A method and system for cryoablation plan evaluation

Abstract

The present application relates to the technical field of cryoablation, and provides a cryoablation plan evaluation method, comprising the following steps: S1: obtaining a pre-designed puncture path and treatment parameters; S2: performing temperature field distribution calculation on a target area requiring cryoablation and tissue organs around the target area based on the puncture path and the treatment parameters; and S3: performing quantitative analysis based on the calculation result of the temperature field distribution, and evaluating the control rate of the target area and the damage degree of the tissue organs. Compared with the path planning of the existing navigation software, the temperature field distribution calculation and the quantitative analysis based on the calculation result of the temperature field distribution are introduced, the planned puncture path and treatment parameters can be subjected to temperature field numerical simulation in the actual treatment process, and the evaluation of the temperature field numerical simulation result can be performed. The effect of the current treatment scheme can be known before treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cryoablation, and in particular to a cryoablation plan evaluation method and system. BACKGROUND

[0002] Cryoablation refers to a method of freezing diseased tissue by low-temperature technology to achieve in situ inactivation of solid tissue. The principle is to use low temperature to rapidly cool the diseased tissue to destroy cells and cause cell necrosis or apoptosis, thereby achieving the treatment purpose. Since cryoablation uses a physical method of energy exchange to achieve the treatment purpose, its trauma and side effects on the human body are much lower than those of conventional radiotherapy and chemotherapy.

[0003] The development of cryotherapy technology has roughly gone through the following stages:

[0004] Liquid nitrogen cryoablation therapy: Liquid nitrogen cryotherapy equipment is a liquid nitrogen cryotherapy equipment with adjustable temperature. Liquid nitrogen is delivered to the probe tip through a concentric sleeve with a vacuum outer layer protection, so that the temperature is maintained at about -196℃, thereby performing cryotherapy on the tissue of the treatment site.

[0005] Image-guided cryoablation therapy: With the development of imaging equipment, CT, ultrasound and other imaging equipment monitoring technologies have been integrated into the clinical application of cryotherapy. Image-guided cryoablation therapy technology can monitor the position and size of the ice ball during cryotherapy, effectively reducing damage to normal tissue and promoting the rapid development of cryoablation technology. The second generation of cryotherapy technology has developed rapidly with the maturity of imaging technologies such as ultrasound imaging, opening a new era of minimally invasive cryoablation.

[0006] Argon-nitrogen low-temperature cryoablation therapy: With the development of cryotherapy, a new type of cryotherapy equipment has been developed using the Joule-Thomson throttling refrigeration principle. This equipment uses argon throttling refrigeration and nitrogen throttling heating to achieve rapid cryotherapy and rewarming needle extraction. Later, a super-low-temperature freezing and high-intensity rewarming combined treatment mode and technical solution were developed.

[0007] At present, CT image navigation or ultrasound image monitoring is used in almost all ablation procedures in the puncture process. Most procedures also use navigation software for preoperative planning. However, preoperative planning is only a definition of the puncture target point, segmentation of critical tissue and organs, and selection of the puncture path, including assessment of the puncture distance of the path, whether there are important organs or tissues around the path, and whether the risk is high. However, these considerations are limited to geometric planning of the puncture path, and do not achieve a true cryoablation plan. Since there is a lack of simulation of the treatment process and evaluation of the simulation results, the plan cannot guarantee the best treatment effect. SUMMARY

[0008] In view of the above problems, the present application aims to provide a cryoablation plan evaluation method and system, which introduces a temperature field calculation function and a quantitative evaluation method on the basis of the original puncture path geometry planning, can numerically simulate the actual treatment process for the designed puncture path and treatment parameters, and quantitatively evaluate the obtained temperature field temperature simulation results by temperature volume histogram (TVH), so that the effect of the current treatment plan can be known before actual treatment, thereby reducing the side effects caused by the uncertainty of the plan and reducing the risk of surgery.

[0009] The above application object of the present application is achieved by the following technical solutions:

[0010] A cryoablation plan evaluation method, comprising the following steps:

[0011] S1: obtaining a pre-designed puncture path and treatment parameters;

[0012] S2: calculating the temperature field distribution of a target area requiring cryoablation and the surrounding tissue organs based on the puncture path and the treatment parameters;

[0013] S3: performing quantitative analysis based on the calculation results of the temperature field distribution, and evaluating the control rate of the target area and the damage degree of the tissue organs.

[0014] Further, in step S1, before obtaining the pre-designed puncture path and treatment parameters, it further comprises:

[0015] Importing patient image data;

[0016] Based on the patient image data, the delineation and visualization of the target area and the tissue organs are performed;

[0017] Based on the delineated patient image data, the puncture path is designed, and the treatment parameters including the ablation needle model and the freezing time are designed;

[0018] The puncture path and the ablation needle are displayed in two or three dimensions.

[0019] Further, in step S2, the calculation of the temperature field distribution of the target area requiring cryoablation and the surrounding tissue organs based on the puncture path and the treatment parameters is specifically:

[0020] The temperature value of each point of the target area and the tissue organs is calculated by using a method including Comsol multi-physics simulation software;

[0021] The treatment parameters, physical information and geometric information of the heat conduction medium including the target region and the tissue organ are input into the Comsol multi-physical field simulation software, and the temperature value of any point in the geometric space of the heat conduction medium is output through the calculation of the Comsol multi-physical field simulation software, wherein the physical information is the thermal conductivity and specific heat of the heat conduction medium, and the geometric information is the geometric shape of the heat conduction medium.

[0022] Further, in step S3, quantitative analysis is performed based on the calculation result of the temperature field distribution, and the control rate of the target region and the damage degree of the tissue organ are evaluated, specifically:

[0023] The calculation result of the temperature field distribution is quantitatively analyzed by using a temperature volume histogram TVH, and the temperature volume histogram TVH includes an integral mode and a differential mode.

[0024] The integral mode is defined as the ratio of the volume below the current temperature in the region of interest to the total volume of the region of interest, and the differential mode is defined as the ratio of the volume in the same temperature difference interval in the region of interest to the total volume of the region of interest, wherein the region of interest refers to the region that needs to be counted, including the target region and the tissue organ.

[0025] Further, the integral mode is specifically:

[0026]

[0027] Wherein, I represents integration, i, j, k represent the subscript of the voxel v, the voxel is a discrete three-dimensional point with a fixed volume in the target region or the tissue organ, the subscript corresponds to the integer identifier of the three-dimensional coordinates of the voxel, t represents the temperature of the voxel v, t min represents the minimum temperature value, and T represents the temperature threshold value.

[0028] For the integral mode TVH, the higher the ratio of the integral mode calculated by the target region, the higher the control rate of the target region, and the lower the ratio of the integral mode calculated by the tissue organ, the lower the damage degree of the tissue organ.

[0029] Further, the differential mode is specifically:

[0030] The differential mode TVH is specifically:

[0031]

[0032] Wherein, D represents differential, i, j, k represent the subscript of the voxel v, the voxel is a discrete three-dimensional point with a fixed volume in the target area or the tissue organ, the subscript corresponds to the integer identification of the three-dimensional coordinates of the voxel, t represents the temperature of the voxel v, T1, T2 represent temperature thresholds;

[0033] For the differential mode TVH, the higher the ratio of the calculated differential mode in the low temperature interval of the target area is, the higher the control rate of the target area is, and the lower the ratio of the calculated differential mode in the low temperature interval of the tissue organ is, the lower the damage degree of the tissue organ is.

[0034] Further, the cryoablation plan evaluation method of the present application further comprises: when the control rate of the target area and the damage degree evaluation result of the tissue organ in step S3 are not ideal, the puncture path and the treatment parameter are redesigned; and jumping to step S1 to evaluate the puncture path and the treatment parameter.

[0035] A cryoablation plan evaluation system for performing the cryoablation plan evaluation method as described above, comprising:

[0036] A plan acquisition module for acquiring a pre-designed puncture path and treatment parameter;

[0037] A temperature field distribution calculation module for calculating the temperature field distribution of a target area requiring cryoablation and a tissue organ around the target area based on the puncture path and the treatment parameter;

[0038] A temperature field distribution analysis module for performing quantitative analysis based on the calculation result of the temperature field distribution, and evaluating the control rate of the target area and the damage degree of the tissue organ.

[0039] A computer device comprising a memory and one or more processors, the memory storing computer code, the computer code being executed by the one or more processors to cause the one or more processors to perform the method as described above.

[0040] A computer readable storage medium storing computer code, when the computer code is executed, the method as described above is performed.

[0041] Compared with the prior art, the present application includes at least one of the following beneficial effects:

[0042] (1) By providing a cryoablation plan evaluation method, comprising the following steps: S1: obtaining a pre-designed puncture path and treatment parameters; S2: calculating the temperature field distribution of the target area requiring cryoablation and the tissue organs around the target area based on the puncture path and the treatment parameters; S3: Based on the calculation result of the temperature field distribution, quantitative analysis is carried out, and the control rate of the target area and the damage degree of the tissue organs are evaluated. Compared with the existing navigation software path planning, the above technical solution introduces temperature field distribution calculation and quantitative analysis based on temperature field distribution calculation results, which can perform temperature field numerical simulation on the planned puncture path and treatment parameters in the actual treatment process, and evaluate the temperature field numerical simulation results. The effect of the current treatment plan can be known before treatment.

[0043] (2) It lays a technical foundation for standardizing cryoablation treatment prescriptions in clinical practice, which is of great clinical significance. At the same time, it can also reduce the side effects caused by the uncertainty of the plan and reduce the risk of surgery. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The overall flowchart of the cryoablation plan evaluation method of the present application;

[0045] Figure 2 The integral module TVH schematic diagram of the present application;

[0046] Figure 3 The integral module TVH schematic diagram of the present application;

[0047] Figure 4 The overall structure diagram of the cryoablation plan evaluation system of the present application. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0049] Those skilled in the art can understand that, unless specifically stated, the singular forms "a", "an" and "the" used herein also include the plural forms. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0050] At present, CT image navigation or ultrasound image monitoring is used in almost all clinical ablation procedures during puncture, and most of the procedures also use navigation software for preoperative planning. However, preoperative planning is only the definition of the puncture target point, the segmentation of the key tissue and organs, and the selection of the puncture path, including the evaluation of the puncture distance of the path, whether there are important organs or tissues around the path, and whether the risk is high or not. However, these considerations are limited to the geometric planning of the puncture path, and a real sense of cryoablation plan is not realized. Since there is no simulation of the treatment process and evaluation of the simulation results, the plan cannot guarantee the best treatment effect.

[0051] The present application provides a cryoablation plan evaluation method and system, which introduces temperature field calculation function and quantitative evaluation method on the basis of original puncture path geometric planning, can simulate the actual treatment process of the designed puncture path and treatment parameters, and perform quantitative temperature volume histogram (TVH) evaluation on the obtained temperature field temperature simulation results. The effect of the current treatment scheme can be known before actual treatment, thereby reducing the side effects caused by the uncertainty of the plan and reducing the risk of surgery.

[0052] The following is described by specific embodiments:

[0053] First embodiment

[0054] As shown in Figure 1 , the present embodiment provides a cryoablation plan evaluation method, comprising the following steps:

[0055] S1: obtaining a pre-designed puncture path and treatment parameters.

[0056] Specifically, the present application simulates the temperature field distribution for the pre-designed puncture path and the set treatment parameters. The target control rate and tissue organ loss degree of the pre-designed puncture path and treatment parameters are simulated to evaluate the treatment effect of the current set puncture path.

[0057] For the pre-designed puncture path and treatment parameters, the steps include:

[0058] (1) Importing and localizing management of patient image data

[0059] The importing of patient image data refers to importing patient DICOM image data through two ways of local DICOM file directory and DICOM network transmission. The local management of patient data refers to the loading, saving, list display and list retrieval of plan data.

[0060] (2) Target area and tissue organ delineation and visualization

[0061] Based on the patient image data, the delineation and visualization of the target region and the tissue organ are performed. The target region refers to the region such as liver tumor, lung nodule, etc. that needs to be frozen ablated, and the tissue organ refers to the blood vessels, kidneys, etc. near the target region. The delineation refers to marking and displaying the target region and the tissue organ near the target region on the image data. The visualization refers to the two-dimensional and three-dimensional visualization of the patient's body and the delineated target region and tissue organ.

[0062] In the embodiment, the automatic delineation of the target region and the tissue organ adopts the artificial intelligence semantic segmentation technology, specifically adopts the Unet++ neural network, and through data labeling, model training, model deployment and reasoning, the target region is segmented to realize the automatic delineation of the human target region and the tissue organ.

[0063] (3) Puncture path and treatment parameter plan design

[0064] The plan refers to the design of the puncture and treatment plan. Based on the delineated patient image data, the puncture path is designed, and the treatment parameters including the ablation needle model and the freezing time are designed and edited. The puncture path and the ablation needle are displayed in two-dimensional or three-dimensional visualization.

[0065] S2: Based on the puncture path and the treatment parameters, the temperature field distribution of the target region that needs to be frozen ablated and the tissue organ around the target region is calculated, specifically:

[0066] The temperature value of each point of the target region and the tissue organ is calculated by using the Comsol multi-physics field simulation software. The treatment parameters, the physical information and the geometric information of the heat conduction medium including the target region and the tissue organ are input into the Comsol multi-physics field simulation software. The temperature value of any point in the geometric space of the heat conduction medium is output after the calculation of the Comsol multi-physics field simulation software. The physical information is the thermal conductivity and specific heat of the heat conduction medium, and the geometric information is the geometric shape of the heat conduction medium.

[0067] S3: Based on the calculation result of the temperature field distribution, the quantitative analysis is performed, and the control rate of the target region and the damage degree of the tissue organ are evaluated.

[0068] Specifically, after the temperature field calculation obtains the temperature distribution in the target region and the tissue and organ region near the target region, some statistical quantitative analysis is needed to evaluate the control rate of the target region and the damage degree of the tissue and organ. The control rate of the target region refers to the killing degree of the tumor by the temperature field generated by the current treatment plan. The present application uses the tools provided by the software based on the temperature field calculation results to evaluate the plan and determine whether the specified treatment plan meets the requirements. These evaluation tools include the display of the temperature field on the image, temperature volume histogram (TVH) analysis, etc.

[0069] The temperature volume histogram (TVH) is used to quantitatively analyze the calculation results of the temperature field distribution. The temperature volume histogram (TVH) includes an integral mode and a differential mode. The integral mode is defined as the ratio of the volume below the current temperature in the region of interest to the total volume of the region of interest. The differential mode is defined as the ratio of the volume in the same temperature difference interval in the region of interest to the total volume of the region of interest. The region of interest refers to the region that needs to be counted, including the target region and the tissue and organ.

[0070] As shown in Figure 2 , it is an integral module TVH schematic diagram. The integral mode TVH calculation formula is:

[0071]

[0072] Where I represents integration, i, j, k represent the subscript of the voxel v, the voxel is a discrete three-dimensional point with a fixed volume in the target region or the tissue and organ, the subscript corresponds to the integer identifier of the three-dimensional coordinates of the voxel, t represents the temperature of the voxel v, t min represents the minimum temperature value, and T represents the temperature threshold value.

[0073] For the integral mode TVH, the higher the ratio of the integral mode calculated by the target region, the higher the control rate of the target region, and the lower the ratio of the integral mode calculated by the tissue and organ, the lower the damage degree of the tissue and organ.

[0074] As shown in Figure 3 , it is a differential module TVH schematic diagram. The differential mode TVH calculation formula is:

[0075]

[0076] Where D represents the differential, i, j, k represent the subscripts of the voxel v, the voxel is a discrete three-dimensional point with a fixed volume in the target area or the tissue organ, the subscripts correspond to the integer identifiers of the three-dimensional coordinates of the voxel, t represents the temperature of the voxel v, and T1, T2 represent temperature thresholds.

[0077] For the differential mode TVH, the higher the ratio of the differential mode calculated for the target area in the low-temperature range, the higher the control rate of the target area; the lower the ratio of the differential mode calculated for the tissues and organs in the low-temperature range, the lower the degree of damage to the tissues and organs.

[0078] Furthermore, this embodiment also includes: when the target area control rate and the tissue / organ damage assessment results in step S3 are not ideal, redesigning the puncture path and the treatment parameters; skipping to step S1 to evaluate the puncture path and the treatment parameters. This continues until the designed treatment plan achieves the best target area control rate and the minimum tissue / organ damage.

[0079] Furthermore, this embodiment also includes outputting the specified plan and treatment parameters, TVH assessment results in the form of printed reports or plan documents. The plan data can also be backed up via local hard drive backup or burned to optical disc, and when data recovery is needed, this backup data can be restored to the system.

[0080] Second Embodiment

[0081] like Figure 4 As shown, this embodiment provides a cryoablation planning evaluation system for performing the cryoablation planning evaluation method as described in the first embodiment, comprising:

[0082] Module 1, which is used to acquire pre-designed puncture paths and treatment parameters;

[0083] Temperature field distribution calculation module 2 is used to calculate the temperature field distribution of the target area to be cryoablated and the surrounding tissues and organs based on the puncture path and the treatment parameters.

[0084] Temperature field distribution analysis module 3 is used to perform quantitative analysis based on the calculation results of the temperature field distribution, and to evaluate the control rate of the target area and the degree of damage to the tissues and organs.

[0085] A computer readable storage medium stores computer code which, when executed, performs the method described above. It is understood by those skilled in the art that all or part of the steps in the above-described embodiments of the various methods can be instructed by a program to relevant hardware, and the program can be stored in a computer readable storage medium, which can include a read only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0086] The above description is only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements shall be considered as falling within the protection scope of the present application.

[0087] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict each other, they shall be considered as falling within the scope of the present application.

[0088] It should be noted that the above-described embodiments can be freely combined as needed. The above description is only preferred embodiments of the present application, and it should be noted that, for ordinary skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements shall be considered as falling within the protection scope of the present application.

Claims

1. A method of cryoablation plan evaluation, the method comprising: The method comprises the following steps: S1: obtaining a pre-designed puncture path and treatment parameters; S2: calculating a temperature field distribution of a target area requiring cryoablation and tissue organs around the target area based on the puncture path and the treatment parameters; S3: performing quantitative analysis based on the calculation result of the temperature field distribution to evaluate the control rate of the target area and the damage degree of the tissue organs; In step S3, the quantitative analysis based on the calculation result of the temperature field distribution to evaluate the control rate of the target area and the damage degree of the tissue organs is specifically: The temperature volume histogram (TVH) is used to quantitatively analyze the calculation result of the temperature field distribution, and the temperature volume histogram (TVH) includes an integral mode and a differential mode; The integral mode is defined as the ratio of the volume below the current temperature in the region of interest to the total volume of the region of interest, and the differential mode is defined as the ratio of the volume in the same temperature difference interval in the region of interest to the total volume of the region of interest, wherein the region of interest refers to the region requiring statistics including the target area and the tissue organs.

2. The cryoablation plan evaluation method of claim 1, wherein, In step S1, before obtaining the pre-designed puncture path and treatment parameters, it further comprises: Importing patient image data; Based on the patient image data, the delineation and visualization of the target area and the tissue organs are performed; Based on the delineated patient image data, the puncture path is designed, and the treatment parameters including the ablation needle model and the freezing time are designed; The puncture path and the ablation needle are displayed in two dimensions or three dimensions.

3. The cryoablation plan evaluation method of claim 1, wherein, In step S2, the calculation of the temperature field distribution of the target area requiring cryoablation and the tissue organs around the target area based on the puncture path and the treatment parameters is specifically: The temperature value of each point of the target area and the tissue organs is calculated by using a method including Comsol multi-physics simulation software; The treatment parameters, physical information and geometric information of the heat conduction medium including the target area and the tissue organs are input into the Comsol multi-physics simulation software, and the temperature value of any point in the geometric space of the heat conduction medium is output after calculation by the Comsol multi-physics simulation software, wherein the physical information is the thermal conductivity and specific heat of the heat conduction medium, and the geometric information is the geometric shape of the heat conduction medium.

4. The cryoablation plan evaluation method of claim 1, wherein, The integral mode is specifically: The integral mode TVH is specifically: wherein, represents an integral, represents a voxel of a discrete three-dimensional point having a fixed volume in the target region or one of the tissue organs, the subscript corresponds to the integer identification of the three-dimensional coordinates of the voxel, represents the voxel temperature, represents a temperature threshold; For the integral mode TVH, the higher the ratio of the integral mode calculated by the target area, the higher the control rate of the target area, and the lower the ratio of the integral mode calculated by the tissue organs, the lower the damage degree of the tissue organs.

5. The cryoablation plan evaluation method of claim 1, wherein, The differential mode is specifically: The differential mode TVH is specifically: wherein, represents a differential, represents a voxel of a subscript, the voxel being a discrete three-dimensional point having a fixed volume in the target region or one of the tissue organs, the subscript corresponding to an integer identification of three-dimensional coordinates of the voxel, represents the voxel of a temperature, , represents a temperature threshold; For the differential mode TVH, the higher the ratio of the differential mode calculated by the target area in the low temperature interval, the higher the control rate of the target area, and the lower the ratio of the differential mode calculated by the tissue organs in the low temperature interval, the lower the damage degree of the tissue organs.

6. The cryoablation plan evaluation method of claim 1, wherein, Further comprising: When the control rate of the target region in step S3 and the evaluation result of the damage degree of the tissue and organs are not ideal, the puncture path and the treatment parameters are redesigned; Jump to step S1 to evaluate the puncture path and the treatment parameters.

7. A cryoablation plan evaluation system for performing the cryoablation plan evaluation method according to any one of claims 1 to 6, characterized by Comprise: A planning acquisition module is configured to acquire a pre-designed puncture path and treatment parameters; A temperature field distribution calculation module is configured to calculate the temperature field distribution of a target region requiring cryoablation and the tissue and organs around the target region based on the puncture path and the treatment parameters; A temperature field distribution analysis module is configured to perform quantitative analysis based on the calculation result of the temperature field distribution, and evaluate the control rate of the target region and the damage degree of the tissue and organs.

8. A computer device comprising a memory and one or more processors, wherein the memory stores computer code, and the computer code, when executed by the one or more processors, causes the one or more processors to perform the method of any one of claims 1 to 6.

9. A computer-readable storage medium storing computer code, wherein when the computer code is executed, the method of any one of claims 1 to 6 is performed.

Images