System and method for radiation dose planning for cardiac radiation therapy

Abstract

A system and method (400) for simulating radiation effects for cardiac ablation may include a processor that generates (402) a cardiac simulation model configured to simulate electrical activity of a patient's heart. The processor may determine (404) a simulated post-radiation state of the patient's heart by adjusting the heart simulation model to account for the effects of the radiation treatment plan on the simulated electrical activity of the patient's heart. The processor may simulate a simulated post-radiation state of the heart with the stimulus using the adjusted heart simulation model to evoke a cardiac rhythm disorder (406), determine (408) whether the cardiac rhythm disorder is evoked based on electrical activity generated when simulating the simulated post-radiation state of the heart with the stimulus, and output (410) an indication of whether the cardiac rhythm disorder is evoked. If the cardiac rhythm disorder is induced, the processor may suggest to modify the radiation plan.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 17 / 855,257, filed on June 30, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application generally relates to systems and methods for planning cardiac radiation therapy. In particular, the present application relates to systems and methods for simulating the effects of radiation on the electrical or electrophysiological properties of the heart and optimizing or adjusting the radiation dose distribution based on the simulation results to reduce or eliminate the recurrence of one or more cardiac pathological conditions. The simulation involves simulating one or more pathological conditions and checking for potential recurrence. Background Art

[0004] Cardiac ablation is generally an invasive medical procedure used to treat a variety of heart diseases, such as atrial fibrillation (AFib), atrial flutter, atrial tachycardia, ventricular tachycardia (VT), atrioventricular nodal reentrant tachycardia (AVNRT), paroxysmal supraventricular tachycardia (PSVT), Wolff-Parkinson-White syndrome or cardiac tumors. Standard radioactive heart surgery requires a doctor to insert a catheter into the patient's body to access the patient's heart. Heat or extreme cold is then applied to destroy abnormal areas of the heart and disintegrate abnormal electrical signals passing through the heart. The operation can be risky for at least some types of patients, and patients are usually monitored in an intensive care unit after surgery. Some risks associated with standard radiofrequency ablation include bleeding or infection at the catheter insertion site, blood vessel damage, heart valve damage, new or worsening arrhythmias, slow heart rate, blood clots, stroke or heart attack, pulmonary vein stenosis, kidney damage from contrast agents used during the procedure, and / or death in rare cases.

[0005] Cardiac radiotherapy ablation (also called cardiac radioablation) is a non-invasive form of cardiac ablation. Instead of a catheter, a dose of radiation is used to target abnormal areas of the heart to destroy or alter them. The use of radiation can mitigate some of the risks associated with invasive procedures and provide relief for high-risk heart disease patients who may have run out of other options. However, cardiac radioablation has its own risks and challenges. Among these are the risk of damaging surrounding healthy tissue, particularly in the heart area. This risk requires accurate radiation in terms of the radiation area(s) and the radiation dose(s).

[0006] Prior to a radiotherapy ablation procedure, radiotherapy treatment planning is performed. The purpose of treatment planning is to optimize the radiation angles and / or radiation doses at various angles to ensure that a high radiation dose is delivered to the target area and a low radiation dose is applied to intervening tissues. Summary of the invention

[0007] According to a first aspect of the present invention, there is provided a method of simulating the effects of radiation for cardiac ablation, as defined in claim 1 .

[0008] According to a second aspect of the present invention, there is provided a system for simulating the effects of radiation for cardiac ablation, as defined in claim 11 .

[0009] Optional features are defined in the dependent claims.

[0010] Embodiments described herein relate to optimizing or improving the radiation dose distribution for radiation cardiac ablation to reduce or eliminate the recurrence of arrhythmias associated with cardiac pathological conditions. A computer system can generate a patient-specific cardiac simulation model that can mimic or reproduce the electrical activity of the patient's heart. In the cardiac simulation model, a set of parameters can be used to model electrical activity or activation signals. The computer system can determine the effect of a radiation distribution (or radiation treatment plan) on a parameter set and adjust the parameter set accordingly, wherein the parameter set models the electrical activity or signal generated by the cardiac simulation model. The adjusted cardiac simulation model represents or corresponds to the post-radiation state of the heart to reproduce the electrical activity of the patient's heart. The computer system can virtually stimulate arrhythmias associated with cardiac pathological conditions in the adjusted cardiac simulation model, and check whether the stimulation causes the recurrence of the arrhythmia. If the recurrence of arrhythmia is detected, the computer system can adjust the radiation distribution (or radiation treatment plan), for example, by changing the radiation dose value and / or changing the target area. The computer system can iteratively adjust the radiation distribution and / or parameters of the cardiac simulation model, and / or check for recurrence of the arrhythmia until the arrhythmia no longer recurs or is undetectable. When the pathological condition no longer recurs or is undetectable, the corresponding radiation distribution can be used to further plan the radiation treatment plan.

[0011] According to one aspect, a method for simulating the effects of radiation for cardiac ablation may include one or more processors generating a cardiac simulation model of a patient's heart based on medical images and / or electrophysiological data of the patient. The cardiac simulation model may be configured to simulate the electrical activity of the patient's heart. The method may include one or more processors determining a simulated post-radiation state of the patient's heart by adjusting the cardiac simulation model to take into account the effects of a radiation treatment plan on the simulated electrical activity of the patient's heart. The radiation treatment plan specifies radiation doses to be applied to different areas of the patient's heart. The method may include one or more processors using the adjusted cardiac simulation model to simulate a simulated post-radiation state of a heart with stimulation for inducing a cardiac arrhythmia, determining whether a cardiac arrhythmia is induced based on the electrical activity generated when simulating the simulated post-radiation state of the heart with stimulation, and / or outputting an indication of whether a cardiac arrhythmia is induced in the simulated post-radiation state of the heart.

[0012] In some implementations, the cardiac rhythm disorder is associated with at least one of ventricular tachycardia (VT), atrial tachycardia, ventricular fibrillation, or atrial fibrillation. In some implementations, electrical activity is defined in the cardiac simulation model using multiple parameters of multiple electrical activation signals. Each electrical activation signal can be associated with a corresponding region of the patient's heart. Adjusting the cardiac simulation model can include adjusting the parameters of the electrical activation signals associated with the region of the patient's heart expected to receive radiation under the radiation treatment plan. Each electrical activation signal can have multiple phases, and each phase can be defined by one or more corresponding parameters. Adjusting the parameters of the electrical activation signals can include determining changes in the parameters of each phase of the electrical activation signal due to the effect of the corresponding radiation dose on the region of the patient's heart expected to receive radiation, and modifying the parameters of each phase of the electrical activation signal based on the determined changes.

[0013] In some implementations, electrical activity is defined in the heart simulation model using one or more parameters of conduction velocity. Adjusting the heart simulation model may include adjusting at least one of the one or more parameters of conduction velocity. In some implementations, determining a simulated post-radiation state of the heart may include identifying tissue of the patient's heart that is expected to become electrically inert in response to the radiation treatment plan.

[0014] In some implementations, simulating a simulated post-radiation state of a heart with stimulation for inducing a cardiac rhythm disorder can include simulating a virtual catheter-based stimulation in the post-radiation state of the heart.

[0015] In some implementations, the method may also include proposing one or more modifications to the radiation treatment plan after determining that the cardiac rhythm disorder is induced. The one or more modifications to the radiation treatment plan may include at least one of: modifying a radiation dose to a first region of the heart specified in the radiation treatment plan, or modifying a second region of the heart that is expected to receive radiation under the radiation treatment plan.

[0016] According to another aspect, a system for simulating the effects of radiation for cardiac ablation may include one or more processors and a memory for storing computer code instructions. The computer code instructions, when executed, cause the one or more processors to generate a cardiac simulation model of the patient's heart based on the patient's medical images and / or electrophysiological data. The cardiac simulation model may be configured to simulate the electrical activity of the patient's heart. The one or more processors may determine a simulated post-radiation state of the heart by adjusting the cardiac simulation model to take into account the effects of the radiation treatment plan on the simulated electrical activity of the patient's heart. The radiation treatment plan specifies the radiation dose to be applied to different areas of the patient's heart. The one or more processors may use the adjusted cardiac simulation model to simulate a simulated post-radiation state of a heart with stimulation for inducing arrhythmia, determine whether arrhythmia is induced in the simulated post-radiation state of the patient's heart, and / or output an indication of whether arrhythmia is induced in the simulated post-radiation state of the patient's heart.

[0017] In some implementations, the cardiac rhythm disorder can be associated with at least one of ventricular tachycardia (VT), atrial tachycardia, ventricular fibrillation, or atrial fibrillation. In some implementations, electrical activity can be defined in the cardiac simulation model using multiple parameters of multiple electrical activation signals. Each electrical activation signal can be associated with a corresponding region of the patient's heart. When adjusting the cardiac simulation model, one or more processors can adjust the parameters of the electrical activation signal associated with the region of the patient's heart expected to receive radiation under the radiation treatment plan. Each electrical activation signal can have multiple stages, and each stage can be defined by one or more corresponding parameters. When adjusting the parameters of the electrical activation signal, the one or more processors can determine the changes in the parameters of each stage of the electrical activation signal due to the effect of the corresponding radiation dose on the region of the patient's heart expected to receive radiation, and modify the parameters of each stage of the electrical activation signal based on the determined changes.

[0018] In some implementations, electrical activity can be defined in the cardiac simulation model using one or more parameters of conduction velocity. When adjusting the cardiac simulation model, the one or more processors can adjust at least one of the one or more parameters of conduction velocity. In some implementations, when determining a simulated post-radiation state of the heart, the one or more processors can identify cardiac tissue of the patient that is expected to become electrically inert in response to the radiation treatment plan.

[0019] In some implementations, when simulating a simulated post-radiation state of a heart with stimulation for inducing a cardiac rhythm disorder, the one or more processors may simulate virtual catheter-based stimulation in the post-radiation state of the heart.

[0020] In some implementations, after determining that a cardiac arrhythmia is induced, the one or more processors may also propose one or more modifications to the radiation treatment plan. The one or more modifications to the radiation treatment plan may include at least one of: modifying a radiation dose to a first region of the heart specified in the radiation treatment plan, or modifying a second region of the heart that is expected to receive radiation under the radiation treatment plan.

[0021] According to yet another aspect, a computer-readable medium may include computer code instructions stored thereon. The computer code instructions, when executed, may cause one or more processors to generate a cardiac simulation model of a patient's heart based on medical images and / or electrophysiological data of the patient. The cardiac simulation model may be configured to simulate the electrical activity of the patient's heart. The one or more processors may determine a simulated post-radiation state of the heart by adjusting the cardiac simulation model to take into account the effects of a radiation treatment plan on the simulated electrical activity of the patient's heart. The radiation treatment plan specifies radiation doses to be applied to different areas of the patient's heart. The one or more processors may use the adjusted cardiac simulation model to simulate a simulated post-radiation state of a heart with stimulation for inducing arrhythmia, determine whether arrhythmia is induced in the simulated post-radiation state of the patient's heart, and / or output an indication of whether arrhythmia is induced in the simulated post-radiation state of the patient's heart. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A block diagram of a computer environment for implementing the methods and processes described herein is shown according to one embodiment.

[0023] Figure 2 is a block diagram illustrating one implementation of a system architecture according to one embodiment.

[0024] Figure 3 is a block diagram of a system for simulating radiation effects on electrical properties of the heart, according to one embodiment.

[0025] Figure 4 is a flow chart illustrating a method of simulating the effects of radiation on the electrical or electrophysiological properties of the heart according to one embodiment.

[0026] Some or all of the drawings are schematic diagrams for illustrative purposes. The foregoing information and the following detailed description include illustrative examples of various aspects and implementations, and provide an overview or framework for understanding the nature and character of the claimed aspects and implementations. The accompanying drawings provide illustration and further understanding of the various aspects and implementations, and are incorporated into and constitute a part of this specification. DETAILED DESCRIPTION

[0027] The following is a more detailed description of various concepts and implementations thereof related to methods, devices, and systems for predicting the location of a cardiac region for planning cardiac radiotherapy ablation. The various concepts introduced above and discussed in more detail below can be implemented in a variety of ways, as the described concepts are not limited to any particular way of implementation. Examples of specific implementations and applications are primarily for illustrative purposes.

[0028] Compared to catheter-based ablation, cardiac radiotherapy ablation promises to be a safer and more effective ablation strategy, primarily due to its noninvasive nature and potential ability to target full layers of the myocardium. However, various challenges remain to be overcome to make this promise a reality. These challenges are primarily due to the stringent requirements for radiation accuracy. The heart consists of multiple structures at risk, including the coronary arteries and valves. These structures should be spared from radiation (or treated with relatively low levels of radiation) to avoid permanent and severe damage to the heart. At the same time, treatment aims to deliver a high enough radiation dose to abnormal areas of the heart to destroy or at least alter the characteristics (e.g., electrophysiological properties) of these areas. This trade-off makes radiotherapy in general, and even more so for the heart, a complex undertaking.

[0029] One of the technical challenges associated with cardiac radiation therapy is planning and evaluating the efficacy of a radiation plan or corresponding radiation dose distribution. In other words, given a radiation dose distribution, how can we evaluate its effect on the patient's heart and determine whether it is sufficient to heal the patient's heart. To evaluate the efficacy of radiation, doctors typically try to induce VT in the patient's heart using catheter stimulation after the radiation treatment is completed. However, this method is invasive and cannot be used for radiation dose planning because the stimulation is performed after the radiation treatment.

[0030] In the present disclosure, systems and methods for simulating the effects of radiation on a patient's heart are described. A cardiac simulation model configured to reproduce cardiac electrical activity is used. The effects of radiation are modeled as changes or adjustments to parameters of the cardiac simulation model. Digital catheter stimulation can be applied to the adjusted cardiac simulation model to determine whether a cardiac rhythm disorder can be induced. If a cardiac rhythm disorder is successfully induced, the radiation dose distribution can be adjusted to obtain a better therapeutic effect.

[0031] Figure 1An example computer environment 100 for planning cardiac radiation therapy according to an example embodiment is illustrated. In brief overview, the computer environment 100 may include a cardiac radiation therapy planning system 102, a radiation effect simulation system 104, a database 106, and a communication network 108. The cardiac radiation therapy planning system 102 may include an imaging device 110, an electrophysiology system 114, and one or more computing devices 112. The radiation effect simulation system 104 may include one or more computing devices (such as computing devices 116a and 116b), referred to herein individually or collectively as (multiple) computing devices 116. The (multiple) computing devices 116 are configured to simulate the effects of radiation on the heart or cardiac electrical activity. The cardiac radiation therapy planning system 102, the radiation effect simulation system 104, and the database 106 may be communicatively coupled via the communication network 108.

[0032] The communication network 108 may include a local area network (LAN), a wireless local area network (WLAN), a metropolitan area network (MAN), a wide area network (WAN), the Internet, a cellular network, other types of networks, or combinations thereof. The network 108 may include wired and wireless communications according to one or more standards and / or based on one or more transmission media. Communications on the network 108 may be performed according to various communication protocols, such as the Transmission Control Protocol and Internet Protocol (TCP / IP), the User Datagram Protocol (UDP), and the IEEE communication protocol.

[0033] The cardiac radiotherapy planning system 102 may include one or more imaging devices 110, an electrophysiology system 114, and one or more computing devices 112. The imaging device 110 may include a computed tomography (CT) scanner, a magnetic resonance (MR) scanner, a positron emission tomography (PET) scanner, or a combination thereof, etc. The imaging device 110 may acquire medical images of the patient's heart during at least a portion of the cardiac cycle. In some implementations, the imaging device 110 may acquire an image sequence depicting cardiac motion or deformation during the cardiac cycle or a portion thereof. The acquired medical images may include CT images, computed tomography angiography (CTA) images, MR images, PET images, other types of medical images, or a combination thereof.

[0034] The electrophysiology system 114 is configured to perform electrophysiology studies on the patient, for example, to evaluate the electrical system of the heart and diagnose abnormal heartbeats or arrhythmias. The electrophysiology system 114 may include one or more catheters, a plurality of wire electrodes, and a computing device connected to the wire electrodes to record electrical signals. The doctor inserts the catheter into a vein in the patient's groin, and then inserts the wire electrodes into the patient's heart via the catheter and the vein. In some implementations, the electrophysiology system 114 may include a plurality of electrocardiogram (ECG) electrodes, which are placed on the surface of the patient's body (e.g., chest) via a multi-electrode vest. The natural electrical impulses of the heart can be transmitted by the wire electrodes and recorded by the computing device of the electrophysiology system 114. The computing device of the electrophysiology system 114 can send electrical signals through the electrodes to stimulate the heart tissue, thereby trying to cause an abnormal heart rhythm.

[0035] The computing device 112 may receive medical images from the imaging device 110 and electrophysiology study data from the electrophysiology system 114. The computing device 112 may also obtain other medical data of the patient, such as ECG data, blood pressure data, and / or other patient data. The computing device 112 may be configured to run or perform radiation simulations as part of radiation therapy planning. A radiation therapy planner may use the computer device 112 to simulate one or more sets of radiation therapy parameters to determine which set of parameters may result in a desired radiation dose distribution. The computer device 112 may also send the acquired patient data (such as medical images and / or electrophysiology study data) to the database 106.

[0036] The radiation effects simulation system 104 (or corresponding (multiple) computing devices 116) can be configured to use the acquired patient medical images and / or electrophysiology study data to generate a cardiac simulation model that is configured to mimic the patient's heart with respect to electrical activity. The effects of radiation on the patient's heart can be simulated as adjustments to the parameters of the cardiac simulation model. The adjusted cardiac simulation model can be simulated with digital catheter stimulation to induce arrhythmia. If the arrhythmia is successfully induced, the radiation dose distribution may not be effective in healing the heart. Testing for potential recurrence of arrhythmia is a predictor of spontaneous recurrence of arrhythmia in the heart of a patient after radiation treatment. Simulation of the effects of radiation and digital stimulation can help improve radiation treatment plans and their efficacy. The functional attributes of the radiation effects simulation system 104 (or corresponding (multiple) computing devices 116) will be discussed in detail below. Figure 3-Figure 4 for further discussion.

[0037] In some implementations, the computing device 116 may be configured to execute computer instructions to perform any of the methods described herein or operations thereof. The computing device(s) 116 may generate and display an electronic platform to display information indicating or related to the effects of radiation on the heart. The electronic platform may include a graphical user interface (GUI) for receiving input data and / or displaying an indication of whether a cardiac rhythm disorder was successfully induced. An example of an electronic platform generated and hosted by the computing device(s) 116 may be a web-based application or website that is configured to be displayed on different electronic devices, such as a mobile device, a tablet computer, a personal computer, and the like.

[0038] Although Figure 1 A network-based implementation is shown, but it is noted that the methods described herein can be implemented by a single computing device that receives medical images and / or electrophysiological data of a patient and predicts the effects of radiation on the patient's heart according to the methods described herein. The computer environment 100 is not necessarily limited to the components described herein and can include additional or alternative components (not shown for brevity) that should be considered within the scope of the embodiments described herein. For example, the computer environment 100 can include additional or alternative databases, such as within the cardiac radiotherapy planning system 102 or within the radiation effects simulation system 104. Furthermore, the number of computing devices within the cardiac radiotherapy planning system 102 or within the radiation effects simulation system 104 can vary according to various implementations.

[0039] See also Figure 2 , a block diagram depicting one implementation of a system architecture of a computing system 200 is shown according to an example embodiment, which computing system 200 may be employed to implement the methods described herein. The computing system 200 may include a computing device 202. The computing device 202 may represent Figure 1 1 and 116. The computing device 202 may include, but is not limited to, a computed tomography (CT) scanner, a medical linear accelerator device, a desktop, a laptop, a hardware computer server, a workstation, a personal digital assistant, a mobile computing device, a smart phone, a tablet computer, or other types of computing devices. The computing device 202 may include one or more processors 204 for executing computer code instructions, a memory 206, and a bus 208 that communicatively couples the processor 204 and the memory 206.

[0040] The one or more processors 204 may include a microprocessor, a general purpose processor, a multi-core processor, a digital signal processor (DSP) or a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other types of processors. The one or more processors 204 may be communicatively coupled to the bus 208 to process information. The memory 206 may include a main memory device 210, such as a random access memory (RAM) or other dynamic storage device, which is coupled to the bus 208 to store information and instructions executed by the processor 204. The main memory device 210 may be used to store temporary variables or other intermediate information during the execution of instructions by the processor 204 (e.g., instructions related to the methods described herein, such as method 400). The computing device 202 may include a read-only memory (ROM) 212 or other static storage device, which is coupled to the bus 208 to store static information and instructions for the processor 204. For example, the ROM 212 may store, for example, a medical image of a patient received as input. The ROM 212 may store computer code instructions related to the methods described herein or computer code instructions representing the implementation of the methods described herein. A storage device 214 , such as a solid-state device, magnetic disk, or optical disk, may be coupled to bus 208 for storing (or providing as input) information and / or instructions.

[0041] The computing device 202 may be communicatively coupled to the input device 216 and / or the output device 218, or may include the input device 216 and / or the output device 218. The computing device 202 may be coupled to the output device 218 via the bus 218. The output device 218 may include a display device, such as a liquid crystal display (LCD), a thin film transistor LCD (TFT), an organic light emitting diode (OLED) display, an LED display, an electronic paper display, a plasma display panel (PDP), or other display, etc., for displaying information to a user. The output device 218 may include a communication interface for communicating information to other external devices. An input device 216 (such as a keyboard including alphanumeric keys and other keys) may be coupled to the bus 208 for communicating information and command selections to the processor 204. In another implementation, the input device 216 may be integrated into a display device, such as integrated into a touch screen display. The input device 216 may include a cursor control, such as a mouse, a trackball, or cursor direction keys, for communicating direction information and command selections to the processor 204 and for controlling cursor movement on the display device.

[0042] According to various implementations, the methods described herein or corresponding operations may be implemented as an arrangement of computer code instructions executed by (multiple) processors 204 of a computing system 200. The arrangement of computer code instructions may be read into a main storage device 210 from another computer-readable medium (such as a ROM 212 or a storage device 214). Executing the arrangement of computer code instructions stored in the main storage device 210 may enable the computing system 200 to perform the methods described herein or their operations. In some implementations, one or more processors 204 in a multi-processor arrangement may be employed to execute computer code instructions representing the implementation of the methods or processes described herein. In some other implementations, hard-wired circuits may be used in place of software instructions or in combination with software instructions to implement illustrative implementations of the methods described herein or their operations. In general, implementations are not limited to any particular combination of hardware circuits and software. The functional operations described in this specification may be implemented in other types of digital electronic circuits, computer software, firmware, hardware, or a combination thereof.

[0043] See now Figure 3 , Figure 1 , is a block diagram of a radiation effect simulation system 104 according to one embodiment. The radiation effect simulation system 104 is a system for simulating the effects of radiation on a patient's heart, including effects on electrophysiological properties or electrical activity of the heart and / or pathological effects associated with potential recurrence of rhythm disturbances associated with pathological conditions. In brief overview, the radiation effect simulation system 104 may include a simulation model generator 302 for generating a cardiac simulation model, a radiation effect estimator 304, a rhythm disturbance simulator 306, a rhythm disturbance detector 308, and a radiation therapy plan update component 310.

[0044] The radiation effect simulation system 104 may include or may be connected to a database 106. The database 106 may include image data 312, electrophysiology data 314, and / or other patient data 316. The image data 312 may include CT images, CTA images, and / or other medical images of the patient. The electrophysiology data 314 may include electrophysiology research data of the patient, which depicts the electrical activity of the patient's heart in at least one cardiac cycle or a portion thereof. For example, the electrophysiology data 314 may include one or more electrical signals generated by the patient's heart and recorded by the electrophysiology system 114 via one or more electrodes. The electrophysiology system 114 may record (multiple) electrical signals according to an invasive or non-invasive procedure. Other patient data 316 may include blood pressure data, ECG data, medical history data, demographic data, or a combination thereof.

[0045] Each of components 302, 304, 306, 308, and / or 310 may be implemented as a software component, a hardware component, a firmware component, or a combination of software, firmware, and / or hardware. For example, any of these components may be implemented as computer code instructions that are executed by one or more processors (e.g., processor 204) to perform corresponding functional steps or processes. Any of components 302, 304, 306, 308, and / or 310 may be implemented as digital circuits. Figure 4 The functional steps or processes associated with each of these components are described in more detail.

[0046] Figure 4 A flow chart is shown illustrating an embodiment of a method 400 for planning cardiac radiation therapy to simulate the effects of radiation on electrical or electrophysiological properties of a heart according to an example embodiment. In brief overview, the method 400 may include generating a cardiac simulation model of a heart (step 402). For example, one or more processors may generate a cardiac simulation model of a patient's heart based on medical images and / or electrophysiological data of the patient, the cardiac simulation model being configured to simulate electrical activity of the patient's heart.

[0047] The method 400 may also include determining a simulated post-radiation state of the heart by adjusting the heart simulation model to account for the effects of the radiation treatment plan on the simulated electrical activity of the heart (step 404). For example, the one or more processors may determine a simulated post-radiation state of the patient's heart by adjusting the heart simulation model to account for the effects of the radiation treatment plan on the simulated electrical activity of the patient's heart, wherein the radiation treatment plan specifies radiation doses to be applied to different regions of the patient's heart.

[0048] Method 400 may include simulating a post-radiation state of a heart with stimulation for inducing a cardiac arrhythmia (step 406).For example, one or more processors may use the adjusted cardiac simulation model to simulate a post-radiation state of a heart with stimulation for inducing a cardiac arrhythmia.

[0049] Method 400 may include determining whether a cardiac rhythm disorder is induced (step 408).For example, one or more processors may determine whether a cardiac rhythm disorder is induced based on electrical activity generated while simulating a post-radiation state of a heart with stimulation.

[0050] Method 400 may include outputting an indication of whether a cardiac rhythm disorder was induced in the simulated post-radiation state of the heart (step 410).For example, one or more processors may output an indication of whether a cardiac rhythm disorder was induced in the simulated post-radiation state of the heart.

[0051] The method 400 may be implemented by the computing device(s) 116 or its processor(s), such as the processor 204 .

[0052] Go back and see Figure 1-Figure 4 , the method 400 may include the processor(s) 204 or the simulation model generator 302 generating a cardiac simulation model of the patient's heart using the patient's image data 312 and electrophysiology data 314 (step 402). Prior to a cardiac ablation procedure, the imaging device 110 may acquire the patient's image data 312. The image data 312 may include a cardiac gated CTA image, a CT image, an MR image, other types of medical images, or a combination thereof. In addition, the electrophysiology system 114 may record the patient's electrophysiology study data 314, which depicts the electrical activity of the patient's heart. The computing device 112 may store the image data 312 and the electrophysiology data 314 in the database 106.

[0053] A doctor or other medical professional may, for example, mark or delineate the ROI to be irradiated on one or more of the acquired medical images of the patient based on the image data 312 and the electrophysiology data 314. For example, the doctor may manually identify (e.g., on a display of the computing device 112) or mark the boundaries of the ROI to be irradiated. In some implementations, the computing device 112 may process the marked (multiple) images to refine the boundaries of the ROI, for example, using an image segmentation algorithm, an object identification algorithm, other image processing algorithms, or a combination thereof. The computing device 112 may use the refined (or initially marked) ROI boundaries to identify the ROI in other unmarked images of the patient. In some implementations, the doctor may mark the ROI on all acquired medical images.

[0054] In some implementations, the ROI may include or may be one or more segments of a standardized N-segment model, where N is an integer. For example, the standardized N-segment model may include a standardized AHA 17-segment heart model. The standardized N-segment model represents a standard geometric description or segmentation of the heart. The computing device 112 may identify the segments based on a parametric model of the heart chamber, for example, as described in “Four-Chamber Heart Modeling and Automatic Segmentation for 3-D Cardiac CT Volumes Using Marginal Space Learning and Steerable Features” (IEEE Transactions on Medical Imaging 27, No. 11 (November 2008) 1668-81), the contents of which are incorporated herein by reference. In some implementations, other standardized geometric models of the heart may be used. An operator of the computing device 112 may identify the ROI as one or more segments of the standardized N-segment model, for example, via a user interface displayed by the computing device 112.

[0055] The medical image acquired by the imaging device 110 may be a two-dimensional image. The processor 204 or the simulation model generator 302 may generate a patient-specific geometric model of the patient's heart using the medical image data 312. The patient-specific geometric model may include a three-dimensional (3D) model that depicts the anatomical characteristics of the patient's heart (e.g., shape, size, and / or various anatomical regions). For example, the processor 204 or the simulation model generator 302 may generate a 3D mesh of the patient's heart using the medical image of the patient. The processor 204 or the simulation model generator 302 may add one or more layers on top of the 3D mesh to reflect different regions or segments of the patient's heart.

[0056] In some implementations, the processor 204 or the simulation model generator 302 may register the electrophysiological data with the generated (multiple) 3D models of the patient's heart. In some implementations, the processor 204 or the simulation model generator 302 may combine the electrophysiological data with the generated (multiple) 3D models of the patient's heart, as described in U.S. Pat. No. 9,463,072, the contents of which are incorporated herein by reference. The electrical activity of the patient's heart varies spatially on the surface of the heart and through the myocardium. In general, the heart includes myocardial contractile cells and myocardial conduction cells. Myocardial conduction cells account for about one percent of the cells in the atria and ventricles, and they form the cardiac conduction system, which includes the sinoatrial node (SA) and the atrioventricular node (AV). Myocardial conduction cells generate electrical impulses and propagate them throughout the heart. Myocardial contractile cells account for about ninety-nine percent of the cells in the atria and ventricles. They also conduct electrical impulses and are primarily responsible for contraction, which pumps blood to the whole body in response to electrical impulses. In this way, the heart acts as an electromechanical system, in which electrical impulses are generated by the cardiac conduction system and propagated to myocardial contractile cells to trigger contraction.

[0057] The processor 204 or the simulation model generator 302 can generate a simulated electrical model that is configured or constructed to mimic or reproduce the electrical activity of the patient's heart. The simulated electrical model can be configured to generate a signal similar to the signal of the electrophysiological data 314. The simulated electrical model can be a network of connected nodes, each of which represents a block or a portion of the myocardium (or heart). Each node in the simulated electrical model can be associated with a corresponding activation signal and a corresponding conduction velocity. The corresponding activation signal can be a function that reaches a peak or spike relatively quickly and then slowly decays to zero over time. Each activation signal of the corresponding node can be defined by a corresponding set of parameters.

[0058] In some implementations, each electrical activation signal can have multiple phases, and each phase can be defined by one or more corresponding parameters. In other words, each phase of the activation signal can be described by a parameterized mathematical formula. For example, a first phase of the activation signal can be a steep ramp, which is described or defined by a first parameterized mathematical formula having one or more first parameters. A second phase of the activation signal can exhibit a slow decay and can be described or defined by a second parameterized mathematical formula having one or more second parameters.

[0059] The parameters of each activation signal or its phase can be related to the underlying biology of the corresponding block or portion of the myocardium. For example, the parameters of the activation signal can be set based on experimental data. Similarly, the conduction velocity parameters corresponding to various nodes or portions of the myocardium can be set based on experimental data. The results of experiments conducted on animal hearts and / or human hearts can be used to set the parameters of the simulated electrical model, including the parameters of the activation signal and / or the conduction velocity parameters.

[0060] The conduction velocity associated with each node is related to or depends on the activation signal of the node or corresponding heart block or part. In a healthy state, the steepness of the slope of the activation signal is the main determinant of the conduction velocity. The steeper the slope, the higher the conduction velocity. In other words, the speed at which the electrical signal propagates through the myocardium or through the node network depends on how steep the slope of the activation signal is. As an illustrative example, if the activation signal associated with the corresponding node reaches its peak value within 100 microseconds, and the threshold for activation of the adjacent node is about half of the peak amplitude, then the adjacent node will be activated within about 50 microseconds. However, if the activation signal reaches a peak value within 500 microseconds, then the adjacent node will be activated within about 250 microseconds. In the heart, the first cell is activated or triggered (e.g., exhibits a corresponding activation signal) by the activation signal of the adjacent cell. Therefore, the steeper the slope of the activation signal of the adjacent cell, the faster the first cell is activated, which is how the properties of a single cell affect the conduction velocity.

[0061] Furthermore, the decay phase of the activation signal depends on the slope or peak value of the same activation signal. The decay phase may follow a predefined pattern described by a parameterized mathematical formula, and the first value of the decay phase depends on the peak value of the activation signal. The higher the peak value, the higher the first value of the decay phase of the activation signal. Thus, the parameters of the mathematical formula of the decay phase vary as the peak value of the activation signal varies.

[0062] The processor 204 or the simulation model generator 302 can model the conduction velocity and activation signal based on the experimental data of healthy tissue and abnormal tissue. Specifically, the parameterized function can be predefined based on the experimental data of healthy tissue and abnormal tissue. In addition, the processor 204 or the simulation model generator 302 can use, for example, a lookup table or some other data structure to set the conduction velocity parameters and the parameterized function or parameter values ​​of the corresponding stage, wherein the data structure maintains parameter values ​​for various tissue conditions (e.g., healthy tissue, tissue exhibiting VT, tissue exhibiting AFib, tissue exhibiting atrial flutter, tissue exhibiting atrial tachycardia, tissue exhibiting AVNRT, tissue exhibiting PSVT, tissue associated with Wolff-Parkinson-White syndrome or tumor tissue, etc.). The processor 204 or the simulation model generator 302 can identify the nodes corresponding to the abnormal tissue based on the registration of the simulated electrical model with the 3D model of the patient's heart. Specifically, the processor 204 or the simulation model generator 302 can identify the nodes associated with the ROI and model its parameters accordingly. The processor 204 or the simulation model generator 302 can analyze the electrophysiology data 314 to extract the measurement of the electrical activity of the patient's heart. The measurement of electrical activity can include the total activation time of the left ventricle or the right ventricle, the measurement such as QRS duration, electrical axis, QT interval duration, point-by-point activation time and / or the voltage value measured by the catheter device as part of the electroanatomical mapping extracted from the ECG data. (Multiple) processors 204 or simulation model generators 302 can simulate the corresponding measurement of electrical activity and compare it with the measurement extracted from the electrophysiology data 314. (Multiple) processors 204 or simulation model generators 302 can modify the conduction velocity and activation signal to minimize the difference between the simulated and data-based electrical activity measurements. For example, an iterative algorithm (such as BOBYQA) can be used to estimate the optimal value of the conduction velocity in one area of ​​the heart. In short, multiple conduction velocity candidate values ​​can be selected, and for each selection, a corresponding simulated measurement of electrical activity can be generated. Based on which conduction velocity values ​​produce simulated measurements of electrical activity that are closest to the data-based measurements, new candidate values ​​can be generated. The algorithm can terminate when the difference between the simulated and data-based measurements of electrical activity falls below a certain threshold, or when a maximum number of candidate values ​​have been generated. Other methods of modifying conduction velocity and activation signals to minimize the difference between simulated and data-based measurements of electrical activity are disclosed in U.S. Pat. Nos. 10,733,910, 10,483,005, 10,241,968, and 10,141,077, the contents of which are incorporated herein by reference.

[0063] In theory, the nodes of the analog electrical model can represent different cells of the heart. However, implementing the analog electrical model at the cellular level would produce a very complex model. Modeling the cardiac electrical system at a coarse granularity (e.g., where each node corresponds to a separate myocardial block or section) results in a less complex model while still providing accurate modeling. Typically, adjacent healthy cells of the same type (e.g., myocardial contractile cells) have similar electrical properties.

[0064] The processor 204 or the simulation model generator 302 can register the simulated electrical model with the geometric (or 3D) model. Each node in the simulated electrical model is mapped to its position in the 3D model. The cardiac simulation model includes the 3D model and the registered simulated electrical model. In some implementations, the (multiple) processors 204 or the simulation model generator 302 can use other patient data 316 to generate a cardiac simulation model of the patient's heart. For example, the (multiple) processors 204 or the simulation model generator 302 can use the patient's age or the patient's medical history to estimate one or more model parameters.

[0065] The method 400 may include the processor 204 or the radiation effect estimator 304 determining a simulated post-radiation state of the patient's heart by adjusting the cardiac simulation model to take into account the effect of the radiation treatment plan on the simulated electrical activity of the patient's heart (step 404). The radiation treatment plan may include a radiation dose delivery distribution that specifies the radiation doses to be applied to different areas of the patient's heart. The radiation treatment plan may not be a complete plan at this stage. The radiation effect estimator 304 may receive the radiation treatment plan or the radiation dose delivery distribution from the cardiac radiotherapy planning system 102 or the computing device 112. In some implementations, the radiation dose delivery distribution may be the radiation dose prescribed by the patient's physician. The radiation effect estimator 304 assumes that radiation has been delivered according to the radiation dose delivery distribution and estimates the effect of the assumed delivered radiation on the electrical properties or electrical activity of the patient's heart.

[0066] The effects of radiation in the ROI or target volume can be simulated as changes in the electrophysiological properties of cardiac tissue. For example, radiation triggers upregulation of cardiac conduction proteins (such as NaVi.5 and Cx43), which can be modeled as an increase in conduction velocity. The radiation dose-dependent increase in conduction velocity in the ROI can be defined based on experimental results, for example, as in Zhang, David M., Rachita Navara, Tiankai Yin, Jeffrey Szymanski, Uri Goldsztejn, Camryn Kenkel, Adam Lang, et al., “Cardiac Radiotherapy Induces Electrical Conduction Reprogramming in the Absence of Transmural Fibrosis,” (Nature Communications 12, no. 1 (December 2021): 5558) Figure 3 , the contents of which are incorporated herein by reference. The article is hereinafter referred to as "Zhang". In addition, the radiation effect estimator 304 can model new fibrosis that may be generated under high levels of radiation as reduced conduction velocity or even zero conduction velocity.

[0067] The experimental results published by at least Zhang can indicate that radiation increases conduction velocity within viable myocardium. In addition, relatively high levels of radiation doses can cause cells to die and become electrically inactive. In other words, if the radiation dose applied to cardiac tissue exceeds a given threshold, the tissue dies and becomes electrically inert (e.g., unresponsive to electrical simulation, no electrical capture, and no electrical pulse propagation). The radiation dose threshold can be determined based on the experimental results. In general, the experimental results can include changes in conduction velocity measured for multiple delivered radiation doses.

[0068] The processor 204 or the radiation effect estimator 304 can interpolate the experimentally measured values. The processor 204 or the radiation effect estimator 304 can infer or identify a radiation dose threshold that causes fibrosis or dead tissue. The interpolated experimental results with the identified threshold can be maintained in one or more data structures, such as (multiple) lookup tables or (multiple) link tables. The (multiple) data structures can maintain a mapping between radiation dose levels (or values) and corresponding changes in conduction velocity (or corresponding conduction velocity). The (multiple) data structures can also maintain a mapping between radiation dose levels (or values) and corresponding changes in activation signal parameters (or corresponding activation signal parameters). The mapping can include corresponding changes in parameters for each stage of the activation signal parameters (or corresponding parameters for each stage of the activation signal). Changes in activation signal parameters (in terms of radiation dose levels) can be inferred from changes in conduction velocity, or can be defined based on experimental results measuring changes in activation signal parameters.

[0069] The processor 204 or the radiation effect estimator 304 can, for example, identify nodes of the simulated electrical model belonging to the ROI based on the registration of the simulated electrical model with the 3D model, and determine the radiation dose associated with the node or the corresponding block or portion of the heart based on the radiation dose distribution. The processor 204 or the radiation effect estimator 304 can determine the conduction velocity change and the activation signal parameter change for each node in the ROI based on the corresponding radiation dose and the (multiple) mappings maintained in one or more data structures. The processor 204 or the radiation effect estimator 304 can update the conduction velocity and the parameters of the activation signal for each node in the ROI. In the case where the activation signal is parameterized by stage, the processor 204 or the radiation effect estimator 304 can determine the change in the parameters for each stage of the activation signal and update the stage parameters accordingly.

[0070] Updating or adjusting the parameters of the conduction velocity and activation signal results in an updated or adjusted heart simulation model that reflects the effects of the "delivered" radiation on the electrical properties (or electrical activity) of the heart. In other words, the updated or adjusted heart simulation model represents a simulated post-radiation state of the patient's heart as if the radiation was delivered according to the radiation distribution (or radiation therapy treatment plan). The initial conduction velocity and initial activation signal represent a simulated pre-radiation state, while the adjusted conduction velocity and adjusted activation signal represent a simulated post-radiation state of the patient's heart.

[0071] The method 400 may include the processor 204 or the rhythm disorder simulator 306 to simulate a simulated post-radiation state of a patient's heart with stimulation for inducing a rhythm disorder (step 406). The rhythm disorder may be associated with at least one of ventricular tachycardia (VT), atrial tachycardia, ventricular fibrillation, atrial fibrillation, or other cardiac pathological conditions. The processor 204 or the rhythm disorder simulator 306 may apply one or more digital catheter-based stimulations to the post-radiation state of the heart. For example, in real life, a doctor would use a catheter to stimulate the heart with a rapid stimulation sequence to induce VT. If the radiation does not completely heal the heart, the heart will begin to contract chaotically, exhibiting induced VT. Induced VT is a strong predictor of spontaneous VT after radiation.

[0072] The processor 204 or the rhythm disorder simulator 306 can digitally simulate the presence of a catheter that delivers very rapid pacing to the heart simulation model. The digital simulation of the presence of the catheter can include applying a rapid pulse sequence to one or more nodes of the heart simulation model. The (multiple) nodes to which the rapid pulse sequence is applied can depend on the type of rhythm disorder to be induced. For example, for VT, the (multiple) stimulated nodes correspond to tissue of the left ventricle or the right ventricle. For atrial tachycardia, the (multiple) stimulated nodes correspond to tissue of one of the left atrium or the right atrium.

[0073] The method 400 may include the processor 204 or the rhythm disorder detector 308 determining whether a rhythm disorder is induced in the simulated post-radiation state of the heart (step 408). The processor 204 or the rhythm disorder detector 308 may determine whether a rhythm disorder is induced in the simulated post-radiation state of the heart based on the electrical activity generated when simulating the simulated post-radiation state of the heart with stimulation. The processor 204 or the rhythm disorder detector 308 may determine or calculate a simulated ECG signal of the heart simulation model, for example, as described in U.S. Patent No. 9,463,072, the contents of which are incorporated herein by reference. The processor 204 or the rhythm disorder detector 308 may analyze the simulated ECG signal to determine whether a rhythm disorder is induced in the simulated post-radiation state of the heart.

[0074] In some implementations, the processor 204 or the rhythm disorder detector 308 can determine the frequency, period, or autocorrelation signal of the simulated ECG signal. If the frequency, period, or autocorrelation signal does not indicate a normal periodic simulated ECG signal, the processor 204 or the rhythm disorder detector 308 can infer that a rhythm disorder is induced in the simulated post-radiation state of the heart. If a rhythm disorder is induced, this strongly indicates that the radiotherapy treatment plan is ineffective for healing the heart. In this case, the radiotherapy treatment plan should be adjusted, or the patient should undergo additional radiation treatment courses, for example, if the patient has already received radiation according to a simulated radiotherapy treatment plan, a new radiotherapy treatment plan is adopted.

[0075] The method 400 may include the processor 204 or the radiotherapy plan update component 310 outputting an indication of whether a cardiac arrhythmia is induced in the simulated post-radiation state of the heart. In some embodiments, the processor 204 or the radiotherapy plan update component 310 may cause the simulated ECG signal to be displayed on a display device such as the output device 218. The physician will recognize whether a cardiac arrhythmia is induced based on the simulated ECG signal. In some implementations, the processor 204 or the radiotherapy plan update component 310 may display a text or visual indicator indicating whether a cardiac arrhythmia is induced. The processor 204 or the radiotherapy plan update component 310 may output an audio signal indicating whether a cardiac arrhythmia is induced.

[0076] In some implementations, the processor 204 or the radiotherapy plan update component 310 can recommend or propose one or more modifications to the radiotherapy plan after determining that a cardiac arrhythmia is induced. The modification can include modifying the radiation dose for the ROI specified in the cardiac tissue or the radiotherapy plan or modifying (e.g., expanding) the ROI expected to receive radiation under the radiotherapy plan. For example, the processor 204 or the radiotherapy plan update component 310 can examine the electrical activity of various nodes of the heart simulation model when stimulated to induce a cardiac arrhythmia. The processor 204 or the radiotherapy plan update component 310 can identify abnormal tissue in the ROI in the post-irradiation state based on the electrical activity of the corresponding nodes. If the electrical activity of a node is abnormal, the processor 204 or the radiotherapy plan update component 310 can identify the node as abnormal and recommend increasing the radiation dose at the corresponding location or portion in the heart. The processor 204 or the radiotherapy plan update component 310 can examine the electrical activity at the nodes corresponding to the tissue surrounding the ROI. If it is determined that the electrical activity of a node or corresponding tissue is abnormal or chaotic, the processor 204 or the radiation therapy plan update component 310 can identify such tissue as abnormal or unhealthy and recommend expanding the ROI to include surrounding tissue.

[0077] Once the radiation treatment plan (or radiation dose distribution) is updated, steps 404 to 410 may be repeated with the updated radiation therapy treatment plan (or radiation dose distribution). In some implementations, the processor 204 may perform steps 404 to 410 for multiple radiation treatment plans and select the plan that maximizes the probability of acute termination of a cardiac arrhythmia (or a corresponding pathological condition) for application to the patient. The radiation plan that maximizes the probability of acute termination of ventricular tachycardia (VT) is selected for execution in the patient. In order to estimate the probability of acute termination of a cardiac arrhythmia (e.g., VT), one possible approach is to calculate the number of different programmed stimulation strategies that result in sustained or discontinued cardiac arrhythmias in a simulated post-radiation state. The processor 204 may identify the radiation treatment plan that results in the least number of stimulations that induce a cardiac arrhythmia as the plan that maximizes the probability of acute termination of a cardiac arrhythmia (or a corresponding pathological condition).

[0078] In some implementations, if it is determined that a cardiac arrhythmia will not be induced, the processor 204 or the radiation therapy plan update component 310 can shrink the ROI (or reduce the radiation dose). The processor 204 can perform steps 404 to 410 on the updated treatment plan and determine whether a cardiac arrhythmia is induced. The processor 204 can continue to shrink the ROI (or reduce the radiation dose) and repeat steps 404 to 410 until a cardiac arrhythmia begins to be induced. The processor 204 can select a treatment plan with a minimum ROI (or minimum radiation dose) that will not induce a cardiac arrhythmia. In some implementations, the radiation dose to at least some tissue in the ROI modifies the electrical properties of the tissue without damaging the tissue or rendering the tissue electrically inert.

[0079] In some implementations, method 400 can be used after or during radiation. In this case, if invasive ECG measurements are available, the estimated conduction velocity in step 404 is further optimized after each radiation dose delivery to match the ECG-based indicator. For example, the conduction velocity at each point of the heart can be scaled by a factor k to minimize the difference between the simulated ECG and the measured ECG. In some implementations, a first dose delivery session is performed, and then ECG measurements are taken and the post-radiation state of the heart is updated accordingly. The updated post-radiation state of the heart is used to optimize dose delivery in subsequent sessions.

[0080] It should be noted that the examples discussed in this specification are for illustrative purposes only and should not be construed as limiting. For example, other techniques may be used to estimate or adjust the effects of radiation on the electrical properties of the heart. In addition, other types of criteria may be used to determine whether a cardiac rhythm disorder is induced in a simulated cardiac post-radiation state.

[0081] Each method described in this disclosure, such as Figure 4The method 400 may be performed by computer code instructions stored on a computer readable medium. When the computer code instructions are executed by one or more processors of a computing device, the computing device may perform the method.

[0082] While the present disclosure has been particularly shown and described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention described in the present disclosure.

[0083] Although the present disclosure contains many specific embodiment details, these details should not be interpreted as limitations on the scope of any invention or the scope that may be claimed, but should be interpreted as descriptions of specific features of specific embodiments of specific inventions. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although the above-mentioned features may be described as acting in certain combinations, and even initially claimed as such, in some cases, one or more features in the claimed combination may be deleted from the combination, and the claimed combination may be a variant for a sub-combination or a sub-combination.

[0084] Similarly, although the operations are depicted in a particular order in the accompanying drawings, it should not be understood that it is required to perform these operations in the illustrated particular order or in sequence, or to perform all illustrated operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated in a single software product or packaged into multiple software products.

[0085] References to "or" may be construed as being inclusive, so that any term described using "or" may indicate any of a single, a plurality, and all of the stated terms.

[0086] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the particular order shown or sequential order to achieve the desired results. In some embodiments, multitasking and parallel processing may be advantageous.

Claims

1. A method for simulating the effects of radiation for cardiac ablation, the method comprising: generating, by one or more processors, a cardiac simulation model of a heart of the patient based on medical images and electrophysiological data of the patient, the cardiac simulation model being configured to simulate electrical activity of the heart of the patient; determining, by the one or more processors, a simulated post-radiation state of the heart of the patient by adjusting the cardiac simulation model to account for the effects of a radiation treatment plan on simulated electrical activity of the heart of the patient, the radiation treatment plan specifying radiation doses to be applied to different regions of the heart of the patient; using, by the one or more processors, the adjusted cardiac simulation model to simulate the simulated post-irradiation state of the heart with stimulation for inducing a cardiac rhythm disorder; determining, by the one or more processors, whether the cardiac rhythm disorder is induced based on electrical activity generated while simulating the simulated post-radiation state of the heart with the stimulation; as well as An indication of whether the cardiac rhythm disorder was induced in the simulated post-radiation state of the heart is output by the one or more processors.

2. The method of claim 1, wherein the heart rhythm disorder is associated with at least one of ventricular tachycardia (VT), atrial tachycardia, ventricular fibrillation, or atrial fibrillation.

3. The method of claim 1 or claim 2, wherein the electrical activity is defined in the heart simulation model using a plurality of parameters of a plurality of electrical activation signals, each electrical activation signal being associated with a corresponding region of the heart of the patient, and wherein adjusting the heart simulation model comprises: Parameters of electrical activation signals associated with regions of the heart of the patient expected to receive radiation under the radiation treatment plan are adjusted.

4. The method of claim 3, wherein each electro-activation signal has a plurality of phases and each phase is defined by one or more corresponding parameters, and wherein adjusting the parameters of the electro-activation signal comprises: determining a change in a parameter of each phase of the electrical activation signal due to an effect of a corresponding radiation dose on the region of the heart of the patient expected to receive radiation; as well as The parameters of each phase of the electrical activation signal are modified based on the determined changes.

5. A method according to any of the preceding claims, wherein the electrical activity is defined in the heart simulation model using one or more parameters of conduction velocity.

6. The method of claim 5, wherein adjusting the heart simulation model comprises adjusting at least one of the one or more parameters of the conduction velocity.

7. The method of any of the preceding claims, wherein determining the simulated post-radiation state of the heart comprises identifying tissue of the heart of the patient that is expected to become electrically inert in response to the radiation treatment plan.

8. The method of any of the preceding claims, wherein simulating the simulated post-radiation state of the heart with the stimulation for inducing the cardiac arrhythmia comprises simulating a virtual catheter-based stimulation in the post-radiation state of the heart.

9. The method according to any one of the preceding claims, further comprising: After determining that the cardiac rhythm disorder is induced, one or more modifications to the radiation treatment plan are proposed.

10. The method of claim 9, wherein the one or more modifications to the radiation treatment plan include at least one of: modifying a radiation dose specified in the radiation treatment plan to the first region of the heart; or A second region of the heart scheduled to receive radiation under the radiation treatment plan is modified.

11. A system for simulating the effects of radiation for cardiac ablation, the system comprising: one or more processors; as well as a memory for storing computer code instructions which, when executed, cause the one or more processors to: generating a cardiac simulation model of a heart of the patient based on the medical image and electrophysiological data of the patient, the cardiac simulation model being configured to simulate electrical activity of the heart of the patient; determining a simulated post-radiation state of the heart by adjusting the heart simulation model to account for the effects of a radiation treatment plan on the simulated electrical activity of the heart of the patient, the radiation treatment plan specifying radiation doses to be applied to different regions of the heart of the patient; using the adjusted heart simulation model to simulate the simulated post-irradiation state of the heart with stimulation for inducing cardiac arrhythmia; determining whether the cardiac rhythm disorder is induced in the simulated post-radiation state of the heart of the patient; as well as An indication of whether the cardiac arrhythmia is induced in the simulated post-radiation state of the heart of the patient is output.

12. The system of claim 11, wherein the heart rhythm disorder is associated with at least one of ventricular tachycardia (VT), atrial tachycardia, ventricular fibrillation, or atrial fibrillation.

13. The system of claim 11 or claim 12, wherein the electrical activity is defined in the heart simulation model using a plurality of parameters of a plurality of electrical activation signals, each electrical activation signal being associated with a corresponding region of the heart of the patient, and wherein adjusting the heart simulation model comprises: Parameters of electrical activation signals associated with regions of the heart of the patient expected to receive radiation under the radiation treatment plan are adjusted.

14. The system of claim 13, wherein each electro-activation signal has a plurality of phases and each phase is defined by one or more corresponding parameters, and wherein in adjusting the parameters of the electro-activation signal, the one or more processors are configured to: determining changes in parameters of each phase of the electrical activation signal due to the effect of a corresponding radiation dose on the region of the heart of the patient expected to receive radiation; and The parameters of each phase of the electrical activation signal are modified based on the determined changes.

15. The system of any one of claims 11 to 14, wherein the electrical activity is defined in the heart simulation model using one or more parameters of conduction velocity.

16. The system of claim 15, wherein when adjusting the heart simulation model, the one or more processors are configured to adjust at least one of the one or more parameters of the conduction velocity.

17. A system according to any one of claims 11 to claim 16, wherein when determining the simulated post-radiation state of the heart, the one or more processors are configured to identify tissue of the heart of the patient that is expected to become electrically inert in response to the radiation treatment plan.

18. A system according to any one of claims 11 to claim 17, wherein when simulating the simulated post-radiation state of the heart having the stimulation for inducing the arrhythmia, the one or more processors are configured to simulate virtual catheter-based stimulation in the post-radiation state of the heart of the patient.

19. The system of any one of claims 11 to 18, wherein the one or more processors are further configured to: After determining that the cardiac rhythm disorder is induced, one or more modifications to the radiation treatment plan are proposed.

20. The system of claim 19, wherein the one or more modifications to the radiation treatment plan include at least one of: modifying a radiation dose specified in the radiation treatment plan to the first region of the heart; or A second region of the heart scheduled to receive radiation under the radiation treatment plan is modified.

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