Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/34—Trocars; Puncturing needles
  • A61B17/3403—Needle locating or guiding means
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N5/1001—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy using radiation sources introduced into or applied onto the body; brachytherapy
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1477—Needle-like probes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/00234—Surgical instruments, devices or methods for minimally invasive surgery
  • A61B2017/00238—Type of minimally invasive operation
  • A61B2017/00274—Prostate operation, e.g. prostatectomy, turp, bhp treatment
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/34—Trocars; Puncturing needles
  • A61B17/3403—Needle locating or guiding means
  • A61B2017/3405—Needle locating or guiding means using mechanical guide means
  • A61B2017/3411—Needle locating or guiding means using mechanical guide means with a plurality of holes, e.g. holes in matrix arrangement
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00315—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for treatment of particular body parts
  • A61B2018/00547—Prostate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00571—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for achieving a particular surgical effect
  • A61B2018/00577—Ablation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/02—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques
  • A61B2018/0293—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by cooling, e.g. cryogenic techniques using an instrument interstitially inserted into the body, e.g. needle
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/1815—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves
  • A61B2018/1869—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using microwaves with an instrument interstitially inserted into the body, e.g. needles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
  • A61B2018/2005—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser with beam delivery through an interstitially insertable device, e.g. needle
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
  • A61B2034/101—Computer-aided simulation of surgical operations
  • A61B2034/102—Modelling of surgical devices, implants or prosthesis
  • A61B2034/104—Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
  • A61B34/10—Computer-aided planning, simulation or modelling of surgical operations
  • A61B2034/107—Visualisation of planned trajectories or target regions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
  • A61N5/1001—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy using radiation sources introduced into or applied onto the body; brachytherapy
  • A61N5/1007—Arrangements or means for the introduction of sources into the body
  • A61N2005/1012—Templates or grids for guiding the introduction of sources
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N7/00—Ultrasound therapy
  • A61N7/02—Localised ultrasound hyperthermia
  • A61N2007/025—Localised ultrasound hyperthermia interstitial

Definitions

• the invention relates to a planning device and system for positioning treatment applicators, as well as to a planning method and computer program for positioning treatment applicators.
• treatment applicators utilizing thermal ablation or forms of radiation therapy is getting increasingly popular for cancer treatments due to their applicability to non-re sectable tumors and the rapid recovery of the patient.
• an optimal placement of the applicators is crucial, which is often determined based on the tumor position and size, the device manufacturers’ specifications, and the physician’s experience. While it is common to utilize a manual placement of ablation devices, also image- guided systems are known, for example from US 2019/0008591 Al and EP 3 777 748 Al.
• a planning device for positioning treatment applicators comprises a providing unit configured to provide a distance to be considered between applicator entry points, and a processor configured to conduct an optimization iteration step which determines an optimal applicator configuration comprising a first applicator entry point, inactivate all entry points within the distance from the first applicator entry point such that these entry points are unavailable to further optimization iteration steps, conduct a further optimization iteration step which determines an optimal applicator configuration comprising a further applicator entry point.
• the device provides positioning support for ablation treatment applicators, wherein the processor is further configured to receive a three-dimensional medical image data descriptive of a subject and receive a desired ablation volume, wherein the desired ablation volume is registered to the three-dimensional medical image data.
• the term desired ablation volume is a label for a particular ablation volume.
• the desired ablation volume is registered to the three-dimensional medical image data. That is to say the desired ablation volume marks a region or identifies a region of the three- dimensional medical image data.
• the processor is further configured to receive one or more protected volumes, wherein the one or more protected volumes are registered to the three-dimensional medical image data.
• the one or more protected volumes may for example be volumes which could injure the subject if they are sonicated or ablated too much.
• the one or more protected volumes may be used to protect organs or critical anatomical structures.
• the processor is further configured to generate a discrete set of ablation applicator positions registered to the three-dimensional medical image data.
• the locations around the desired ablation volume may be used to generate a pattern or set of discrete ablation applicator positions. These for example could be generated using a predetermined pattern or algorithm for generating the discrete set.
• the processor is further configured to receive a discrete set of ablation patterns.
• the discrete set of ablation patterns comprises multiple ablation patterns.
• the discrete set of ablation patterns could be ablation patterns for a single applicator, for example oriented in different directions and/or with different amounts of power supply. In other examples the discrete set of ablation patterns may be from multiple applicators.
• the processor is further configured to initialize a composite ablation binary mask registered to the three-dimensional medical image data.
• the step of initializing the composite ablation binary mask may be to create a blank or unused composite ablation binary mask.
• the term composite ablation binary mask is used to identify a particular binary mask.
• the composite ablation binary mask in this case is an ablation binary mask that stores the composite or intersection of all the ablation patterns that are used.
• the processor is further configured to determine an unablated volume by comparing the composite ablation binary mask to the desired ablation volume, wherein the unablated volume is registered to the three-dimensional medical image data.
• the composite ablation binary mask may be used to identify regions that have already been ablated or are intended to be ablated using the configurations on the sequential ablation applicator configuration list. A comparison between the desired ablation volume and the composite ablation binary mask can be used to find a region which still needs to be ablated or additional applicators added so that ablation occurs.
• the processor is further configured to determine an applicator configuration comprising at least one applicator entry point using a chosen objective function dependent upon the one or more protected volumes, the unablated volume, the discrete set of ablation patterns, the discrete set of ablation applicator positions, and inactivated applicator entry points.
• the chosen applicator configuration specifies one of the discrete set of applicator entry points and one of the discrete set of ablation patterns.
• a chosen objective function can be used to evaluate the various combinations of the discrete set of ablation patterns in each of the discrete set of applicator entry points.
• the chosen objective function is used to choose the best choice.
• the chosen objective function may be used to objectively measure such things as coverage of the unablated volume as well as avoiding the one or more protected volumes.
• the processor is further configured to update the composite ablation binary mask by calculating a union between the composite ablation binary mask and the one of the discrete set of ablation patterns located at the one of the discrete set of ablation applicator positions.
• the chosen objective function may comprise a quadratic ablation coverage-based objective function, a minimum/maximum ablation coverage function, and a uniform quadratic coverage function.
• a use of any of these functions may be beneficial because they are effective at both choosing regions to ablate as well as protecting critical regions which are specified in the one or more protected volumes.
• the entry points are at least one of the following: grid holes of a grid template, skin entry points.
• the grid template can be one of the following: rigid grid template, flexible grid template, in particular transperineal grid template, breast template, flexible lead template, grid attached to gynecological (GYN) applicator. Said templates may be used to segment regions of interests, such as target lesions and risk organs.
• no template is used.
• the entry points are skin entry points.
• the distance can be at least one of the following: minimum distance in a template or skin surface plane, in particular a minimum Euclidean distance, maximum distance in a template or skin surface plane, in particular a maximum Euclidean distance.
• the distance can further be a minimum and/or maximum distance between applicator trajectories. Generally, the inactivation of all entry points is based on the first applicator entry point and the distance from the first application entry point.
• further optimization iterations are conducted until no further optimal applicator configuration is determinable considering the inactivated grid holes or entry points.
• the processor is further configured to conduct a refinement iteration step at which an applicator configuration is removed from the solution and replaced by another applicator configuration, and a further optimization iteration step is conducted to determine an optimal applicator configuration.
• the applicator configuration to be removed is selected orderly, i.e. one-by-one, from the optimal applicator configurations.
• the applicator configuration to be removed can be selected based on a list of all applicators, wherein the applicator configurations to be removed can be automatically selected subsequently, i.e. one after the other, from the list, for instance, until all applicator configurations of the applicator list have been removed at least once or any other abortion criterion is met.
• the refinement iterations are stopped when every applicator configuration was removed once during the iterations or when the removed applicator configuration is determined again as the result of the iteration step.
• the applicator configuration to be removed is selected by means of coverage-based functional values or derivatives to select a least optimal applicator configuration.
• Coverage-based functional values are values quantifying a coverage that a set of applicator configurations provides to a region of interest, for example, a tumor.
• an applicator configuration can be removed from the solution and a coverage-based functional value can be determined for the remaining applicator configuration.
• This can be repeated and a remaining applicator configuration can be determined for which the coverage-based functional value and thus the coverage of the region of interest is changed least with respect to the full set of applicator configurations.
• the removed applicator configuration is then the least optimal applicator configuration and can be selected.
• the least optimal applicator configuration refers to the applicator configuration that changes the coverage-based functional value the least with respect to the coverage-based functional value of the full set of applicator configurations.
• the providing unit can comprise at least one of the following: graphical user interface, configuration file, database.
• the providing unit is configured to provide the distance to be considered between applicator entry points to the processor.
• the providing unit can also be a receiving unit for receiving the distance, for instance, from a storage or a user input, and providing the same to the processor for further processing.
• the device can further comprise a graphical user interface configured to visualize at least one of the following: optimal set of applicator positioning configurations, inactivated entry points, distance to be considered between entry points.
• the graphical user interface of the providing unit and the graphical user interface of the device may be the same graphical user interface or differ from each other.
• the graphical user interface may comprise at least one of the following: Text field, continuous slider, discrete slider, radio button or pull-down menu, scroll-wheel interaction while visualizing radius on top of grid/patient anatomy.
• the device may be configured for being updated, in particular on demand after changing setting as implemented and/or in real-time upon changing settings.
• an ablation system comprises an ablation treatment applicator and a planning device as defined in any of claims 1-12.
• the ablation treatment applicator my utilize at least one of the following ablation principles: Focused Ultrasound (FU), Microwave (MW), Radiofrequency (RF), Focal Laser Ablation (FLA), Cryo-ablation, Irreversible Electroporation (IRE), or Brachytherapy.
• Applicable treatment organs can be prostate, breast, kidney, liver, cervix.
• Applicable treatment workflows can be focal, quadrant, hemi-gland prostate, whole-gland prostate, partial breast treatment. Said classifications depend upon the goal of the ablation procedure.
• a focal treatment may affect only a small area within the prostate, a quadrant treatment a quadrant portion of the prostate gland, a hemi-gland treatment typically affects half of the gland, wherein a whole-gland treatment affects the complete gland.
• a partial breast treatment is directed towards ablating the breast partially.
• a planning method for positioning treatment applicators comprises providing a distance to be considered between entry points and geometric information of a target to be treated, conducting an optimization iteration step which determines an optimal applicator configuration comprising a first applicator entry point based on the geometric information of the target to be treated, inactivating all applicator entry points within the distance from the first applicator entry point such that these entry points are unavailable to further optimization iteration steps, conducting a further optimization iteration step which determines a further optimal applicator configuration comprising a further applicator entry point based on the geometric information of the target to be treated.
• the entry points are at least one of the following: grid holes of a grid template, skin entry points.
• a planning computer program for positioning treatment applicators comprising program code means for causing a computer to carry out the steps of the method as defined in claim 14.
• the device for providing positioning support for treatment applicators of claim 1 the ablation system of claim 13, the method for providing positioning support for treatment applicators of claim 14, and the computer program of claim 15, have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims.
• Fig. 1 shows schematically and exemplarily an embodiment of an ablation systems comprising an ablation treatment applicator and a positioning support device
• Fig. 2 shows schematically and exemplarily an embodiment of the positioning support device
• Fig. 3 illustrates the use of a grid template to provide positioning support for treating an organ
• Fig. 4 illustrates a method for providing positioning support for treatment applicators
• Fig. 5 illustrates the steps of the method
• Fig. 6 provides an alternative example of an illustration of different steps of the method.
• Fig. 7 illustrates a computer program for providing positioning support for treatment applicators.
• Fig. 1 shows an ablation system 100.
• the ablation system 100 comprises treatment applicators 8 that are configured as ablation treatment applicators 20 for percutaneous cancer treatments.
• the ablation treatment applicators 20 may utilize for example Focused Ultrasound (FU), Microwave (MW), Radiofrequency (RF), Focal Laser Ablation (FLA), Cryo-ablation, Irreversible Electroporation (IRE) or Brachytherapy. All these therapy modalities require the insertion of applicators 8 into the tumor or affected organ.
• a grid template 14 comprising grid holes 12 is utilized.
• the applicators 8 are inserted into the grid holes 12 of the grid template 14.
• the grid holes 12 are an example of entry points 10.
• applicators 8 are inserted into certain grid holes 12 to treat the affected organ or tumor.
• the ablation system 100 comprises a device 2 for providing position support for the treatment applicators 8.
• the device 2 comprises a providing unit 4 as shown in Fig. 2.
• the providing unit 4 is configured for providing a distance r to be considered between applicator entry points 10.
• These applicator entry points 10 may be grid holes 12 of the grid template 14, as shown in Fig. 1, or arbitrary skin entry points, also called free hand entry points.
• the providing unit may comprise a graphical user interface, a configuration file or a database.
• the device 2 furthermore comprises a graphical user interface 21 configured to visualize a set of applicator positioning configurations to finally assist the user in inserting the applicators 8 into the grid holes 12 of the grid template 14 or arbitrary skin entry points.
• the distance r which is to be considered between applicator entry points 10 is a distance in a surface plane 16 of the grid template 14, as shown in Fig. 1.
• Fig. 3 shows an example of different applicator trajectories 18 leading towards an organ 24 to be treated.
• the device 2 furthermore comprises a processor 6.
• the processor 6 of the device 2 is configured to conduct an optimization iteration step which determines an optimal applicator configuration comprising a first applicator entry point 10 and inactivating all entry points 22 within the distance r from the currently selected entry point 10 such that these entry points 22 are unavailable to further optimization iterations.
• the processor 6 is further configured to conduct a further optimization iteration step which determines a further optimal applicator configuration comprising a further applicator entry point 10.
• step 0 the planner takes care to provide a set of segmented regions of interest. This process may be done automatically or based on user input. The segmentation into cancerous, risk, and healthy tissue is of interest. The planner will also take care to translate a prescribed clinical protocol (i.e., a list of prescribed clinical goals/constraints) to corresponding ablation-based mathematical objective functions (e.g., convex quadratic functions) which will be optimized during the subsequent optimization steps.
• a prescribed clinical protocol i.e., a list of prescribed clinical goals/constraints
• ablation-based mathematical objective functions e.g., convex quadratic functions
• step 1 the current best applicator configuration that minimizes the ablationbased objective function value is selected from the discrete set generated at step 0.
• step 2 given a new set of selected applicator configurations at step 1, the corresponding applicators’ positions are locally refined along with the corresponding ablation binary masks.
• an ablation-based objective function is used to guide the optimizer towards the optimal set of applicators’ tip positions, orientations and delivered ablation binary masks.
• steps 1 and 2 are executed repeatedly until a solution satisfying all clinical constraints is reached, and/or the user-defined maximum number of applicators was selected.
• tissue volume under consideration is segmented into structures and binary masks S k are provided for each k-th structure of interest (i.e. tumor, organs at risk, normal tissue, etc.).
• the physician prescribes a clinical protocol with a list of all ablation coverage-based goals that need to be satisfied.
• a typical goal in thermal ablation therapy is the delivery of conformed ablation over locally cancer cells while sparing as much as possible all nearby healthy tissues. This goal is challenging because ablation of large target volumes conflicts with normal tissue ablation-induced damage tolerance.
• the initial discrete set of ablation applicator configurations is generated.
• the expected ablation zone for each j-th combination of ablation power and delivery time values is converted to a corresponding 3D ablation binary mask: , . > rl if the position x is inside the expected ablated zone
• a discrete set C of N c applicator configurations is built.
• each applicator configuration consists of a combination of discretized applicator paths (i.e. skin insertion point, direction and final applicator tip position), and the expected binary mask A c produced by a power-delivery time setting.
• N c discretized applicator paths
• N c the expected binary mask A c produced by a power-delivery time setting.
• N c for the set C
• only applicator configurations with binary masks at least partly overlapping the tumor region will be considered.
• a moderate sampling factor and a coarse spatial discretization of the applicator positions and directions can be used to populate the set C.
• the composite ablation binary mask A is defined as the union of all related ablation binary masks A s :
• S k indicates the binary mask of the k-th segmented region of interest
• is the cardinality (i.e. the size) operator
• indicates the cardinality of the intersection between the cumulative ablated volume and the structure (i.e. the portion of segmented structure which is currently ablated).
• the physician could prescribe thresholds for ablation coverage in all regions of interest, e.g. a given minimum (and/or maximum) volume fraction t of a k-th structure is ablated.
• thresholds for ablation coverage in all regions of interest e.g. a given minimum (and/or maximum) volume fraction t of a k-th structure is ablated.
• quadratic ablation coverage-based objective functions might be used as optimization constraints:
• //( ⁇ ) is the Heaviside step function
• t is the prescribed minimum (maximum) ablation fractional volume threshold
• v k indicates the current ablated fractional structure volume produced by the composite ablation A (see Equ. E3).
• the quantities and w R represent manually set importance weights for all ablation coverage -based objective functions and a regularization term, respectively.
• the regularization term R (A) is optional, and might have different forms. This can be used to enforce some requested specific ablation zone characteristics. For example, we could use a Tikhonov regularization to avoid a too high cardinality (i.e. size) for the composite ablation binary mask A, or a regularization term to control (e.g. reduce) the size of the overlaps (i.e. intersections) among all delivered applicators’ ablation binary masks leading to redundant ablations of tumor sub-regions.
• optimal discrete applicator configurations are selected as follows: It is assumed that a discrete set C of N c applicator configurations is given, and for each configuration c-th an ablation binary mask A c has been computed. P is defined as the set of currently selected applicators configurations, and A its corresponding composite (i.e. union) ablation zone binary mask computed as indicated in Equ. E2.
• a goal for some examples that use set covering greedy iterative algorithm is to add to the selection set a new applicator configuration c* which can potentially lead to an improved value of the ablation-based function F(A) at Equ. (E6).
• c represents the index of the ablation applicator configuration
• Nc is the total number of applicators’ configurations in the discrete set C.
• the v fc (A c , S k ) quantities can be precomputed at beginning, the v fc (A, S k ) values are given and known from the previous algorithm iteration, while only the final term v k (A n A c , S k ) may be computed to get the new v k (A U A c , S k ) value for all N c ablation device configurations. Since the cardinality of the intersection set (A Cl A c ) is obviously smaller than the cardinality of the union set (A U A c ), computing v k (A U A c , S k ) using the Equ. 9 can drop enormously the required computation time.
• an iterative local refinement of the selected applicator configurations is conducted.
• the corresponding applicators’ spatial positioning and delivered ablation binary mask can be locally refined by solving a mixed discrete-continuous iterative constrained optimization problem.
• This local refinement step is not mandatory, and could be dropped when the spatial discretization used for the generation of the initial set C of applicator configurations at the initial step is considered accurate enough by the physician.
• an iterative local refinement step can be performed to improve the precision of the delivered applicator configurations and consequently to increase the ablation coverage of the tumor.
• the optimal local rigid transformations of all currently selected applicators’ ablation masks are determined by minimizing an ablation-based functional related to the treatment goals.
• an optimal roto-translation transformation (R, t) is computed and applied to the applicator position/direction in order to increase the ablation coverage of the tumor. This can be achieved by minimizing the function introduced at Equ. E6 with respect to the parameters of rigid transformations R p , t p used to transform the selected applicator tip positions and directions and associated binary masks at each grid position x: A[R p , t p ](x) — UpepAp (R p x + tp) (El l)
• this local refinement step will toggle between the applicator’s positioning optimization and the optimal binary masks selection till a user-prescribed ablation-based objective functional precision, and/or a maximum number of local refinement iterations, is achieved.
• the procedure parameters (P, R* P , t are optimized in an iterative strategy that toggles between an optimal selection of applicator configurations out of an initial discrete set, and a local refinement of the currently selected applicator configurations using continuous optimization methods. Firstly, the best applicator configuration is selected out of a big set of discrete applicator configurations, then, during the second step, all currently selected applicators are locally repositioned to improve the total ablation coverage of the tumor, and so on.
• the algorithm iterations will be stopped if/when a given relative ablation coverage-based functional F precision is achieved, and/or a given maximum number of selected ablation applicator was reached. In these cases, the last achieved solution with N set selected applicators is returned.
• the optimized plan can be delivered by clinical experts.
• implanted applicators are continuously tracked in real-time.
• these tracked misplacements can be taken into account to adaptively re-optimize the remaining set of applicators and the corresponding composite ablation in order to re-establish the expected plan quality.
• Fig. 4 shows a related method 200 for providing positioning support for treatment applicators 8.
• the method 200 comprises providing 202 a distance r to be considered between entry points 10 and geometric information of a target to be treated, conducting 204 an optimization iteration step and determining which determines an optimal applicator configuration comprising selecting a first applicator entry point 10 based on the geometric information of the target to be treated, inactivating 206 all applicator entry points 22 within the distance r from the currently first selected applicator entry point 10 such that these entry points 22 are unavailable to further optimization iterations steps, conducting 208 a further optimization iteration step which determines and determining a further optimal applicator configuration comprising selecting a further applicator entry point 10 based on the geometric information of the target to be treated.
• the iteration steps which determine an optimal applicator configuration comprising selecting a first applicator entry point 10 may again be based on the algorithm described above.
• Fig. 5 and Fig. 6 The steps conducted by the device 2 and the method 200 are illustrated with regard to Fig. 5 and Fig. 6.
• an optimization iteration has been conducted that includes an optimal applicator configuration comprising selecting an applicator entry point 10.
• all entry points 22 within the distance r from the entry point 10 are inactivated such that these entry points 22 are unavailable to further optimization iterations.
• a further optimization iteration is conducted and a further optimal applicator configuration comprising selecting a further applicator entry point 10 is determined.
• all entry points 22 within a distance r from the now selected entry point 10 are inactivated.
• the iteration steps are conducted until no further optimal applicator configurations can be determined considering the inactivated entry points 22.
• the inactivated entry points 22 form a circular inactivation mask, as shown in grey color enforced around each currently selected entry point 10.
• the method has the advantage to reduce the optimization freedom, also called solver freedom, only progressively along the iterations. At the very beginning, all entry points 10 or grid holes 12 will be active and selectable, however, the more the solver will select entry points 10 or grid holes 12 during iterations, the more constrained the solver search and solution space will become, since more and more entry points 10 will become inactive. The solution produced by the solver using such a technique will ensure a minimum distance r defined by the user is enforced.
• Fig. 6 shows another example at which the proposed iterations are applied to a grid template 14, comprising grid holes 12 that are spaced apart from each other.
• applicators 8 may be inserted into every grid hole 12. This is shown in the left of Fig. 6.
• grid holes 12 will be inactivated.
• only grid holes 22 along a virtual vertical and horizontal axis (not shown in Fig. 6) through the entry point 10 will be deactivated.
• In the right grid template 14, also grid holes 22 that are diagonal to a virtual horizontal or vertical axis going through entry point 10 will be deactivated.
• the distance r may be a minimum distance in a template or a skin surface plane 16 (see Fig. 1), in particular a minimum Euclidean distance.
• the distance r may also be a maximum distance in the template or skin surface plane 16, in particular a maximum Euclidean distance.
• the distance r may also be a minimum and/or maximum distance between applicator trajectories 18 as shown in Fig. 3.
• the optimization comprises a heuristic iterative discrete optimization.
• the optimization iteration considers at least one of the following: grid geometry information of a grid template 14, regional ablation coverage goals, manufacturer ablation zones for the selected applicator 8 to be used for the treatment, segmentation mesh considering regions of interest, in particular lesions and organs at risk, leading grid position.
• the grid geometry information of the grid template 40 may comprise at least one of the following: grid model, grid size, number of grid holes, distance between grid holes.
• the processor 6 of the device 2 as shown in Fig. 2 may further be configured to conducting a refinement iteration at which an optimal applicator configuration is removed from the solution and replaced by a new optimal applicator configuration.
• the refinement iteration can comprise removing optimal applicator configurations one- by-one, i.e. orderly, with each iteration step.
• a list of applicators can be used, wherein in each iteration step of the refinement iteration an applicator configuration corresponding to an applicator of the list of applicators is removed.
• the applicator configurations can be removed subsequently, i.e. as defined by the sequence of applicators on the list.
• the applicator configuration can be selected and removed that when removed from the current solution, does degrade the functional as little as possible.
• This applicator configuration can be regarded as the least optimal application configuration, i.e.
• the respective least optimal application configuration can be determined based on coverage functional values that can be computed for a given set of applicators and ablation zones, for instance, utilizing equation E7 as described above. Moreover, also functional derivatives could be analytically computed or discretely approximated based on the coverage-based functional values, if needed, to determine the least optimal applicator configuration.
• Fig. 7 shows a computer program 300.
• the computer program 300 provides support for position planning for treatment applicators 8.
• the computer program 300 comprises program code means 302 for causing a computer to carry out the steps of the method as shown in Fig. 4.
• the device 2 or the method 200 may further be configured to provide at least one of the following delivery parameters: Brachytherapy catheters positions, thermal ablation propositions, dual times, ablation times/power values.
• delivery parameters Brachytherapy catheters positions, thermal ablation propositions, dual times, ablation times/power values.
• a single unit or device may fulfill the functions of several items recited in the claims.
• the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
• Procedures like conducting an optimization iteration or inactivating all applicator entry points within the distance from the currently selected entry point, et cetera, performed by one or several units or devices can be performed by any other number of units or devices.
• These procedures can be implemented as program code means of a computer program and/or as dedicated hardware.
• a computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.
• the invention relates to a planning device for providing positioning support for treatment applicators.
• the device comprises a providing unit configured for providing a distance to be considered between applicator entry points and a processor. It has been found that when utilizing treatment applicators, in particular ablation treatment applicators, placing two or more applicators closely together increases the risk of ablating and damaging more tissue than required for the therapy success. By configuring the processor to inactivate all entry points within a distance r from a currently selected entry point such that these entry points are unavailable to further optimization iterations, and then conducting a further optimization iteration, an optimal applicator configuration can be provided that is effective with regard to the therapy success while the risk of ablating more tissue than required is reduced.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Surgery (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Robotics (AREA)
• Pathology (AREA)
• Radiology & Medical Imaging (AREA)
• Surgical Instruments (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=79021732

Family Applications (1)

Country Status (5)

Families Citing this family (4)

Citations (3)

Family Cites Families (2)

• 2021
  • 2021-12-03 EP EP21212152.9A patent/EP4190252A1/en not_active Withdrawn
• 2022
  • 2022-11-23 JP JP2024532223A patent/JP2024542643A/ja active Pending
  • 2022-11-23 US US18/712,864 patent/US20250017658A1/en active Pending
  • 2022-11-23 WO PCT/EP2022/082920 patent/WO2023099299A1/en not_active Ceased
  • 2022-11-23 CN CN202280080118.2A patent/CN118369055A/zh active Pending
  • 2022-11-23 EP EP22821963.0A patent/EP4440455B1/en active Active

Patent Citations (3)

Also Published As

Similar Documents

Legal Events