Method and device for evaluating cell inactivation rate during microwave ablation based on reduced scattering coefficient

Abstract

The present invention discloses a microwave ablation cell inactivation rate evaluation method and device based on reduced scattering coefficient, which belongs to the field of microwave ablation efficacy evaluation. The reduced scattering coefficient of the ablation area collected during microwave ablation of the liver is input into a pre-constructed cell inactivation rate evaluation model to match the corresponding cell inactivation rate according to the reduced scattering coefficient; the ablation effect of microwave ablation of the liver is evaluated according to the cell inactivation rate. Therefore, the cell inactivation rate of the tissue can be predicted in real time according to the reduced scattering coefficient of the tissue obtained during the microwave ablation process, and the microwave ablation is evaluated by process parameters and converted into parameters based on the degree of tissue protein coagulation as the evaluation basis, which is helpful for more accurate clinical evaluation of the ablation efficacy.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave ablation efficacy evaluation, and in particular to a method and device for evaluating microwave ablation cell inactivation rate based on reduced scattering coefficient. Background Art

[0002] Temperature is an instantaneous indicator and a process parameter of microwave ablation. The effect of microwave ablation is the cumulative effect of thermal damage under the combined action of temperature and time. Therefore, temperature cannot accurately evaluate the effect of microwave ablation. The result parameters such as protein coagulation degree and tissue hardness should accurately reflect the effect of tissue microwave ablation. At present, the reduced scattering coefficient is mainly used as a determining factor for tumor cell inactivation in clinical practice, which cannot correctly reflect the degree of ablation of tumor tissue. Only the reduced scattering coefficient measurement cannot obtain other relevant parameters of tumor tissue in the ablation process in real time, including protein coagulation degree, tissue hardness, enzyme activity, etc. How to associate the efficacy evaluation factors (physical parameters) that characterize the degree of protein coagulation and tissue hardness with tissue inactivation indicators (cell inactivation rate) is the key problem to be solved in microwave ablation.

[0003] The thermal effect of microwave ablation can lead to changes in tissue cell structure and changes in the tertiary structure of multiple proteins at the molecular level. Therefore, the optical properties of tissues will change during microwave ablation. The use of minimally invasive functional near-infrared spectroscopy can achieve real-time measurement of tissue optical parameters during ablation. Studies have shown that the infrared optical parameters of liver tissue (reduced scattering coefficient μ′ s During microwave ablation, μ′ will change dynamically due to cell inactivation and protein denaturation. s It can more stably react to the protein coagulation state during the ablation process. However, there is currently a lack of microwave ablation efficacy evaluation standards and evaluation models based on the reduced scattering coefficient. How to use the reduced scattering coefficient to complete the accurate real-time efficacy evaluation of the microwave ablation process requires more detailed research.

[0004] Currently, there is no effective evaluation model for the inactivation rate of cells during microwave ablation of the liver in vivo based on the reduced scattering coefficient. Summary of the invention

[0005] The present invention provides a method and device for evaluating the cell inactivation rate of microwave ablation based on reduced scattering coefficient, which estimates the cell inactivation rate of microwave ablated tissue through the reduced scattering coefficient obtained in real time, and accurately evaluates the ablation effect.

[0006] The first aspect of the present invention provides a method for evaluating the cell inactivation rate of microwave ablation based on a reduced scattering coefficient, comprising the following steps:

[0007] Collect the reduced scattering coefficient of the ablation area during liver microwave ablation;

[0008] Inputting the reduced scattering coefficient into a pre-constructed cell inactivation rate evaluation model to match the corresponding cell inactivation rate according to the reduced scattering coefficient;

[0009] The ablation effect of liver microwave ablation was evaluated according to the cell inactivation rate.

[0010] In one embodiment of the present invention, before collecting the reduced scattering coefficient of the ablation area during liver microwave ablation, the method further includes:

[0011] Obtain the reduced scattering coefficients corresponding to different ablation areas of the liver;

[0012] Obtain cell inactivation rates in different ablation areas;

[0013] The reduced scattering coefficient and cell inactivation rate in different ablation areas were fitted and modeled, and the relevant model equation with the maximum goodness of fit was used as the cell inactivation rate evaluation model corresponding to the reduced scattering coefficient and cell inactivation rate.

[0014] In one embodiment of the present invention, obtaining cell inactivation rates in different ablation regions includes:

[0015] The cell activity flow cytometry experiment was used to obtain the proportions of naked nucleus cells, living cells, necrotic or late apoptotic cells, and early apoptotic cells in different ablation areas. The sum of the proportions of necrotic or late apoptotic cells and early apoptotic cells was taken as the cell inactivation rate in different ablation areas.

[0016] In one embodiment of the present invention, the different ablation areas include completely destroyed tissue, edge of completely destroyed tissue, congested zone, edge of congested zone and normal area.

[0017] A second aspect of the present invention provides a device for evaluating the cell inactivation rate of microwave ablation based on a reduced scattering coefficient, comprising:

[0018] A microwave ablation module, comprising an ablation needle, a microwave source and a main control board connected in sequence, and used for performing microwave ablation on the liver;

[0019] A reduced scattering coefficient monitoring module, comprising a near-infrared optical fiber probe, a spectrometer and a light source connected in sequence, for collecting the reduced scattering coefficient of the ablation area during liver microwave ablation;

[0020] The mobile terminal is used to control the microwave ablation module and receive the reduced scattering coefficient of the ablation area collected by the reduced scattering coefficient monitoring module, and input the reduced scattering coefficient into a pre-constructed cell inactivation rate evaluation model to obtain the cell inactivation rate corresponding to the reduced scattering coefficient, and evaluate the ablation effect of liver microwave ablation based on the cell inactivation rate.

[0021] In one embodiment of the present invention, the mobile terminal is also used to perform fitting modeling using the pre-acquired reduced scattering coefficients and cell inactivation rates of different ablation areas, and use the relevant model equation with the maximum goodness of fit as the cell inactivation rate evaluation model corresponding to the reduced scattering coefficients and cell inactivation rates.

[0022] In one embodiment of the present invention, obtaining cell inactivation rates in different ablation regions includes:

[0023] The cell activity flow cytometry experiment was used to obtain the proportions of naked nucleus cells, living cells, necrotic or late apoptotic cells, and early apoptotic cells in different ablation areas. The sum of the proportions of necrotic or late apoptotic cells and early apoptotic cells was taken as the cell inactivation rate in different ablation areas.

[0024] In one embodiment of the present invention, the different ablation areas include completely destroyed tissue, edge of completely destroyed tissue, congested zone, edge of congested zone and normal area.

[0025] The method and device for evaluating the cell inactivation rate of microwave ablation based on the reduced scattering coefficient of the embodiment of the present invention estimate the cell inactivation rate of microwave ablated tissue by acquiring the reduced scattering coefficient in real time, accurately evaluate the ablation effect, and establish a cell inactivation rate evaluation model based on the reduced scattering coefficient, which evaluates microwave ablation based on the process parameter (temperature) and converts it into a result parameter (reduced scattering coefficient) based on the degree of tissue protein coagulation as the basis for evaluation, which helps to evaluate the ablation efficacy more accurately in clinic.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 A flowchart of a method for evaluating microwave ablation cell inactivation rate based on reduced scattering coefficient provided according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of a device for an in vivo microwave ablation and reduced scattering coefficient monitoring system for rabbit liver according to an embodiment of the present invention;

[0030] Figure 3 A flowchart for modeling a cell inactivation rate evaluation model provided according to an embodiment of the present invention;

[0031] Figure 4 A regional division diagram of a rabbit liver after ablation in vivo according to an embodiment of the present invention;

[0032] Figure 5 The cell activity distribution diagram of five regions of the rabbit liver after in vivo ablation according to an embodiment of the present invention;

[0033] Figure 6 A curve diagram of a cell inactivation rate evaluation model provided according to an embodiment of the present invention;

[0034] Figure 7 The present invention is a schematic structural diagram of a microwave ablation cell inactivation rate assessment device based on reduced scattering coefficient provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0036] Figure 1 The present invention provides a flowchart of a method for evaluating the cell inactivation rate of microwave ablation based on the reduced scattering coefficient according to an embodiment of the present invention.

[0037] like Figure 1 As shown, the method for evaluating the cell inactivation rate of microwave ablation based on the reduced scattering coefficient includes the following steps:

[0038] In step S101, the reduced scattering coefficient of the ablation area during liver microwave ablation is collected.

[0039] The embodiment of the present invention can obtain the cell inactivation rate of the ablation area by using the reduced scattering coefficient of the ablation area during liver microwave ablation. During liver microwave ablation, the reduced scattering coefficient of the ablation area is collected in real time.

[0040] In an embodiment of the present invention, the reduced scattering coefficient of the ablation area during liver microwave ablation is collected using a rabbit liver in vivo microwave ablation and reduced scattering coefficient monitoring system, which is mainly composed of a microwave ablation module and a reduced scattering coefficient monitoring module.

[0041] exist Figure 2 In the figure, 1 is a PC, 2 is a main control board, 3 is a spectrometer, 4 is a light source, 5 is a microwave source, 6 is a near-infrared optical fiber probe, 7 is a microwave ablation needle, and 8 is a subject.

[0042] The microwave ablation module includes a main control board 2 , a microwave source 5 , and a microwave ablation needle 7 , and the reduced scattering coefficient monitoring module includes a spectrometer 3 , a light source 4 , and a near-infrared optical fiber probe 6 .

[0043] A minimally invasive incision was made in the rabbit's abdominal cavity to ensure that the liver could be seen, and then the ablation needle 2 was horizontally inserted into the rabbit's liver 7. The near-infrared optical fiber probe 6 and the microwave ablation needle 7 were set in parallel in the rabbit's liver.

[0044] The microwave ablation module and the reduced scattering coefficient monitoring module are both connected to a PC to control the microwave ablation module and the reduced scattering coefficient monitoring module. The PC is used to set the ablation power and ablation time, and send them to the main control board, and then microwave ablation is performed using a microwave source and a microwave ablation needle. The reduced scattering coefficient monitoring module is used to collect the reduced scattering coefficient.

[0045] In an embodiment of the present invention, the spectrometer is an FX2000 fiber optic spectrometer, the light source is an HL-2000 halogen light source, the microwave source is a 2450MHZ microwave source, the near-infrared fiber optic probe is a Y-type near-infrared fiber optic probe, and the microwave ablation needle is a KY-2450-B1 microwave ablation needle.

[0046] A rabbit weighing about 3 kg was selected as the experimental subject. A minimally invasive opening was made in the abdominal cavity of the animal to ensure that the liver could be seen. Then the ablation needle was inserted horizontally into the liver. The near-infrared fiber probe was tied together with the ablation needle and inserted into the liver. The tip of the probe was kept parallel to the energy radiation point of the ablation needle. The ablation power was set to 20 W and the ablation time was set to 60 s. The reduced scattering coefficient monitoring module was started at the beginning of ablation.

[0047] In step S102, the reduced scattering coefficient is input into a pre-constructed cell inactivation rate evaluation model to match the corresponding cell inactivation rate according to the reduced scattering coefficient.

[0048] In step S103, the ablation effect of liver microwave ablation is evaluated according to the cell inactivation rate.

[0049] The reduced scattering coefficient collected in real time is input into the cell inactivation rate evaluation model, and the corresponding cell inactivation rate can be obtained through matching.

[0050] In one embodiment of the present invention, before collecting the reduced scattering coefficient of the ablation area during liver microwave ablation, the method further includes:

[0051] Obtain the reduced scattering coefficients corresponding to different ablation areas of the liver;

[0052] Obtain cell inactivation rates in different ablation areas;

[0053] The reduced scattering coefficient and cell inactivation rate in different ablation areas were fitted and modeled, and the relevant model equation with the maximum goodness of fit was used as the cell inactivation rate evaluation model corresponding to the reduced scattering coefficient and cell inactivation rate.

[0054] like Figure 3As shown, the process of establishing the cell inactivation rate evaluation model of the present invention.

[0055] S1, build Figure 2 The monitoring system shown performs minimally invasive microwave ablation of the liver;

[0056] S2, 1-2 days after the prognosis, the liver is removed, different ablation areas are marked, and the corresponding reduced scattering coefficient (μ' s );

[0057] S3, sampling the marked different ablation areas and performing cell flow cytometry experiments respectively;

[0058] S4, obtain the cell inactivation rate (Ψ) in different ablation areas;

[0059] S5, the experiment was repeated 20 times to obtain the average reduced scattering coefficient and average cell inactivation rate in different ablation areas;

[0060] S6, the average reduced scattering coefficient and average cell inactivation rate in different regions were fitted and modeled to obtain Ψ-μ' s Related models.

[0061] When evaluating the ablation effect according to the obtained cell inactivation rate, a preset threshold can be set. If it is greater than the preset threshold, the effect is judged to be good, otherwise, it is poor, and the ablation parameters are adjusted accordingly. There is no specific limitation on this.

[0062] In an embodiment of the present invention, obtaining cell inactivation rates in different ablation regions includes:

[0063] The cell activity flow cytometry experiment was used to obtain the proportions of naked nucleus cells, living cells, necrotic or late apoptotic cells, and early apoptotic cells in different ablation areas. The sum of the proportions of necrotic or late apoptotic cells and early apoptotic cells was taken as the cell inactivation rate in different ablation areas.

[0064] like Figure 4 As shown, the in vivo liver ablation area can be subdivided into a coagulation area (completely destroyed tissue), an edge of the coagulation area (edge ​​of completely destroyed tissue), a transition area (congested zone), an edge of the transition area (edge ​​of the congested zone), and a normal area (normal tissue). The device of the present invention can be used to measure the average reduced scattering coefficient of different areas.

[0065] like Figure 5As shown in the figure, the Annexin V-FITC / PI method was used for cell activity flow cytometry experiment. Normal cells (living cells) have intact cell membranes. At this time, the phosphatidylserine (PS) in the components of the cell membrane is located on the inner side of the cell membrane. When the cell undergoes apoptosis, the PS originally on the inner side of the cell membrane is turned outward to the surface of the cell membrane. Therefore, the membrane protein V (Annexin V) with high affinity to PS and labeled with fluorescein can be used to detect early apoptotic cells. Annexin V-FITC (Fluorescein Isothiocyanate) single positive is an early apoptotic cell, Annexin V-FITC and PI (Propidium Iodide) double positive cells are necrotic or late apoptotic cells, and PI single positive cells are naked nucleus cells.

[0066] like Figure 4 As shown (the four quadrants correspond to cells of different activities, upper left: naked nucleus cells, lower left: live cells, upper right: necrotic or late apoptotic cells, lower right: early apoptotic cells). The cells in the upper right quadrant and the lower right quadrant can be counted as cells that have lost their activity (inactivated), and the cell inactivation rate (Ψ) can be calculated. The cell inactivation rate in the normal area is 5.78%, the cell inactivation rate in the periphery of the transition area is 41.52%, the cell inactivation rate in the transition area is 67.85%, the cell inactivation rate in the periphery of the coagulation area is 90.1%, and the cell inactivation rate in the coagulation area is 98.8%.

[0067] After in vivo ablation and cell activity experiments on 20 groups of rabbit livers, it was found that the cell inactivation rate of completely damaged tissue (coagulation area) was 97.86%-98.8%, the cell inactivation rate of the edge of completely damaged tissue (outside the coagulation area) was 83.28%-90.1%, the cell inactivation rate of the congestion zone (transition area) was 64.1%-70.85%, the cell inactivation rate of the edge of the congestion zone (outside the transition area) was 24.8%-41.52%, and the cell inactivation rate of normal tissue (normal area) was 2.2%-7.2%. The reduced scattering coefficient of different regions of the 20 groups of rabbit livers was measured and the cell inactivation rate was calculated, and the average reduced scattering coefficient and average cell inactivation rate of different regions of the rabbit liver after in vivo ablation were obtained, as shown in Table 1.

[0068] Table 1

[0069]

[0070] like Figure 6As shown, the average reduced scattering coefficients and the corresponding average cell inactivation rates in different regions are fitted and modeled. The two have a positive correlation and have the highest goodness of fit (R2) on the first-order polynomial, whose R2 is closest to 1. The Ψ-E correlation model obtained is as follows:

[0071] Ψ=6.8542μ′ s -22.513

[0072] Among them, R 2 =0.9977.

[0073] According to the microwave ablation cell inactivation rate assessment method based on the reduced scattering coefficient proposed in an embodiment of the present invention, the cell inactivation rate of the tissue can be predicted in real time based on the reduced scattering coefficient of the tissue obtained during the microwave ablation process, and the microwave ablation evaluation based on the process parameter (temperature) can be converted into a result parameter (reduced scattering coefficient) based on the degree of tissue protein coagulation as an evaluation basis, which helps to more accurately evaluate the ablation efficacy in clinical practice.

[0074] Next, a microwave ablation cell inactivation rate evaluation device based on reduced scattering coefficient proposed in an embodiment of the present invention will be described with reference to the accompanying drawings.

[0075] Figure 7 Schematic diagram of the structure of a microwave ablation cell inactivation rate assessment device based on reduced scattering coefficient according to an embodiment of the present invention.

[0076] like Figure 7 As shown, the microwave ablation cell inactivation rate assessment device 10 based on reduced scattering coefficient includes: a microwave ablation module 100 , a reduced scattering coefficient monitoring module 200 and a mobile terminal 300 .

[0077] Among them, the microwave ablation module 100 includes an ablation needle, a microwave source and a main control board connected in sequence, which are used to perform microwave ablation on the liver; the reduced scattering coefficient monitoring module 200 includes a near-infrared optical fiber probe, a spectrometer and a light source connected in sequence, which are used to collect the reduced scattering coefficient of the ablation area during microwave ablation of the liver; the mobile terminal 300 is used to control the microwave ablation module and receive the reduced scattering coefficient of the ablation area collected by the reduced scattering coefficient monitoring module, and input the reduced scattering coefficient into a pre-constructed cell inactivation rate evaluation model to obtain the cell inactivation rate corresponding to the reduced scattering coefficient, and evaluate the ablation effect of liver microwave ablation according to the cell inactivation rate.

[0078] In an embodiment of the present invention, the mobile terminal is also used to perform fitting modeling using the pre-acquired reduced scattering coefficients and cell inactivation rates of different ablation areas, and use the relevant model equation with the maximum goodness of fit as a cell inactivation rate evaluation model corresponding to the reduced scattering coefficients and cell inactivation rates.

[0079] In an embodiment of the present invention, obtaining cell inactivation rates in different ablation regions includes:

[0080] The cell activity flow cytometry experiment was used to obtain the proportions of naked nucleus cells, living cells, necrotic or late apoptotic cells, and early apoptotic cells in different ablation areas. The sum of the proportions of necrotic or late apoptotic cells and early apoptotic cells was taken as the cell inactivation rate in different ablation areas.

[0081] In an embodiment of the present invention, different ablation areas include completely destroyed tissue, edge of completely destroyed tissue, congested zone, edge of congested zone and normal area.

[0082] It should be noted that the aforementioned explanation of the embodiment of the method for evaluating the cell inactivation rate of in vivo liver microwave ablation based on the reduced scattering coefficient is also applicable to the device for evaluating the cell inactivation rate of in vivo liver microwave ablation based on the reduced scattering coefficient of this embodiment, and will not be repeated here.

[0083] The microwave ablation cell inactivation rate assessment device based on the reduced scattering coefficient proposed in an embodiment of the present invention can monitor the reduced scattering coefficient of the ablation area in the process of liver microwave ablation in real time, and input the reduced scattering coefficient into a pre-constructed cell inactivation rate assessment model to obtain the cell inactivation rate corresponding to the reduced scattering coefficient match, evaluate the ablation effect of liver microwave ablation based on the cell inactivation rate, and evaluate the microwave ablation based on the process parameter (temperature) and convert it into a result parameter (reduced scattering coefficient) based on the degree of tissue protein coagulation as an evaluation basis, which is helpful for clinical more accurate evaluation of the ablation efficacy.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0086] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

Claims

1. A microwave ablation cell inactivation rate evaluation device based on reduced scattering coefficient, characterized in that: include: A microwave ablation module, comprising an ablation needle, a microwave source and a main control board connected in sequence, and used for performing microwave ablation on the liver; A reduced scattering coefficient monitoring module, comprising a near-infrared optical fiber probe, a spectrometer and a light source connected in sequence, for collecting the reduced scattering coefficient of the ablation area during liver microwave ablation; The mobile terminal is used to control the microwave ablation module and receive the reduced scattering coefficient of the ablation area collected by the reduced scattering coefficient monitoring module, and input the reduced scattering coefficient into a pre-constructed cell inactivation rate evaluation model to obtain the cell inactivation rate corresponding to the reduced scattering coefficient, and evaluate the ablation effect of liver microwave ablation based on the cell inactivation rate.

2. The device according to claim 1, characterized in that The mobile terminal is also used to perform fitting modeling using the pre-acquired reduced scattering coefficients and cell inactivation rates of different ablation regions, and to use the relevant model equation with the maximum goodness of fit as a cell inactivation rate evaluation model corresponding to the reduced scattering coefficients and cell inactivation rates.

3. The device according to claim 2, characterized in that Obtain cell inactivation rates in different ablation areas, including: The cell activity flow cytometry experiment was used to obtain the proportions of naked nucleus cells, living cells, necrotic or late apoptotic cells, and early apoptotic cells in different ablation areas. The sum of the proportions of necrotic or late apoptotic cells and early apoptotic cells was taken as the cell inactivation rate in different ablation areas.

4. The device according to claim 2 or 3, characterized in that The different ablation areas include completely destroyed tissue, edge of completely destroyed tissue, congested zone, edge of congested zone and normal area.

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