System for adjusting radiation therapy delivery

Abstract

Disclosed herein is a radiation therapy system comprising: a radiation delivery system for delivering radiation to a target area of a patient; a computer data storage device configured to store a current radiotherapy plan, the current radiotherapy plan comprising a plurality of control points, each control point defining a value of at least one radiation delivery variable; a delivery control module configured to retrieve a current radiotherapy plan and control the radiation delivery system to deliver radiation to the target area based on the current radiotherapy plan; and a plan adjustment module.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to radiation therapy, and in particular, the present disclosure relates to systems and methods for delivering adaptive radiation therapy to a patient. BACKGROUND

[0002] Radiation therapy can be described as the use of ionizing radiation, such as X-rays, to treat a human or animal body. Radiation therapy is often used to treat a tumor within a patient or subject. In such treatment, ionizing radiation is used to irradiate and thereby destroy or damage cells forming part of the tumor. In radiation therapy, it is desirable to deliver a prescribed dose of radiation to a target region of the patient, such as a tumor, and limit radiation to other parts of the patient, such as healthy tissue and organs at risk (OARs).

[0003] The treatment planning process typically involves acquiring one or more medical images, such as a CT image of the patient, and segmenting it to identify the target region and OARs in the vicinity of the target region. The segmentation process can be performed manually or using automated segmentation techniques. A clinician determines radiation treatment parameters, such as by prescribing a radiation dose to be delivered to the target region and maximum doses that can be safely delivered to various OARs. The treatment planning process can then involve optimizing various radiation delivery variables to meet the prescribed radiation treatment parameters, such as determining a number of treatment sessions (or “fractions”) in which radiation therapy should be performed, angles at which a radiation beam should be applied during each fraction, beam energy, duration of application of the radiation beam at these angles, and beam shape at each delivery angle. In some or all of these steps, the clinician can be assisted by software. This aspect of the treatment planning, which is performed prior to patient treatment (and if there are gradual changes, sometimes between treatment fractions), can be described as “offline” treatment planning.

[0004] However, characteristics of the tumor, such as its shape and size, can change over the course of multiple treatments. Similarly, other patient information and characteristics of the patient’s anatomy can change in unforeseen ways between fractions in both cases. Therefore, an “online” adaptive radiation therapy technique can be used to update and re-optimize the radiation therapy plan and / or delivery variables immediately prior to treatment of the patient. According to the online adaptive radiation therapy technique, the patient should be imaged again immediately prior to treatment, and the treatment plan for that day’s fraction can be adapted and / or re-optimized according to the most recent available medical images. The online adaptive radiation therapy technique thus allows for consideration of inter-fraction anatomical changes as part of an online treatment workflow.

[0005] Additionally, the position or orientation of the tumor can change during the course of the fraction, which can be due to inter-fraction motion (e.g., patient breathing). In this case, inter-fraction imaging during delivery can provide "real-time" adjustment information in the form of "gating" radiation delivery, i.e., periodically turning the beam on and off, and / or providing an over-ride of the multi-leaf collimator control ("tracking") to cause the shape of the beam to differ from that specified in the treatment plan.

[0006] However, current "real-time" adjustment techniques involve adjusting a fixed treatment plan. This mechanism requires an "over-ride" feature in the radiation delivery system to interrupt and modify the execution of the original fixed treatment plan. This existing "real-time" adjustment is effective, but only utilizes some of the degrees of freedom available within the radiation therapy delivery system to control and optimize the radiation therapy delivery. It is desirable to further optimize the adjusted treatment and utilize further degrees of freedom of the delivery system for real-time adjustment to further improve the radiation delivery to the tumor and reduce the radiation delivery to adjacent healthy tissue.

[0007] The present invention seeks to address these and other drawbacks encountered in the prior art by providing improved systems and methods for delivering radiation therapy to a patient. SUMMARY

[0008] The present invention is set out in the independent claims. Optional features are set out in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

[0009] A specific example will now be described by way of example only and with reference to the drawings in which:

[0010] Figure 1 A radiation therapy apparatus or device according to the present disclosure is shown;

[0011] Figure 2 A radiation therapy workflow for fixed treatment plan delivery is shown;

[0012] Figure 3 A radiation therapy workflow for fixed treatment plan delivery with gating and / or tracking is shown;

[0013] Figure 4 A radiation therapy system according to the present invention is shown;

[0014] Figure 5 A radiation therapy workflow for adjusted treatment plan delivery according to the present disclosure is shown;

[0015] Figure 6 A method of generating radiation therapy radiation according to the present disclosure is shown;

[0016] Figure 7a block diagram showing one implementation of a radiation therapy system; and

[0017] Figure 8 a computer readable medium is shown, or more generally, a computer program product is shown. DETAILED DESCRIPTION

[0018] Overview

[0019] In a non-limiting overview provided to aid in understanding, a system and method are provided that enable real-time adjustment of radiation therapy, where at least one radiation delivery variable of a current radiation therapy plan is modified during treatment to generate a new current radiation therapy plan. The new current radiation therapy plan is saved in a computer data storage device (e.g., computer memory) and can replace the existing treatment plan to form the basis of the ongoing treatment. The new plan can be updated periodically or even continuously based on real-time information about the target region and saved in the computer data storage device to form the basis of the ongoing treatment, allowing the new plan to be delivered using features such as control point interpolation provided by the delivery control module. This is in contrast to current methods that are not truly adaptive and do not generate and save a new treatment plan in this manner, but rather simply use a direct control override mechanism to completely bypass the delivery control module and the "control points" defined in the treatment plan.

[0020] Using the system and / or method, radiation therapy can be delivered in a manner that adjusts to real-time anatomy or changes from earlier deliveries and provides more precise dose delivery and targeting of the tumor. More precise targeting in turn means that the treatment plan can use narrower positional margins, reducing the amount of radiation delivered to healthy tissue and potentially reducing the number of fractions needed, providing better outcomes for the patient.

[0021] Further, the system and / or method of the present disclosure provides a method for adjusting radiation therapy that can further improve delivery by generating future control points in the radiation therapy plan, which allows for adjustments beyond the limitations of a system based on real-time overrides, and also allows for adjustments to the treatment plan for future treatment fractions based on real-time information from the current fraction.

[0022] Further, by storing the generated plan in the computer data storage device used for the original plan, separation of the adjustment architecture and the delivery architecture can be achieved, for example, allowing the plan adjustment module to be fitted to an existing delivery system with only minor modifications.

[0023] Other examples and advantages are set forth below.

[0024] Detailed description

[0025] Disclosed herein are systems, devices, methods, and apparatuses related to radiation therapy. In the case of a linac-based radiation therapy device that is highly complex and has many interrelated components, the terms "system," "device," "apparatus," and "machine" can be used interchangeably to describe the radiation therapy device as a whole, or as a collection of components of the radiation therapy device. Likewise, the group of components primarily responsible for generating and delivering radiation to a patient can be interchangeably referred to as a "radiation delivery system" or "radiation therapy delivery apparatus" or "beam delivery device," etc., as will be understood by those skilled in the art.

[0026] Figure 1 An exemplary radiation therapy (RT) device 100 is shown. Those skilled in the art will be well familiar with the device and its constituent components, but a general description of it is provided here to provide useful collateral information for the present disclosure. The radiation therapy device 100 is based on a linac.

[0027] Figure 1 The illustrated device combines magnetic resonance (MR) imaging capability and linac-based radiation therapy capability, and is referred to as an MR-linac device. MR-linacs are particularly well suited for delivering adaptive therapy, as MR images can be taken immediately prior to or during treatment. To provide useful collateral information for the present invention, a general description of the device and its constituent components will be provided. Figure 1 The illustrated device is in accordance with the present disclosure, and is suitable for use with the disclosed systems and devices. However, the present disclosure can be implemented in any radiation therapy device, for example in a linac-based radiation therapy device with CBCT imaging capability.

[0028] Figure 1 The device 100 in FIG. 1 includes an MR imaging apparatus 112 and a radiation therapy (RT) apparatus that can include a linac device. The MR imaging apparatus 112 is shown in cross-section in the figure. In operation, the MR scanner produces MR images of a patient, and the linac device generates a radiation beam and shapes and directs it toward a target region within the patient's body in accordance with a radiation therapy plan. The depicted device does not show the usual "shell" that can cover the MR imaging apparatus 112 and the RT apparatus in a commercial setting such as a hospital.

[0029] Figure 1The illustrated MR-linac device includes a radio frequency wave source 102, a waveguide 104, an electron source 106, a radiation source 106, a collimator 108 (e.g., a multi-leaf collimator configured to collimate and shape the beam), an MR imaging apparatus 112, and a patient support surface 114. In use, the device also includes a housing (not shown) that, together with the ring gantry, defines a bore. The movable support surface 114 can be used to move a patient or other object into the bore when MR scanning and / or when radiation therapy is to begin. The MR imaging apparatus 112, the RT apparatus, and the object support surface actuator are communicatively coupled to a controller or processor. The controller is also communicatively coupled to a memory device that includes computer-executable instructions that are executable by the controller.

[0030] The RT apparatus includes a radiation source and a radiation detector (not shown). Typically, the radiation detector is positioned diametrically opposite the radiation source. The radiation detector is adapted and configured to generate radiation intensity data. In particular, the radiation detector is positioned and configured to detect the intensity of radiation that has passed through the object. The radiation detector can also be described as a radiation detection apparatus, and can form part of a portal imaging system.

[0031] The radiation source can include a beam generation system. For a linac, the beam generation system can include the RF energy source 102, the electron gun 106, and the waveguide 104. The radiation source is attached to a rotatable gantry 116 to rotate with the gantry 116. In this way, the radiation source is rotatable around the patient so that the treatment beam 110 can be applied around the gantry 116 from different angles. In a preferred embodiment, the gantry is continuously rotatable. In other words, the gantry can be rotated 360 degrees around the patient, and can in fact continue to rotate beyond 360 degrees. The gantry can be ring-shaped. In other words, the gantry can be a ring gantry.

[0032] The radio frequency wave source 102 (e.g., a magnetron) is configured to generate radio frequency waves. The radio frequency wave source 102 is coupled to the waveguide 104 via a circulator 118, and is configured to input radio frequency wave pulses into the waveguide 104. The radio frequency waves can pass from the radio frequency wave source 102 through an RF input window and into a radio frequency input connection pipe or tube. The electron source 106 (e.g., an electron gun) is also coupled to the waveguide 104, and is configured to inject electrons into the waveguide 104. In the electron gun 106, when the filament is heated, electrons are thermionically emitted from the cathode filament. The temperature of the filament controls the number of electrons injected. The electrons are injected into the waveguide 104 in synchronization with the radio frequency waves being pumped into the waveguide 104. The design and operation of the radio frequency wave source 102, the electron source, and the waveguide 104 is such that the radio frequency waves accelerate the electrons to very high energies as the electrons propagate through the waveguide 104.

[0033] The radiation source is configured to direct a therapeutic radiation beam 110 towards a patient positioned on a patient support surface 114. The radiation source can comprise a heavy metal target, where high-energy electrons exiting the waveguide are directed towards this heavy metal target. When the electrons hit the target, X-rays are produced in various directions. A primary collimator can block X-rays travelling in certain directions and only let the forward travelling X-rays pass creating the therapeutic beam 110. The X-rays can be filtered and can pass one or more ion chambers for dose measurement. These ion chambers measure the dose delivered by the beam, for example using monitor units (MU). The beam can be shaped in various ways by a beam shaping device, for example by using a multi-leaf collimator 108, before it enters the patient as part of the radiotherapy.

[0034] In some embodiments, the radiation source is configured to emit an X-ray beam or a particle beam, such as an electron particle beam. Such embodiments allow the apparatus to provide electron beam therapy, an external beam therapy where electrons instead of X-rays are directed towards the target region. By adjusting components of the linear accelerator, it is possible to "switch" between a first mode of emitting X-rays and a second mode of emitting electrons. In essence, by moving the heavy metal target in or out of the electron beam path and replacing it with a so-called "electron window", it is possible to switch between the first and second modes. The electron window is essentially transparent to electrons and allows the electrons to exit the flight tube.

[0035] The object or patient support surface 114 is configured to move between a first position substantially outside the bore and a second position substantially inside the bore. In the first position, a patient or object can be fixed on the patient support surface. Then, the support surface 114 and the patient can be moved inside the bore to the second position in order to image the patient by the MR imaging device 112 and / or image or treat using the RT device. The movement of the patient support surface is effected and controlled by an object support surface actuator, which can be described as an actuation mechanism. The actuation mechanism is configured to move the object support surface in a direction parallel to and defined by a central axis of the bore. The terms "object" and "patient" are used interchangeably here, such that the object support surface can also be described as a patient support surface. The object support surface can also be referred to as a movable or adjustable treatment couch or table.

[0036] Figure 1The illustrated radiotherapy apparatus / device also includes an MR imaging device 112. The MR imaging device 112 is configured to acquire images of a patient or subject positioned (i.e., located) on the subject support surface 114. The MR imaging device 112 can also be referred to as an MR imager. The MR imaging device 112 can be a conventional MR imaging device that operates in a known manner to acquire MR data (e.g., MR images). Those skilled in the art will appreciate that such an MR imaging device 112 can include a main magnet, one or more gradient coils, one or more receive coils, and a radio frequency pulse applicator. Operation of the MR imaging device is controlled by a controller.

[0037] The controller is a computer, processor, or other processing device. The controller can be formed of multiple discrete processors; for example, the controller can include an MR imaging device processor that controls the MR imaging device 110, an RT device processor that controls operation of the RT device, and a subject support surface processor that controls operation and actuation of the subject support surface. The controller is communicatively coupled to a memory, such as a computer readable medium.

[0038] The linear accelerator apparatus also includes several other components and systems that will be appreciated by those skilled in the art. For example, to ensure that the linear accelerator does not leak radiation, appropriate shielding is also provided.

[0039] In conventional radiation therapy methods, a dose for a target / tumor is determined and prescribed, and then delivered in multiple sessions, which reduces the impact of the radiation delivered to the patient's healthy tissue. Thus, prior to commencing treatment, a radiation therapy plan is determined by a clinician. As noted above, this treatment plan can be delivered, for example, via conventional image-guided radiation therapy (IGRT) or via online adaptation techniques. In addition, offline plan adaptation can be performed.

[0040] In conventional radiation therapy, a fixed treatment plan is prepared that is suitable for delivering a prescribed dose, based on a CT scan taken some time before the course of treatment. Preparing the plan involves determining the number of sessions (or "fractions") of radiation therapy that should be performed, the angle of the radiation beam that should be applied during each fraction, the energy of the radiation beam that should be applied, the beam shape(s) at each delivery angle, etc. Thus, parameters to be used for each of these variables are determined at an initial planning stage, which can be considered as degrees of freedom of the radiation delivery system. The plan is delivered in multiple fractions, each fraction being performed on a different day, and can require the patient to visit the clinic individually.

[0041] A typical radiation therapy plan for a particular fraction includes a sequence of control points. Each control point specifies a measure of progress - monitor units (MU or percent MU) - to deliver. In other words, the goal of a fraction is to deliver a particular dose (e.g., 1000 MU) to the tumor, and each control point will deliver a particular fraction of the total dose (e.g., 0 MU for the first, 50 MU for the second, 85 MU for the third, etc.). MU is used as a measure of fraction progress, and sometimes interpolation between control points is required. For example, assume control point n has 100 MU, and the next control point n+1 has 110 MU, and the current MU counter is at 105 MU at a particular instant. The desired delivery position at that instant is typically derived by interpolating between control point n and control point n+1. This interpolation mechanism can dictate the amount of MU delivered at various positions.

[0042] Each control point also specifies a set of delivery variables for each degree of freedom of the radiation therapy system. These positions can also be considered and referred to as radiation delivery variables or parameters. In a simplified example, there can only be a single radiation delivery variable, a multi-leaf collimator (MLC) shape variable, in which case the control points can be described as a set of predetermined MLC shapes that are planned to be delivered at a particular point during a treatment fraction. However, the degrees of freedom, and thus the radiation delivery variables, can include, for example, leaf and septa positions defining a multi-leaf collimator (MLC) shape, gantry angles, beam energies and / or intensities, and one or more patient support surface positions. It is useful to visualize the sequence of control points as a function or graph of position versus MU, which dictates how the radiation is distributed using the degrees of freedom of the radiation therapy system. The discrete steps in the sequence, from one control point to the next, can approximate a smooth continuous motion while delivering the radiation. However, a discontinuity can also be specified with two adjacent control points having the same MU but different positions. In this case, the radiation must be stopped briefly while the position is changed. This basic layout of a plan can be used in different ways. For example, an intensity modulated radiation therapy (IMRT) plan alternates between radiation at a first set of fixed positions and then moving to the next set of positions, and repeating the process until all control points have been delivered. In contrast, a volumetric modulated arc therapy (VMAT) treatment plan approximates a continuous dynamic motion. The systems and methods of the present disclosure are not limited to a particular treatment plan type or treatment mode or way of specifying a treatment plan.

[0043] In conventional systems without patient imaging capability, the system is designed to input a plan and deliver it to completion. If a problem arises during the intended delivery of the plan, it is also possible to re-plan and deliver a so-called partial plan. Such an approach is referred to herein as a "fixed treatment plan" delivery.

[0044] Figure 2A radiotherapy workflow 200 for this fixed treatment plan delivery is illustrated. In box 202, a CT scan of the patient is performed prior to any treatment. In box 204, a plan is executed to generate a treatment plan to deliver a prescribed dose to the patient via multiple fractions. The treatment plan includes multiple control points and delivery variables, as described above. The treatment plan can be repeated in the same manner for each fraction of the treatment. Box 206 illustrates the implementation of each of these fractions by a treatment system (e.g., a linac-based radiotherapy device). In box 208, the fixed plan from box 204 is delivered to the patient via the radiotherapy device.

[0045] according to Figure 2 The conventional fixed-plan delivery shown does not include any adjustments based on any changes that occur after the initial CT scan at box 202. However, this fixed-plan delivery method is only suitable for certain types of adjustments, particularly inter-fraction adjustments. In this case, the plan can be adjusted based on images acquired just prior to delivery, as in an online adjusted radiotherapy workflow. The adjusted plan is then imported into the delivery section of the system. This adjusted plan is fixed and is not updated during treatment, and is delivered to completion in the conventional radiotherapy workflow.

[0046] Known techniques for handling intra-fractional motion include gating and tracking. Gating uses real-time imaging during irradiation to pause the beam if the target tumor moves significantly beyond the intended location. Tracking utilizes real-time imaging to guide the MLC shape directly toward the moving target tumor. In "rigid tracking," the MLC shape remains rigid, matching the plan but moving with the target, while in "deformable tracking," the shape can also change to match tumor deformation. This system is still based on fixed plan delivery, but adds possibilities for pausing the beam and / or real-time control of the MLC shape based on imaging. The other degrees of freedom of the system still follow a fixed plan.

[0047] Figure 3 A radiotherapy workflow 300 for fixed treatment plan delivery is illustrated, which features inter-fractional adjustments and inter-fractional adjustments in the form of gating and / or tracking. In box 302, the patient undergoes an initial pre-treatment CT scan, such as... Figure 2 Workflow 200 is shown in box 202. (And...) Figure 2 Similarly, in box 304, treatment plans with or for multiple fractions are designed based on preprocessed CT scans. Box 306 indicates the implementation of each of these fractions by a treatment system (e.g., a linear accelerator-based radiotherapy device). Figure 3In workflow 300, a planning adjustment element exists within the radiotherapy apparatus, represented by box 308. The imaging capability at box 310 is used to acquire an image 312 of the patient prior to delivery of each fraction. The planning adjustment element at box 308 adjusts the original predetermined fixed plan for that fraction based on image 312, for example, based on inter-fractional changes that have occurred since the original plan was prepared at box 304. The imaging capability at box 310 can also provide imaging 314 during delivery. This real-time imaging allows for real-time MLC adjustment / tracking at box 316, taking the form of overriding predetermined MLC variables provided by the fixed plan. At box 318, the fixed plan from box 304 is delivered to the patient, modified via inter-fractional adjustments and MLC overriding.

[0048] In one example, the control point in the original fixation plan specifies a particular MLC shape to be delivered to a specific MU in the fraction. However, real-time imaging information 310 indicates that the tumor has slightly changed shape. An offset can be applied to the MLC shape specified at that control point to account for this change. Importantly, however, in this previous workflow, the original and predetermined fixation plan remains in memory and is only adjusted via "over-control" and interruption. Accordingly, of the many available degrees of freedom and delivery variables in the treatment plan, only a limited number are adjusted by conventional real-time adjustment techniques. For example, only the MLC shape can be adjusted via over-control. However, in this conventional adjustment, the plan's control points are not affected, and control point interpolation does not account for any fraction-related changes.

[0049] Figure 4 A radiotherapy system 400 according to this disclosure is shown, which provides an improved method for updating treatment plans by generating and storing new radiotherapy plans during radiation delivery, thereby enabling comprehensive real-time adjustment of radiotherapy.

[0050] The radiotherapy system 400 includes a computer data storage device 402, which serves as a planning data storage device. The computer data storage device 402 is a suitable computer-based memory. The computer data storage unit 402 stores the current radiotherapy plan 403. Similar to the fixed treatment plans discussed herein, the current radiotherapy plan 403 includes multiple control points, each defining the value of at least one radiation delivery variable. As described above, the original current radiotherapy plan 403 can be developed in a conventional manner based on preprocessed CT imaging and then stored in the planning data storage device 402.

[0051] The radiotherapy system 400 includes a planning and adjustment module 404. Optionally, the radiotherapy system 400 includes an imaging system 406, such as an imaging system capable of performing the patient imaging described herein, such as an MR imaging system and / or a CBCT imaging system. The imaging system is adapted and configured to acquire images of a target region of the patient.

[0052] The radiotherapy system 400 includes a radiation delivery control module 408 and a radiation delivery system 410. The delivery control module 408 is configured to retrieve the current radiotherapy plan 403 and, based on the current radiotherapy plan 403, control the radiation delivery system 410 to deliver radiation to a target area. A plan adjustment module 404 is configured to receive information about the target area during radiation delivery according to the current radiotherapy plan 403. The information about the target area can be acquired “in real time,” for example, during radiation delivery to the target area. The information may be based on imaging information acquired by an imaging system, such as measurements of target offset that can be determined from images; however, the information does not always need to be based on imaging information. The information may alternatively or additionally include information about the target area acquired using other instruments, such as patient position monitoring devices based on optical or pressure sensors. This information may include information representing movement due to patient respiration. In some examples, the information about the target area includes location information measured during radiation delivery, and location information related to at least one of the patient position and the radiation delivery system position. For example, the radiation delivery system position may include location information of at least one radiation delivery system component measured during radiation delivery.

[0053] The planning adjustment module 404 is also configured to adjust the current radiotherapy plan 403 based on information to generate a new current radiotherapy plan during radiation delivery according to the current radiotherapy plan 403, wherein the adjustment includes modifying at least one radiation delivery variable of at least one control point of the current radiotherapy plan and storing the new current radiotherapy plan in the planning data storage device 402.

[0054] Therefore, system 400 enables general real-time adjustments to radiotherapy plans, where any degree of freedom of the plan can be adjusted based on real-time information, and provides storage of the plan so that it can be delivered by a radiotherapy delivery system. Figure 2 and Figure 3 Compared to the known fixed scheduling, gating, and tracking techniques shown in workflows 200 and 300, the systems and / or methods disclosed herein allow for more comprehensive and real-time adjustments to the schedule.

[0055] Figure 5 The use of this disclosure is shown Figure 4The system 400 is used to deliver an exemplary improved adjusted radiotherapy workflow 500 for adjusted treatment. Similarly, Figure 4 System 400 can be used to implement Figure 5 Adjusting the radiotherapy workflow 500. Workflow 500 can be combined with... Figure 2 and Figure 3 The workflows 200 and 300 are compared.

[0056] In box 502, obtain the patient's pre-processed CT scan for planning purposes, such as... Figure 2 and Figure 3 As shown in boxes 202 and 302. In box 504, the initial treatment plan is calculated as described above, which can be used as the initial current radiotherapy plan 403 and stored in the computer data storage device 402. Box 506 represents the treatment system, in this example an MR linear accelerator, which will be used to deliver multiple fractions of the initial treatment plan. The processing system 506 has a plan adjustment module at box 508, which corresponds to... Figure 4 The plan adjustment module 404. In Figure 5 In the example, the planning adjustment module 404 includes a planning data storage device 402 that stores the initial (or initial current) radiotherapy plan. In block 510, the radiotherapy system implementing workflow 500 has imaging capabilities, as per [reference to...]. Figure 4 The description indicates that it can be used to obtain information about the target. In this example, the imaging capability is MR imaging capability. As mentioned above, in other examples, alternative or additional sources can be used to obtain information about the target.

[0057] In box 510, imaging at box 508 provides images 514 from before and / or during delivery to the planning adjustment module. Then, in box 518, the planning adjustment module generates a new current radiotherapy plan, as per the... Figure 4 As described. New radiotherapy plans can be based on image 514, taking into account inter-fractional and / or intra-fractional variations (e.g., due to respiration or drift). With Figure 2 and Figure 3 Workflows 200 and 300 (where the initial fixed plan is delivered in boxes 208 and 318) differ. Figure 5 In workflow 500, within box 518, a new current radiotherapy plan is delivered. Therefore, improved delivery based on real-time information can be achieved.

[0058] exist Figure 2 and Figure 3 In the standard workflows 200 and 300, the fixed and predetermined plans based on preprocessed CT images are delivered by the radiation delivery system, with minor modifications to the control of variables at the delivery system. Figure 5In workflow 500, a self-adjusting plan for the current and / or future fractions is generated at the planning adjustment module and provided to the radiation delivery system for execution, thereby enabling more comprehensive adjustments. For example, if drift in the target area increases the risk to adjacent organs, the treatment plan can be replanned (e.g., by changing the gantry angle) to better account for organs at risk.

[0059] also, Figure 4 and Figure 5 Examples and Figure 2 and Figure 3 The significant difference between standard workflows 200 and 300 lies in the method of plan storage. In standard workflows, the computer data storage device or memory that holds the initial fixed plan is not modified or adjusted. However, between retrieving the plan from memory and delivering the plan, variables are controlled or provided with specific offsets. Figure 4 and Figure 5 The currently disclosed improved method enables plans to be fully or completely updated in real time and stored in place of previous plans, thereby allowing for continuous plan adjustments and providing a favorable separation between the plan adjustment module architecture (or plan adjustment logic) and the radiation delivery system architecture (or radiation delivery system logic). Therefore, the method of this disclosure allows for the delivery of different types of adjustment treatments, particularly as processor speeds increase over time. Furthermore, it eliminates the need to modify or update the radiation delivery system architecture to implement these types of adjustment treatments. Thus, workflow organization and operational availability can be improved.

[0060] In some examples, plan generation and delivery are performed in parallel, thereby speeding up the process. In such examples, a starting point for the "current radiotherapy plan" can be provided in a simple form without specified control points, such as treatment goals. A treatment goal could be, for example, delivering a prescribed dose to a target area. Based on this treatment goal, for example, an "updated" plan including control points can be generated based on imaging during the treatment. In such examples, the generated plan "update" does not necessarily need to fully specify the new current radiotherapy plan, and only the update needs to specify enough plan to maintain delivery until the next plan "update" is generated. The "update" will continue until the initially prescribed dose has been delivered.

[0061] The degrees of freedom that can be modified by the method of this disclosure, and therefore the radiation delivery variables, may include at least one of the following: the angle at which the radiation beam should be applied during each fraction, the beam energy at which the radiation beam should be applied, the duration of application of the radiation beam at these angles, the weight of a particular beam, the beam shape at each delivery angle, the position of the blades and diaphragms that define the shape of the multi-leaf collimator, and patient position parameters, such as the position of the patient support surface.

[0062] In some examples, adjusting the current radiotherapy plan involves modifying a subset of the aforementioned delivery variables.

[0063] The methods disclosed herein can also be used to implement conventional radiotherapy workflows. For example, it can be achieved through... Figure 4 and Figure 5 Fixed schedule delivery is achieved by omitting any adjustments to the schedule adjustment module. This can also be used for existing workflows for drift correction or other similar methods that typically require restarting processing with a new schedule. Figure 4 and Figure 5 This is achieved by delivering a portion of a series of planned updates instead of delivering them individually. Regular gating and tracking methods can also be implemented through planned updates.

[0064] The following description Figure 4 and Figure 5 Further optional features in the examples.

[0065] In some examples, system 400 can set constraints on the specification of permitted plan updates or the generation of new plans. For example, constraints can be set such that, among all available degrees of freedom or delivery variables, adjustments to the current radiotherapy plan are enabled only for a subset of those variables (such as variables related to the MLC shape), which will thus achieve class-tracking adjustments. Advantageously, this can allow incremental advancement, gaining the benefits of a specific delivery paradigm while limiting complexity. Thus, such an example is no more complex than existing tracking over-control systems, but still benefits from the other advantages of the improved system disclosed herein.

[0066] In some examples, system 400 includes one or more auxiliary monitoring modules to monitor both the adjustment and the transmission. Monitoring the adjustment can depend on the type of adjustment used and can be selected in conjunction with the adjustment method used for treatment. This monitoring can further improve the effectiveness and safety of the system.

[0067] In some examples, the delivery control module can be configured to achieve delivery by skipping, under-quantifying, and / or rearranging control points (e.g., to avoid unnecessary anomaly handling) and reporting actual deliveries to the planning adjustment module. In such examples, the delivery module can take the actual deliveries into account and correct them in later planning updates to more effectively achieve the desired treatment outcomes.

[0068] In some examples, the current radiotherapy plan 403 includes a treatment objective, and adjusting the current radiotherapy plan includes modifying at least one radiation delivery variable based on the treatment objective. The treatment objective may include at least one of a prescribed dose, such as a prescribed minimum dose for a target region and a prescribed maximum dose for an organ at risk.

[0069] In some examples, adjusting the current radiotherapy plan 403 also includes adding control points to and / or removing control points from the current radiotherapy plan. This is in stark contrast to existing adjustment techniques, which only involve superimposing the MLC shape associated with the currently delivered control point. This approach allows the number of control points to be adjusted in real time, which can improve processing efficiency and reduce the number of fractions required. In one example, an optimization process is continuously performed during treatment, seeking to optimize the delivery of the remaining MUs in that fraction based on multiple variables, including the number and schedule arrangement of control points, and the radiation delivery variables associated with each control point. The MUs delivered so far during treatment are recorded.

[0070] In one example, control points can be added to allow planning and delivery to operate in parallel. In one example, the system can deliver the current set of 100 control points while planning the next 100 control points, then add them to the end of the current plan, preferably before the delivery of the current control points is complete. In this way, the plan can be repeatedly expanded for continuous delivery by adding new control points over time.

[0071] In some examples, the delivery control module 408 is also configured to retrieve a new current radiotherapy plan and control the radiation delivery system based on the new current radiotherapy plan to deliver radiation to the target area. Further updates, such as those that adapt the new current radiotherapy plan to generate another new current radiotherapy plan, can then be provided, thus offering a continuous and iterative process in which the “current” plan is continuously updated and re-saved in real time.

[0072] In some examples, the delivery control module 408 is also configured to retrieve a new current radiotherapy plan during radiation delivery according to the current radiotherapy plan, and control the radiation delivery system to change to deliver radiation to the target area based on the new current radiotherapy plan. This approach allows radiation to be delivered continuously while changing to a new, adjusted treatment plan.

[0073] In some examples, the planning adjustment module 404 is also configured to, during radiation delivery according to the new current radiotherapy plan, adjust the new current radiotherapy plan based on further information about the target area to generate a further new radiotherapy plan, and store the further new current radiotherapy plan in a computer data storage device. In other words, Figure 4 The System 400 allows the plan to be adjusted and updated multiple times during radiation delivery or during the course of treatment.

[0074] In some examples, adjusting the current radiotherapy plan also includes modifying at least one radiation delivery variable of the range of multiple control points, and optionally includes removing control points subsequent to said range. For example, this approach allows for consideration of observed patient changes in the remainder of the treatment plan and allows for the optional removal of further subsequent control points, for example, if the efficiency of radiation delivery will be improved by adjusting the plan to the point that subsequent control points of the initial plan are no longer needed. In some examples, the range of the modified multiple control points corresponds to control points that have not yet been delivered in the delivered radiotherapy fraction (the current radiotherapy fraction), or control points that are planned for delivery at a later point. In such examples, this disclosure enables the system to adjust the radiotherapy plan for a specific fraction during or within that fraction.

[0075] In some examples, the adjustment is also based on the remaining dose delivered in the current portion of the radiotherapy.

[0076] In some examples, the adjustment is also based on the remaining MU to be delivered in the current radiotherapy portion.

[0077] In some examples, the planning adjustment module is also configured to determine the drift of the target area based on this information and adjust the current radiotherapy plan in response to the drift.

[0078] In some examples, radiation delivery according to the current radiotherapy plan is delivery of a current control point associated with the current radiotherapy plan, and at least one control point of the current radiotherapy plan (where delivery variables are modified) is a future control point planned for a future time point compared to the current control point. In such examples, future control points can be planned for future fractions planned for future time points compared to the current or current fraction being delivered.

[0079] Figure 6 A method 600 for generating radiotherapy radiation according to this disclosure is shown. Method 600 will use... Figure 4 The system 400 is implemented therein, and the components of the system 400 correspond to the corresponding components used in the method 600. Similarly, those disclosed herein... Figure 4 System 400 and Figure 5 Each feature of workflow 500, including optional features, may optionally form another part of method 600.

[0080] At box 602, the method includes storing a current radiotherapy plan at a computer data storage device 402, the current radiotherapy plan including a plurality of control points, each control point defining a value for at least one radiation delivery variable. In one example, an initial treatment plan is prepared and stored in a known manner prior to processing fractions.

[0081] In box 604, the method includes retrieving the current radiotherapy plan via delivery control module 408 and controlling the radiation delivery system based on the current radiotherapy plan to deliver radiation to a target area of ​​the patient. In one example, the current radiotherapy plan specifies a series of MLC shapes to be delivered at specific MU points in a fraction, and these doses and beam shapes are delivered via delivery system 518.

[0082] In box 606, the method includes receiving information about a target area via a planning adjustment module 404 during radiation delivery according to a current radiotherapy plan. In one example, imaging information is received from an MR imager during treatment.

[0083] In box 608, the method includes adjusting the current radiotherapy plan to generate a new current treatment plan via a plan adjustment module 404 based on this information during radiation delivery according to the current radiotherapy plan, wherein the adjustment includes modifying at least one radiation delivery variable for at least one control point of the current radiotherapy plan. In this example, MR imaging information indicates that the patient has slightly shifted off the treatment table, and the tumor position has changed, such as the shape of the tumor as seen along the “beam eye diagram.” In existing adjustment methods, such changes can be identified, but require, for example, a high amount of gating, or pausing treatment while calculating a new fixed treatment plan for fractionation. In contrast, in this method, the MLC position and shape can be adjusted not only for the current control point but also for all future control points and each delivery angle.

[0084] In block 610, the method includes storing a new current radiotherapy plan in a computer data storage device via a plan adjustment module 404 during radiation delivery according to the current radiotherapy plan. In this example, the adjusted MLC shape and position are stored in the computer data storage device 402 as the new current radiotherapy plan.

[0085] In this way, the treatment plan can be continuously updated based on real-time imaging information. Treatment can then continue based on the latest available radiotherapy plan. Not only can the current control point be adjusted based on imaging information and, for example, the remaining MU to be delivered to the patient during fractionation, but future control points and their associated delivery variables can also be adjusted.

[0086] Current methods exceed the controllable limits of variables in existing plans. Any variable in a range of delivery variables can be recalculated and delivered based on real-time information. Compared to existing methods, this increases the number of updatable variables (including variables associated with future control points, which can even be realized in future fractions). The method of this invention provides a greater degree of adaptability, thus providing patients with more precise and personalized radiotherapy.

[0087] Now describing this disclosureFigures 4 to 6 Further optional features in the examples.

[0088] In some examples, a new current radiotherapy plan is generated during radiation delivery, such that when the current radiotherapy plan is adjusted, the treatment delivery is used as a continuous delivery without restarting the MU count or other overall plan progress indicators. For example, suppose the machine is delivering a 1000 MU plan and a point of, for example, 400 MU appears, indicating that the target area has drifted, albeit excessively. Using a fixed-plan delivery mode, the workflow would stop, recalculate, and update the delivery with a new plan of 600 MU. However, in this example, the currently disclosed method would recalculate control points in the range of 400 MU to 1000 MU while continuing to deliver the current radiotherapy plan in parallel (provided the drift remains sufficiently acceptable for delivery to continue—if not, the current delivery will be stopped). The MU count may increase further when the updated plan takes over, but the system will ensure that 1000 MU is delivered when the plan is complete. Although delivery and replanning overlap, this is achievable regardless of the exact time of transition from the old current radiotherapy plan to the new one. Therefore, in some examples, the monitoring unit MU count determined by System 400 is continuous between the current radiotherapy plan and the new current radiotherapy plan.

[0089] In some examples, generating a new current radiotherapy plan involves expanding, truncating, or replacing at least some of the current radiotherapy plans. In some examples, the delivery control module discards control points from already delivered current or new current radiotherapy plans. Furthermore, updates do not necessarily overlap with control points delivered at that moment, as in the drift correction example above. The system can also be used to incrementally expand plans in an on-the-fly manner.

[0090] In some examples, the system is configured to transmit the running MU counts to the planning and adjustment module in real time. Advantageously, this helps to avoid unnecessary updates or modifications to control points within the already transmitted MU range. For example, a dose monitor or ionization chamber can monitor the MUs, and the processor can be configured to maintain the total running MU counts and transmit them to the planning and adjustment module.

[0091] In some examples, the system is configured to transmit at least some of the actual locations used during delivery to the planning adjustment module in real time. This provides the planning adjustment module with a record of the delivered treatment and enables the planning adjustment module to generate a new current radiotherapy plan that corrects for deficiencies in the earlier delivery.

[0092] In some examples, when all control points of the current or new radiotherapy plan have been delivered, the planning module notifies the completion of treatment with updates and / or flags indicating the completion of delivery of the current radiotherapy plan. This mechanism enables the planning module to send a delivery termination signal to the delivery control module. The updates and / or flags can indicate the success / failure of delivery and / or the termination reason associated with the end of delivery.

[0093] In some examples, the new current radiotherapy plan includes enable and / or disable delivery flags, which respectively indicate which points should be irradiated or disabled in the new current radiotherapy plan. Advantageously, the flags are used to limit unnecessary communication between the planning architecture and the delivery architecture. Such flags can also be used, or alternatively, to implement a method corresponding to the "gating" approach, and / or to provide time periods during which radiation delivery is prohibited to allow for mobile equipment.

[0094] In some examples, system 400 includes an interface for updating the radiotherapy plan based on the new current plan. Advantageously, the interface provides separation between the plan specification and the coding and carrier mechanisms. Preferably, for compatibility reasons, the plan specification (e.g., sequence of MUs and positions) should ideally follow the established treatment planning software as closely as possible, while the coding (e.g., Protobuf, iCom, XML, etc.) and carrier (e.g., TCP / IP, ZeroMQ, etc.) mechanisms are more dependent on performance and efficiency requirements. It should also be understood that the interface can take many different forms, such as an embedded library within the adjustment module, and is not necessarily limited to a communication protocol. The interface can be arranged as a direct interface between the plan adjustment module 404 and the delivery control module 408, but is not required to be arranged this way. This interface can be used to transmit plan updates and responses, as well as "actual value" feedback, from the delivery control module 408 to the plan adjustment module 404 in real time. Advantageously, a specially defined interface allows for the development of adjustment solutions based on common standards.

[0095] System 400 may also provide a user interface for manual intervention, enabling users to review, verify, and / or approve the generated new current radiotherapy plan before it is retrieved by the delivery control module 408. Similarly, system 400 may include a monitoring module for reviewing and / or verifying the implementation of the radiotherapy plan.

[0096] In some examples, a plan update, in the form of generating a new current radiotherapy plan, may or may not significantly alter the control point of delivery at that moment. In other words, if radiation delivery remains within permissible limits, it can continue uninterrupted; otherwise, the system will pause radiation, move to the new location specified in the new current radiotherapy plan, and resume radiation. Advantageously, conventional delivery systems are already capable of handling and recovering from tolerance anomalies and are therefore equipped to handle any anomalies that may be triggered during transitions from the current plan to the next.

[0097] Preferably, system 400 delivers control points in a time-efficient manner, while also taking into account the advance information provided by the control points. For example, suppose a moving gantry is used to advance delivery at the maximum dose rate, but the gantry angle must double per degree of MU. The dose rate cannot increase beyond the maximum value, and the gantry speed cannot change abruptly. Therefore, ideally, the gantry should begin decelerating in advance to avoid unnecessary aberration triggering and recovery. In this example, if controlled correctly, the gantry will decelerate to half its previous speed. The dose rate will also slow down proportionally, but will double at appropriate times, coordinated during planned execution.

[0098] In some examples, the system includes a watchdog timer or equivalent mechanism to ensure the communication lines operate correctly during treatment plan delivery. Delivery is prevented if a plan update is blocked. In some examples, the new current radiotherapy plan includes MU authorization parameters, which indicate how much the MU count is allowed to increase without further updates (or without generating a new current radiotherapy plan). If the system progresses to the MU count provided by the MU authorization parameters without receiving a new current radiotherapy plan, delivery can be paused or stopped. The plan adjustment module can receive MU count updates in real time and can therefore authorize the early delivery of the appropriate portion of the MU. The advantage of this approach is that it protects delivery from communication problems in both directions. Delivery is paused or stopped if MU count communication fails or a plan update fails.

[0099] Advantageously, in the examples disclosed herein, the generation of a new current radiotherapy plan is handled separately from plan execution. The processing time required for plan generation / updating itself can increase proportionally to the length of the update sequence. On the other hand, plan execution may operate within a fixed real-time clock cycle, and therefore, if an update block is executed, even briefly, it may be interrupted. This separate processing, combined with feeds to internal control points, such as via shared memory or in real-time within smaller sequences, can contribute to improved computational performance.

[0100] In some examples, the planning adjustment module 404 includes a computer data storage device 402. In some examples, the delivery control module 408 includes a computer data storage device 402. In some examples, the planning adjustment module 404 is configured to store a new current radiotherapy plan in the computer data storage device 402 by sending the new current radiotherapy plan to the delivery control module 408. In some examples, at least one of the planning adjustment module 404 and the delivery control module 408 includes a computer data storage device 402, and a direct interface is provided between the planning adjustment module 404 and the delivery control module 408 as described above.

[0101] In some examples, particularly those where the initial current radiotherapy plan includes a treatment target or a prescribed dose without specifying control points, the radiotherapy system disclosed herein includes a radiation delivery system for delivering radiation to a target area of ​​a patient, a computer data storage device configured to store the current radiotherapy plan, and a delivery control module configured to retrieve the current radiotherapy plan and, based on the current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area. In these examples, the system also includes a plan adjustment module configured to, during radiation delivery according to the current radiotherapy plan: receive information about the target area based on the current radiotherapy plan, generate a new current radiotherapy plan, and store the new current radiotherapy plan in the computer data storage device.

[0102] In some examples, particularly those for generating plans in parallel with delivery, the radiotherapy system disclosed herein includes a computer data storage device configured to store the current radiotherapy plan, and a plan adjustment module configured to generate the current radiotherapy plan during radiation delivery. The current radiotherapy plan includes multiple control points, each defining the value of at least one radiation delivery variable, and is stored in the computer data storage device. In these examples, the system also includes a delivery control module configured to retrieve the current radiotherapy plan and, based on the current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area.

[0103] The radiotherapy plans described in this article, such as new current radiotherapy plan examples, may specifically correspond to radiation delivery plans.

[0104] In some examples, the radiotherapy plans described herein include information representing interpolated delivery variables between control points, which may include interpolated values ​​of radiation delivery variables.

[0105] In some examples, the planning adjustment module 404 can generate a new current radiotherapy plan in the form of a "plan update". A plan update can specify the value of at least one radiation delivery variable. Therefore, in some examples, the new current radiotherapy plan is a plan update, and the delivery control module 408 is configured to modify the current radiotherapy plan during delivery based on the plan update. A plan update does not require specifying the complete treatment plan.

[0106] The planning adjustment module 404 can transmit or send planning updates to the delivery control module 408, which can appropriately store the corresponding new current radiotherapy plan in the computer data storage device 402, and / or the planning adjustment module 404 can transmit planning updates to the computer data storage device 402 itself. Therefore, the method described herein for storing a new current radiotherapy plan in the computer data storage device 402 may include the planning adjustment module 404 generating and / or communicating and / or sending planning updates. In some examples, the delivery control module 408 is configured to append planning updates to the current radiotherapy plan during delivery, for example, by planning control points specified in the planning update after the last control point of the current radiotherapy plan.

[0107] In some examples, the delivery control module 408 may be arranged to respond to the planning adjustment module 404 regarding a specific plan update. The response may include an indication of acceptance / rejection of the plan update, which may further indicate the reason for rejecting the plan update. Additionally or alternatively, the response may include optimization feedback.

[0108] As described above, generating a new current radiotherapy plan may include expanding, truncating, or replacing at least some of the current radiotherapy plans. In some examples, system 400 is arranged to merge new plan input parameters provided by plan adjustment module 404 with current plan parameters in a plan update to form a new current radiotherapy plan. For example, parameters specified in the plan update may be used to expand, replace, or co-locate with parameters of the current radiotherapy plan, and can be done without restarting the MU count of the current delivery. As explained herein, these parameters may be control points or a set of control points. Such merging, etc., may be implemented at plan adjustment module 404 or delivery control module 408. Advantageously, the message size can be reduced by, for example, specifying a plan update that merges control points to be updated with control points to be inherited from the previous current plan into a new current plan.

[0109] In some examples, the delivery control module 408 is configured to determine timing and / or velocity information for delivering a new current radiotherapy plan using the radiation delivery system. In these examples, timing calculation steps can be performed to enable delivery of the current or new current radiotherapy plan in the shortest possible or desired time. This approach can be implemented each time a plan update or new current radiotherapy plan is generated, and can be implemented by the delivery control module 408 and / or the plan adjustment module 404. This example is particularly advantageous in dynamic techniques such as VMAT, especially for rapid benchtop movement.

[0110] In the timing calculation step, the calculation of the optimal or preferred speed for any point in the delivery can depend on the next step in the plan. Therefore, the timing calculation step can be performed before delivery, allowing subsequent control logic to focus on the planned delivery point. For these calculations, it is generally more efficient to perform them once on each plan update than once on each control clock cycle.

[0111] In some examples, system 400 can calculate timing information, such as dose rate and velocity, and add this information to the current or new radiotherapy plan. Such calculations can take into account constraints on gantry (or stage) deceleration. For example, this constraint means that the gantry must decelerate earlier due to later constraints (reverse constraints) in later control intervals. Similarly, constraints on acceleration are imposed from control intervals, and constraints on gantry velocity are imposed in later control intervals (forward constraints). In some examples, if it is a minimum dose rate constraint, a lower bound may also exist or alternatively exist for all degrees of freedom of movement.

[0112] Timed calculation steps are beneficial because plan changes can potentially trigger tolerance anomalies and position recovery, which can significantly slow down delivery. This depends on the specific constraints applicable at any given time. For example, if the dose rate or bench speed is the limiting factor at some point in delivery, further changes to the plan for moving the relevant blades are unlikely to cause anomalies. However, if blade movement is the limiting factor, requiring more blade movement in a plan update is likely to trigger anomalies. One way to minimize such anomaly handling is to specify additional parameters in the plan, such as those that help optimize to reserve some capacity for increased movement without triggering any anomalies. An example of this is a plan update that specifies maximum expected speeds (for the entire plan or for each control point). Some target areas move more than others, so the expected maximum speeds can be set by adjustment based on the specific circumstances of the process and / or situation. Note that these will be the maximum speeds expected during movement in the target areas, not confused with the optimal axis speed during delivery.

[0113] For the planning and adjustment module 404, it is useful to have optimized visibility, to see what optimization decisions were made during delivery, and to see where the constraints are, and therefore the planning and adjustment module 404 can be arranged accordingly. For the delivery control module 408, it is useful to provide real-time feedback of actual values ​​(actual MU with timestamps, actual axis positions, etc.), and for the planning and adjustment module 404, it is useful to be able to reconstruct the dose to the target region, and it may also be useful to use information about the target region in dose reconstruction.

[0114] In some examples, the authorized MUs can be specified by or to system 400. The authorized MUs are the number of MUs authorized for delivery by system 400. Authorized MUs are presented here as a way to prevent communication failures, such as between adjustment and transmission, but may be useful under various conditions where applications outside the transmission must participate in time-critical communications (e.g., secondary monitoring) with the transmission. Delivery control module 408 can be arranged to allow radiation to proceed only to the lowest of all received authorized MU values. This mechanism prevents various failure conditions, including failures in outgoing messages, failures in incoming messages, and failures in the external application itself. This is because radiation for authorized MUs before the actual MUs requires all three of these failures to remain operational. A failure of any one of these will cause one or more authorized MU sources to stop, thus stopping radiation after the difference between the actual MU and the authorized MUs has been exceeded.

[0115] In some examples, the new current radiotherapy plan includes an indication of the authorized monitoring unit (MU) count for authorized delivery of the delivery control module 408.

[0116] In some examples, delivery control module 408 includes a real-time control submodule and a plan update implementation submodule. The real-time control submodule is arranged to work with a real-time clock cycle, while the plan update implementation submodule is arranged to perform the steps necessary to implement plan updates (such as preprocessing steps like checking the plan) in parallel with delivery. A bridging approach can be used between the two submodules. In one example, bridging involves two submodules communicating via shared memory, for example, copying a new current radiotherapy plan to a region of memory and sending a reference to it to the real-time environment. An alternative approach for bridging is for the plan update implementation submodule to segment the new current radiotherapy plan into pieces and send each piece individually to the real-time control submodule as needed. Advantageously, using two submodules implements a scalable solution that allows for large intermittent updates or frequent small updates without interrupting any delivery stream.

[0117] In some examples, system 400 may use a method that includes delaying the transition to suspend the beam if the transition would cause delivery to exceed the tolerance.

[0118] In some examples, interpolation is used to interpret the new current radiotherapy plan to determine the desired axis position of the radiation delivery system for the current MU count.

[0119] In some examples, new current radiotherapy plans and / or plan updates include status decision points. These are points where the delivery can switch between radiation (potentially in motion) and recovery status, for example, for a plan that only moves within the schedule or returns to its position after a plan update that exceeds tolerance.

[0120] In some examples, new current radiotherapy plans and / or plan updates include control information for axes used to control dose rate and radiation and recovery status. The dose rate and axis position must remain synchronized during radiation, while the axis can move independently as the position recovers. Control can also be optimized by incorporating optimization information previously calculated in the plan update.

[0121] In some examples, the planning adjustment module 404 is configured to determine delivery schedules. This example can advantageously improve the efficiency of the planning / adjustment algorithm by allowing adjustments to focus on the relevant parts of the plan at any given time. For example, the scope of already delivered MUs may no longer be applicable.

[0122] Further examples of the adjustment method implemented in this disclosure are as follows:

[0123] • Adjust the rest of the plan to make slow or intermittent changes to the target area (the plan update will then run until completion, but the possibility of further changes as needed is still allowed).

[0124] • Adjustments are made only to the short-term MU range in front to allow for faster changes to the target area (based on inevitable further updates in a short period of time).

[0125] Similarly, incremental planning (and perhaps in conjunction with adjustments) can focus on planning short MU ranges in advance, ideally in sync with delivery. Therefore, excluding delivered MU ranges and unspecified MU ranges, there exists a related currently planned MU range (plus the corresponding control point range).

[0126] These examples are helpful, but not necessary:

[0127] • Delivery progress is visible in the planning adjustment module.

[0128] • Scheduled updates do not require adjustments or specified delivery completion.

[0129] • Planned updates do not necessarily require adjusting or specifying control points within the MU scope that have already been delivered and are therefore no longer relevant.

[0130] • Delivery reaching the end of the current control point does not necessarily require delivery to end.

[0131] In some examples, delivery ends when dose coverage is complete, which can be indicated by the adjustment module. However, other constraints can also be applied, such as the maximum permissible MU for delivery, which can force termination.

[0132] In some examples, MU scaling can be implemented. The dose to the target area is not necessarily proportional to the machine's MU output. The relationship between dose and MU is complex and requires time-consuming calculations to develop a plan. Changes to the plan may, in principle, require changes to the MU to achieve the correct dose to the target area. Therefore, it is useful to introduce a measure of delivery progress that is proportional to the dose (e.g., the percentage of expected dose coverage) rather than proportional to the MU (e.g., the percentage of MU or total MU). In this case, the current and / or new current radiotherapy plan can also indicate scaling between the dose and MU at each control point. This determines that increases in dose are consistent with increases in MU based on effective scaling within the control point interval. In this way, changes in the MU required at control points can be indicated by changing the MU scaling value, while maintaining the same dose value within the control points.

[0133] In another exemplary embodiment of system 400 and workflow 500, the method can be summarized such that the radiotherapy system disclosed herein includes a radiation delivery system for delivering radiation to a target area of ​​a patient; a delivery control module configured to control the radiation delivery system to deliver radiation to the target area based on a current radiotherapy plan; and a plan adjustment module configured to receive information about the target area during radiation delivery according to the current radiotherapy plan; generate a plan update based on the current radiotherapy plan and the information about the target area, the plan update including information representing at least one delivery variable; and transmit the plan update to the delivery control module, wherein the delivery control module is further configured to modify and / or replace the current radiotherapy plan based on the plan update to generate a new current radiotherapy plan, and deliver radiation to the target area based on the new current radiotherapy plan.

[0134] The exemplary implementation may further include any one or more optional features described elsewhere in this document.

[0135] In some examples, a plan update includes at least one of the following: at least one radiation delivery variable for at least one control point of the new current radiotherapy plan; the range of the control point, each control point specifying a corresponding monitoring unit value; information representing the scaling of the monitoring units; a sign indicating delivery completion; a sign indicating whether radiation has been delivered; and / or the value of the authorized monitoring unit quantity used for delivery.

[0136] In the methods disclosed herein, an exemplary delivery workflow for scheduling updates is as follows:

[0137] • Initial delivery (the current initial plan has no control points).

[0138] • A plan update can begin (a plan update can also begin after confirmation and start).

[0139] • Confirm delivery (authorized delivery).

[0140] • Start (radiation delivery begins).

[0141] • Delivery ends after adjustments are complete.

[0142] On the other hand, an example delivery workflow for regular fixed-schedule delivery is as follows:

[0143] • Load the delivery plan (initialize delivery).

[0144] • If applicable, initiate direct external control.

[0145] • Confirm and begin.

[0146] • Delivery ends when the delivery reaches the designated MU at the end of the control point.

[0147] In some examples of the methods disclosed herein, during delivery initialization, the initial state of a particular patient may have no starting control point (“empty” plan). In such examples, the first plan update is functionally distinct from any other plan update and provides an “update” from the initial empty state.

[0148] Advantageously, using the methods disclosed herein, radiotherapy plans can be adjusted in a manner that does not require specifying the plan to be completed or the scope already delivered.

[0149] Advantageously, the method disclosed herein allows for modularization of radiotherapy adjustments, separating the management and optimization of the delivery side (planning execution, delivery rate, etc.) from the management and optimization of the planning and adjustment sides (planning optimization, image processing, adjustment algorithms, etc.). Advantageously, the method disclosed herein can be used to adjust the plan using any suitable adjustment algorithm to determine and / or modify the delivery process during delivery. In current methods, the adjustment side of the system must manage the adjustments while also implementing the delivery functionality (because direct external control bypasses the delivery logic within the delivery system).

[0150] Advantageously, the method disclosed herein can facilitate incremental planning during delivery, i.e., parallel planning with delivery.

[0151] Advantageously, the method disclosed herein achieves rapid delivery of treatment by reducing gaps in treatment that would otherwise require adjustments to the plan, and the plan can also be adjusted as needed with an appropriate level of granularity.

[0152] The systems disclosed herein may include radiotherapy devices, including radiotherapy delivery devices, also known as radiation delivery systems, such as... Figure 1 and Figure 7 As shown. Therefore, the system may include a computing system, image acquisition equipment, treatment equipment, input devices and / or output devices, such as Figure 7 As shown.

[0153] Figure 7 A block diagram of one implementation of a radiotherapy system 700 is shown. The radiotherapy system 700 includes a computing system 710 in which a set of instructions for causing the computing system 710 to perform any or more of the methods discussed herein can be executed.

[0154] The computing system 710 should be considered to include any number or set of machines, such as one or more computing devices that individually or jointly execute a set (or more) of instructions to perform any or more of the methods discussed herein. That is, the hardware and / or software may be provided in a single computing device or distributed across multiple computing devices in the computing system. In some implementations, one or more elements of the computing system may be connected (e.g., networked) to other machines, such as in a local area network (LAN), intranet, extranet, or the Internet. One or more elements of the computing system may operate as a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. One or more elements of the computing system may be a personal computer (PC), tablet computer, set-top box (STB), personal digital assistant (PDA), cellular phone, network device, server, network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) specifying the actions to be taken by that machine.

[0155] The computing system 710 includes controller circuitry 711 and memory 713 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM). Memory 713 may include static memory (e.g., flash memory, static random access memory (SRAM), etc.) and / or auxiliary memory (e.g., data storage device) that communicate with each other via a bus (not shown).

[0156] The controller circuit 711 represents one or more general-purpose processors, such as microprocessors, central processing units, accelerated processing units, etc. More specifically, the controller circuit 711 may include a Complex Instruction Set Computing (SISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing combinations of instruction sets. The controller circuit 711 may also include one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, etc. The one or more processors of the controller circuit may have a multi-core design. The controller circuit 711 is configured to execute processing logic for performing the operations and steps discussed herein.

[0157] The computing system 710 may also include network interface circuitry 718. The computing system 710 may be communicatively coupled to input device 720 and / or output device 730 via input / output circuitry 717. In some implementations, input device 720 and / or output device 730 may be elements of the computing system 710. Input device 720 may include alphanumeric input devices (e.g., keyboard or touchscreen), cursor control devices (e.g., mouse or touchscreen), audio devices (e.g., microphone), and / or haptic input devices. Output device 730 may include audio devices (e.g., speaker), video display units (e.g., liquid crystal display (LCD) or cathode ray tube (CRT)), and / or haptic output devices. In some embodiments, input device 720 and output device 730 may be provided as a single device or as separate devices.

[0158] In some implementations, the computing system 710 may include image processing circuitry 719. Image processing circuitry 719 may be configured to process image data 780 (e.g., image or imaging data), such as medical images acquired from one or more imaging data sources, a treatment device 750, and / or an image acquisition device 740. Image processing circuitry 719 may be configured to process or preprocess image data. For example, image processing circuitry 719 may convert received image data into a specific format, size, resolution, etc. In some implementations, image processing circuitry 719 may be combined with controller circuitry 711.

[0159] In some embodiments, the radiotherapy system 700 may further include an image acquisition device 740 and / or a treatment device 750, such as in Figures 1 to 3Examples are disclosed herein. Image acquisition device 740 and treatment device 750 may be provided as a single device. In some implementations, treatment device 750 is configured to, for example, perform imaging in addition to providing treatment and / or during treatment. Treatment device 750 includes the main radiation delivery component of a radiotherapy system, such as a linear accelerator.

[0160] The image acquisition device 740 can be configured to perform positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI) or other suitable imaging techniques.

[0161] Image acquisition device 740 can be configured to output image data 780, which can be accessed by computing system 710. Treatment device 750 can be configured to output treatment data 760, which can be accessed by computing system 710.

[0162] The computing system 710 can be configured to access or acquire treatment data 760, planning data 770, and / or image data 780. Treatment data 760 can be obtained from an internal data source (e.g., from memory 713) or from an external data source (e.g., treatment device 750 or an external database). Planning data 770 can be obtained from memory 713 and / or from an external source such as a planning database. Planning data 770 may include information acquired from one or more of image acquisition device 740 and treatment device 750. Accordingly, the computing system 710 is arranged to implement the methods disclosed herein concerning processing planning and processing quality standards.

[0163] The various methods described above can be implemented by a computer program. The computer program may include computer code (e.g., instructions) 810 arranged to instruct a computer to perform one or more of the methods described above. The steps of the methods described above can be performed in any suitable order. The computer program and / or code 810 for performing such methods can be provided to a device on one or more computer-readable media, such as a computer, or more generally, a computer program product 800, such as... Figure 8As depicted. The computer-readable medium may be temporary or non-temporary. One or more computer-readable media 800 may be, for example, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, or propagation media for data transmission, such as for downloading code over the Internet. Alternatively, the one or more computer-readable media may take the form of one or more physical computer-readable media such as semiconductor or solid-state memory, magnetic tape, removable computer floppy disk, random access memory (RAM), read-only memory (ROM), rigid disk, and optical disk (such as CD-ROM, CD-R / W, or DVD). Instructions 810 may also reside wholly or at least partially within memory 713 and / or controller circuitry 711 during execution by computing system 710, which also constitute computer-readable storage media.

[0164] In one implementation, the modules, components, and other features described herein may be implemented as discrete components or integrated into functional hardware components such as ASICs, FPGAs, DSPs, or similar devices.

[0165] A "hardware component" is a tangible (e.g., non-transitory) physical component (e.g., a group or one or more processors) capable of performing a specific operation and which can be configured or arranged in a specific physical manner. A hardware component may include dedicated circuitry or logic permanently configured to perform certain operations. A hardware component may include dedicated processors, such as FPGAs or ASICs. A hardware component may also include programmable logic or circuitry temporarily configured by software to perform certain operations.

[0166] Furthermore, modules and components can be implemented as firmware or functional circuitry within a hardware device. Additionally, modules and components can be implemented as any combination of hardware devices and software components, or solely as software (e.g., code stored or otherwise embodied in a machine-readable medium or in a transmission medium).

[0167] Unless otherwise specified, as is apparent from the discussion below, it should be understood that throughout the description, the use of terms such as “receive,” “determine,” “compare,” “enable,” “hold,” “identify,” “compute,” “display,” and “store” refers to the actions and processes of a computer system or similar electronic computing device that manipulates and converts data represented as physical (electronic) quantities in the registers and memory of the computer system into other data or other information storage, transmission, or display devices similarly represented as physical quantities in the memory or registers of the computer system.

[0168] It should be understood that the above description is intended to be illustrative and not restrictive. Many other implementations will become apparent to those skilled in the art after reading and understanding the above description. Although this disclosure has been described with reference to specific exemplary implementations, it will be appreciated that this disclosure is not limited to the described implementations but can be practiced with modifications and changes within the spirit and scope of the appended claims. Therefore, the specification and drawings should be regarded as illustrative and not restrictive. Consequently, the scope of this disclosure should be determined by referring to the full scope of the appended claims and their equivalents.

Claims

1. A radiotherapy system, comprising: A radiation delivery system used to deliver radiation to a target area of ​​a patient; A computer data storage device configured to store a current radiotherapy plan, the current radiotherapy plan including a plurality of control points, each control point defining the value of at least one radiation delivery variable; A delivery control module is configured to retrieve the current radiotherapy plan and, based on the current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area; and The planning adjustment module is configured to, during radiation delivery according to the current radiotherapy plan: Receive information about the target area; The current radiotherapy plan is adjusted based on the information to generate a new current radiotherapy plan, wherein the adjustment includes modifying at least one radiation delivery variable at at least one control point of the current radiotherapy plan; as well as The new current radiotherapy plan is stored in the computer data storage device.

2. The system according to any one of the preceding claims, wherein, The current radiotherapy plan includes a treatment target based on a prescribed dose, and adjusting the current radiotherapy plan includes modifying the at least one radiation delivery variable based on the treatment target.

3. The system according to any one of the preceding claims, wherein, Adjusting the current radiotherapy plan also includes adding control points to the current radiotherapy plan and / or removing control points from the current radiotherapy plan.

4. The system according to any one of the preceding claims, wherein, The at least one radiation delivery variable represents one of the following: gantry angle, beam energy of the radiation beam to be applied, duration of radiation beam application at the gantry angle, weight of a particular beam, or patient position parameter.

5. The system according to any one of the preceding claims, wherein, The delivery control module is also configured to retrieve the new current radiotherapy plan and, based on the new current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area.

6. The system according to any one of the preceding claims, wherein, The delivery control module is also configured to retrieve the new current radiotherapy plan during radiation delivery according to the current radiotherapy plan and to control the radiation delivery system based on the new current radiotherapy plan to change the delivery of radiation to the target area.

7. The system according to any one of the preceding claims, wherein, The plan adjustment module is also configured to adjust the new current radiotherapy plan based on further information about the target area during radiation delivery according to the new current radiotherapy plan to generate a further new radiotherapy plan, and to store the further new current radiotherapy plan in the computer data storage device.

8. The system according to any one of the preceding claims, wherein, Adjusting the current radiotherapy plan further includes modifying at least one radiation delivery variable within the range of the plurality of control points, and optionally also includes removing at least one control point subsequent to the range.

9. The system according to claim 8, wherein, The range of the plurality of control points corresponds to control points that have not yet been delivered in the current fraction of radiotherapy.

10. The system according to any one of the preceding claims, wherein, The adjustment is also based on the remaining dose delivered in the current fraction of radiotherapy.

11. The system according to any one of the preceding claims, further comprising an imaging system for acquiring an image of the target region of the patient, wherein, The information about the target area is based on imaging information acquired through the imaging system.

12. The system according to any one of the preceding claims, wherein, Information about the target area includes location information measured during radiation delivery, which is related to at least one of the following: patient location and radiation delivery system location.

13. The system according to any one of the preceding claims, wherein, The plan adjustment module is also configured to determine the drift of the target region based on the information, and to adjust the current radiotherapy plan in response to the drift.

14. The system according to any one of the preceding claims, wherein, The delivery of radiation according to the current radiotherapy plan is the delivery of the current control point associated with the current radiotherapy plan; and Wherein, the at least one control point in the current radiotherapy plan is a future control point planned at a future time point compared to the current control point.

15. The system according to any one of the preceding claims, wherein, The plan adjustment module is configured to store the new current radiotherapy plan in the computer data storage device by sending the new current radiotherapy plan to the delivery control module.

16. The system according to any one of the preceding claims, wherein, The new current radiotherapy plan is a plan update, and the delivery control module is configured to modify the current radiotherapy plan based on the plan update during delivery.

17. The system according to any one of the preceding claims, wherein, The delivery control module is configured to determine timing and / or speed information for delivering the new current radiotherapy plan using the radiation delivery system.

18. The system according to any one of the preceding claims, wherein, The monitoring unit (MU) counts determined by the system are continuous between the current radiotherapy plan and the new current radiotherapy plan.

19. The system according to any one of the preceding claims, wherein, The new current radiotherapy plan includes an indication of the authorized monitoring unit (MU) count for the authorized delivery of the delivery control module.

20. A method for generating radiotherapy radiation, the method comprising: The current radiotherapy plan is stored in a computer data storage device. The current radiotherapy plan includes multiple control points, each control point defining the value of at least one radiation delivery variable. The delivery control module retrieves the current radiotherapy plan and controls the radiation delivery system based on the current radiotherapy plan to deliver radiation to the patient's target area. as well as During radiation delivery according to the current radiotherapy plan, via the planning adjustment module: Receive information about the target area; The current radiotherapy plan is adjusted based on the information to generate a new current treatment plan, wherein the adjustment includes modifying at least one radiation delivery variable at at least one control point of the current radiotherapy plan; as well as The new current radiotherapy plan is stored in the computer data storage device.

21. The method according to claim 20, wherein, The current radiotherapy plan includes a treatment target based on a prescribed dose, and adjusting the current radiotherapy plan includes modifying the at least one radiation delivery variable based on the treatment target.

22. The method according to claim 20 or 21, wherein, Adjusting the current radiotherapy plan also includes adding control points to the current radiotherapy plan and / or removing control points from the current radiotherapy plan.

23. The method according to any one of claims 20 to 22, wherein, The at least one radiation delivery variable represents one of the following: gantry angle, weight of a particular beam, or patient position parameter.

24. The method according to any one of claims 20 to 23, wherein, The method further includes: retrieving the new current radiotherapy plan at the delivery control module and controlling the radiation delivery system based on the new current radiotherapy plan to deliver radiation to the target area.

25. The method according to any one of claims 20 to 24, wherein, The method further includes: at the delivery control module, during the delivery of radiation according to the current radiotherapy plan, retrieving the new current radiotherapy plan, and controlling the radiation delivery system to change the delivery of radiation to the target area based on the new current radiotherapy plan.

26. The method according to any one of claims 20 to 25, wherein, The method further includes: at the planning adjustment module, during radiation delivery according to the new current radiotherapy plan, adjusting the new current radiotherapy plan based on further information about the target area to generate a further new radiotherapy plan, and storing the further new current radiotherapy plan in the computer data storage device.

27. The method according to any one of claims 20 to 26, wherein, Adjusting the current radiotherapy plan further includes modifying at least one radiation delivery variable within the range of the plurality of control points, and optionally also includes removing at least one control point subsequent to the range.

28. The method according to claim 27, wherein, The range of the plurality of control points corresponds to control points that have not yet been delivered in the current fraction of radiotherapy.

29. The method according to any one of claims 20 to 28, wherein, The adjustment is also based on the remaining dose delivered in the current fraction of radiotherapy.

30. The method according to any one of claims 20 to 29, wherein, The information about the target region includes imaging information acquired by an imaging system used to acquire images of the target region of the patient.

31. The method according to any one of claims 20 to 30, wherein, The information about the target area includes location information measured during radiation delivery, which is related to at least one of the following: patient location and radiation delivery system location.

32. The method according to any one of claims 20 to 31, wherein, The method further includes: at the planning adjustment module, determining the drift of the target region based on the information, and adjusting the current radiotherapy plan in response to the drift.

33. The method according to any one of claims 20 to 32, wherein, The delivery of radiation according to the current radiotherapy plan is the delivery of the current control point associated with the current radiotherapy plan; and Wherein, the at least one control point in the current radiotherapy plan is a future control point planned at a future time point compared to the current control point.

34. The method according to any one of claims 20 to 33, wherein storing the new current radiotherapy plan in the computer data storage device by the planning adjustment module includes sending the new current radiotherapy plan to the delivery control module.

35. The method according to any one of claims 20 to 34, wherein, The new current radiotherapy plan is a plan update, and the method further includes modifying the current radiotherapy plan based on the plan update during delivery via the delivery control module.

36. The method according to any one of claims 20 to 35, further comprising: The delivery control module determines the timing and / or speed information for delivering the new current radiotherapy plan using the radiation delivery system.

37. The method according to any one of claims 20 to 36, wherein, The monitoring unit (MU) counts determined by the system are continuous between the current radiotherapy plan and the new current radiotherapy plan.

38. The method according to any one of claims 20 to 37, wherein, The new current radiotherapy plan includes an indication of the authorized monitoring unit (MU) count for the authorized delivery of the delivery control module.

39. A computer-readable medium comprising instructions which, when executed by a processor, cause to perform the method of any one of claims 20 to 38.

40. A radiotherapy system, comprising: A radiation delivery system used to deliver radiation to a target area of ​​a patient; A computer data storage device configured to store the current radiotherapy plan; A delivery control module is configured to retrieve the current radiotherapy plan and, based on the current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area; and The planning adjustment module is configured to, during radiation delivery according to the current radiotherapy plan: Receive information about the target area; Generate a new current radiotherapy plan based on the current radiotherapy plan; as well as The new current radiotherapy plan is stored in the computer data storage device.

41. A radiotherapy system, comprising: A radiation delivery system used to deliver radiation to a target area of ​​a patient; A computer data storage device configured to store the current radiotherapy plan; The planning adjustment module is configured to: Generate a current radiotherapy plan, which includes multiple control points, each control point defining the value of at least one radiation delivery variable, and... The current radiotherapy plan is stored in the computer data storage device; and A delivery control module is configured to retrieve the current radiotherapy plan and, based on the current radiotherapy plan, control the radiation delivery system to deliver radiation to the target area.

42. A radiotherapy system, comprising: A radiation delivery system used to deliver radiation to a target area of ​​a patient; A delivery control module is configured to control the radiation delivery system to deliver radiation to the target area based on the current radiotherapy plan; and The planning adjustment module is configured to, during radiation delivery according to the current radiotherapy plan: Receive information about the target area; A plan update is generated based on the current radiotherapy plan and information about the target area, the plan update including information representing at least one delivery variable; as well as The plan update is transmitted to the delivery control module; The delivery control module is further configured to modify and / or replace the current radiotherapy plan based on the plan update to generate a new current radiotherapy plan, and to deliver radiation to the target area based on the new current radiotherapy plan.

43. The system according to claim 42, wherein, The plan update includes at least one of the following: at least one radiation delivery variable for at least one control point of the new current radiotherapy plan; the range of control points, wherein each control point specifies a corresponding monitoring unit value; Information representing the scaling of the monitoring unit; A sign indicating that delivery is complete; A sign indicating whether radiation is being delivered; and / or the value of the authorized monitoring unit quantity used for delivery.

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