRT can be used to deliver more complex radiation treatment doses. Intensity modulated radiotherapy (IMRT) encompasses various radiation treatment techniques that essentially alter the intensity of the radiation treatment beam directed to the target region. In IMRT, instead of having MLCs shape the radiation treatment beam to match a specific profile, MLCs are used to create an array of beam shapes that generate the desired intensity modulation and desired 3D dose distribution via overlapping radiation fields of (potentially) different intensities.

[0023] In some embodiments, a binary MLC comprises multiple leaf pairs arranged in two opposing rows. Each row of leaves is used to form a treatment slice by positioning the leaves in a closed or open position relative to the beam. In some embodiments, the sup-inf field width (e.g., the width formed by the openings of the leaf pairs in the MLC) is constant across all leaves of the MLC. Disadvantageously, this means that such a system cannot make the field of the radioactive treatment beam conform to the target profile along the target length. Due to this limitation, the field size in a binary MLC is generally limited to less than 5 cm. Larger field sizes are generally undesirable for treating most target areas due to radiation exposure to non-target regions.

[0024] One solution to the above problems is to use a dynamic jaw to better conform the field to the target region at the top and bottom. However, this technique does not allow the field to conform to the edge of the target along its length because the field size is limited by the jaw and is constant across the entire MLC. Another solution is to use a non-binary, conformal MLC. However, such an MLC may be slower, potentially negatively impacting disposal time. Another solution is presented here.

[0025] Advantageously, the embodiments described herein allow the MLC to conform the treatment beam field to the target region while minimizing radiation exposure to non-treatment areas. Furthermore, the embodiments described herein allow for larger field sizes (e.g., greater than 5 cm), thereby increasing the treatment rate. Additionally, as described herein, the embodiments allow the MLC to modulate the flux field not only in the IEC-Xb direction but also in the IEC-Yb direction. Furthermore, the embodiments described herein allow for more modulation opportunities in the longitudinal direction. This can allow for treatment planning with wider spacing (e.g., close to 1), where sup-inf modulation is handled by longitudinal modulation of the MLC leaves. Alternatively, a tighter spacing can be maintained by utilizing additional opportunities to modulate the treatment beam in the same sup-inf region.

[0026] The systems and methods described herein achieve the above advantages through the application of high-speed MLCs. An example of such a high-speed MLC, as described herein, is an electromagnetic MLC (eMLC). However, it should be noted that alternative variations of high-speed MLCs can be used to perform the operations described herein. For the purposes of this invention, a high-speed MLC can be any MLC capable of performing very fast leaf motion (e.g., approximately traversing a 5 cm field in less than 100 ms). It should be noted that although “eMLC” is used throughout this invention, the systems and methods described herein are equally compatible with any other form of high-speed MLC.

[0027] Furthermore, for the purposes of this specification, the terms "flux," "intensity," and "dose" are used as follows: Flux is the number of photons or X-rays that pass through a unit area perpendicular to the radiation beam. Flux rate is the flux per unit time. Intensity is the energy that passes through a unit area per unit time. Flux and intensity are unrelated to what happens within the patient's body, and more precisely, are not dose. Dose is the energy absorbed by tissue due to the effects of radiation. Radiation dose is measured in gray (Gy), where each Gy corresponds to a fixed amount of energy absorbed per unit mass of tissue (e.g., 1 joule / kg). Dose differs from flux but increases / decreases with increasing / decreasing flux.

[0028] The terms "target" and "target area" can refer to one or more reference points near (within a certain proximity to) the treatment area (e.g., a tumor). In another embodiment, the target can be a bone structure. In yet another embodiment, the target can refer to the patient's soft tissue. As described herein, the target can be any defined structure or region that can be identified and tracked.

[0029] Figure 1A A helical radiation delivery system 800 according to an embodiment of the present invention is illustrated. The helical radiation delivery system 800 may include a linear accelerator (LINAC) 850 mounted to a toroidal gantry 820. The LINAC 850 is used to generate a radiation beam (i.e., a treatment beam) by guiding an electron beam toward an X-ray emission target. The treatment beam can deliver radiation to a target region (i.e., a tumor). The treatment system also includes a multi-leaf collimator 860 coupled to the distal end of the LINAC 850. As described herein, the MLC 860 may be an eMLC. The MLC includes a housing for accommodating a plurality of leaves, wherein these leaves movably adjust the aperture of the MLC to achieve the shaping of the treatment beam. The toroidal gantry 820 is generally toroidal in shape, wherein a patient 830 extends through an aperture of the toroidal ring, and the LINAC 850 is mounted on the periphery of the ring and rotates about an axis passing through its center to irradiate the target region using a beam delivered from one or more angles around the patient. During treatment, the patient 830 may move synchronously through the aperture of the gantry on a treatment bed 840.

[0030] The helical radiology delivery system 800 includes an imaging system comprising a LINAC 850 as an imaging source and an X-ray detector 870. The LINAC 850 is used to generate megavolt-level X-ray images (MVCT) of the region of interest (ROI) of the patient 830 by guiding a series of X-ray beams incident on the X-ray detector 870 to the ROI of the patient 830, wherein the X-ray detector 870 is positioned relative to the LINAC 850 to image the patient 830 for positioning and to generate a pre-treatment image. In one embodiment, the helical radiology delivery system 800 may further include an auxiliary imaging system comprising a kV-level imaging source 810 orthogonally (e.g., 90 degrees apart) mounted on a ring gantry 820 relative to the LINAC 850 and aligned to project imaging X-ray beams onto the target region and, after passing through the patient 830, illuminate the imaging plane of the detector.

[0031] Figure 1B A radiation treatment system 1200 that can be used according to an alternative embodiment described herein is shown. As shown in the figure... Figure 1B The configuration of a radiation treatment system 1200 is shown. In the illustrated embodiment, the radiation treatment system 1200 includes a linear accelerator (LINAC) 1201 serving as a radiation treatment source, and an MLC 1205 (e.g., an eMLC) coupled to the distal end of the LINAC 1201 to shape the treatment beam. In one embodiment, the LINAC 1201 is mounted at one end of a robotic arm 1202 having multiple (e.g., five or more) degrees of freedom to position the LINAC 1201, thereby irradiating pathological anatomy structures (e.g., targets) within an operating volume surrounding the patient using beams delivered from multiple angles and in multiple planes. Treatment may involve a beam path having a single isocentric point, multiple isocentric points, or a non-isocentric tendency.

[0032] During the procedure, the LINAC 1201 can be positioned at multiple distinct nodes (predefined locations where the LINAC 1201 stops and can deliver radiation) using the mobile robotic arm 1202. At each node, the LINAC 1201 can deliver one or more radiation treatment beams to the target, with the beam shape determined by the leaf position in the MLC 1205. The nodes can be arranged in an approximately spherical distribution around the patient. The specific number of nodes and the number of treatment beams applied at each node can vary depending on the location and type of the pathological anatomy to be treated.

[0033] In another embodiment, during radiation delivery, the robotic arm 1202 and its end effector LINAC 1201 can move continuously between nodes. The radiation beam shape and 2D intensity map are determined by the rapid movement of the leaflets in the MLC 1205 during the continuous movement of the LINAC 1201.

[0034] The radiation treatment system 1200 includes an imaging system 1210 having a processing device 1230 connected to x-ray sources 1203A and 1203B (i.e., imaging sources) and fixed x-ray detectors 1204A and 1204B. Optionally, the x-ray sources 1203A, 1203B and / or the x-ray detectors 1204A, 1204B can be movable, wherein in this case they can be repositioned to maintain alignment with the target, or optionally to image the target from different orientations or acquire multiple x-ray images and reconstruct three-dimensional (3D) cone-beam CT. In one embodiment, as those skilled in the art will understand, the x-ray source is not a point source, but an array of x-ray sources. In one embodiment, a LINAC 1201 is used as an imaging source, wherein the LINAC power level is reduced to an acceptable level for imaging.

[0035] Imaging system 1210 can perform computed tomography (CT) imaging such as cone-beam CT or spiral megavolt-level computed tomography (MVCT), and the images generated by imaging system 1210 can be two-dimensional (2D) or three-dimensional (3D). Two x-ray sources 1203A and 1203B can be mounted in a fixed position on the ceiling of the operating room and can be aligned to project x-ray imaging beams from two different angular positions (e.g., spaced 90 degrees) onto an imaging plane that intersects at a central point such as the machine (here referred to as the treatment center, which provides a reference point for positioning the patient on treatment bed 1206 during treatment) and irradiates the respective detectors 1204A and 1204B after passing through the patient. In one embodiment, imaging system 1210 provides stereoscopic imaging of the target and surrounding volume of interest (VOI). In other embodiments, imaging system 1210 may include more or fewer than two x-ray sources and more or fewer than two detectors, and any detector may be movable rather than fixed. In other embodiments, the positions of the x-ray source and detector can be interchanged. As is known to those skilled in the art, detectors 1204A and 1204B can be made of an array of scintillation materials (e.g., amorphous silicon) for converting x-rays into visible light and CMOS (complementary metal-oxide-semiconductor) or CCD (charge-coupled device) imaging units for converting light into digital images, wherein the digital image can be compared with a reference image during image registration, which transforms the coordinate system of the digital image to the coordinate system of a reference image. The reference image can be, for example, a digitally reconstructed radiographic image (DRR), which is a virtual x-ray image generated from a 3D CT image based on simulating the x-ray image formation process by projecting rays through a CT image.

[0036] In one embodiment, the IGRT delivery system 1200 further includes an auxiliary imaging system 1239. The imaging system 1239 is a cone-beam computed tomography (CBCT) system, such as the medPhoton Imaging Ring system. Alternatively, other types of volumetric imaging systems may be used. The auxiliary imaging system 1239 includes a rotatable gantry 1240 (e.g., a ring) attached to an arm and track system (not shown), wherein the arm and track system allows the rotatable gantry 1240 to move along one or more axes (e.g., along an axis extending from the head to the feet of the treatment bed 1206). An imaging source 1245 and a detector 1250 are mounted to the rotatable gantry 1240. The rotatable gantry 1240 can rotate 360 ​​degrees about the axis extending from the head to the feet of the treatment bed. Therefore, the imaging source 1245 and the detector 1250 can be positioned at multiple different angles. In one embodiment, the imaging source 1245 is an X-ray source, and the detector 1250 is an X-ray detector. In one embodiment, the auxiliary imaging system 1239 includes two independently rotatable rings. An imaging source 1245 may be mounted to the first ring, and a detector 1250 may be mounted to the second ring. In one embodiment, the rotatable gantry 1240 is positioned at the foot of the treatment bed during radiological treatment delivery to avoid collisions with the robotic arm 1202.

[0037] like Figure 1B As shown, the image-guided radiotherapy system 1200 can also be associated with a treatment delivery workstation 150. The treatment delivery workstation may be located remotely from the radiotherapy system 1200 in a different room from the treatment room where the patient is located. As described herein, the treatment delivery workstation 150 may include processing devices (which may be processing device 1230 or other processing devices) and memory, wherein the processing devices and memory modify the treatment delivery to the patient 1225 based on target motion detection based on one or more image registrations.

[0038] Figure 1CA C-arm radiation delivery system 1400 is illustrated. In one embodiment, in the C-arm system 1400, the beam energy of the LINAC can be adjusted during treatment, allowing the LINAC to be used for both x-ray imaging and radiation treatment. In another embodiment, system 1400 may include an onboard kV-level imaging system for generating x-ray images and a separate LINAC for generating a higher-energy therapeutic radiation beam. System 1400 includes a gantry 1410, a LINAC 1420, an MLC 1470 (e.g., an eMLC) coupled distally to the LINAC 1420 for beam imaging, and a field imaging detector 1450. The gantry 1410 can be rotated to an angle corresponding to a selected projection and is used to acquire x-ray images of the VOI of a patient 1430 on a treatment bed 1440. In embodiments including a field imaging system, the LINAC 1420 can generate an x-ray beam that passes through a target of the patient 1430 and is incident on the field imaging detector 1450, thereby creating an x-ray image of the target. After an X-ray image of the target has been generated, the beam energy of the LINAC 1420 can be increased, thus enabling the LINAC 1420 to generate a beam for treating the target region of the patient 1430. In another embodiment, a kV-level imaging system can generate an X-ray beam passing through the target of the patient 1430, thereby creating an X-ray image of the target. In some embodiments, the field imaging system can acquire field images during delivery of the treatment. The field imaging detector 1450 can measure the outgoing radiation flux after the beam passes through the patient 1430. This allows for the localization of internal or external reference points or anatomical structures (e.g., tumors or bone) within the field image.

[0039] Optionally, the kV-level imaging source or field imager and operating method described herein can be used with other types of gantry-based systems. In some gantry-based systems, the gantry rotates the kV-level imaging source and LINAC about an axis passing through an isocenter. A gantry-based system includes a ring-shaped gantry with the patient's body extending through a hole in the ring / ring, and the kV-level imaging source and LINAC are mounted on the circumference of the ring and rotate about an axis passing through an isocenter. A gantry-based system may also include a C-arm gantry, in which the kV-level imaging source and LINAC are cantilevered on an axis passing through an isocenter and rotate about that axis. In another embodiment, the kV-level imaging source and LINAC can be used in a robotic arm-based system, wherein the system includes a robotic arm to which the kV-level imaging source and LINAC are mounted as described above. The invention can also be used in other such systems, such as rack-based LINAC systems, static imaging systems associated with radiotherapy and radiosurgery, proton therapy systems using integrated image guidance, interventional radiology, and intraoperative X-ray imaging systems.

[0040] Figure 2A A multi-leaf collimator (MLC) 31 for delivering a radiation dose to a target region, according to an embodiment described herein, is shown. The MLC 31 includes two opposing rows of leaves 33, each leaf 37 being sequentially positioned within the radiation field. The two rows of leaves 33 are positioned to collimate the beam 30 into a desired shape. In one embodiment, each leaf 37 may travel beyond the midpoint of the collimator to provide flexibility in achieving the desired collimation. This configuration illustrates leaf states of being fully open (41), partially open (43), and closed (45).

[0041] In the example of radiotherapy, each gantry angle has a beam associated with that particular gantry angle, which is then collimated into multiple shapes by an MLC. The treatment beam 30 passes through a shaping aperture 47 formed by a leaf 37. The resulting collimated beam continues onto a target 14 within the patient 38. Figure 2A The diagram also illustrates how a treatment bundle can be visualized or conceptualized as a number of different sub-bundles 49. The blades 37 of the MLC 31 are moved to various locations to achieve a desired shape or aperture for a specified time period, thus realizing a flux map 51 for that particular bundle. Modulation of the conceptualized sub-bundles is achieved by sequentially and monotonically moving the blades to desired locations to achieve the desired shape or aperture, such that the duration of exposure of the conceptualized sub-bundle controls the intensity of that sub-bundle. In one embodiment, "monotonically" here means an ordered sequence of apertures, where the sequence is determined by a continuum from one aperture to a subsequent aperture, or where individual blades increase in one direction during a given aperture series. In other words, the sequence of apertures will be determined by the mechanical constraints of the MLC, rather than by how to achieve better treatment delivery. In one embodiment, the sequence will start with aperture 1, then 2, then 3, and so on, rather than from 1 to 3, then to 5, and then back to 2. The MLC can deliver a sequence of shapes instead of using a single conformal shape. The net radiation received at any given rack location is based on the degree to which different shapes allow radiation to pass through or block it. Figure 2A As seen, the shape of the MLC 31 shown does not directly correspond to the small bundle intensity of the flux diagram 51. As will be understood, the depicted flux diagram shows the cumulative intensity of the various shapes the MLC takes for that particular rack angle.

[0042] A common limitation of conventional angioplasty MLCs is the relatively slow movement of the leaflets defining the shape. Using a large number of shapes or shapes requiring significant leaflet movement can lead to longer patient procedures. Similarly, the speed of the leaflets can limit the ability of conventional angioplasty MLCs to deliver time-sensitive procedures (such as those utilizing the synchronized movement of delivery components, e.g., gantry, bed, X-ray energy, etc.). Partly for these reasons, existing 2D intensity map delivery techniques are limited to bundles delivered from static locations. Alternatively, existing systems that allow continuous movement of the radiation source generally only allow a single aperture shape or deformation from one aperture shape to another as the radiation source moves, and do not allow delivery of 2D intensity maps from individual radiation source locations.

[0043] Figure 2B A bottom view of a multi-leaf MLC 61 according to an embodiment described herein is shown. The binary MLC 61 has a plurality of leaves 63 arranged in two rows 65, 67. Each row of leaves is used to form a disposal slice by positioning the leaves in a closed or open position relative to the bundle. Figure 2B As shown, the blades can work in coordination to open simultaneously (A), close simultaneously (B), or have only one blade open / close (C). In a conventional binary MLC, blade 63 opens (A) to the same, uniform width throughout a single location segment. In a conventional shaped MLC, blade 63 can open (A) to different widths throughout a single location segment. A common limitation of conventional binary MLCs is that blade 63 may not open to various different widths for any given time fraction during each location segment. Therefore, it can be difficult to shape the radiation beam to the target region while minimizing radiation exposure to non-target regions. Advantageously, the methods and systems described herein allow the benefits of shaped MLCs (e.g., blade 63 can open to various different widths for any given time fraction during each location segment) while maintaining the speed of the binary MLC.

[0044] Figure 2CA perspective view of a multi-leaf high-speed MLC 62 according to an embodiment described herein is shown. In one embodiment, the radiation modulation device includes an electromagnetically actuated MLC (eMLC) 62 comprising a plurality of leaves 66 operably movable from one position to another to provide intensity modulation. The leaves 66 can be moved at a sufficient speed to any position between a minimum open position and a maximum open position such that leaf sequencing or positioning is not significantly affected by any previous or future position of any individual leaf. In other words, the leaf speed is sufficient such that the mechanics of the MLC does not unduly influence the determination of the leaf position for delivery of a radiotherapy treatment or fraction at any given time. Each leaf 66 is independently controlled by an actuator (not shown, but described more fully below) such as a motor or magnetic drive, such that, as described in more detail below, the leaf 66 can be controllably moved from fully open, fully closed, or to any position between open and closed. The actuator may be suitably controlled by a computer 74 and / or a controller.

[0045] In one embodiment, the MLC 62 is remotely coupled to the LINAC of the radiation treatment delivery system. The processing apparatus of the computer 74 can control multiple leaf pairs 66 of the MLC 62 simultaneously with the activation of the radiation beam of the radiation treatment system, such that for each of the multiple radiation beam delivery position segments corresponding to a range of radiation beam positions within a discrete time interval, each of the multiple opposing leaf pairs 66 opens as a fixed opening for a certain time fraction within the discrete time interval and closes for the remaining time fraction within the discrete time interval. In one embodiment, the fixed opening and the time fraction form overlapping radiation fields of different intensities, which combine to generate an intensity-modulated flux field delivered to the treatment target. In one embodiment, the fixed opening conforms to the shape of the treatment target, projects backward along the radiation beam onto the MLC, and is within the maximum travel range of the multiple leaf pairs within the MLC. Figures 4A-4C and Figure 5B To further describe this concept.

[0046] In one embodiment, the processing apparatus of computer 74 can control MLC 62 to modulate the sub-beam intensity of the radiation beam on multiple sub-beams used to subdivide the flux field into a 2D grid, and deliver multiple independent 2D sub-beam intensity modes from multiple gantry angles while the gantry moves continuously. For Figures 3A-3F and Figure 5A To further describe this concept.

[0047] In one embodiment, the LINAC, including MLC 62, is mounted on a rotating frame, wherein a radiation beam delivered from the radiation beam position range rotates around a treatment target. The treatment target can move axially through a hole in the rotating frame, and the radiation beam delivered from the radiation beam position range can follow a helical path around the treatment target. In another embodiment, the LINAC and MLC 62 are mounted on a robotic arm, and the radiation beam delivered from the radiation beam position range is non-coplanar.

[0048] Figure 2D A top view of the leaves of a multi-leaf high-speed MLC 240 according to an embodiment described herein is shown.

[0049] The central portion 302 of the MLC 240 includes an internal blade guide 301, an aperture 1050, and a portion located on the blade guide.

[0050] Fourteen blade pairs (1010–1039) are located at various positions between the internal supports of 301. Although 14 blade pairs are shown, more or fewer blade pairs may be provided depending on the design requirements of a particular system. In one embodiment, there are 64 blade pairs. In another embodiment, there are 96 blade pairs. In yet another embodiment, there are 32 blade pairs. Clearly, the radiation is collimated through this section 302 of the collimator.

[0051] exist Figure 2D In this configuration, each leaf is positioned in a specific location to define a specific aperture or shape 1050 through which radiation can pass (also referred to herein as a state). The control scheme and actuators described herein are used to control leaf pairs 1010 and 1011 to 1038 and 1039 to achieve synchronized volume and intensity modulation. Alternatively, one or more controllable jaws are used to provide primary collimation of the beam defined by the inner edges 301i and frames 97A, 97B (i.e., the jaws will block the open spaces between support frame B and leaf pairs 1010 / 1011, and between support frame A and leaf pairs 1038 / 1039). Additionally or alternatively, one or more pairs of jaws can be adjusted to reduce the size of the primary collimated beam to less than the frame size.

[0052] Figure 2EA typical blade arrangement used in a multi-leaf high-speed MLC according to an embodiment described herein is shown. A collimation field 1040 with a centerline 1030 is provided by a pair of jaws or other collimator devices. In an exemplary embodiment, two blades form complementary blade pairs for shaping and modulating the collimation field 1040. For example, blades 1010 and 1011 are one blade pair. Blades 1018 and 1019 are another blade pair, and blades 1024 and 1025 are yet another blade pair. Each blade in each pair can be positioned anywhere within the field 1040. The inner edges of the blades within each blade pair face each other and can create openings; the collection of openings formed by the blade pairs forms an aperture 1050. Aperture 1050 is as previously described... Figure 2D The aperture corresponds to and is set according to the treatment plan. In one embodiment, the aperture 1050 is determined before administering radiotherapy to the patient during the treatment planning process and appears at a specific point during the delivery of the treatment plan. As described herein, the aperture 1050 can be varied based on several factors, such as the three-dimensional shape of the treatment area, intensity modulation, flux, and the small beam size within the treatment volume. The embodiments of the high-speed MLC described herein achieve volume and intensity modulation individually or in combination by providing rapid state control.

[0053] Figures 3A-3C A typical leaf opening time profile according to the embodiments described herein is shown. Unlike using a conventional MLC, by using an eMLC (or some other suitable high-speed MLC), the flux transmitted at each point along the direction of travel of the leaf pair (e.g., the IEC-Yb direction) can be precisely controlled while a continuously moving radiation source (e.g., a LINAC) traverses an arc short enough to be considered a location. To generate a schedule for such a high-speed MLC, the leaf opening time profile can be determined. In one embodiment, the leaf opening time profile indicates the opening time of the leaf pair within a discrete time interval.

[0054] To generate eMLC plans, the leaf opening time profiles of each leaf pair in each location segment can be divided into discrete bundles. As described below, the optimizer can determine the ideal leaf opening time for each bundle. Based on the leaf opening time profiles, the front and rear leaf motion profiles for each leaf pair can be generated, thus allowing the leaves to move in only a single direction within each location segment. In one embodiment, the leaves alternate between moving from back to front and from front to back in consecutive location segments, so that when a leaf pair completes its journey in one location segment, the leaf pair will be in position to begin its journey in the next location segment.

[0055] Figure 3A An exemplary leaf opening time profile is shown. As shown, the leaf pair opening times, represented by bars on the IEC-Yb axis, may differ for each leaf pair. Note that in the leaf motion profile algorithm described above, the total time required to deliver the opening times of all leaf pairs is:

[0056]

[0057] Or, equivalent to:

[0058]

[0059] If the total time is less than the discrete time interval of the position segment, then the leaf motion profile can be centered within the position segment, such as... Figure 3B As shown. Figure 3C The anterior lobe movement 302 and posterior lobe movement 304, which are centered in this position segment, are shown.

[0060] Figures 3D-3F A typical optimized leaf opening time profile according to the embodiments described herein is shown. In one embodiment, a modulation factor constraint can be applied to the leaf opening time profile such that the leaf opening time is not excessive (and therefore the delay processing time is not excessive). To generate the modulation factor, the average bundle opening time is calculated for all non-zero bundles across all leaves and location segments. The discrete time interval is then determined as the average opening time multiplied by the desired modulation factor. For each location segment and leaf, the bundle opening time is then adjusted such that the total leaf opening time is no greater than the discrete time interval corresponding to the location segment.

[0061] Several methods exist for making such adjustments. In one embodiment, the opening time of each cluster exceeding the discrete time interval can be reduced to equal the projection time, and then the minimum cluster opening time can be increased until the total leaf opening time is less than or equal to the discrete time interval, such as... Figures 3D-3F As shown.

[0062] Figure 3G A typical leaf opening time profile incorporating the maximum velocity is shown according to the embodiments described herein. It is worth noting that the leaf movement of a high-speed MLC is fast, but not instantaneous. To generate a practically deliverable plan, the leaf motion profile can take into account the finite leaf velocities of the MLC. In one embodiment, this can be achieved by incorporating the maximum leaf velocity (and possibly the leaf acceleration) into the generated leaf profile. In one embodiment, the algorithm may strive to keep the area in each column constant. In exemplary profile 306, instantaneous leaf motion is altered to leaf motion with finite velocities. Note that leaf motion in each segment can begin slightly earlier, so that the overall opening time of the small bundle remains unaffected. In one embodiment, if the starting point of travel in the next projection overlaps with the ending point of travel in the current projection, the leaf can change direction before reaching its ending point, resulting in a slightly smaller throughput delivered to the target region. Figure 5A Further description Figures 3A-3G The operation.

[0063] Figures 4A-4CVarious typical blade arrangements conforming to target region 401 according to embodiments described herein are illustrated. Each blade pair is positioned in a specific manner such that the blade pair openings define a specific aperture or shape to conform to target region 401. During disposal, radiation passes through the aperture defined by the combined blade pairs and strikes the target region below. High-speed MLCs (e.g., eMLCs) such as those described herein open and close each blade pair to an open or closed state during discrete time intervals. Each blade pair may open within different time fractions (e.g., open time fractions) during the discrete time interval, and each blade pair may open to different widths during the respective open time fractions. Furthermore, the disposal beam can be activated throughout the entire discrete time interval.

[0064] Advantageously, by activating the treatment bundle throughout the entire discrete time interval and allowing each leaf pair to open to a specified width (which may differ from the width of other leaf pairs) only within a fraction of the discrete time interval, precise radiation doses can be delivered to various complex target region shapes. Figure 5B Further description Figures 4A-4C The operation.

[0065] Figure 5A This is a flowchart illustrating a method 500 used for a fast sliding window with high-speed MLC according to an embodiment described herein. Generally, method 500 can be performed by processing logic, which may include hardware (e.g., processing device, circuitry, dedicated logic, programmable logic, microcode, device hardware, etc.), software (e.g., instructions that run or execute on the processing device), or a combination thereof. In some embodiments, method 500 may be performed by… Figure 1A The processing logic of the radiation treatment system 800 is performed.

[0066] like Figure 5A As shown, method 500 can be initiated at block 502 by processing logic via a collimator mounted to a rack of the radiation disposal system to shape the radiation beam directed to the target. In one embodiment, the collimator is a multi-leaf collimator (MLC) comprising multiple leaf pairs. As described herein, the MLC may be a high-speed MLC (e.g., an eMLC).

[0067] The processing logic at block 504 can utilize a processing device to modulate the sub-beam intensity of the radiation beam across multiple sub-beams, wherein these multiple sub-beams subdivide the flux field into a 2D grid. In one embodiment, the sub-beam intensity is modulated by independently modulating the travel rates of the leading and trailing blades in each blade pair as each blade pair moves from one end of a corresponding travel path to the other end of that corresponding travel path in a one-way trip. For Figures 3A-3G Additional details corresponding to the modulation of sub-beam intensity are provided.

[0068] In various embodiments, the 2D mesh described herein is a rectangular mesh. In other embodiments, the 2D mesh can be of any shape. In one embodiment, the first axis of the 2D sub-bundle mesh is determined by the index of the leaf pair along one axis of the MLC, and the second axis of the 2D mesh is along the travel line of the leaf pair.

[0069] The processing logic at block 506 can deliver multiple independent 2D sub-bundle intensity patterns from multiple rack angles. In one embodiment, multiple independent 2D sub-bundle intensity patterns can be delivered from multiple rack angles while the rack moves continuously. In one embodiment, each of the multiple leaf pairs changes direction when delivering the flux pattern for each subsequent rack angle.

[0070] In one embodiment, the processing logic may constrain the motion of multiple leaf pairs used to deliver 2D flux patterns from a specific rack angle to occur within a time period less than a pre-selected time period (e.g., for...). Figures 3D-3F (as described above). In one embodiment, the processing logic can center the blade pair motion, which requires less than a pre-selected time period for a specific rack angle, within the pre-selected time period (e.g., regarding...). Figures 3A-3F (as described above). In one embodiment, the first leaf of a leaf pair, which is located after the second leaf in the leaf pair when delivering an intensity pattern from a particular rack angle, does not reach the end of its journey before reversing its direction to deliver an intensity pattern for a subsequent rack angle (e.g., the leaf pair does not need to wait for other leaf pairs to finish their journey before reversing its direction).

[0071] In one embodiment, the continuous motion of the gantry can be helical motion. For example, processing logic can cause the gantry to rotate continuously, where a 2D sub-beam intensity pattern for a particular gantry angle is approximated by delivering the intensity pattern over a small arc. As used herein, a "small arc" can refer to a sub-arc of rotation of the total gantry, which is small enough that it can be considered a single gantry angle for planning the expected dose distribution. In one embodiment, a "small arc" can refer to a rotation of approximately 7 degrees around the total gantry. In other embodiments, other arc sizes can be used to deliver the one-dimensional small-beam intensity pattern.

[0072] In one embodiment, the processing logic moves the target axially through the center of the frame via an axial support (e.g., a treatment bed), wherein the frame and the axial support move simultaneously during target irradiation for helical delivery. In one embodiment, the pitch is greater than or equal to 0.5 during target irradiation. In other embodiments, other pitches greater than or less than 0.5 may be used.

[0073] Figure 5BThis is a flowchart illustrating a method 501 for delivering a binary MLC with a field width per leaf according to an embodiment. Generally, method 501 can be performed by processing logic, which may include hardware (e.g., processing device, circuitry, dedicated logic, programmable logic, microcode, device hardware, etc.), software (e.g., instructions that run or execute on the processing device), or a combination thereof. In some embodiments, method 501 may be performed by… Figure 1A The processing logic of the radiation treatment system 800 is performed.

[0074] like Figure 5B As shown, method 501 may, at block 503, determine multiple beam delivery location segments in processing logic simultaneously with the activation of the beam to initiate MLC leaf control instructions. In one embodiment, as described herein, each of the multiple beam delivery location segments corresponds to a range of beam positions within a discrete time interval (e.g., along an arc of the gantry of the radiation disposal system). For example, a beam delivery location segment (e.g., a protrusion) may correspond to a beam delivered from at least one of: different locations; and different directions.

[0075] In other words, a location segment can be considered a location node from which the LINAC can deliver a radioactive treatment beam along a specific direction. A location segment can include a range of locations (e.g., a region). For example, an arc in a helical treatment delivery system can be divided into multiple discrete location segments (e.g., where each location segment includes some degree around the arc). In one embodiment, a location segment can include approximately seven degrees around the arc (e.g., a seven-degree gantry rotation). In other non-helical embodiments, the location segment can be defined according to three-dimensional space. In one embodiment, different directions remain constant while following a linear trajectory of the radioactive beam sweeping across the length of the treatment target at different locations. In one embodiment, the different directions are non-coplanar.

[0076] At block 505, the processing logic generates multiple openings for each of the multiple beam delivery position segments, each of which corresponds to one of the multiple leaf pairs of the MLC. Advantageously, the multiple openings for each of the multiple position segments can correspond to different widths. For example, in one embodiment, two or more of the multiple openings correspond to different widths in the same position segment. In one embodiment, the multiple openings conform to the shape of the disposal target, project backward along the beam onto the MLC, and are within the maximum travel range of the multiple leaf pairs within the MLC.

[0077] At block 507, the processing logic generates multiple leaf opening time fractions for each of the multiple beam delivery location segments, each leaf opening time fraction corresponding to one of a plurality of leaf pairs in the MLC. In one embodiment, the leaf opening time fraction is a discrete-time amount less than the discrete-time interval. In another embodiment, the leaf opening time fraction may be equal to the discrete-time amount of the discrete-time interval. Advantageously, the leaf opening time fraction allows each of the multiple leaf pairs to be open within different amounts of time during the discrete-time interval. For example, in this embodiment, two or more of the multiple leaf opening time fractions during the discrete-time interval may be different.

[0078] At block 509, the processing logic utilizes the processing device to control multiple leaf pairs of the MLC simultaneously with the activation of the radiation beam of the radiation disposal system, such that each leaf pair opens as a corresponding opening within a corresponding leaf opening time fraction of a plurality of leaf opening time fractions during a discrete time interval corresponding to the position range of the radiation beam. In one embodiment, the disposal beam is activated throughout the entire discrete time interval (e.g., when the LINAC travels through the position segment).

[0079] In one embodiment, multiple leaf opening time fractions form overlapping radiation fields of varying intensities, which combine to generate an intensity-modulated flux field delivered to the treatment target. Advantageously, this operation allows the radiotreatment delivery system to effectively time-modulate the radiotreatment beam while precisely conforming to the shape of the target region.

[0080] Figure 6 Examples of different systems 600 are shown, in which a set of instructions can be executed to enable the system to perform any one or more of the methods discussed herein. In alternative implementations, the machine can be connected (e.g., networked) to other machines in a LAN, intranet, extranet, and / or the Internet. Each system can operate as a server or client in a client-server network environment, as a peer-to-peer (or distributed) network environment, or as a server or client in a cloud computing infrastructure or environment.

[0081] A system is a machine capable of executing a set of instructions (sequence or otherwise) that specifies the actions to be taken by the machine. Furthermore, although a single machine is shown, the term "machine" should also be considered as encompassing any collection of machines that individually or jointly execute one or more sets of instructions to perform any one or more of the methods discussed herein.

[0082] As described below and Figure 6As shown, system 600 may include a diagnostic imaging system 605, a treatment planning system 610, and a treatment delivery system 615. The diagnostic imaging system 605 may be any system capable of generating medical diagnostic images of the patient, which can be used for subsequent medical diagnosis, treatment planning, treatment simulation, and / or treatment delivery. For example, the diagnostic imaging system 605 may be a computed tomography (CT) system, a magnetic resonance imaging (MRI) system, a positron emission tomography (PET) system, or a combination of these systems. For ease of discussion, the diagnostic imaging system 605 may be discussed from time to time below regarding x-ray imaging modalities. In other embodiments, other imaging modalities such as those discussed above may also be used.

[0083] In one embodiment, the diagnostic imaging system 605 includes an imaging source 620 for generating an imaging beam (e.g., X-rays) and an imaging detector 630 for detecting and receiving the beam generated by the imaging source 620 or an auxiliary beam or emission simulated by the beam from the imaging source (e.g., in an MRI or PET scan).

[0084] In one embodiment, the imaging source 620 and the imaging detector 630 may be coupled to the digital processing system 625 to control imaging operations and process image data. In one embodiment, the diagnostic imaging system 605 may receive imaging commands from the treatment delivery system 615 and / or the treatment planning system 610.

[0085] The diagnostic imaging system 605 includes a bus or other component 680 for transmitting data and commands between the digital processing system 625, the imaging source 620, and the imaging detector 630. The digital processing system 625 may include one or more general-purpose processors (e.g., microprocessors), dedicated processors such as digital signal processors (DSPs), or other types of processing devices such as controllers or field-programmable gate arrays (FPGAs). The digital processing system 625 may also include other components (not shown) such as memory, storage devices, and network adapters. The digital processing system 625 may be configured to generate digital diagnostic images in standard formats, such as the Medical Digital Imaging and Communication (DICOM) format. In other embodiments, the digital processing system 625 may generate other standard or non-standard digital image formats. The digital processing system 625 may transmit diagnostic image files (e.g., the aforementioned DICOM formatted files) to the treatment delivery system 615 via a data link 683, which may be, for example, a direct link, a local area network (LAN) link, or a wide area network (WAN) link such as the Internet. Additionally, information can be transmitted between communication media push-pull systems between connected systems, such as in remote diagnostic or treatment planning configurations. In remote diagnostic or treatment planning, users can utilize embodiments of the present invention to diagnose or treat patients, despite physical separation between the system user and the patient.

[0086] In one embodiment, the treatment delivery system 615 includes a therapeutic and / or surgical radiation source 660 for delivering a prescribed radiation dose to a target volume in accordance with a treatment plan. The treatment delivery system 615 may also include an imaging system 665 for performing computed tomography (CT) imaging such as cone-beam CT, and the images generated by the imaging system 665 may be two-dimensional (2D) or three-dimensional (3D).

[0087] The treatment delivery system 615 may also include a digital processing system 670 for controlling the radiation source 660, receiving and processing data from the diagnostic imaging system 605 and / or the treatment planning system 610, and controlling patient support devices such as the treatment bed 675. The digital processing system 670 may be connected to or be part of a camera feedback system. The digital processing system 670 may be configured to perform any of the operations described herein. The digital processing system 670 may include devices representing one or more general-purpose processors (e.g., microprocessors), dedicated processors such as digital signal processors (DSPs), or other types of devices such as controllers or field-programmable gate arrays (FPGAs). The processing means of the digital processing system 670 may be configured to execute instructions for performing the operations described herein.

[0088] In one embodiment, the digital processing system 670 includes a system memory, which may include random access memory (RAM) or other dynamic storage devices coupled to the processing device for storing information and instructions to be executed by the processing device. The system memory may also be used to store temporary variables or other intermediate information during instruction execution by the processing device. The system memory may also include read-only memory (ROM) and / or other static storage devices for storing static information and instructions of the processing device.

[0089] The digital processing system 670 may also include a storage device representing one or more storage devices (e.g., a disk drive or optical disk drive) for storing information and instructions. The storage device may be used to store instructions for performing the disposal delivery steps discussed herein. The digital processing system 670 may be coupled to the radiation source 660 and the disposal bed 675 via a bus 692 or other types of control and communication interface.

[0090] In one embodiment, the treatment delivery system 615 includes an input device 678 and a display 677 connected to a digital processing system 670 via a bus 692. The display 677 may show trend data for identifying the rate of target movement (e.g., the rate of movement of the target volume being treated). The display may also show the patient's current radiation exposure and the patient's projected radiation exposure. The input device 678 allows clinicians to adjust parameters of the treatment delivery plan during treatment.

[0091] The disposal planning system 610 includes a processing device 640 for generating and modifying disposal plans and / or simulation plans. The processing device 640 may represent one or more general-purpose processors (e.g., microprocessors), special-purpose processors such as digital signal processors (DSPs), or other types of devices such as controllers or field-programmable gate arrays (FPGAs). The processing device 640 may be configured to execute instructions for performing the simulation generation and / or disposal planning operations discussed herein.

[0092] The processing planning system 610 may also include a system memory 635, which may include random access memory (RAM) or other dynamic storage devices coupled to the processing device 640 via a bus 686 for storing information and instructions to be executed by the processing device 640. The system memory 635 may also be used to store temporary variables or other intermediate information during instruction execution by the processing device 640. The system memory 635 may also include read-only memory (ROM) and / or other static storage devices coupled to the bus 686 for storing static information and instructions of the processing device 640.

[0093] The disposal planning system 610 may also include a storage device 645, which represents one or more storage devices (e.g., a disk drive or optical disk drive) coupled to the bus 686 for storing information and instructions. The storage device 645 may be used to store instructions for performing the disposal planning steps discussed herein.

[0094] The processing device 640 may also be coupled to a display device 650, such as a cathode ray tube (CRT) or a liquid crystal display (LCD), for displaying information (e.g., a 2D or 3D representation of VOI) to a user. An input device 655, such as a keyboard, may be coupled to the processing device 640 to communicate information and / or command selections to the processing device 640. One or more other user input devices (e.g., a mouse, trackball, or cursor arrow keys) may also be used to communicate directional information, select commands from the processing device 640, and control cursor movement on the display 650.

[0095] The treatment planning system 610 may share its database (e.g., data stored in storage device 645) with a treatment delivery system such as the treatment delivery system 615, making it possible for the system to be exported from the treatment planning system prior to treatment delivery. The treatment planning system 610 may be linked to the treatment delivery system 615 via a data link 690, which in one embodiment may be a direct link, a LAN link, or a WAN link.

[0096] It should be noted that when data links 683, 686, and 690 are implemented as LAN or WAN connections, any one of the diagnostic imaging system 605, treatment planning system 610, and / or treatment delivery system 615 can be located separately, allowing these systems to be physically isolated from each other. Alternatively, any one of the diagnostic imaging system 605, treatment planning system 610, and / or treatment delivery system 615 can be integrated with each other in one or more systems.

[0097] As will be apparent from the foregoing description, various aspects of the present invention can be implemented, at least in part, in software. That is, the technology can be implemented in response to processing devices 625, 640, or 670 (see...). Figure 6 This invention is executed in a computer system or other data processing system, for example, by executing a sequence of instructions contained in memory. In various implementations, hardware circuitry may be used in conjunction with software instructions to implement the invention. Therefore, the technology is not limited to any particular combination of hardware circuitry and software or any particular source of instructions executed by the data processing system. Furthermore, throughout this specification, various functions and operations may be described as being executed or advanced by software code for simplification. However, those skilled in the art will recognize that such expressions mean that these functions are obtained by the execution of code by processing device 625, 640, or 670.

[0098] Machine-readable media can be used to store software and data that, when executed by a general-purpose or special-purpose data processing system, enable the system to perform the various methods of the present invention. The executable software and data can be stored in various locations, including, for example, system memory and storage devices or any other means capable of storing at least one of the software programs or data. Therefore, machine-readable media includes any means that provides (i.e., stores) information in a form accessible to a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device having a collection of one or more processors, etc.). For example, machine-readable media include recordable / non-recordable media such as read-only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, etc. Machine-readable media can be non-transitory computer-readable storage media.

[0099] Unless explicitly stated in the foregoing discussion, it should be understood that terms such as “receive,” “locate,” “perform,” “transmit,” or “cause” can refer to the actions and processing of a computer system or similar electronic computing device, wherein the computer system or similar electronic computing device manipulates data represented as physical (e.g., electronic) quantities in the registers and memories of the computer system and transforms that data into other data similarly represented as physical quantities in the computer system's memory or registers or other such information storage or display devices. The methods described herein can be implemented using computer software. If written in a programming language conforming to recognized standards, sequences of instructions designed to implement these methods can be compiled to execute on various hardware platforms and cooperate with various operating systems. Furthermore, implementations of the invention are described without reference to any particular programming language. It should be understood that implementations of the invention can be carried out using various programming languages.

[0100] It should be noted that the methods and apparatus described herein are not limited to medical diagnostic imaging and treatment only. In alternative implementations, the methods and apparatus herein can be used for applications outside the medical field, such as industrial imaging and nondestructive testing of materials. In such applications, for example, "treatment" can generally refer to the implementation of an operation controlled by a treatment planning system, such as the application of a beam (e.g., a radiation beam, a sound beam, etc.), and "target" can refer to a non-anatomical object or region.

[0101] The invention has been described in the foregoing specification with reference to specific exemplary implementations. However, it will be apparent that various modifications and changes can be made without departing from the broader spirit and scope of the invention as set forth in the appended claims. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A system for delivering a radiation dose, comprising: A frame, used to move around the target to be irradiated; A radioactive source, which is mounted to the frame and guided inward toward the target; as well as A collimator, mounted to the gantry and in front of the radiation source, is configured to guide the radiation beam through an aperture between complementary leaflets of a leaf pair to the target as the gantry moves continuously through a series of position segments. The collimator is configured to modulate the sub-beam intensity of the radiation beam on a plurality of sub-beams for subdividing the flux field into a two-dimensional grid (2D grid). Modulating the sub-beam intensity includes modulating the travel of the complementary leaflets of the leaf pair to alternate between moving together in a first direction in a first consecutive position segment of the series of position segments and moving together in a second direction opposite to the first direction in a second consecutive position segment of the series of position segments. The two-dimensional sub-beam intensity pattern (2D sub-beam intensity pattern) is delivered as the gantry moves continuously through the series of position segments.

2. The system according to claim 1, wherein, The rack is used for continuous rotation, and the 2D sub-beam intensity pattern for a specific rack angle is approximated by delivering the 2D sub-beam intensity pattern at a specific position segment including the specific rack angle.

3. The system according to claim 1, wherein, The collimator is a multi-leaf collimator (MLC) comprising multiple leaf pairs, wherein the first axis of the 2D mesh is along a direction orthogonal to the travel lines of the multiple leaf pairs, and the second axis of the 2D mesh is along the travel lines of the multiple leaf pairs; as well as Modulating the sub-bundle intensity includes modulating the travel rate of the leaf pair as the leaf pair moves from one end of the travel line to the other end of the travel line in a single journey.

4. The system according to claim 3, wherein, The rack moves through a first position segment of the series of position segments within a first discrete time interval, and also includes constraining the movement of the leaf pair during the first position segment to deliver the 2D sub-bundle intensity pattern within the first discrete time interval.

5. The system of claim 1, further comprising an axial support member for axially moving the target through the center of the frame, and wherein, The frame and the axial support move simultaneously during the irradiation of the target to perform helical delivery.

6. The system according to claim 5, wherein, The pitch is greater than 0.

5.

7. The system according to claim 1, wherein, The system is a helical radiotherapy delivery system.

8. The system according to claim 1, wherein, The system described is a robot-based linear accelerator radiation treatment system, namely the LINAC radiation treatment system.

9. The system according to claim 1, wherein, The system is a rack-based radiotherapy delivery system.

10. A non-transitory computer-readable medium comprising instructions that, when executed by a processing device of a radiation treatment delivery system, cause the processing device to: The radiation beam is shaped to the target by means of a collimator installed on the gantry of the radiation treatment system, which is continuously moved through a series of position sections while the aperture between the complementary blades of the collimator's blade pair is guided to the target. The processing device modulates the sub-beam intensity of the radiation beam on a plurality of sub-beams, the plurality of sub-beams subdividing the flux field into a two-dimensional grid, i.e., a 2D grid, wherein modulating the sub-beam intensity includes modulating the travel of the complementary leaves of the leaf pair to alternate between moving together in a first direction in a first consecutive position segment of the series of position segments and moving together in a second direction opposite to the first direction in a second consecutive position segment of the series of position segments; While the rack continuously moves through the series of position segments, a two-dimensional sub-beam intensity mode, i.e., a 2D sub-beam intensity mode, is delivered. in, The collimator is a multi-leaf collimator (MLC) comprising multiple leaf pairs, wherein a first axis of the 2D mesh is orthogonal to the travel lines of the multiple leaf pairs, and wherein a second axis of the 2D mesh is along the travel lines of the multiple leaf pairs; and Modulating the sub-bundle intensity includes modulating the travel rate of the leaf pair as the leaf pair moves from one end of the travel line to the other end of the travel line in a single journey.

11. The non-transitory computer-readable medium according to claim 10, wherein, The processing apparatus is also used to continuously rotate the rack, and wherein the 2D sub-beam intensity pattern for a specific rack angle is approximated by delivering the 2D sub-beam intensity pattern over a specific positional segment including the specific rack angle.

12. The non-transitory computer-readable medium according to claim 10, wherein, The processing device is also used to constrain the motion of multiple leaf pairs used to deliver 2D meshes from a specific rack angle to occur within a time period less than a pre-selected time period.

13. The non-transitory computer-readable medium according to claim 12, wherein, For the specific frame angle, the blade pair movement needs to be centered within the pre-selected time period, which is shorter than the pre-selected time period.

14. The non-transitory computer-readable medium according to claim 13, wherein, The first leaf of the leaf pair, located after the second leaf in the leaf pair when delivering the 2D sub-bundle intensity pattern from the specific rack angle, does not reach its end of travel before reversing its direction to deliver the 2D sub-bundle intensity pattern for subsequent rack angles.

15. The non-transitory computer-readable medium of claim 10, wherein the processing apparatus is further configured to axially move the target through the center of the frame via an axial support, wherein, The frame and the axial support move simultaneously during the irradiation of the target to perform helical delivery.

16. The non-transitory computer-readable medium according to claim 15, wherein, The pitch is greater than 0.

5.

17. A computer program product comprising a program that, when executed by a processing device of a radiation treatment delivery system, causes the processing device to: The radiation beam is shaped to the target by means of a collimator installed on the gantry of the radiation treatment system, which is continuously moved through a series of position sections while the aperture between the complementary blades of the collimator's blade pair is guided to the target. The processing device modulates the sub-beam intensity of the radiation beam on a plurality of sub-beams, the plurality of sub-beams subdividing the flux field into a two-dimensional grid, i.e., a 2D grid, wherein modulating the sub-beam intensity includes modulating the travel of the complementary leaves of the leaf pair to alternate between moving together in a first direction in a first consecutive position segment of the series of position segments and moving together in a second direction opposite to the first direction in a second consecutive position segment of the series of position segments; While the rack continuously moves through the series of position segments, a two-dimensional sub-beam intensity mode, i.e., a 2D sub-beam intensity mode, is delivered. in, The collimator is a multi-leaf collimator (MLC) comprising multiple leaf pairs, wherein a first axis of the 2D mesh is orthogonal to the travel lines of the multiple leaf pairs, and wherein a second axis of the 2D mesh is along the travel lines of the multiple leaf pairs; and Modulating the sub-bundle intensity includes modulating the travel rate of the leaf pair as the leaf pair moves from one end of the travel line to the other end of the travel line in a single journey.

Images