Methods and apparatus for delivering therapeutic radiation to a patient

Abstract

These teachings facilitate utilizing a radiation treatment platform (114) with a moving radiation source (115) and using an optimized radiation treatment plan (113) during a radiation treatment session to support irradiating a treatment target (105) in a patient (104). These teachings specifically provide for configuring the radiation treatment platform (114) as a semi-fan trajectory arrangement. These teachings then provide for starting the radiation treatment session with the radiation source (115) at a first position and the isocenter (301) of the treatment target (105) at a first location. These teachings then provide for moving the radiation source (115) from the first position in synchronization with moving the isocenter (301) from the aforementioned first location during the radiation treatment session.

Description

Technical Field

[0001] These teachings generally involve using radiation to treat the planned target volume of a patient in accordance with a radiation treatment plan. Background Technology

[0002] The use of radiation to treat medical conditions encompasses known existing technological fields. For example, radiation therapy includes a crucial component of many treatment programs aimed at reducing or eliminating unwanted tumors. Unfortunately, the applied radiation itself cannot distinguish between unwanted substances and adjacent tissues, organs, etc., necessary or even vital for the patient's continued survival. Therefore, radiation is typically applied cautiously, at least attempting to confine the radiation to a given target volume. So-called radiation treatment programs generally function in this regard.

[0003] A radiation treatment plan typically involves specifying values ​​for each parameter among various treatment platform parameters during each of multiple consecutive fields. Treatment plans for the radiation treatment phase are usually generated through a process known as optimization. As used herein, "optimization" will be understood as improving candidate treatment plans without necessarily ensuring that the result of optimization is actually a single optimal solution. Such optimization typically involves (usually while observing one or more corresponding limits in these aspects) automatically adjusting one or more treatment parameters and mathematically calculating possible corresponding treatment outcomes to identify a given set of treatment parameters that represents a good trade-off between desired therapeutic outcomes and the avoidance of undesirable side effects.

[0004] Many radiation treatment platforms include one or more multi-leaf collimators. A multi-leaf collimator consists of multiple individual components (called "leaves") formed of a high atomic number material (such as tungsten) that can independently move into and out of the path of the radiation therapy beam to selectively block (and thus shape) the beam. Typically, the leaflets of a multi-leaf collimator are organized in pairs, which are collinearly aligned relative to each other and can selectively move toward and away from each other. A typical multi-leaf collimator has many such pairs of leaflets, often more than twenty, fifty, or even one hundred.

[0005] While multi-leaf collimators are effective in many situations, they can sometimes present corresponding problems. Multi-leaf collimators typically offer either thick blades (i.e., 0.5 to 1.0 cm thick) or only a limited field size. However, small treatment targets are often too small for thick blades to support high-quality treatment programs, while larger targets may be too large to be covered by the maximum aperture size available to the multi-leaf collimator. Summary of the Invention

[0006] In a first aspect, the present invention provides an apparatus as defined in claim 1.

[0007] In a second aspect, the present invention provides a method as defined in claim 11.

[0008] Optional features are defined in the dependent claims. Attached Figure Description

[0009] The aforementioned needs are met at least in part by providing methods and apparatus to facilitate the generation of an applicable therapeutic radiation treatment program as described in the following detailed description, particularly when studied in conjunction with the accompanying drawings, in which:

[0010] Figure 1 Including block diagrams configured according to various embodiments of these teachings;

[0011] Figure 2 Includes flowcharts configured according to various embodiments of these teachings;

[0012] Figure 3 Includes schematic diagrams configured according to various embodiments of these teachings;

[0013] Figure 4 Including schematic diagrams configured according to various embodiments of these teachings; and

[0014] Figure 5 This includes schematic diagrams configured according to various embodiments of these teachings.

[0015] The elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the size and / or relative position of some elements may be exaggerated relative to other elements to aid in understanding the various embodiments of this teaching. Furthermore, common but well-known elements that are useful or necessary in commercially viable embodiments are often not described to facilitate a less obstructed view of these different embodiments of this teaching. Certain actions and / or steps may be described or depicted in a particular order of occurrence, and those skilled in the art will understand that such specificity regarding the order is not actually necessary. The terms and expressions used herein have the ordinary technical meaning consistent with those of those skilled in the art, unless otherwise specifically indicated herein. Unless otherwise specifically indicated, the word “or” as used herein should be interpreted as having a disjunctive paradigm rather than a conjunctive paradigm. Detailed Implementation

[0016] Generally, these different embodiments facilitate the use of a radiation treatment platform with a mobile radiation source during the radiation treatment phase and the use of an optimized radiation treatment plan to support the irradiation of treatment targets within the patient's body. These teachings specify that the radiation treatment platform is configured in a semi-fan-shaped trajectory arrangement. These teachings then specify that the radiation treatment phase begins with an isocenter of the radiation source at a first location and the treatment target at a first location. Then, during the radiation treatment phase, these teachings specify that the radiation source is moved from the first location in synchronization with the movement of the isocenter from the aforementioned first location.

[0017] One method, these teachings specify moving the isocenter by moving a patient support bed that includes a portion of the radiation treatment platform. If necessary, the radiation source is moved via a gantry comprising a portion of the radiation treatment platform. Another method involves moving the radiation source along an arcuate gantry path, which may include, for example, an arc exceeding 180° about the patient's internal curvature. These teachings are highly flexible in these respects and will accommodate, for example, arcuate paths including, for example, an arc of at least 350° about the patient's internal curvature.

[0018] By means of a method, these teachings are further adapted to specify the aforementioned semi-sector trajectory arrangement for a radiation processing platform, and then to optimize the radiation processing schedule for radiation processing platform parameters other than the semi-sector trajectory arrangement, thereby providing the aforementioned optimized radiation processing schedule. In such a configuration, optimization of the radiation processing schedule may include not optimizing the predetermined semi-sector trajectory pattern. By means of a method, specifying the semi-sector trajectory arrangement includes specifying the predetermined trajectory pattern.

[0019] These teachings are flexible in practice and will be adapted to various modifications and / or supplementary activities. As an example of these aspects, moving a radiation source from a first location in sync with moving an isocenter from a first location may include simultaneously moving both the radiation source and the isocenter to at least a portion of the radiation processing phase.

[0020] With this configuration, targets that, in other schemes, are too large to be fully irradiated by a single field due to limitations in the aperture size of the multi-leaf collimator used (e.g.), can still be fully processed throughout the entire process. The aforementioned benefits can be achieved without increasing the complexity of the radiation treatment program optimization process by excluding trajectory path parameters from automatic variation and testing during the optimization process.

[0021] These and other benefits will become clearer after a thorough review and study of the following detailed description. Refer now to the accompanying drawings, especially... Figure 1 An illustrative device 100 will be presented that is compatible with many of the teachings in these teachings.

[0022] In this particular example, the enabling device 100 includes a control circuit 101. As a “circuit”, the control circuit 101 therefore includes a structure that includes at least one (and typically many) conductive paths (such as paths made of conductive metals such as copper or silver) that transmit electricity in an ordered manner. These paths typically also include corresponding electrical components (whichever is passive (such as resistors and capacitors) and active (such as any of a variety of semiconductor-based devices) to allow the circuit to implement the control aspects of these teachings.

[0023] Such control circuitry 101 may include a fixed-purpose hardwired hardware platform (including, but not limited to, application-specific integrated circuits (ASICs) (which are integrated circuits designed specifically for a particular purpose rather than for general purposes), field-programmable gate arrays (FPGAs), etc.), or may include partially or fully programmable hardware platforms (including, but not limited to, microcontrollers, microprocessors, etc.). These architectural options of such structures are well known and understood in the art and need not be further described herein. The control circuitry 101 is configured (e.g., by using corresponding programming that will be well understood by those skilled in the art) to perform one or more of the steps, actions, and / or functions described herein.

[0024] Control circuitry 101 is operatively coupled to memory 102. Memory 102 may be integrated into control circuitry 101 or may be physically separated from control circuitry 101 (wholly or partially) as needed. Memory 102 may also be local to control circuitry 101 (where, for example, both share a common circuit board, chassis, power supply, and / or housing), or may be partially or wholly remote to control circuitry 101 (where, for example, memory 102 is physically located in another facility, metropolitan area, or even country compared to control circuitry 101).

[0025] In addition to optimizing target information, patient geometry, field geometry, and semi-sector trajectory parameters, the memory 102 can also be used, for example, to non-transitory store computer instructions that, when executed by the control circuit 101, cause the control circuit 101 to operate as described herein. (As used herein, this reference to "non-transitory" will be understood to mean the non-transitory state of the stored content (and thus excludes the case where the stored content constitutes only a signal or wave), rather than the volatility of the storage medium itself; therefore, the memory 102 includes both non-volatile memory (such as read-only memory (ROM)) and volatile memory (such as dynamic random access memory (DRAM)).

[0026] Alternatively, the control circuitry 101 may also be operatively coupled to the user interface 103. The user interface 103 may include any of a variety of user input mechanisms (such as, but not limited to, keyboards and keypads, cursor control devices, touch-sensitive displays, voice recognition interfaces, gesture recognition interfaces, etc.) and / or user output mechanisms (such as, but not limited to, visual displays, audio converters, printers, etc.) to facilitate receiving information and / or instructions from the user and / or providing information to the user.

[0027] If necessary, the control circuitry 101 can also be operatively coupled to a network interface (not shown). In this configuration, the control circuitry 101 can communicate with other components (both internal and external to the device 100) via the network interface. Network interfaces, including both wireless and non-wireless platforms, are well known in the art and require no further explanation here.

[0028] By means of a method, computed tomography apparatus 106 and / or other imaging apparatus 107 known in the art can acquire some or all of any desired patient-related imaging information.

[0029] In this illustrative example, control circuitry 101 is configured to ultimately output an optimized radiation processing plan 113. This radiation processing plan 113 typically includes specified values ​​for each parameter among various processing platform parameters during each of multiple consecutive fields. In this case, the radiation processing plan 113 is generated through an optimization process. Various automated optimization processes specifically configured to generate such radiation processing plans are known in the art. Since this teaching is not overly sensitive to any particular choice in these aspects, further elaboration of these aspects is not provided herein except where particularly relevant to the details of this specification.

[0030] In one method, control circuitry 101 is operatively coupled to a radiation treatment platform 114, which is configured to deliver therapeutic radiation 112 to a corresponding patient 104 according to an optimized radiation treatment plan 113. These teachings are generally applicable to any of a wide variety of radiation treatment platforms. In a typical application setup, radiation treatment platform 114 will include a radiation source 115 that can be selectively moved along an arcuate path via a gantry. The arcuate path may comprise a complete or near-complete circle, depending on the desired effect. In one method, control circuitry 101 controls the movement of radiation source 115 along the arcuate path and can accordingly control when radiation source 115 begins to move, stops moving, accelerates, decelerates, and / or the speed at which radiation source 115 travels along the arcuate path.

[0031] Radiation source 115 may include, for example, an X-ray source based on a radio frequency (RF) linear particle accelerator (linac-based), such as the Varian Linatron M9. A linac is a particle accelerator that greatly increases the kinetic energy of charged subatomic particles or ions by subjecting charged particles to a series of oscillating potentials along a linear beamline, which can be used to generate ionizing radiation (e.g., X-rays) 116 and high-energy electrons.

[0032] A typical radiation treatment platform 114 may also include one or more support devices 110 (such as treatment beds) for supporting the patient 104 during the treatment phase, one or more patient fixation devices 111, a gantry or other movable mechanism that allows selective movement of the radiation source 115, and / or one or more beamforming devices 117 (such as jaws, multi-leaf collimators, etc.) to provide selective beamforming and / or beam modulation as needed. In a typical application setting, it is assumed herein that the patient support device 110 can be selectively controlled by control circuitry 101 to move in any direction (i.e., any X, Y, or Z direction) during the radiation treatment phase. Since the foregoing elements and systems are well known in the art, detailed descriptions of these aspects are not provided herein except where relevant to the description.

[0033] For reference Figure 2 The process 200, which can be implemented in conjunction with the above application settings, will be described. Generally, the process 200 facilitates the irradiation of the treatment target (105) in the patient (104) using a radiation treatment platform (114) with a mobile radiation source (115) and an optimized radiation treatment plan (113) during the radiation treatment phase.

[0034] In option 201, the process 200 may specify a semi-sector trajectory arrangement for the radiation processing platform 114. This includes specifying a predetermined trajectory pattern.

[0035] The semi-fan trajectory arrangement is known and understood in the art, although it is more typical in imaging environments such as during cone-beam computed tomography (CBCT). In the latter case, a small image planner, insufficient in size to capture enough data for a large CBCT volume using the so-called semi-fan approach, is used, where the panel is asymmetrically positioned around the centerline of the KV source. In a typical arrangement, only half of the target region is captured as a 2D image, but once the gantry has moved a full circle, all directions are covered, and a complete image of the target region is obtained.

[0036] Those skilled in the art will understand that the term "half-fan" is a useful naming convention and is not intended to be literally accurate. That is, any given exposure field is not necessarily exactly half of the target area. Rather, it is understood that most fields, and often each field, expose only a portion of the complete target area.

[0037] In optional box 202, the process 200 can then specify radiation processing platform parameters other than the half-sector trajectory arrangement to optimize the radiation processing plan, thereby providing an optimized radiation processing plan 113. In this configuration, the parameters specifying and controlling the aforementioned half-sector trajectory arrangement (e.g., parameters corresponding to a predetermined radiation source trajectory pattern) are static and do not change during the optimization process, which tests variations of the half-sector trajectory arrangement. Other examples of these aspects include, but are not limited to, jaw configuration, collimator angle, multi-leaf collimator support position, beam energy, and, at least in appropriate application settings, the maximum utilized dose rate. These teachings will also adapt to certain sectors that are predefined as not delivering radiation (e.g., between the start and end angles of the corresponding arc).

[0038] In block 203, the process 200 specifies that the radiation processing platform 114 is configured in a semi-sector trajectory arrangement. This may include, for example, configuring the radiation processing platform 114 in accordance with the semi-sector trajectory arrangement specified in block 201 above.

[0039] In box 204, the process 200 then begins the radiation processing phase with the isocenter of the first-positioned radiation source 115 and the processing target 105 at the first location. Those skilled in the art will understand that the isocenter is the spatial point through which the central beam of radiation 112 passes. More precisely, the isocenter is a spatial point relative to the processing machine around which the various components of the system rotate. In a typical application setting, the bench-based rotation of radiation source 115 defines a first axis that cuts through a second axis defined by rotation around patient support device 110. In a typical application setting, beamforming device 117 will also rotate about an axis pointing towards the isocenter. These teachings will also be adapted to robotic patient support systems where the robot's arm does not have a defined axis of rotation passing through the isocenter, but the robot is able (through coordinated movement of its joints) to move the patient to achieve effective rotation about an axis passing through the isocenter. Another way to define the isocenter for many current machines would be to utilize a common point in the beam centerline from various bench angles.

[0040] In a typical prior art application setup, the radiation source would begin at a first location and then move along an arcuate path around the patient 104. More specifically, the isocenter, typically located within the treatment volume 105, would not move during the treatment phase. However, according to the present process 200, during the radiation treatment phase 115, the radiation source would move from the first location in sync with the movement of the isocenter from the first position. While the movement of the radiation source 115 typically involves moving the latter via a platform that includes a portion of the radiation treatment platform 114, the movement of the isocenter could be achieved by moving the patient support device 110 (e.g., by moving a patient support bed that includes a portion of the radiation treatment platform).

[0041] To support the semi-fan-shaped trajectory arrangement, the movement of the radiation source 115 may include moving the radiation source 115 along an arc-shaped path that is more than, for example, 180° with respect to the patient's inner curvature, up to and including an arc of at least 350° with respect to the patient's inner curvature.

[0042] The synchronous movement of the isocenter, together with the movement of the radiation source 115, may include the simultaneous movement of both the radiation source 115 and the isocenter for at least a portion of the radiation treatment phase and possibly the entire radiation treatment phase. This teaching will also adapt to synchronous movement between these two factors that does not include the simultaneous movement of both the radiation source 115 and the isocenter.

[0043] In this configuration, these teachings allow for modulation of intensity (fluence) within a relatively large treatment volume 105, despite the limited spatial angle of the radiation treatment platform 114. Although only a portion of the treatment volume 105 is irradiated from most or all angles, beams from opposite treatment directions are generally used to satisfactorily treat the entire treatment volume 105. These teachings support satisfactory dosing using a multi-leaf collimator, for example, by utilizing directional treatment bed movement, thereby supporting treatment volumes that are particularly wide in the X / Y directions, whereas in other configurations, the multi-leaf collimator can only adjust a radiation cone that is limited in size compared to the treatment volume 105.

[0044] Those skilled in the art will understand that these teachings do not require sophisticated trajectory optimization. Rather, the latter can be defined simply using geometric tools. It should also be understood that these teachings can be configured to suture doses delivered from opposite directions to reduce the impact of intra-fractional patient movement.

[0045] Some specific examples of the above aspects will now be presented. It should be understood that the specific details of these examples are intended for illustrative purposes and are not intended to impose any particular limitations on these teachings.

[0046] Figure 3The use of a semi-fan-shaped arc corresponding to the radiation cones is schematically depicted, wherein two illustrative opposing radiation cones, indicated by reference numerals 302 and 303, combine to completely irradiate the target structure constituting the treatment volume 105 of the patient 104. The figure also shows the synchronous movement of the isocenter 301, which, in conjunction with the movement of the radiation source 115 around the gantry path 304, allows the radiation cones, which in other schemes would be too small to cover the entire treatment volume 105, to effectively still completely cover the structure. As described above, the movement of the isocenter 301 occurs by means of controlled and selective movement of the patient 104, which is achieved by corresponding controlled and selective movement of the patient support device 110 via, for example, control circuitry 101. It should be understood that selective movement can occur in any useful direction, and specifically in any direction in the X, Y, or Z directions (assuming a Cartesian reference point).

[0047] Figure 4 The use of semi-fan-shaped arcs corresponding to the radiating cones is schematically depicted, wherein the first pair of illustrative relative radiating cones combined to completely irradiate the target structure constituting the treatment volume 105 of the patient 104 is indicated by reference numerals 302 and 303, and the second pair of illustrative relative radiating cones is indicated by reference numerals 401 and 402. In this example, the treatment volume 105 has an elongated shape. In this case, the synchronous movement of the isocenter 301 follows an elliptical path to best adapt to the shape of the treatment volume 105.

[0048] Figure 5 A double-semi-sector solution employing two gantry paths is schematically depicted, with particular emphasis on the use of semi-sectoral arcs corresponding to the radiation cones. A first pair of illustrative opposing radiation cones, corresponding to the first gantry path 304 and combined to fully irradiate the target structure constituting the treatment volume 105 of the patient 104, are indicated by reference numerals 302 and 303. A second pair of illustrative opposing radiation cones, corresponding to the second gantry path 503 (where the radiation source 115 moves backward along its previously forward-moving gantry path), and combined to again fully irradiate the target structure constituting the treatment volume 105, are indicated by reference numerals 501 and 502.

[0049] Those skilled in the art will recognize that various modifications, alterations, and combinations can be made to the above embodiments without departing from the scope of the invention. As one example of these aspects, these teachings would adapt the use of automated tools to convert user-defined, normal, isocentric arcs into necessary semi-sector arcs. As another example, these teachings would allow a user to request the desired width of the overlapping area between corresponding semi-sectors. As yet another example of these aspects, these teachings would include a transformation of the solution to include the use of semi-sector arcs as part of the collimator angle optimization process. Therefore, such modifications, alterations, and combinations are considered to be within the scope of the inventive concept.

Claims

1. An apparatus for irradiating a treatment target within a patient during a radiation treatment phase, the apparatus comprising: A radiation processing platform with a mobile radiation source configured in a semi-fan-shaped trajectory arrangement; The control circuitry is configured to apply radiation to the target in accordance with an optimized radiation treatment plan in the following manner: The radiation treatment phase begins at the isocenter of the radiation source at the first location and the treatment target at the first location within the treatment target; as well as During the radiation treatment phase, the radiation source is moved from the first location in sync with the movement of the isocenter from the first position within the treatment target.

2. The apparatus of claim 1, wherein the radiation treatment platform includes a patient support bed, and wherein the control circuitry is configured to move the isocenter by moving the patient support bed.

3. The apparatus of claim 1 or 2, wherein the control circuitry is configured to move the radiation source by moving the radiation source via a bench, the bench comprising a portion of the radiation processing platform.

4. The apparatus of claim 1 or 2, wherein the radiation processing platform is configured to move the radiation source along an arc-shaped path.

5. The device of claim 4, wherein the arcuate path comprises an arc of more than 180 degrees about the patient's inner curvature.

6. The device of claim 5, wherein the arcuate path comprises an arc of at least 350 degrees about the patient's internal curvature.

7. The apparatus according to claim 1 or 2, wherein the control circuit is further configured to: Specify the semi-sector trajectory arrangement for the radiation processing platform; For the radiation processing platform parameters other than the semi-sector trajectory arrangement, optimize the radiation processing plan for the radiation processing platform to provide the optimized radiation processing plan.

8. The apparatus of claim 7, wherein specifying the semi-sectoral trajectory arrangement includes specifying a predetermined trajectory pattern.

9. The apparatus of claim 8, wherein the control circuitry is configured to optimize the radiation processing schedule for radiation processing platform parameters other than the semi-sectoral trajectory arrangement by not optimizing the predetermined trajectory pattern.

10. The apparatus of claim 1 or 2, wherein the control circuitry is configured to move the radiation source from the first position in synchronization with moving the isocenter from the first position by simultaneously moving both the radiation source and the isocenter to at least a portion of the radiation processing phase.

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