Determining ablation probe configuration

Abstract

This application discloses a medical system (100, 300) including a processor (104). Execution of machine-executable instructions (112) causes the processor (104) to: receive (200) three-dimensional medical image data (114) describing a subject (318); receive (202) a desired ablation volume (116), wherein the desired ablation volume is registered to the three-dimensional medical image data; receive (204) one or more protected volumes (118); generate (206) a discrete set of ablation probe locations (120); receive (208) a discrete set of ablation patterns (130); initialize (210) a composite ablation binary mask (122); and initialize (212) a sequential list of ablation probe configurations (124). The execution of the machine-executable instructions also enables the processor to iteratively generate a list of sequential ablation probe configurations by repeating the following operations: determining (214) the unablated volume (126) by comparing the composite ablation binary mask with the desired ablation volume; determining (216) the selected ablation probe configuration (128) using a selected objective function (132) that depends on one or more protected volumes, unablated volumes, ablation pattern discrete sets, and ablation probe location discrete sets; updating (218) the composite ablation binary mask by calculating the union between the composite ablation binary mask and an ablation pattern in the ablation pattern discrete set located at an ablation probe location in the ablation probe location discrete set; and adding (220) the selected ablation probe configuration to the list of sequential ablation probe configurations.

Description

Technical Field

[0001] This invention relates to ablation probes, and in particular to the placement of ablation probes. Background Technology

[0002] Ablation probes can be used to treat tumors through ablation. Examples include microwave ablation probes, thermal ablation probes, cryoablation probes, and focused ultrasound ablation probes. In particular, thermal ablation for cancer treatment is becoming increasingly popular due to its suitability for non-reselective tumors and the rapid recovery of patients.

[0003] US Patent Application Publication US 2014058387 A1 discloses a system and method for ablation planning, including defining the shape and size of one or more ablation volumes based on treatment probabilities, and determining a target volume to be treated. Process planning is provided by determining the number and location of planned ablations within the target volume using one or more ablation volumes. A joint probability distribution of at least two planned ablations within the target volume is determined. The final configuration is visualized to determine whether the treatment probabilities based on the target volume meet the planning objectives.

[0004] Document US2011 / 0015628A1 discloses the importation of a planned target volume, typically selected by a physician but potentially computer-recognized, during ablation planning. A lookup table is used to generate or select an ablation solution comprising multiple ablation volumes. Ablations sharing a common axis along an insertion line are grouped into blocks. Alternatively, the planned target volume is enclosed in a sphere, and a pre-calculated ablation scheme (e.g., a 6- or 14-sphere scheme) is identified to cover the planned target volume sphere. Optionally, a mathematical algorithm is performed to increase the axis through the ablation sphere, thereby producing an elliptical ablation volume enclosing the PTV.

[0005] Another document, EP 2373241A1, discloses a system that combines treatment planning and image guidance and navigation for interventional procedures. This system includes: a radiofrequency ablation treatment planning component capable of creating an initial treatment plan, adjusting the treatment plan to take into account data received during the procedure, and transmitting the treatment plan to a navigation component; a navigation system component guiding an ablation probe; and a feedback subsystem for determining the actual ablation probe position / orientation and actual ablation size / shape via an imaging and / or tracking system, and for exchanging information between the planning component and the navigation component.

[0006] Yaniv, Z. et al., in their paper "Needle-based Interventions With the Image-Guided Surgery Toolkit (IGSTK): From Phantoms to Clinical Trials", IEEE Transactions on Biomedical Engineering, Vol. 57, No. 4, April 2010, pp. 922-933, proposed three image-guided navigation systems developed for needle-based interventional radiology procedures. Summary of the Invention

[0007] The present invention provides medical systems, computer program products, and methods in the independent claims. Embodiments are given in the dependent claims.

[0008] The difficulty in planning the ablation process lies in the fact that probes can be freely placed and often have a continuously variable power supply. Properly planning the placement of ablation probes can be extremely difficult. Embodiments may provide a system that offers an improved way of determining the location of ablation probes. This can be provided, for example, in the form of a sequential list of ablation probe configurations, which can be displayed as a list or graphically.

[0009] This can be achieved by receiving three-dimensional medical image data, the desired ablation volume, and a set of one or more protected volumes. The system then creates a discrete set of ablation probe locations and receives a discrete set of ablation patterns. An objective function is selected to evaluate each of the ablation patterns in the discrete set at each of the discrete sets of ablation probe locations. The selected objective function is then used to select the probe location and ablation pattern. This process is repeated to create a sequential list of ablation probe configurations. The advantage of this is that it can consider multiple types of ablation probes and configurations, which is impossible with algorithms that perform continuous optimization.

[0010] In one aspect, the present invention provides a medical system including a memory storing machine-executable instructions and a processor configured to control the medical system. Execution of the machine-executable instructions causes the processor to receive three-dimensional medical image data describing a subject. Execution of the machine-executable instructions also causes the processor to receive a desired ablation volume. The term "desired ablation volume" is a label for a specific ablation volume. The desired ablation volume is registered to the three-dimensional medical image data. That is, the desired ablation volume marks a region or identifies a region of the three-dimensional medical image data.

[0011] The execution of machine-executable instructions also causes the processor to receive one or more protected volumes. These protected volumes are registered to three-dimensional medical image data. One or more protected volumes may, for example, be volumes that would harm the subject if subjected to excessive ultrasound treatment or ablation. For instance, one or more protected volumes may be used to protect organs or critical anatomical structures.

[0012] The execution of machine-executable instructions also enables the processor to generate a discrete set of ablation probe positions registered to the 3D medical image data. However, the position and orientation of the ablation probe are typically freely selectable when positioning it. In this case, the locations around the desired ablation volume can be used to generate discrete ablation probe position patterns or sets. These can be generated, for example, using predetermined patterns or algorithms for generating discrete sets. The execution of machine-executable instructions also enables the processor to receive a discrete set of ablation patterns.

[0013] A discrete set of ablation patterns comprises multiple ablation patterns. This discrete set can be ablation patterns used for a single ablation probe, for example, oriented in different directions and / or with different power supplies. In other examples, the discrete set of ablation patterns can come from multiple ablation probes. Execution of machine-executable instructions also causes the processor to initialize a composite ablation binary mask registered to the three-dimensional medical imaging data. For example, the step of initializing a composite ablation binary mask could be creating a blank or unused composite ablation binary mask. The term composite ablation binary mask is used to identify a specific binary mask. In this case, a composite ablation binary mask is an ablation binary mask that stores the composite or intersection of all ablation patterns used.

[0014] The execution of machine-executable instructions also causes the processor to initialize a sequential list of ablation probe configurations. Initially, this list may be empty. As the algorithm continues, different ablation probe configurations are added to the sequential list.

[0015] The execution of machine-executable instructions also enables the processor to generate a sequential list of ablation probe configurations by first determining the unablated volume through a comparison of a composite ablation binary mask with the desired ablation volume. The unablated volume is registered to the 3D medical image data. The composite ablation binary mask can be used to identify areas that have been ablated or are intended to be ablated using configurations from the sequential list of ablation probe configurations. The comparison between the desired ablation volume and the composite ablation binary mask can be used to locate areas that still require ablation or to add additional probes for ablation to occur.

[0016] The execution of machine-executable instructions also enables the processor to generate a sequential list of ablation probe configurations by using a selected objective function to determine the selection of ablation probe configurations. The selected objective function depends on one or more protected volumes, unablated volumes, discrete sets of ablation patterns, and discrete sets of ablation probe locations. The selected ablation probe configuration specifies an ablation probe location in the discrete set of ablation probe locations and an ablation pattern in the discrete set of ablation patterns. In this step, the selected objective function can be used to evaluate various combinations of discrete sets of ablation patterns within each of the discrete sets of ablation probe locations.

[0017] Choosing an objective function is crucial for making the optimal choice. It can be used to objectively measure coverage similar to unablated volumes and to avoid one or more protected volumes.

[0018] Selecting an ablation probe configuration specifies an ablation probe location in a discrete set of ablation probe locations and an ablation pattern in a discrete set of ablation patterns. Execution of the machine-executable instructions further enables the processor to update the composite ablation binary mask by calculating the union of the composite ablation binary mask with an ablation pattern located at an ablation probe location in the discrete set of ablation probe locations, thereby generating a sequential list of ablation probe configurations. After selecting an ablation probe configuration, this selection is then used to update the composite ablation binary mask to indicate which region the selected ablation probe will subsequently ablate. Execution of the machine-executable instructions also enables the processor to generate a sequential list of ablation probe configurations by adding the selected ablation probe configuration to the sequential list of ablation probe configurations.

[0019] The execution of machine-executable instructions also causes the processor to repeatedly generate a sequential list of ablation probe configurations until one or more of a predetermined set of criteria are met. For example, the operator can specify the maximum number of ablation probes to use. The method can stop after adding the maximum number of discrete sets of ablation patterns to the selected ablation probe configuration. Other criteria can be used, such as specifying the minimum amount of desired ablation volume covered by a compound ablation binary mask. Another criterion could be the maximum amount of one or more protected volumes to be ablated. In some cases, the method can also prevent any one of the one or more protected volumes from being ablated.

[0020] This medical system could be beneficial because it provides a highly efficient way to determine the location of the ablation probe used to perform ablation of the desired ablation volume. The method uses discrete locations to position the ablation probe, in the form of a discrete set of ablation probe locations and a discrete quantity of ablation patterns. For example, this may not reach an optimal solution, but it is computationally very efficient because it achieves a solution very close to any optimal value. This has, for example, the advantage of being able to quickly consider and use a wider variety of ablation probes to assemble an ablation probe configuration for a particular subject.

[0021] The above embodiments are applicable to both simultaneous insertion of multiple ablation probes into the subject and sequential insertion of ablation probes. The choice of objective function can be interpreted as solving an optimization problem defined using that objective function.

[0022] In another embodiment, the execution of machine-executable instructions further enables the processor to update the sequential list of ablation probe configurations by iteratively assigning each of the discrete sets of ablation probe locations to spatially contiguous probe locations and modifying the spatially contiguous probe locations using a second objective function. In this embodiment, the determination of the sequential list of ablation probe configurations is performed in two main steps. In the first step, a discrete set of probe locations and ablation modes is first determined. In the second step, the discrete set of ablation probe configurations is modified to be spatially contiguous, and then each of these configurations is iteratively improved. This embodiment can be advantageous because it can provide a sequential list of ablation probe configurations very close to the optimum using extremely fast and efficient numerical methods.

[0023] The second objective function can be the same as the chosen objective function, or it can be a different objective function.

[0024] In another embodiment, a spatially continuous probe position is a spatially continuous linear position and / or a spatially continuous rotation. In this embodiment, a spatially continuous probe position could be, for example, how far the ablation probe moves in a linear direction and / or how far it rotates. This can also help optimize a sequential list of ablation probe configurations.

[0025] In another embodiment, the medical system also includes a display. Execution of machine-executable instructions further causes the processor to display a sequential list of ablation probe configurations on the display screen. This can be advantageous because a practitioner can have a sequential list of ablation probe configurations in a format that enables the practitioner to use the ablation probes.

[0026] In another embodiment, the sequential list of ablation probe configurations is a list used to index the grid positions and insertion depths of the ablation probe insertion block. As used herein, the indexed ablation probe insertion block is a structure or guide external to the subject and mounted in a fixed position relative to the subject. The practitioner can select one of several different guides into which the ablation probe can be inserted. These can, for example, be assigned index values ​​or labels. The practitioner can then insert the ablation probe into the indexed ablation probe insertion block at a specific depth. The provision of the grid positions and insertion depth list provides the practitioner with simple guidance in inserting the ablation probe into the subject at the correct location. For example, this can be done sequentially, or it can be done simultaneously with more than one probe.

[0027] In another embodiment, the sequential list of ablation probe configurations is displayed as a diagram of the free positions of the ablation probes specified in the sequential list. For example, the diagram of the free positions of the ablation probes can be overlaid on a medical image. This can be useful for practicing physicians to correctly position the ablation probes.

[0028] In another embodiment, the medical system also includes a medical imaging system configured to acquire three-dimensional medical image data. Execution of machine-executable instructions further enables the processor to control the medical imaging system to acquire the three-dimensional medical image data. This can be advantageous, for example, because the medical system allows for the measurement of the subject's internal anatomy and the designation of the ablation probe's position.

[0029] In another embodiment, the medical imaging system is a magnetic resonance imaging system.

[0030] In another embodiment, the medical imaging system is an ultrasound system.

[0031] In another embodiment, the medical imaging system is a computed tomography (CT) system.

[0032] In another embodiment, the execution of the machine-executable instructions further enables the processor to control the medical imaging system to acquire real-time ablation probe tracking data. The execution of the machine-executable instructions also enables the processor to use the real-time ablation probe tracking data to determine the position of the ablation probe registered to the three-dimensional medical image data. The execution of the machine-executable instructions further enables the processor to use a display to draw the ablation probe position superimposed on the three-dimensional medical image data in real time. This embodiment may be advantageous because it provides a way for a physician to not only specify the location of the ablation probe but also actually display where the ablation probe is when inserting it. This can help the physician to correctly locate the ablation probe.

[0033] In another embodiment, execution of the machine-executable instructions further causes the processor to determine the measurement location of the selected ablation probe configuration from a sequential list of ablation probe configurations. Execution of the machine-executable instructions also causes the processor to recalculate the sequential list of ablation probe configurations using the measurement location as a fixed location. In this embodiment, the medical imaging system measures the actual location where the ablation probe is placed; this is the measurement location. This provides more detailed information about where the ablation actually occurs. In this case, the sequential list of ablation probe configurations is then recalculated using the actual measurement location of the selected ablation probe. This embodiment can be advantageous because it can help to ablate the desired ablation volume more efficiently.

[0034] In another embodiment, execution of the machine-executable instructions further causes the processor to measure the ablation volume using a medical imaging system. Execution of the machine-executable instructions also causes the processor to correct the desired ablation volume by subtracting the desired ablation volume from the desired ablation volume. Execution of the machine-executable instructions further causes the processor to recalculate the sequential list of ablation probe configurations using the corrected desired ablation volume. This embodiment may be advantageous because, in contrast to indirect quantities such as the location of the ablation probes, the actual ablation volume is measured. This may be advantageous because, in some cases, tissue behavior may differ from the pattern indicated by the ablation pattern's dissipation concentration.

[0035] For example, different types of medical imaging systems can be used to measure ablation volume in different ways. For instance, if the medical imaging system is magnetic resonance imaging (MRI), it can, for example, measure the spatially relevant temperature of the subject as a function of time. Other medical imaging techniques can, for example, examine or detect damage caused by ablation. For instance, if tissue is damaged, its form in an ultrasound scan may differ from that of untreated tissue.

[0036] In another embodiment, the selection of the objective function includes a secondary ablation coverage-based objective function, a minimum / maximum ablation coverage function, and a uniform secondary coverage function. Using any of these functions can be beneficial, as they are effective in selecting the region to be ablated and in protecting key regions specified within one or more protected volumes.

[0037] In another embodiment, the predetermined set of criteria includes the maximum number of ablation probes allowed.

[0038] In another embodiment, the predetermined set of criteria includes ablation coverage targets for desired ablation volumes. For example, ablation can be stopped if the desired ablation coverage target is reached or exceeded.

[0039] In another embodiment, the ablation mode discrete set includes ablation modes for cryogenic ablation probes.

[0040] In another embodiment, the ablation mode discrete set includes ablation modes for laser ablation probes.

[0041] In another embodiment, the ablation mode discrete set includes ablation modes for microwave ablation probes.

[0042] In another embodiment, the ablation pattern discrete set includes ablation patterns for a focused ultrasound ablation probe.

[0043] In another embodiment, the ablation mode discrete set includes ablation modes for radiofrequency ablation probes.

[0044] In another embodiment, the ablation mode discrete set includes ablation modes for irreversible electroporation probes.

[0045] In another aspect, the present invention provides a computer program product comprising machine-executable instructions executed by a processor controlling a medical system. Execution of the machine-executable instructions causes the processor to receive three-dimensional medical image data describing a subject. Execution of the machine-executable instructions also causes the processor to receive a desired ablation volume. The desired ablation volume is registered to the three-dimensional medical image data. Execution of the machine-executable instructions further causes the processor to receive one or more protected volumes. The one or more protected volumes are registered to the three-dimensional medical image data.

[0046] The execution of the machine-executable instructions also causes the processor to generate a discrete set of ablation probe positions registered to the 3D medical image data. The execution of the machine-executable instructions also causes the processor to receive a discrete set of ablation patterns. The discrete set of ablation patterns includes multiple ablation patterns. The execution of the machine-executable instructions also causes the processor to initialize a composite ablation binary mask registered to the 3D medical image data. The execution of the machine-executable instructions also causes the processor to initialize a sequential list of ablation probe configurations.

[0047] The execution of the machine-executable instructions also enables the processor to generate a sequential list of ablation probe configurations by determining the unablated volume through comparison of a composite ablation binary mask with the desired ablation volume. The unablated volume is registered to the three-dimensional medical image data. The execution of the machine-executable instructions further enables the processor to generate a sequential list of ablation probe configurations by using a selected objective function that depends on one or more protected volumes, unablated volumes, ablation pattern discrete sets, and ablation probe location discrete sets. Selecting an ablation probe configuration specifies an ablation probe location in the ablation probe location discrete set and an ablation pattern in the ablation pattern discrete set.

[0048] The execution of the machine-executable instructions further causes the processor to update the composite ablation binary mask by calculating the union between the composite ablation binary mask and one or more discrete sets of ablation patterns located at one of the discrete sets of ablation probe locations, thereby generating a sequential list of ablation probe configurations. The execution of the machine-executable instructions further causes the processor to generate a sequential list of ablation probe configurations by adding selected ablation probe configurations to the sequential list of ablation probe configurations. The execution of the machine-executable instructions further causes the processor to repeatedly generate the sequential list of ablation probe configurations until one or more of a predetermined set of criteria (134) are satisfied. The advantages of this embodiment have already been discussed above.

[0049] In another aspect, the present invention provides a method for operating a medical system. The method includes receiving three-dimensional medical image data describing a subject. The method further includes receiving a desired ablation volume. The desired ablation volume is registered to the three-dimensional medical image data. The method further includes receiving one or more protected volumes, wherein the one or more protected volumes are registered to the three-dimensional medical image data; the method further includes generating a discrete set of ablation probe positions registered to the three-dimensional medical image data. The method further includes receiving a discrete set of ablation patterns. The discrete set of ablation patterns includes multiple ablation patterns. The method further includes initializing a composite ablation binary mask registered to the three-dimensional medical image data. The method further includes initializing a sequential list of ablation probe configurations. The method further includes generating a sequential list of ablation probe configurations by determining unablated volumes by comparing the composite ablation binary mask to the desired ablation volume. Unablated volumes are registered to the three-dimensional medical image data.

[0050] The method further includes generating a sequential list of ablation probe configurations by determining the selected ablation probe configuration using a chosen objective function, which depends on one or more protected volumes, unablated volumes, discrete sets of ablation patterns, and discrete sets of ablation probes. The selected ablation probe configuration specifies an ablation probe location in the discrete set of ablation probe locations and an ablation pattern in the discrete set of ablation patterns. The method also includes generating a sequential list of ablation probe configurations by updating the composite ablation binary mask by calculating the union of the composite ablation binary mask with an ablation pattern located at an ablation probe location in the discrete set of ablation patterns.

[0051] The method also includes generating a sequential list of ablation probe configurations by adding selected ablation probe configurations to a sequential list of ablation probe configurations. The method further includes repeatedly generating the sequential list of ablation probe configurations until one or more of a predetermined set of criteria are met. The advantages of this embodiment have been discussed above. It should be understood that one or more of the above embodiments of the invention can be combined, provided that the combined embodiments are not mutually exclusive.

[0052] As those skilled in the art will understand, aspects of the invention can be embodied as apparatus, method, or computer program product. Therefore, aspects of the invention can take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which are generally referred to herein as “circuit,” “module,” or “system.” Furthermore, aspects of the invention can take the form of a computer program product contained in one or more computer-readable media having computer-executable code contained thereon.

[0053] Any combination of one or more computer-readable media can be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. As used herein, "computer-readable storage medium" encompasses any tangible storage medium capable of storing instructions executable by a processor of a computing device. A computer-readable storage medium may be referred to as a computer-readable non-transitory storage medium. A computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be capable of storing data accessible to a processor of a computing device. Examples of computer-readable storage media include, but are not limited to: floppy disks, hard disk drives, solid-state drives, flash memory, USB thumb drives, random access memory (RAM), read-only memory (ROM), optical discs, magneto-optical discs, and processor register files. Examples of optical discs include compact discs (CDs) and digital multipurpose optical discs (DVDs), such as CD-ROMs, CD-RWs, CD-Rs, DVD-ROMs, DVD-RWs, or DVD-R discs. The term computer-readable storage medium also refers to various types of recording media accessible by a computer device via a network or communication link. For example, data can be retrieved via a modem, the Internet, or a local area network. Computer executable code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic cable, RF, or any suitable combination thereof.

[0054] Computer-readable signal media may include propagated data signals containing computer-executable code, for example, in baseband or as a carrier wave. Such propagated signals may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and may communicate, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device.

[0055] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that can be directly accessed by a processor. "Computer storage device" or "storage device" is another example of a computer-readable storage medium. Computer storage is any non-volatile computer-readable storage medium. In some embodiments, computer memory can also be computer memory, and vice versa.

[0056] As used herein, "processor" includes electronic components capable of executing programs or machine-executable instructions or computer-executable code. References to a computing device including "processor" should be interpreted as potentially containing more than one processor or processing core. A processor can be, for example, a multi-core processor. A processor can also refer to a collection of processors within a single computer system or distributed across multiple computer systems. The term computing device should also be interpreted as potentially referring to a collection or network of computing devices, each including one or more processors. Computer-executable code can be executed by multiple processors, which can be within the same computing device or even distributed across multiple computing devices.

[0057] Computer executable code may include machine-executable instructions or programs that cause a processor to execute aspects of the present invention. Computer executable code for performing the aspects of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Java, Smalltalk, C++, etc.) and traditional procedural programming languages ​​(such as the "C" programming language or similar programming languages ​​compiled into machine-executable instructions). In some cases, computer executable code may be in the form of a high-level language or in a pre-compiled form and may be used in conjunction with an interpreter that generates machine-executable instructions on the spot.

[0058] Computer executable code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0059] Aspects of the invention have been described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block or part of a block in a flowchart, illustration, and / or block diagram may, where applicable, be implemented by computer program instructions in the form of computer-executable code. It should also be understood that combinations of blocks from different flowcharts, illustrations, and / or block diagrams may be combined when not mutually exclusive. These computer program instructions may be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, executable via the processor of the computer or other programmable data processing apparatus, create a manner for implementing the functions / actions specified in the flowcharts and / or one or more block diagram blocks.

[0060] These computer program instructions may also be stored in a computer-readable medium that can instruct a computer, other programmable data processing apparatus or other device to operate in a particular manner, such that the instructions stored in the computer-readable medium produce an article of writing which includes instructions that implement the functions / actions specified in a flowchart and / or one or more block diagram blocks.

[0061] Computer program instructions may also be loaded onto a computer, other programmable data processing apparatus or other equipment to cause a series of operational steps to be performed on the computer, other programmable apparatus or other equipment, thereby creating a computer-implemented process, such that the instructions, which execute on the computer or other programmable data processing apparatus, provide for implementing the functions / actions specified in the flowchart and / or one or more block diagram blocks.

[0062] As used herein, a "user interface" is an interface that allows a user or operator to interact with a computer or computer system. A "user interface" may also be referred to as a "human-machine interface device." A user interface can provide information or data to and / or receive information or data from an operator. A user interface enables input from an operator to be received by the computer and can provide output from the computer to the user. In other words, a user interface allows an operator to control or manipulate a computer, and the interface allows the computer to indicate the effects of the operator's control or manipulation. The display of data or information on a monitor or graphical user interface is an example of providing information to an operator. Receiving data via a keyboard, mouse, trackball, touchpad, pointing stick, graphics tablet, joystick, game controller, webcam, headset, pedals, wired gloves, remote control, and accelerometer are all examples of user interface components capable of receiving information or data from an operator.

[0063] As used herein, "hardware interface" encompasses the interface that enables a computer system's processor to interact with and / or control external computing devices and / or devices. A hardware interface may allow the processor to send control signals or instructions to external computing devices and / or devices. A hardware interface may also enable the processor to exchange data with external computing devices and / or devices. Examples of hardware interfaces include, but are not limited to: Universal Serial Bus (USB), IEEE 1394 port, parallel port, IEEE 1284 port, serial port, RS-232 port, IEEE-488 port, Bluetooth connectivity, wireless LAN connectivity, TCP / IP connectivity, Ethernet connectivity, control voltage interface, MIDI interface, analog input interface, and digital input interface.

[0064] As used herein, "display" or "display device" encompasses an output device or user interface suitable for displaying images or data. Displays can output visual, audio, and / or tactile data. Examples of displays include, but are not limited to: computer monitors, television screens, touchscreens, tactile electronic displays, Braille screens, cathode ray tubes (CRTs), memory tubes, bistable displays, electronic paper, vector displays, flat panel displays, vacuum fluorescent displays (VFs), light-emitting diode (LED) displays, electroluminescent displays (ELDs), plasma display panels (PDPs), liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, projectors, and head-mounted displays.

[0065] In this paper, three-dimensional medical image data is defined as reconstructed three-dimensional data representing the visualization of anatomical data. Visualization can be performed using a computer.

[0066] Magnetic resonance (MR) imaging data is defined herein as recorded measurements of radio frequency signals emitted by atomic spins by the antenna of a magnetic resonance apparatus during a magnetic resonance imaging scan. Magnetic resonance imaging (MRI) images, or MR images, are defined herein as reconstructed two-dimensional or three-dimensional visualizations of anatomical data contained within magnetic resonance imaging data. Examples of MRI images may be two-dimensional or three-dimensional medical image data. Attached Figure Description

[0067] In the following description, preferred embodiments of the invention will be illustrated by way of example only and with reference to the accompanying drawings, wherein:

[0068] Figure 1 An example of a medical system is shown;

[0069] Figure 2 The operation is shown. Figure 1 A flowchart of the methods used in a medical system;

[0070] Figure 3 This illustrates another example of a healthcare system;

[0071] Figure 4 The instructions are shown. Figure 3 A flowchart of the methods used in a medical system;

[0072] Figure 5 An example of a discrete set of ablation patterns is shown;

[0073] Figure 6 A flowchart illustrating another example of the method is shown;

[0074] Figure 7 An example of creating an ablation binary mask is shown;

[0075] Figure 8 A composite ablation binary mask is shown;

[0076] Figure 9 This shows a detailed local representation of the ablation probe location and / or orientation;

[0077] Figure 10 This shows a localized refinement of the ablation zone of the ablation probe;

[0078] Figure 11 A synthetic body model used for ablation numerical simulation is shown;

[0079] Figure 12 It shows the Figure 11 The synthetic phantom was simulated using an ablation probe;

[0080] Figure 13 It shows the Figure 11 The synthetic phantom was simulated using two ablation probes;

[0081] Figure 14 It shows the Figure 11 The synthetic phantom was simulated using three ablation probes;

[0082] Figure 15 It shows the Figure 11 The synthetic phantom was simulated using four ablation probes;

[0083] Figure 16 It shows the Figure 11 The synthetic phantom was simulated using seven ablation probes;

[0084] Figure 17 It shows the Figure 11 The synthetic phantom was simulated using twelve ablation probes;

[0085] Figure 18 It shows Figures 11 to 17 The ablation objective function F(A) for different iterations of the simulation is shown.

[0086] Figure 19 It shows Figures 11 to 17 The simulation shows the fractions of the ablation target area in different iterations;

[0087] Figure 20 It shows Figures 11 to 17 The ablation fractions of the OAR region in different simulation iterations are shown.

[0088] Figure 21 It shows Figures 11 to 17 The ablation fraction of normal tissue in different iterations of the simulation is shown.

[0089] Figure 22 An example of a graphical user interface is shown;

[0090] Figure 23This shows another example of a graphical user interface;

[0091] Figure 24 Another example of a graphical user interface is shown; and

[0092] Figure 25 Another example of a graphical user interface is shown. Detailed Implementation

[0093] Elements with the same numbers in these figures are equivalent elements or perform the same function. If the functions are equivalent, elements already discussed earlier need not be discussed in later figures.

[0094] Figure 1 An example of a medical system 100 is shown; the medical system 100 is shown as including a computer 102 with a processor 104. The processor 104 is intended to represent one or more processors having one or more cores. The processor 104 is shown within a single computer 102, but may also be distributed across multiple computer systems. The processor is also shown connected to an optional hardware interface 106, a user interface 108, and memory 110. The hardware interface 106 enables the processor 104 to communicate with other components of the medical system. For example, if the medical system 100 includes a medical imaging system, the hardware interface 106 enables the processor 104 to control and operate the medical imaging system. The user interface 108 can be a user interface that enables a user or operator to interact with the medical system 100. For example, the user interface 108 may include a display. The memory 110 can be any combination of memory accessible to the processor 104. This can include main memory, cache memory, and non-volatile memory such as flash RAM, hard disk drives, or other storage devices. In some examples, memory 110 may be considered a non-transitory computer-readable medium.

[0095] In some examples, memory 110 may be shown as containing machine-executable instructions 112. Machine-executable instructions 112 enable processor 104 to perform basic data processing techniques and also control other components of medical system 100 (if present). Memory 110 is also shown as containing three-dimensional medical image data 114. Memory 110 is also shown as containing a desired ablation volume 116. The desired ablation volume 116 is registered to the three-dimensional medical image data 114. Memory 110 is also shown as containing one or more protected volumes 118. The one or more protected volumes 118 are also registered to the three-dimensional medical image data 114. The one or more protected volumes 118 may represent organs or sensitive anatomical structures of the subject that should not be ablated. Memory 110 is also shown as containing a discrete set 120 of ablation probe locations. These are locations within the three-dimensional medical image data 114 where ablation probes can be placed.

[0096] Memory 110 is also shown to include a composite ablation binary mask 122. The composite ablation binary mask 122 is a binary mask used to show all the different locations where ablation is performed by multiple ablation probes. It can be used to track the volume that should be ablated. Memory 110 is also shown to include a sequential list 124 of ablation probe configurations. The sequential list 124 of ablation probe configurations contains a list of ablation probe locations and profiles. Each profile may correspond to the selection of a specific ablation probe and the specific power configuration used for that ablation probe.

[0097] In some examples, memory 110 is also shown to contain an unablated volume 126. The unablated volume is the desired ablation volume 116 minus the composite ablation binary mask 122. This is the volume that still needs to be ablated. Memory 110 is also shown to contain a selected ablation probe configuration 128. The selected ablation probe configuration 128 is a selection from one of a location set 120 and an ablation mode set 130. The ablation mode set 130 is also shown to be stored in memory 110. The ablation mode set 130 may, for example, indicate the selection of a particular ablation probe and the operating mode of that ablation probe. For example, power can be selected by having multiple ablation modes for the same ablation probe with different power amounts and / or durations.

[0098] Memory 110 is also shown to contain a selection objective function 132. The selection objective function 132 depends on one or more protected volumes 118 and unablated volumes 126. It is then used to evaluate each of the ablation pattern set 130 and each of the ablation probe location set 120. For example, an optimization procedure can be used to select the optimal solution. Memory 110 is also shown to contain a predetermined set of criteria 134 for stopping the selection of more probes for a sequential list 124 of ablation probe configurations.

[0099] Figure 2 The operation is shown. Figure 1 The flowchart describes a method for a medical system. First, in step 200, three-dimensional medical image data 114 describing the subject is received. In step 202, the desired ablation volume 116 is received. In step 204, one or more protected volumes 118 are received. In step 206, a discrete set of ablation probe locations is generated. In step 210, a composite ablation binary mask 122 is initialized. In step 212, a sequential list of ablation probe configurations 124 is initialized.

[0100] Steps 214, 216, 218, and 220 are performed iteratively. In step 214, the unablated volume 126 is determined by comparing the composite ablation binary mask 122 with the desired ablation volume 116. For example, the composite ablation binary mask 122 can be used to determine which portion of the desired ablation volume 116 has not yet been ablated. Then, in step 216, the selected objective function 132 is used to determine the selected ablation probe configuration 128. The selected objective function uses the unablated volume 126 and one or more protected volumes 118, and then attempts each of the ablation pattern discrete sets 130 at each of the ablation probe location discrete sets 120. The optimal solution is selected and used as the selected ablation probe configuration 128.

[0101] In step 218, the composite ablation binary mask is updated (218) by calculating the union between the composite ablation binary mask and one of the discrete sets of ablation patterns located in one of the discrete sets of ablation probe locations. In step 220, the selected ablation probe configuration is added (220) to the list of sequential ablation probe configurations. The method then proceeds to step 222, which is a question box, and the question is whether any of the criteria in a predetermined set of criteria are met. If the answer is yes, the method proceeds to step 224 and the method ends. If the answer is no, the method returns to step 214 and repeats the iterative process again. It should be noted that each time the list is passed, the composite ablation binary mask 122 will indicate the larger volume of the desired ablation volume 116.

[0102] Figure 3 This illustrates another example of a healthcare system. Healthcare System 300 is similar to... Figure 1 The medical system 100 shown is different in that it additionally includes a magnetic resonance imaging system 302.

[0103] The magnetic resonance imaging system 302 includes a magnet 304. Magnet 304 is a superconducting cylindrical magnet with a hole 306 passing through it. Different types of magnets can also be used; for example, split-type cylindrical magnets and so-called open-type magnets can be used simultaneously. Split-type cylindrical magnets are similar to standard cylindrical magnets, except that the cryostat is divided into two parts to allow for approach to the equiplanar plane of the magnet; such magnets can be used, for example, in conjunction with charged particle beam therapy. Open-type magnets have two magnet sections, one on top of the other, with a sufficiently large space in between to accommodate the subject: the arrangement of these two sections is similar to that of Helmholtz coils. Open-type magnets are popular because the subject is not restricted. Inside the cryostat of the cylindrical magnet, there is a set of superconducting coils.

[0104] An imaging region 308 is located within an aperture 306 of a cylindrical magnet 304, wherein the magnetic field is sufficiently strong and uniform to perform magnetic resonance imaging. A field of view 309 is shown within the imaging region 308. Acquired magnetic resonance data are typically acquired for the field of view 309. A subject 318 is shown supported by a subject support 320 such that at least a portion of the subject 318 is within the imaging region 308 and the field of view 309. Within the imaging region 308, the desired ablation volume 116 and a protected volume 118 are visible.

[0105] Within the aperture 306 of the magnet, there is also a set of magnetic field gradient coils 310, which are used to acquire preliminary magnetic resonance data for spatial encoding of the magnetic spins within the imaging region 308 of the magnet 304. The magnetic field gradient coils 310 are connected to a magnetic field gradient coil power supply 312. The magnetic field gradient coils 310 are intended to be representative. Typically, the magnetic field gradient coils 310 contain three independent coil groups for spatial encoding in three orthogonal spatial directions. The magnetic field gradient power supply provides current to the magnetic field gradient coils. The current supplied to the magnetic field gradient coils 310 is controlled as a function of time and can be ramped or pulsed.

[0106] Adjacent to the imaging region 308 is an RF coil 314, which is used to manipulate the direction of the magnetic spin within the imaging region 308 and to receive radio transmissions also originating from the spin within the imaging region 308. The RF antenna may comprise multiple coil elements. The RF antenna may also be referred to as a channel or antenna. The RF coil 314 is connected to an RF transceiver 316. The RF coil 314 and the RF transceiver 316 may be replaced by separate transmit and receive coils, as well as separate transmitters and receivers. It should be understood that the RF coil 314 and the RF transceiver 316 are representative. The RF coil 314 is also intended to represent a dedicated transmit antenna and a dedicated receive antenna. Similarly, the transceiver 316 may also represent separate transmitters and receivers. The RF coil 314 may also have multiple receive / transmit elements, and the RF transceiver 316 may have multiple receive / transmit channels. For example, if a parallel imaging technique such as SENSE is performed, the RF coil 314 will have multiple coil elements.

[0107] Transceiver 316 and gradient controller 312 are shown as hardware interface 106 connected to computer system 102. Memory 110 is also shown as containing pulse sequence commands 330. Pulse sequence commands 330 are commands or data that can be converted into commands that enable processor 104 to control the operation of magnetic resonance imaging system 302. Memory 110 is also shown as containing magnetic resonance imaging data 332 acquired by controlling magnetic resonance imaging system 302 with pulse sequence commands 330.

[0108] It can be modified in many ways Figure 3The medical system 300 depicted herein can be used to track the position of ablation probes when they are inserted into a subject 318. For example, reference markers can be incorporated into the tip or other areas of the ablation probe. Additionally, the magnetic resonance imaging system 302 can be modified with specialized pulse sequence commands to measure temperature within the subject 318.

[0109] Figure 4 The operation is described Figure 3 Another approach to the 300 medical system. Figure 4 The method described in the middle is similar to Figure 2 The method described herein differs in that it begins at step 400, in which the medical imaging system 302 is controlled to acquire three-dimensional medical image data 114. In this case, the magnetic resonance imaging system is controlled by pulse sequence commands 330, which causes the magnetic resonance imaging system 302 to acquire magnetic resonance imaging data 332. The magnetic resonance imaging data 332 can then be reconstructed into three-dimensional medical image data 114.

[0110] Ablation treatment planning involves the optimal placement of the ablation device, which is typically determined based on the tumor location and size, the device manufacturer's specifications, and the physician's experience. Furthermore, to minimize unnecessary damage to nearby healthy tissue, the ablation zone needs to conform as closely as possible to the tumor contour. Standard thermal ablation procedures usually require the physician to select a set of probe locations and corresponding delivery parameters, such as ablation power and time values ​​from the device manufacturer's specifications. This manual forward planning process can be very lengthy, error-prone, and suboptimal.

[0111] Examples can be provided for discrete inverse programming optimization or hybrid discrete-continuous inverse programming optimization methods to solve thermal treatment planning problems. So far, only the following inputs are required from the clinical expert: a set of segmented regions of interest (3D medical image data 114 and one or more protected volumes 118), a set of clinical objectives to be achieved (the desired ablation volumes 118), and the ablation specifications (a discrete set 130 of ablation patterns) for the device to be used (ablation probe). Then, a set of covered iterative greedy algorithms is used to find the optimal minimum number of ablation device configurations (i.e., spatial probe tip position / orientation and other ablation device parameters) that best meet the provided clinical protocol objectives. The greedy algorithm searches for local minima. Furthermore, an interactive and simple graphical user interface (GUI) is proposed to allow the clinical expert to directly execute the desired set of actions.

[0112] Last but not least, examples can be easily deployed for real-time location guidance and adaptive thermal ablation optimization. In the event of a probe tip misalignment relative to the precise planned location, these tracked misalignments can be taken into account to adaptively reoptimize the undelivered remaining set (list of sequential ablation probe configurations 124) to reconstruct the desired planning quality.

[0113] Examples can be used for percutaneous ablation of cancer. A potential goal of thermal ablation therapy planning is to determine how the ablation probe placement and power distribution change over time, resulting in an optimal ablation distribution that meets clinical protocol objectives (e.g., a certain thermal dose distribution must be delivered to the tumor while preserving as much of the nearby organ at risk (OAR) as possible (one or more protected volumes 118). To safely and effectively perform thermal ablation therapy, it is beneficial to understand the characteristics and limitations of each associated component of the procedure. Given the patient's initial pre-implantation CT (computed tomography) or US (ultrasound) images, the gross tumor volume (GTV) and all nearby normal tissues and organs at risk are delineated manually or automatically. Subsequently, a limited number of probes are actually inserted into and / or around the GTV area. Finally, the corresponding optimal power distribution is calculated over time, resulting in the desired ablation zone covering the tumor. Depending on the receiving organ, size, and location of the tumor, the ablation modality—radiofrequency (RF), focused ultrasound (FU), microwave (MW), laser, or cryoablation—is selected by the physician. The method of inserting the ablation probe into the tumor depends on the receiving organ but typically involves manual placement of the device.

[0114] Treatment planning involves the placement and operation of equipment, which typically depends on the equipment manufacturer's specifications and the physician's experience. Specifically, the power control of the equipment is usually automated by the ablation device or manually selected according to the equipment manufacturer's specifications.

[0115] Figure 5 An example of a discrete set of ablation modes is shown. Each in the set includes an ablation probe 500 and an ablation mode 502. It may also contain data describing the probe 504 and specific operating conditions 506 for individual modes.

[0116] exist Figure 5 In this context, different combinations of microwave probe ablation power and delivery time settings provide a set of "expected" ablation zones. Typically, manufacturers use tissue heating models to estimate the ablation size through finite element analysis. In practice, the size and shape of individual ablations produced by a particular electrode can vary and depend on factors such as the tumor environment, microperfusion within the tissue, and the proximity of the ablation to large blood vessels.

[0117] To ablate identified tumor areas, the standard thermal ablation procedure involves physicians selecting a set of probe locations, along with corresponding ablation power and delivery time values, from a combination set provided in the equipment vendor's datasheet. Figure 5To minimize unnecessary damage to nearby normal tissues and organs at risk (OARs), the ablation zone should be kept within 1–2 cm of the gross tumor outline whenever possible. Manual forward planning can be very lengthy, error-prone, and suboptimal because it does not employ any numerical optimization methods to ensure the selection of the optimal set of ablation devices for patient treatment.

[0118] From a theoretical perspective, the thermal ablation coverage problem falls under the well-known category of set coverage problems. The best solution should present the fewest number of ablations to completely cover the tumor while minimizing collateral damage to nearby healthy tissue. Although the set coverage problem is NP-hard, an exact solution can be achieved using a greedy algorithm with a polynomial-time approximation for set coverage, which selects the set according to a rule: "At each stage, select the set containing the largest number of uncovered elements."

[0119] Figure 6 An example of another method is shown; this method begins at step 600. Next, in step 602, a discrete set of ablation device configurations is generated. This can include various 3D spatial tip positions and orientations, and may also include ablation patterns. Next, in step 604, the set P is initialized with zero selected probes, either for hot-start or previous ablation. The method then proceeds to step 606, where a composite ablation binary mask is calculated. This is the union of all currently selected probe ablation binary masks in set P. Next, in step 608, the ablation objective function is calculated. Then, in step 610, the optimal probe configuration Z is selected and added to set P.

[0120] In some examples, step 612 is optional. In step 612, local refinement of the selected probe configuration is performed for step P. This can be achieved, for example, by changing the discrete position to various positions that can be continuously varied. The method then proceeds to step 614. Step 614 is a question box; whether the stopping condition is met. If true, the method proceeds to step 616. If false, the method returns to step 606 and selects more ablation probes and ablation modes.

[0121] An example application may include one or more of the following five steps, starting from step 0:

[0122] 0. The planner takes note of providing a set of regions of interest for segmentation. This process can be automated or based on user input. The segmentation is of interest into cancerous, at-risk, and healthy tissue. The planner will also take note of converting the prescribed clinical protocol (i.e., the prescribed list of clinical objectives / constraints) into corresponding ablation-based mathematical objective functions (e.g., convex quadratic functions), which will be optimized in subsequent optimization steps. Given ablation device vendor data, corresponding ablation binary masks are generated for all power-time settings provided in the device datasheet. Here, 1's represents the ablation region, and 0's represents the non-ablation region. A 3D mesh of potential ablation probe tip positions and probe orientations is sampled. Finally, a discrete set of ablation device configurations is generated by combining the sampled set of 3D probe tip positions / orientations with all vendor-based ablation binary masks associated with all possible power-time settings.

[0123] 1. Select the current best probe configuration that minimizes the ablation-based objective function value from the discrete set generated in step (0).

[0124] 2. Given the new set of probe configurations selected in step (1), the corresponding probe positions are locally refined together with the corresponding ablation binary masks. As previously done in step (1), an ablation-based objective function is used here to guide the optimizer toward the optimal set of probe tip positions, orientations, and delivered ablation binary masks.

[0125] 3. Repeat steps (1) and (2) until a solution that satisfies all clinical constraints is reached, and / or select the user-defined maximum number of probes.

[0126] 4. Delivery planning. Here, the newly implanted probe can be tracked in real time. In the event of tracking misalignment compared to the precisely planned location, steps (1)-(3) are iteratively re-executed until a new re-optimized solution is found.

[0127] Another aspect of the example is that the optimization problem definition is described in the following steps, starting from step 0.

[0128] 0. Optimization problem definition:

[0129] The tissue volume under consideration is segmented into structures, and a binary mask is provided for each k-th structure of interest (i.e., tumor, organ at risk, normal tissue, etc.).

[0130] Physicians prescribe clinical protocols that list all ablation coverage-based goals that must be met. A typical goal of thermal ablation therapy is to deliver consistent ablation of localized cancer cells while preserving as much of the surrounding healthy tissue as possible. This goal is challenging because the ablation of a large target volume conflicts with the damage tolerance induced by ablation of normal tissue.

[0131] Before introducing a set of objective functions based on ablation coverage, it is necessary to mathematically represent the delivery ablation region of a single probe configuration and the composite ablation resulting from delivery by multiple probe configurations.

[0132] a. Generation of the initial discrete set for ablation probe configuration

[0133] Based on the supplier's equipment datasheet, the desired ablation zone for the j-th combination of each ablation power and delivery time value is converted into a corresponding 3D ablation binary mask:

[0134]

[0135] Figure 7 The diagram illustrates how an ablation device configuration 702, including the specifications of the ablation probe and ablation mode 502, is used to generate an ablation mask 700. The area selected for ablation mode 502 can be seen to create the mask 700. The ablation device configuration uses (power, time) = (60W, 5 minutes) and the corresponding binary ablation mask for the microwave ablation device (right, E1).

[0136] In this invention, N is constructed. c A discrete set C of probe configurations. Here, each probe configuration is a combination of discrete probe paths (i.e., skin insertion point, orientation, and final probe tip position) and a desired binary mask A generated by the power-delivery time setting. c composition( Figure 3 (Right). To maintain a moderately low cardinality N for set C. c Only probe configurations with binary masks having at least partially overlapping tumor regions are considered. Furthermore, since the discrete positions and orientations of the optimally selected probes are subsequently locally refined, set C can be filled using a moderate sampling factor and coarse spatial discretization of the probe positions and orientations.

[0137] Finally, when delivering multiple ablation device configurations, the composite ablation binary mask A is defined as all relevant ablation binary masks A. s Union of:

[0138] A = ∪ s A s (E2)

[0139] b. Ablation structure volume fraction

[0140] The concept of ablation volume fraction is used below to quantify the amount of volume of the structure affected by ablation. Assume the k-th segmented structure, whose current ablation volume fraction v is generated by the composite ablation binary mask A. k It is given by the following formula:

[0141]

[0142] Here S k Let A represent the binary mask for segmenting the region of interest (ROI) k, where |•| is the cardinality (i.e., size) operator, and |A∩S k | indicates the cumulative ablation volume and structure (i.e., the segmented structure portion currently ablated, see...). Figure 8 The cardinality of the intersection between ).

[0143] Figure 8 Two views are shown of a composite ablation binary mask 122 made from three different ablation methods. The left side shows the composite ablation binary mask itself. The right side shows the composite ablation binary mask 122 with the desired ablation volume 116. The area marked 126 is the unablated volume.

[0144] c. Thermal ablation composite objective function

[0145] Typically, all clinical objectives for the region of interest are translated into corresponding bilateral or unilateral closed-precision ablation coverage functions.

[0146] To achieve the required tumor ablation coverage while preserving as much nearby healthy tissue as possible, physicians can specify ablation coverage thresholds for all regions of interest, such as a given minimum (and / or maximum) volume fraction t for ablating the k-th structure. For this purpose, the following objective function based on quadratic ablation coverage can be used as an optimization constraint:

[0147]

[0148]

[0149] Here, H(·) is the Heaviside step function, t is the specified minimum (maximum) ablation volume fraction threshold, and v k This represents the current ablation structure volume fraction generated by composite ablation A (see E3).

[0150] All mathematical goals f i (A) is given as a function of the binary mask A of the composite ablation zone generated by all selected ablation probe configurations (Equation E2).

[0151] The following composite objective function

[0152]

[0153] It can be defined and minimized to achieve the desired ablation coverage.

[0154] Quantity w i and w RThis indicates that importance weights are manually set for all objective functions and regularization terms based on ablation coverage.

[0155] The regularization term R(A) is optional and may have different forms. This can be used to enforce certain requirements for specific ablation region characteristics. For example, we can use Tikhonov regularization to avoid the cardinality (i.e., size) of the composite ablation binary mask A being too high, or use a regularization term to control (e.g., reduce) the size of the overlap (i.e., intersections) between all delivered probe ablation binary masks that result in redundant ablation of tumor subregions.

[0156] 1. Optimal discrete probe configuration selection:

[0157] In this invention, we assume that given N c The probe configuration is a discrete set C, and for each c-th configuration, the ablation binary mask A is calculated. c (Step 0)

[0158] P is defined as the set of currently selected probe configurations, and its corresponding composite (i.e. union) ablation zone binary mask A is shown in E2.

[0159] Some examples of using the set-covering greedy iterative algorithm aim to add new probe configurations c* to the selection set P, which may result in an increase in the value of E6 based on the ablation function F(A).

[0160] To select the optimal probe configuration, in the current step n, the objective function value f is calculated for each possible c-th probe configuration using the following formula. c :

[0161] f c =F(A∪A) c c = 1, ..., N c (E7)

[0162] Here, c represents the index of the ablation probe configuration, and Nc is the total number of probe configurations in the discrete set C.

[0163] In each iteration n, the probe configuration c* corresponding to the minimum objective function value is selected and added to the optimal set c* of probe configurations:

[0164] c * =min{f c}, c = 1, ..., N c (E8)

[0165] a. Accelerate the evaluation of the ablation composite objective function

[0166] This example discloses a greedy iterative algorithm in which multiple optimal probe configurations are selected progressively. The selection of the optimal probe configuration requires computing all N probes in each algorithm iteration. c The objective function f of the ablation device configuration c =F(A∪A) c ).

[0167] Therefore, for all N c The ablation device configuration recalculates the volume fraction v of all ablated structures in each nth iteration of the algorithm. k (Equ.E3).

[0168] These volume calculations can represent a significant bottleneck in algorithm performance.

[0169] To accelerate these v k The calculation can be performed using the following equation:

[0170] v k (A∪A c S k ) = v k (A, S) k )+v k (A c S k )-v k (A∩A c S k (E9)

[0171] The quantities on the right-hand side of E9 can be pre-calculated at the beginning, including these quantities v. k (A c S k These v k (A, S) k The value is given and known from previous algorithm iterations, and only the last term v can be calculated. k (A∩A c S k To obtain the new value v for all ablation device configurations k (A∪A c S k )N c .

[0172] Because the intersection (A∩A) c The cardinality of the set is significantly smaller than that of the union, so we can use Equation 9 (A∪A) c )Calculate v k (A∪A c S k This can greatly reduce the required computation time.

[0173] 2. Iterative local refinement of the selected probe configuration:

[0174] Given the new set P of probe configurations selected in step (1), the spatial positioning of the corresponding probes and the delivered ablation binary mask can be locally refined by solving a hybrid discrete-continuous iterative constraint optimization problem.

[0175] This local refinement step is not mandatory, and can be omitted when the physician deems the spatial discretization of the initial set C used to generate the probe configuration in step (0) to be sufficiently accurate.

[0176] However, if a very coarse spatial discretization is used to reduce the computational burden of step (1), an iterative local refinement step can be performed to improve the accuracy of the delivered probe configuration and thus increase the ablation coverage of the tumor (see below). Figure 9 ).

[0177] In each refinement iteration, firstly, the optimal local rigidity transformation of all currently selected probe ablation masks is determined by minimizing an ablation-based function related to the treatment target.

[0178] Figure 9 The repositioning of the ablation probe is shown. 500 indicates the position. This position can be changed via a rigid shift to position 500'. The newly adjusted ablation position is 902. This provides better coverage of the desired ablation volume 116 while still avoiding the protected volume 118. Figure 9 This paper illustrates the local refinement of the probe position / orientation and its ablation zone binary mask through rigid transformation. Starting with the initially selected discrete probe position and ablation binary mask, the optimal rotation-translation transformation (R,t) is calculated and applied to the probe position / orientation to increase the ablation coverage of the tumor.

[0179] This can be achieved by minimizing the function introduced in E6.

[0180]

[0181] Regarding the rigid transformation parameter R p , t p The probe tip position and orientation selected for x-transformation at each grid location, and the associated binary mask:

[0182] A[R p , t p ](x)=∪ p∈P A p (R p x+t p (E11)

[0183] Optionally, lower and upper bounds can be enforced on the optimization problem to restrict the optimization search to a set of feasible solutions that include only rotational and translational transformations of clinically deliverable probes.

[0184] Ultimately, the optimal rigid transformation parameters for all selected probe configurations were obtained.

[0185] As a second local refinement step, the position of the rigidly transformed probe remains fixed, and the corresponding delivered ablation binary mask A is optimized and updated. p Here, all possible binary masks provided in the device manufacturer's specifications are evaluated at the current position of the rotating and translating probe. Finally, a new set A of ablation masks that produces the minimum ablation coverage objective function value is selected. p (See below) Figure 10 ).

[0186] Figure 10 The optimization of the probe ablation mask is illustrated. In this example, the initial position of the ablation probe 500 is changed, causing the initial position 900 to move to several different adjusted ablation positions 902, 902'. In this case, position 902 better covers the desired ablation volume 116 while still avoiding one or more protected volumes 118. All possible ablation binary masks in the manufacturer's specifications can be evaluated at the current optimal position of the rotating and translating probe. The ablation binary mask that produces the best objective function value is then selected.

[0187] To reduce the computational cost of this local refinement step, we can restrict the objective function evaluation to only updating the ablation binary mask of the last selected probe configuration in step (1), while keeping the binary masks of all other selected probes fixed.

[0188] This iterative local refinement step will switch between probe positioning optimization and optimal binary mask selection until the user-specified ablation-based objective function accuracy and / or the maximum number of local refinement iterations are achieved.

[0189] 3. Iterative optimization strategy: process parameters The optimization is performed in an iterative strategy that uses a continuous optimization method to switch between the optimal selection of probe configuration in the initial discrete set (step 1) and the local refinement of the currently selected probe configuration (step 2).

[0190] Figure 6 A flowchart of the proposed greedy iterative method is given. First, in step (1), the optimal probe configuration is selected from a large set of discrete probe configurations. Then, in the second step, all currently selected probes are locally repositioned to improve the total ablation coverage of the tumor, and so on.

[0191] The algorithm iteration will stop if / when the given accuracy of the ablation coverage function F is reached, and / or when the given maximum number of selected ablation probes is reached. In these cases, it will return to using N. sel The final solution obtained by the selected probe.

[0192] Finally, to improve overall computation time, more than one new probe configuration can be selected in each iteration. This will reduce the number of function calculations required to find the optimal solution at the cost of some degradation in ablation coverage quality.

[0193] By utilizing the prior knowledge of clinical experts, the configuration P of the selected probe and the corresponding composite ablation zone A can be correctly initialized.

[0194] If this initialization is not available, then a completely empty initial setting is assumed (i.e., ...). If the iterative strategy then fills the set P with the most promising probe configuration, then the iterative strategy will fill the set P with the most promising probe configuration.

[0195] 4. Real-time directional guidance and adaptive ablation coverage optimization: The planning optimized in step 3 can be delivered by a clinical expert. Here, the implanted probe is continuously tracked in real time. In the event of a detected misalignment of the probe tip relative to the planned position, these tracked misalignments can be taken into account to adaptively re-optimize the remaining probe set and the corresponding composite ablation (steps (1)-(3)) in order to reconstruct the desired planning quality.

[0196] Figures 11 to 21 An example of evaluation using synthetic data is shown. A 3D synthetic phantom was used, consisting of a tumor volume 1104, an organ at risk (OAR) region 1106, and a healthy tissue region 1102. A 3D isotropic mesh with 20 voxels in each direction was used up to this point, where the target region ( Figure 11 (1104) is a parallelepiped with a size of 7*5*5 voxels, and the OAR region ( Figure 11 (1106) is a cube with 5 voxel edges, while the remaining 3D mesh is divided into normal tissue regions ( Figure 11 ,1102).

[0197] As mentioned above, Figure 11 A synthetic phantom 1100 for use in the simulation method is shown. Within the synthetic system, the large area marked 1102 represents normal tissue. The area indicated by 1104 represents a tumor or the desired ablation volume. The volume marked 1106 represents an OAR or organ at risk equivalent to the protected volume.

[0198] Before initiating the iterative optimization method, an initial discrete set C of ablation device configurations was generated. Simulated ablation probes delivering spherical ablation zones with radii of 0.5, 1, and 2 voxels were used in the experiments. For the spatial position and orientation of the probe tip, only probe configurations with spherical binary masks that at least partially overlap with the tumor region were considered. Finally, the total N was pre-calculated. C =3513 probes were configured as input to the algorithm. The specified optimization protocol and corresponding mathematical objectives are shown in Table I. In this experiment, no regularization was added to the objective function based on composite ablation. Finally, a maximum of 15 ablation probes and a relative objective function accuracy of 1E-15 were used as the stopping criterion.

[0199] After 12 iterations, the optimal set of 12 probe configurations that fully satisfy all specified protocol constraints was returned. The optimal objective function values ​​for each iteration are given in Table II. The ablation regions (blue) for different iterations are shown below. Figure 12 As shown. The ablation composite objective function values ​​for each iteration are plotted on... Figure 13 Finally, the ablation volume fractions of the tumor, OAR, and normal tissue areas are as follows: Figure 14 , 15 As shown in Figure 16.

[0200] Figure 12 The simulation after ablation using a single probe is shown. Region 1200 represents the ablation zone 1200. A single ablation only ablated a portion of the tumor 1104.

[0201] Figure 13 The simulation after ablation using two probes is shown. The ablation zone 1200 has grown. The area marked 1300 is the ablation zone in normal tissue 1102.

[0202] Figure 14 The simulation after ablation using three probes is shown.

[0203] Figure 15 The simulation after ablation using four probes is shown.

[0204] Figure 16 The simulation after ablation using seven probes is shown.

[0205] Figure 17 The ablation was shown after using 12 probes.

[0206] Some experimental results are summarized in Tables I and II below.

[0207]

[0208] Table I: Step 0 - Problem Definition: Clinical Protocol and Corresponding Mathematical Objectives.

[0209]

[0210]

[0211] Table II: Ablation function value and ablation structure volume fraction for each iteration.

[0212] Figure 18 The value of the objective function f, which is a function of the number of probes used (1800), is shown. This is... Figures 11 to 17 The simulation shows the ablation objective function F(A) value for each iteration.

[0213] Figure 19 The fraction of the ablation target 1900 is shown as a function of the number of probes 1800 used. This is the fraction v of the ablation target area. Tumor (A)

[0214] Figure 20 The ablation area v is shown as a percentage of 2000, which is a function of the number of probes used (1800). OAR (A) The score shows that even after using 12 probes, the ablated OAR score did not exceed 1.6%.

[0215] Figure 21 The figure shows the ablation area of ​​normal tissue as a percentage of the probe 1800, which is a function of the probe number 2100. NT (A) score.

[0216] Some examples also provide a GUI for a thermal ablation treatment planning system.

[0217] User interactions and actions performed through the user interface may include one or more of the following functions:

[0218] Select an ablation device for treatment delivery;

[0219] Import diagnostic patient images (e.g., US, CT, MR, etc.);

[0220] Segmenting anatomical structures of interest on the patient's diagnostic images;

[0221] Optional image registration may be required for cancer description;

[0222] Manually (or automatically) select a discrete set of potential skin entry points for treatment delivery;

[0223] Generate a discrete set of ablation probe configurations;

[0224] Define the clinical protocol (i.e., the set of constraints / goals to be met);

[0225] Optimize reverse planning treatment plans;

[0226] Deliver the optimal treatment plan.

[0227] If an adaptive real-time treatment planning and delivery workflow is applied, the last two functions in the list above can be iterated multiple times (see step (4) above).

[0228] exist Figure 22 The document provides an example of a GUI tab for users to select an ablation device. Here, the user can select an ablation device from a list of pre-determined devices, and the manufacturer's data is easily displayed. Finally, the user is prompted to approve the selected device.

[0229] Figure 22 An example of a user interface 2200 is shown. This user interface 2200 has controls 2202 for selecting a list of pre-determined probes. The user interface 2200 also has controls 2204 for selecting probe configurations. This can, for example, determine the power used and delivery time. For operator convenience, the ablation mode can be displayed. The user interface 2200 also includes controls 2206 for approving the selection. Here, the user can select an ablation device from a list of pre-determined devices. Manufacturer data can also be easily displayed.

[0230] Figure 23 A user interface for generating ablation probe configuration is shown. A medical image 114 and possible skin entry points 2302 are shown. These can be selected manually, for example. Control 2204 allows entry points to be added to a list. Control 2304 for adding entry points using a lookup table is present. Control 2206 for approving selections is present. Figure 23 The generation of the discrete set for ablation probe configuration (discrete set of ablation probe locations) is performed. Here, multiple potential skin entry points E1, E2, E3, ... (ab) are selected. If a 2D template mesh is used for treatment delivery in the context of brachytherapy, the list of entry points can also be automatically calculated. Finally, a lookup table for probe configuration is calculated based on the set of entry points, multiple user-given parameters, and device vendor data (c).

[0231] exist Figure 23The diagram shows a model of the GUI tabs used to generate a discrete set of ablation probe configurations (see step (0.a)). Here, a number of potential skin entry points (ab) are manually selected. The entry point set can also be automatically calculated if a 2D template mesh is used for treatment delivery. After providing the list of skin entry points, the user is prompted to set several discretization parameters, such as probe fan-beam angle sampling for calculating straight-line trajectories under a discrete angle set. These probe fan-beam trajector ...

[0232] Figure 24 Another user interface 2400 is shown for the reverse planning tab of thermal ablation. A graph 2402 shows the ablation volume of the lesion and several organs at risk. Figure 24 The section shows the thermal ablation reverse planning tab. Here, lateral, sagittal, frontal, and 3D plotted images of the patient are displayed. Segmented structures can be depicted, for example, with different colors. The optimal total ablation area is visualized and overlaid on the patient images. To facilitate planning evaluation, a volume fraction plot of the ablation structure under the current optimized plan can be provided. Here, for example, a color bar chart can be used to display the current ablation portion of the structure volume. In this plot, up / down arrows can be used to indicate the minimum / maximum ablation volume thresholds specified in the clinical protocol. Finally, clinical protocol constraints can be displayed. Here, the user can provide minimum and maximum threshold sets for ablation volume coverage for each structure. Figure 19 In the example, the user specifies that at least 95% of the tumor lesion must be ablated, while ablation of up to 45%, 25%, and 30% of the OAR volume is also required. Importance weights can also be set to assign different levels of importance to the specified constraints. The structural volume fraction under the current optimization program is also given. Here, traffic lights can be used to highlight constraints that do not meet the specified minimum or maximum volume thresholds (e.g., in red). Additional user-defined optimization stopping criteria can be specified via the GUI, such as the maximum number of optimization iterations, the tolerance of the ablation objective function value, and the maximum number of probes to be used.

[0233] As mentioned above, Figure 24The thermal ablation reverse planning tab is shown. On the left, transverse, sagittal, frontal, and 3D plotted images of the patient are displayed. Segmented structures can be depicted using different colors (blue: lesion, red: organ at risk 1 (OAR1), etc.). The optimal total ablation area is visualized and overlaid on the patient images. On the right, at the top, a volume fraction plot of the ablation structures under the current optimized plan is shown. Vertical bars can be used to depict the current fraction of the structure ablation volume. Arrows are used to indicate the minimum and maximum ablation volume thresholds currently specified in the clinical protocol. In the lower right, the prescribed clinical protocol is presented on the "Ablation Protocol" tab. Here, the user can specify minimum and maximum thresholds ("prescribed") for the ablation volume of each structure. In the example, the user specifies ablation of at least 95% of the tumor lesion, while ablating the maximum 45%, 25%, and 30% of OAR1, 2, and 3. Importance weights can also be set to give more importance to certain specific constraints. The structure fractional volume of the current optimized plan is also displayed under the "projected" column. Here, traffic lights are used to indicate constraints that do not meet the specified minimum / maximum volume thresholds.

[0234] Finally, the optimal delivery sequence of the ablation probes can be displayed according to user requirements (see [link]). Figure 20 (Lower right). All probes can be physically visualized and overlaid on the patient image at optimized locations. Specific probes selected from the listed sequences are automatically highlighted. The probe list provides geometric and delivery information such as skin entry point, vendor ablation area to be used, ablation power, delivery time, etc. The order of probes to be delivered may change dynamically when a 3D probe tip tracking system is available and an adaptive real-time treatment planning and delivery workflow is applied. Here, each time a mismatch is identified between the calculated and delivered probe locations, a new optimization can be performed to restore planning quality, resulting in a new optimal total ablation area and a new corresponding sequence of remaining probes to be delivered.

[0235] Figure 25 Another view of the user interface 2400 is shown. In this example, the probe insertion position 2500 is shown so that the operator knows where to insert the ablation probe. Figure 25The thermal ablation inverse planning tab is shown. When the user clicks the "Probe Planning" tab (bottom right), the sequence of ablation probes to be delivered is displayed. All probes are also physically visualized and overlaid on the patient image. Specific probes can be selected from the list, and they will be automatically highlighted (orange). The probe list provides some geometric and delivery information (e.g., skin entry point, vendor ablation zone to be used, ablation power, delivery time, etc.). When a probe tip tracking system is available and an adaptive real-time treatment planning and delivery workflow is applied, the order of probes to be delivered may change dynamically. Here, each time a mismatch is identified between the calculated and delivered probe positions, a new optimization can be performed to restore planning quality, resulting in a new optimal total ablation and corresponding probe sequence to be delivered.

[0236] Although the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary rather than restrictive; the invention is not limited to the disclosed embodiments.

[0237] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art who practice the claimed invention can understand and implement variations of the disclosed embodiments. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single processor or other element can perform the functions of several items listed in the claims. The fact that some measures are listed only in mutually different dependent claims does not mean that combinations of these measures cannot be advantageously used. Computer programs can be stored / distributed on suitable media, such as optical storage media or solid-state media provided with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope.

[0238] List of numbers in the attached diagram

[0239] 100 Medical System

[0240] 102 Computers

[0241] 104 processor

[0242] 106 Optional Hardware Interfaces

[0243] 108 User Interface

[0244] 110 Memory

[0245] 112 Machine-executable instructions

[0246] 114 Three-dimensional medical imaging data

[0247] 116 Expected ablation volume

[0248] 118 One or more protected volumes

[0249] 120 Discrete Set of Ablation Probe Locations

[0250] 122 Composite Ablation Binary Mask

[0251] 124. List of ablation probe configurations in sequence

[0252] 126 Unmelted volume

[0253] 128 Selected ablation probe configuration

[0254] 130 Ablation Pattern Discrete Set

[0255] 132 The selected objective function

[0256] 134 Standard Preset Set

[0257] 200 Receive three-dimensional medical image data describing the subject;

[0258] 202 Receive the desired ablation volume, wherein the desired ablation volume is registered to three-dimensional medical image data;

[0259] 204 Receive one or more protected volumes, wherein one or more protected volumes are registered to three-dimensional medical image data;

[0260] 206 Generate a discrete set of ablation probe locations registered to the 3D medical image data;

[0261] 208 Receive a discrete set of ablation patterns, wherein the discrete set of ablation patterns includes multiple ablation patterns

[0262] 210 Initialize the composite ablation binary mask registered to the 3D medical image data

[0263] 212 Initialize the sequential list of ablation probe configurations

[0264] 214 The unablated volume is determined by comparing a composite ablation binary mask with the desired ablation volume, wherein the unablated volume is registered to three-dimensional medical image data.

[0265] 216 The selection of ablation probe configuration is determined by using a chosen objective function that depends on one or more protected volumes, unablated volumes, ablation mode discrete sets, and ablation probe location discrete sets.

[0266] 218. The composite ablation binary mask is updated by calculating the union between the composite ablation binary mask and one of the discrete sets of ablation patterns located at one of the discrete sets of ablation probe positions; and

[0267] 220 Select the ablation probe configuration and add it to the list of sequential ablation probe configurations.

[0268] Does 222 satisfy any of the criteria in the predefined set?

[0269] End of 224

[0270] 300 Medical System

[0271] 302 Magnetic Resonance Imaging System

[0272] 304 magnet

[0273] 306 Magnet Hole

[0274] 308 Imaging Area

[0275] 309 View

[0276] 310 Magnetic Gradient Coil

[0277] 312 Magnetic Gradient Coil Power Supply

[0278] 314 RF coil

[0279] 316 transceiver

[0280] 318 subjects

[0281] 320 subjects supported

[0282] 330 Pulse Sequence Command

[0283] 332 Magnetic Resonance Imaging Data

[0284] 400 Acquiring 3D Medical Imaging Data

[0285] 500 ablation probe

[0286] 502 Ablation Mode

[0287] 504 describes the probe data.

[0288] 506 Operating Conditions

[0289] Starting from 600

[0290] 602 Generate a discrete set C of ablation device configurations.

[0291] 604 Initialize set P with zero of the selected probes (or perform a warm start).

[0292] 606 Calculation of a composite ablation binary mask A

[0293] 608 Calculate the ablation objective function value

[0294] 610 Select the "Best" probe configuration in C and add it to set P.

[0295] Local refinement of the probe configuration selected in set P (612)

[0296] Does the 614 stopping criterion meet?

[0297] End of 616

[0298] 700 ablation mask

[0299] 702 Ablation Equipment Configuration

[0300] 800 ablation volume fraction

[0301] 802 successfully ablated volume

[0302] 804 Residual Non-Ablation

[0303] 900 Initial ablation location

[0304] 902 Adjusted ablation site

[0305] 902' Adjusted ablation position

[0306] 1100 Synthetic Phantom

[0307] 1102 Normal tissue

[0308] 1104 Tumor (Desired ablation volume)

[0309] 1106 OAR (Protected Volume)

[0310] 1200 Tumor Ablation Zone

[0311] 1300 Ablation zone within normal tissue

[0312] Number of probes: 1800

[0313] 1802 Objective function value F(A)

[0314] 1900 ablation target fraction

[0315] 2000 ablation OAR score

[0316] 2100 fractions of normal tissue ablated

[0317] 2200 User Interface

[0318] 2202 Control for selecting the list of probes to be requisitioned

[0319] 2204 Control for selecting probe configuration

[0320] 2206 Control for approving selections

[0321] 2300 User Interface

[0322] 2302 Possible skin entry points

[0323] 2304 A control for adding entry points to a list.

[0324] 2306 A control used to automatically calculate lookup tables.

[0325] 2400 User Interface

[0326] 2402 Ablation Volume

[0327] 2500 Probe insertion position.

Claims

1. A medical system (100, 300), comprising: Memory (110), storing machine-executable instructions (112); Processor (104), configured to control the medical system, wherein the execution of machine-executable instructions causes processor (104) to: Receive (200) three-dimensional medical image data (114) describing the subject (318); Receive (202) the desired ablation volume (116), wherein the desired ablation volume is registered to the three-dimensional medical image data (114). Receive (204) one or more protected volumes (118), wherein the one or more protected volumes are registered to the three-dimensional medical image data (114). Generate (206) a discrete set (120) of ablation probe locations registered to the three-dimensional medical image data (114); Receive (208) ablation mode discrete set (130); Initialization (210) is registered to a composite ablation binary mask (122) of the three-dimensional medical image data (114), wherein the composite ablation binary mask stores the composite or intersection of the ablation patterns used; and Initialize (212) a sequential list of ablation probe configurations (124), the sequential list of ablation probe configurations being a list of indexed grid positions and insertion depths of ablation probe insertion blocks; The execution of the machine-executable instructions further enables the processor (104) to generate the sequential list of ablation probe configurations (124) by: The unablated volume (126) is determined (214) by comparing the composite ablation binary mask (122) with the desired ablation volume (116), wherein the unablated volume (126) is registered to the three-dimensional medical image data (114). The selected objective function (132) is used to determine (216) the selected ablation probe configuration (128), which depends on the one or more protected volumes (118), the unablated volumes (126), the ablation pattern discrete set (130), and the ablation probe location discrete set (120), wherein the selected ablation probe configuration (128) specifies an ablation probe location in the ablation probe location discrete set and an ablation pattern in the ablation pattern discrete set; The composite ablation binary mask is updated (218) by calculating the union between the composite ablation binary mask and an ablation pattern in the discrete set of ablation patterns, wherein the ablation pattern is located at the position of an ablation probe in the discrete set of ablation probe positions; and Add (220) the selected ablation probe configuration to the sequential list of ablation probe configurations; and The execution of the machine-executable instructions further causes the processor to repeatedly generate the sequential list of ablation probe configurations until one or more criteria in a predetermined set (134) of criteria are met.

2. The medical system of claim 1, wherein each ablation probe position is defined by: a discrete skin entry point corresponding to a grid position of the indexed ablation probe insertion block, a discrete angle from a set of discrete angles defining the linear trajectory of the ablation probe, and a step size along each linear probe trajectory, wherein the discrete angle is a discretization parameter set by the user.

3. The medical system of claim 1, wherein the execution of the machine-executable instructions further causes the processor to update (612) the sequential list of ablation probe configurations by iteratively performing the following: Each ablation probe position in the discrete set of ablation probe positions is assigned to a probe position that can change continuously; and The probe position, which can change continuously, is modified using a second objective function.

4. The medical system of claim 3, wherein the continuously variable probe position includes linear position and / or rotation.

5. The medical system according to claim 1, 2, 3 or 4, wherein the medical system further includes a display (108), wherein execution of the machine-executable instructions further causes the processor to display the sequential list of ablation probe configurations on the display.

6. The medical system of claim 5, wherein the sequential list of ablation probe configurations is shown as any one of the following: A list of grid locations and insertion depths for indexed ablation probe insertion blocks; and A diagram (2500) of the ablation probes specified in the sequential list of ablation probe configurations.

7. The medical system of claim 5, wherein the medical system further comprises a medical imaging system (302) configured to acquire the three-dimensional medical image data, wherein the execution of the machine-executable instructions further causes the processor to control the medical imaging system to acquire (400) the three-dimensional medical image data.

8. The medical system of claim 7, wherein the execution of the machine-executable instructions further causes the processor to: Control the medical imaging system to acquire real-time ablation probe tracking data; The real-time ablation probe tracking data is used to determine the position of the ablation probe registered to the three-dimensional medical image data; and The display is used to draw the position of the ablation probe superimposed on the three-dimensional medical image data in real time.

9. The medical system of claim 8, wherein the execution of the machine-executable instructions further causes the processor to: Determine the measured location for the selected ablation probe configuration within the sequential list of ablation probe configurations, and Using the measured location as a fixed position, the sequential list of ablation probe configurations is recalculated.

10. The medical system of claim 7, wherein the execution of the machine-executable instructions further causes the processor to: The medical imaging system is used to measure the ablation volume. The desired ablation volume is corrected by removing the ablation volume from the desired ablation volume; and The sequential list of ablation probe configurations is recalculated using the corrected desired ablation volume.

11. The medical system according to claim 1, 2, 3 or 4, wherein the selected objective function includes an objective function based on secondary ablation coverage, a minimum / maximum ablation coverage function, and a uniform secondary coverage function.

12. The medical system according to claim 1, 2, 3 or 4, wherein the predetermined set of standards includes any one of the following: The maximum number of ablation probes allowed; The desired ablation volume and the ablation coverage target; and Its combination.

13. The medical system according to claim 1, 2, 3 or 4, wherein the discrete set of ablation patterns includes ablation patterns for any of the following: ablation modes of cryoablation probe; Laser ablation probe ablation modes; Microwave ablation probe ablation modes; Focused ultrasound ablation probe ablation modes; Radiofrequency ablation probe ablation modes; Irreversible electroporation probe ablation mode; and Its combination.

14. A computer program product comprising machine-executable instructions (112) for execution by a processor (104) controlling a medical system (100, 300), wherein execution of the machine-executable instructions causes the processor to: Receive (200) three-dimensional medical image data (114) describing the subject (318); Receive (202) the desired ablation volume (116), wherein the desired ablation volume is registered to the three-dimensional medical image data; Receive (204) one or more protected volumes (118), wherein the one or more protected volumes are registered to the three-dimensional medical image data; Generate (206) a discrete set of ablation probe locations registered to the three-dimensional medical image data (120); Receive (208) ablation mode discrete set (130); and Initialization (210) is registered to the composite ablation binary mask (122) of the three-dimensional medical image data, wherein the composite ablation binary mask stores the composite or intersection of the ablation patterns used; Initialize (212) a sequential list of ablation probe configurations (124), the sequential list of ablation probe configurations being a list of indexed grid positions and insertion depths of ablation probe insertion blocks; The execution of the machine-executable instructions further enables the processor to generate the sequential list of ablation probe configurations by: The unablated volume (126) is determined (214) by comparing the composite ablation binary mask with the desired ablation volume, wherein the unablated volume is registered to the three-dimensional medical image data; The selected objective function (132) is used to determine (216) the selected ablation probe configuration (128), the selected objective function depending on the one or more protected volumes, the unablated volumes, the ablation mode discrete set and the ablation probe location discrete set, wherein the selected ablation probe configuration specifies an ablation probe location in the ablation probe location discrete set and an ablation mode in the ablation mode discrete set; The composite ablation binary mask is updated (218) by calculating the union between the composite ablation binary mask and an ablation pattern in the discrete set of ablation patterns, wherein the ablation pattern is located at the position of an ablation probe in the discrete set of ablation probe positions; and Add (220) the selected ablation probe configuration to the sequential list of ablation probe configurations; and The execution of the machine-executable instructions further causes the processor to repeatedly generate the sequential list of ablation probe configurations until one or more criteria in a predetermined set (134) of criteria are met.

15. A method of operating a medical system (100, 300), wherein the method comprises: Receive (200) three-dimensional medical image data (114) describing the subject (318); Receive (202) the desired ablation volume (116), wherein the desired ablation volume is registered to the three-dimensional medical image data; Receive (204) one or more protected volumes (118), wherein the one or more protected volumes are registered to the three-dimensional medical image data; Generate (206) a discrete set of ablation probe locations registered to the three-dimensional medical image data (120); Receive (208) ablation mode discrete set (130); and Initialization (210) is registered to the composite ablation binary mask (122) of the three-dimensional medical image data, wherein the composite ablation binary mask stores the composite or intersection of the ablation patterns used; Initialize (212) a sequential list of ablation probe configurations (124), the sequential list of ablation probe configurations being a list of indexed grid positions and insertion depths of ablation probe insertion blocks; The processor used to control the medical system executes machine-executable instructions to generate the sequential list of ablation probe configurations by: The unablated volume (126) is determined (214) by comparing the composite ablation binary mask with the desired ablation volume, wherein the unablated volume is registered to the three-dimensional medical image data; The selected ablation probe configuration is determined (216) using the selected objective function (132), which depends on the one or more protected volumes, the unablated volumes, the ablation mode discrete set, and the ablation probe location discrete set, wherein the selected ablation probe configuration specifies an ablation probe location in the ablation probe location discrete set and an ablation mode in the ablation mode discrete set; The composite ablation binary mask is updated (218) by calculating the union between the composite ablation binary mask and an ablation pattern in the discrete set of ablation patterns, wherein the ablation pattern is located at the position of an ablation probe in the discrete set of ablation probe positions; and Add (220) the selected ablation probe configuration to the sequential list of ablation probe configurations; and The sequential list of ablation probe configurations is repeatedly generated until one or more criteria in a predetermined set of criteria (134) are met.

Images