CT-guided tumor ablation dose regulation and control method and system

Abstract

The invention relates to the technical field of tumor treatment, and discloses a CT-guided tumor ablation dose regulation and control method and system, and the method comprises the steps: obtaining the three-dimensional contour data and gray value distribution of a tumor through CT scanning, calculating the volume and average density of the tumor, and obtaining the initial ablation dose. Initial parameters of ablation equipment are set, an ablation program is started, data are updated at specific time intervals in the ablation process, and the real-time ablation dosage is calculated. And comparing the real-time ablation dose with the initial ablation dose, and adjusting the power of ablation equipment according to a specific formula and a comparison result. The system comprises an imaging and parameter acquisition module, an initial dose calculation module, an ablation equipment control module, a real-time monitoring module, a dose comparison and regulation module and the like. The ablation dosage can be accurately regulated and controlled according to the real-time condition of a tumor, the ablation treatment effect is improved, the damage risk to normal tissue is reduced, an alarm can be given to prompt an operator when the dosage is abnormal, and the high clinical application value is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of tumor treatment, and in particular to a method and system for controlling tumor ablation dose under CT guidance. Background Art

[0002] In the field of tumor treatment, ablation technology has been widely used in recent years as an important local treatment method. CT-guided tumor ablation has brought hope to many patients by virtue of its ability to accurately locate the tumor.

[0003] In traditional tumor ablation treatment, a fixed ablation dose setting mode is often used. Before surgery, doctors estimate an ablation dose based on experience and rough information such as the general type and size of the tumor, and set the ablation device parameters accordingly. However, this method has many disadvantages. On the one hand, tumors in different patients are highly heterogeneous. Even tumors of the same type may have very different internal tissue structures and density distributions. For example, tumors of the same tissue type have different cell arrangement densities in different individuals due to factors such as growth environment and genetic differences. This is reflected in the gray value distribution differences on the CT image, which leads to different actual ablation energies. On the other hand, tumors are not static during the ablation process, and their morphology and internal characteristics will change with the ablation process. The heat generated by ablation may cause the evaporation of water inside the tumor tissue and the collapse of the structure, causing the tumor volume and density to change in real time. If ablation is continued according to the fixed dose initially set, it is very easy to have incomplete ablation or excessive ablation. Excessive ablation may damage surrounding normal tissues and cause a series of complications, such as bleeding, organ dysfunction, etc., which will bring additional pain to patients; incomplete ablation will lead to residual tumors, increase the risk of recurrence, and reduce the cure rate and survival rate of patients. In addition, the existing technical means lack dynamic and precise monitoring and regulation of the ablation process. During the entire ablation operation, it is difficult to obtain accurate volume and density information of the tumor in real time, and it is impossible to adjust the ablation dose in time according to changes in these key indicators, making it difficult to ensure the stability and reliability of the treatment effect. Therefore, it is urgent to develop a CT-guided tumor ablation method that can accurately control the ablation dose according to the real-time status of the tumor, so as to fill the gaps in current technology and improve the quality and safety of tumor ablation treatment. Summary of the invention

[0004] The object of the present invention is to provide a method and system for controlling the dose of tumor ablation under CT guidance, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for controlling the dose of tumor ablation under CT guidance, the method comprising: Turn on the CT scanning device to perform three-dimensional imaging of the tumor site, obtain the three-dimensional contour data of the tumor, and calculate the tumor volume based on the contour data; calculate the average density of the tumor through the gray value distribution of the CT image; Calculate the initial ablation dose based on tumor volume and average density ; The initial parameters of the ablation device are set according to the initial ablation dose, and the ablation procedure is started. During the ablation process, the ablation dose is repeated at specific intervals. , turn on the CT scanning device again to update the 3D contour data and gray value distribution of the tumor, and repeat the above volume, density and dose calculation steps to obtain the real-time ablation dose ; Real-time ablation dose Initial ablation dose In contrast, When the power of the ablation device is reduced, The floating ratio of the preset upper limit of the dose, the power adjustment range is based on the formula: ;in, is the initial power; when When the power of the ablation device is increased, The floating ratio of the preset lower limit of the dose, the power adjustment range is based on the formula: .

[0006] Preferably, according to the contour data, the formula Calculation of tumor volume ,in is the cross-sectional area of ​​the i-th layer, is the distance between two adjacent layers of sections, and n is the number of layers.

[0007] Preferably, the gray value distribution of the CT image is combined with the formula Calculate the mean tumor density ,in is the density value corresponding to the jth pixel, and m is the total number of selected pixels; The method of selecting pixel points is: take the geometric center of the tumor as the center and r as the radius to draw a circle, select the pixel points in the circle to participate in the calculation, and r is calculated based on the maximum diameter R of the tumor through the formula Sure.

[0008] Preferably, the initial ablation dose is calculated The formula is: ; in, is the empirical coefficient, The value of is related to the tissue type of the tumor, and different types of tumors correspond to different constant values.

[0009] Preferably, the initial ablation dose The steps of setting the initial parameters of the ablation device include: , through the formula Calculate initial power ,in The preset initial ablation time; according to the heat dissipation characteristics of the ablation needle, set the initial coolant flow rate , the flow rate and power satisfy the relationship , c is the heat dissipation coefficient.

[0010] Preferably, each time interval In the step of starting the CT scanning device to update data, The value of is related to the growth rate of the tumor. The faster the growth rate, The smaller the value of .

[0011] Preferably, after the step of reducing or increasing the power of the ablation device, the method further includes: continuing to monitor the real-time ablation dose , if N consecutive monitoring results show If the dosage is still above or below the corresponding dosage range, an alarm will be issued to alert the operator, and N is the number of preset alarm thresholds.

[0012] Preferably, a CT-guided tumor ablation dose control system comprises the following modules: The imaging and parameter acquisition module starts the CT scanning device to perform three-dimensional imaging of the tumor site, obtains the three-dimensional contour data of the tumor, calculates the tumor volume based on the contour data, and calculates the average density of the tumor through the gray value distribution of the CT image; The initial dose calculation module calculates the initial ablation dose using a preset formula based on the tumor volume and average density ; Calculate the initial ablation dose The formula is: ; in, is the tumor volume, is the average tumor density, is the empirical coefficient, The value of is related to the tissue type of the tumor, and different types of tumors correspond to different constant values; The ablation device control module determines the initial ablation dose. Set the initial parameters of the ablation device and start the ablation procedure; The real-time monitoring module turns on the CT scanning device again at specific intervals to update the 3D contour data and grayscale value distribution of the tumor, and repeats the above volume, density and dose calculation steps to obtain the real-time ablation dose. ; Dose comparison and control module, real-time ablation dose Initial ablation dose In contrast, When the power of the ablation device is reduced, The preset upper limit of the dosage is the floating ratio; when When the power of the ablation device is increased, The floating ratio is the preset lower limit of the dose.

[0013] Preferably, the ablation device control module includes a power setting submodule, which sets the power according to the energy conversion efficiency of the ablation device. , through the formula Calculate initial power ,in The preset initial ablation time; according to the heat dissipation characteristics of the ablation needle, set the initial coolant flow rate , the flow rate and power satisfy the relationship , c is the heat dissipation coefficient.

[0014] Preferably, the imaging and parameter acquisition module: According to the contour data through the formula Calculation of tumor volume ,in is the cross-sectional area of ​​the i-th layer, is the distance between two adjacent layers of cross sections, and n is the number of layers; By combining the gray value distribution of CT images with the formula Calculate the mean tumor density ,in is the density value corresponding to the jth pixel, and m is the total number of selected pixels. The method for selecting pixels is: take the geometric center of the tumor as the center and r as the radius to draw a circle, select the pixels in the circle to participate in the calculation, and r is calculated based on the maximum diameter R of the tumor through the formula Sure.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The precise dose control capability of the present invention greatly improves the therapeutic effect of tumor ablation. The CT scanning device is used to dynamically monitor the tumor before and during surgery, and the tumor volume and average density are accurately calculated based on the real-time acquired tumor three-dimensional contour data and gray value distribution, and then the initial ablation dose and real-time ablation dose are accurately calculated. Compared with traditional empirical fixed-dose ablation, this dynamic and precise control can ensure that the ablation range completely covers the tumor tissue and avoid tumor residues caused by insufficient dose. For example, for some complex tumors with irregular boundaries and uneven internal density, this method can adjust the dose in real time according to each subtle change, effectively reducing the risk of tumor recurrence and improving the patient's cure rate.

[0016] The present invention has an outstanding protective effect on normal tissues. During the ablation process, once the real-time ablation dose approaches or exceeds the safety threshold, the system can quickly reduce the power of the ablation device according to the established algorithm to prevent excessive ablation from causing thermal damage, bleeding and other complications to surrounding normal tissues. For example, when ablating tumors near important organs such as the liver and kidneys, precise dose control can reduce the risk of damage to normal tissues to a minimum, ensure the integrity of the patient's postoperative organ function, reduce the patient's additional pain caused by surgery, and accelerate the recovery process.

[0017] From the perspective of surgical operation, the present invention improves the overall convenience and efficiency. Medical staff no longer need to frequently estimate the dose and manually adjust the equipment parameters based on limited experience. The system's automated monitoring and control process only requires starting the program according to the initial settings, and the system will then automatically run based on real-time data. Tumor information is automatically updated, doses are compared, and ablation power is adjusted at specific intervals, which not only reduces the workload of medical staff, but also reduces errors caused by human factors, making the entire ablation operation more smooth and accurate, providing a strong guarantee for more patients to receive timely and effective treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a working principle diagram of the tumor ablation dose control method of the present invention; Figure 2 Workflow diagram for the power setting submodule. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] See also Figure 1-2 The present invention provides a technical solution: a method for controlling the dose of tumor ablation under CT guidance, the method comprising: 1. Start CT scanning to obtain tumor data: Before tumor ablation treatment, the patient is placed on the CT scanning bed and adjusted to a suitable position to ensure that the tumor is in the center of the scanning field of view. The CT scanning device is turned on and appropriate scanning parameters are selected, such as tube voltage 120kV, tube current 250mA, and layer thickness 1mm, to perform three-dimensional imaging of the tumor. The three-dimensional contour data of the tumor is obtained through the image post-processing software provided by the CT device. These data accurately outline the morphology of the tumor in space, providing a basis for the subsequent calculation of the tumor volume.

[0021] According to the obtained contour data, the formula is used Calculation of tumor volume For example, suppose that after scanning a liver tumor, the tumor is divided into 50 layers in the axial direction, and the cross-sectional area of ​​each layer is obtained through the image processing algorithm. , the distance between two adjacent layers of cross sections The cross-sectional areas of each layer are 1 mm (determined by the scanning layer thickness). = , = = , then the tumor volume =6.25 At the same time, the gray value distribution of the CT image is used to calculate the average density of the tumor. By formula Determine the radius r. For example, if the maximum diameter of the tumor is R = 4 cm, then r = 2 cm. Draw a circle with this radius on the image and select the pixels within the circle for calculation. Assume that m = 1000 pixels are selected and the density value corresponding to each pixel is , through the formula Calculate the mean tumor density After calculation, the sum of the density values ​​of these 1000 pixels is 1200 (unit: HU, Hounsfield Unit, which is the quantitative unit of material density in CT images), so the average tumor density is .

[0022] (II) Calculation of initial ablation dose: The tumor volume calculated above and the average density , combined with the formula Calculation of initial ablation dose .in, is an empirical coefficient, and its value is related to the tissue type of the tumor. For example, for lung cancer tissue, The value is usually 0.8 (unit: , joules per cubic centimeter per Hounsfield unit, which represents the empirical value of the energy dose required to achieve ablation effect on the tumor tissue per unit volume and unit density); for liver cancer tissue, The value may be 0.9. Assume that the volume of the liver tumor is , average density , then the initial ablation dose of the liver tumor is .

[0023] 3. Set the initial parameters of the ablation device and start the ablation procedure: Based on the energy conversion efficiency of the ablation device , through the formula Calculate initial power For example, the energy conversion efficiency of a certain ablation device (dimensionless, indicating the ratio of the input electrical energy converted by the device into effective energy for ablating the tumor), preset initial ablation time , the initial ablation dose calculated above is , then the initial power .

[0024] According to the heat dissipation characteristics of the ablation needle, set the initial coolant flow rate . The flow rate and power satisfy the relationship ,in Assume that the heat dissipation coefficient of the ablation needle is (Unit: milliliters per watt per minute, indicating the required coolant flow rate per minute at unit power to ensure normal heat dissipation of the ablation needle), then the initial coolant flow rate After setting the initial power, coolant flow rate and other parameters, the ablation procedure of the ablation device is started to start ablation treatment of the tumor.

[0025] 4. Real-time monitoring and dosage control: During the ablation process, at specific time intervals , turn on the CT scanning device again to update the three-dimensional contour data and gray value distribution of the tumor. The value of is related to the growth rate of the tumor. The faster the growth rate, For example, for malignant melanoma with a faster growth rate, It can be set to 2 minutes; for papillary thyroid cancer, which grows relatively slowly, Can be set to 5min.

[0026] After each data update, the above steps of calculating tumor volume, density and dose are repeated to obtain the real-time ablation dose. . The real-time ablation dose Initial ablation dose Contrast. ,in is the preset upper limit of the dosage, assuming (i.e. 10%), the power of the ablation device is reduced. The power adjustment range is based on the formula For example, the initial power , the real-time ablation dose monitored in real time , initial ablation dose , then the power adjustment range , adjusted power .

[0027] like ,in is the preset dosage lower limit floating ratio, assuming (i.e. 10%), the power of the ablation device is increased. The power adjustment range is based on the formula For example, if the real-time ablation dose , other parameters remain unchanged, then the power adjustment range , adjusted power .

[0028] (V) Alarm prompt: After lowering or raising the ablation device power, continue to monitor the real-time ablation dose If continuous The monitoring results showed If the dose is still above or below the corresponding dose range, an alarm will be issued to remind the operator. For example, after adjusting the power, the real-time ablation dose was monitored for 3 consecutive times. Are greater than , then the alarm system of the ablation device will send out an audible and visual alarm to remind the operator to check the operating status of the equipment or adjust the treatment plan in time.

[0029] The tumor ablation dose control system of the present invention comprises an imaging and parameter acquisition module, an initial dose calculation module, an ablation device control module, a real-time monitoring module and a dose comparison and control module.

[0030] The imaging and parameter acquisition module is connected to the data interface of the CT scanning device to receive the three-dimensional imaging data of the tumor site obtained by CT scanning. The three-dimensional contour data of the tumor is extracted from the three-dimensional image data using the image processing algorithm, and the three-dimensional contour data of the tumor is obtained according to the formula Calculation of tumor volume For example, when processing brain tumor images, the tumor is separated from the surrounding tissue through an automatic segmentation algorithm to obtain the cross-sectional area of ​​each layer. The distance between the two adjacent layers , the tumor volume was calculated.

[0031] At the same time, the module is based on the gray value distribution of the CT image, with the geometric center of the tumor as the center, according to the formula Determine the radius , select the pixel points inside the circle, and use the formula Calculate the mean tumor density In practical applications, this module can process large amounts of image data quickly and accurately, providing reliable parameters for subsequent dose calculations.

[0032] The initial dose calculation module receives the tumor volume from the imaging and parameter acquisition module. and the average density Data, combined with preset empirical coefficients (determined by tumor tissue type), using the formula Calculation of initial ablation dose This module can be built-in corresponding to different tumor tissue types Value database, when the tumor tissue type information is entered, the corresponding The calculation efficiency and accuracy are improved.

[0033] The ablation device control module includes a power setting submodule. The power setting submodule is based on the energy conversion efficiency of the ablation device. and the preset initial ablation time , through the formula Calculate initial power For example, when controlling a radiofrequency ablation device, the appropriate initial power is calculated based on the energy conversion efficiency of the device and the preset ablation time.

[0034] At the same time, the module is based on the heat dissipation characteristics of the ablation needle and follows the relationship Setting the initial coolant flow rate The module is connected to the control interface of the ablation device, and sends the calculated initial power and coolant flow rate parameters to the ablation device to realize the initialization control of the ablation device.

[0035] The real-time monitoring module monitors the , send scanning instructions to the CT scanning device to obtain the updated tumor three-dimensional contour data and gray value distribution. Then, repeat the calculation steps of the imaging and parameter acquisition module and the initial dose calculation module to obtain the real-time ablation dose. This module can track the changes of tumors during ablation in real time and provide real-time data support for dose regulation.

[0036] The dose comparison and control module receives the real-time ablation dose from the real-time monitoring module. and the initial ablation dose from the initial dose calculation module .Will and For comparison, when When , a power reduction instruction is sent to the ablation device control module, and according to the formula Calculate the power adjustment range and control the ablation device to reduce the power. When the power is increased, the ablation device control module is sent a power increase instruction, and according to the formula Calculate the power adjustment range and control the ablation device to increase power. This module realizes real-time regulation of ablation dose to ensure the safety and effectiveness of ablation treatment.

[0037] Through the above specific implementations, the CT-guided tumor ablation dose control method and system of the present invention show significant advantages in clinical applications.

[0038] In terms of precise dose control, by acquiring the three-dimensional contour data and grayscale value distribution of the tumor in real time, dynamically calculating the tumor volume, density and ablation dose, and timely adjusting the ablation device power according to the preset dose floating ratio, it can effectively avoid tumor residues due to insufficient ablation dose or damage to surrounding normal tissues due to excessive dose.

[0039] In terms of intelligent equipment control, the various modules of the ablation dose control system work together to achieve a fully automated process from tumor data acquisition, dose calculation to ablation equipment parameter setting and real-time control. This not only reduces the operating burden of medical staff, but also improves the accuracy and repeatability of treatment.

[0040] In terms of safety assurance, by setting alarm thresholds, an alarm is issued in time when the real-time ablation dose continuously exceeds the normal range, reminding the operator to intervene, further ensuring the safety of the treatment process. In actual application, this alarm mechanism effectively avoids many treatment risk events caused by equipment failure or abnormal tumor changes, ensuring the life safety of patients.

[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the dose of tumor ablation under CT guidance, characterized in that: The method comprises: Turn on the CT scanning device to perform three-dimensional imaging of the tumor site, obtain the three-dimensional contour data of the tumor, and calculate the tumor volume based on the contour data; calculate the average density of the tumor through the gray value distribution of the CT image; Calculate the initial ablation dose based on tumor volume and average density ; The initial parameters of the ablation device are set according to the initial ablation dose, and the ablation procedure is started. During the ablation process, the ablation dose is repeated at specific intervals. , turn on the CT scanning device again to update the 3D contour data and gray value distribution of the tumor, and repeat the above volume, density and dose calculation steps to obtain the real-time ablation dose ; The real-time ablation dose Initial ablation dose In contrast, When the power of the ablation device is reduced, The preset upper limit of the dosage is the floating ratio; when When the power of the ablation device is increased, The floating ratio is the preset lower limit of the dose.

2. The method for controlling tumor ablation dose according to claim 1, characterized in that: According to the contour data through the formula Calculation of tumor volume ,in is the cross-sectional area of ​​the i-th layer, is the distance between two adjacent layers of sections, and n is the number of layers.

3. The method for controlling tumor ablation dose according to claim 1, characterized in that: By combining the gray value distribution of CT images with the formula Calculate the mean tumor density ,in is the density value corresponding to the jth pixel, and m is the total number of selected pixels; The method of selecting pixel points is: take the geometric center of the tumor as the center and r as the radius to draw a circle, select the pixel points in the circle to participate in the calculation, and r is calculated based on the maximum diameter R of the tumor through the formula Sure.

4. The method for controlling tumor ablation dose according to claim 1, characterized in that: Calculation of initial ablation dose The formula is: ； in, is the empirical coefficient, The value of is related to the tissue type of the tumor, and different types of tumors correspond to different constant values.

5. The method for controlling tumor ablation dose according to claim 1, characterized in that: According to the initial ablation dose The steps of setting the initial parameters of the ablation device include: , through the formula Calculate initial power ,in The preset initial ablation time; according to the heat dissipation characteristics of the ablation needle, set the initial coolant flow rate , the flow rate and power satisfy the relationship , c is the heat dissipation coefficient.

6. The method for controlling tumor ablation dose according to claim 1, characterized in that: At specific time intervals In the step of starting the CT scanning device to update data, The value of is related to the growth rate of the tumor. The faster the growth rate, The smaller the value of .

7. The method for controlling tumor ablation dose according to claim 1, characterized in that: After the step of reducing or increasing the power of the ablation device, the step further includes: continuing to monitor the real-time ablation dose , if N consecutive monitoring results show If the dosage is still above or below the corresponding dosage range, an alarm will be issued to alert the operator, and N is the number of preset alarm thresholds.

8. A CT-guided tumor ablation dose control system, characterized in that: Includes the following modules: The imaging and parameter acquisition module starts the CT scanning device to perform three-dimensional imaging of the tumor site, obtains the three-dimensional contour data of the tumor, calculates the tumor volume based on the contour data, and calculates the average density of the tumor through the gray value distribution of the CT image; The initial dose calculation module calculates the initial ablation dose using a preset formula based on the tumor volume and average density ; Calculate the initial ablation dose The formula is: ； in, is the tumor volume, is the average tumor density, is the empirical coefficient, The value of is related to the tissue type of the tumor, and different types of tumors correspond to different constant values; The ablation device control module determines the initial ablation dose. Set the initial parameters of the ablation device and start the ablation procedure; The real-time monitoring module turns on the CT scanning device again at specific intervals to update the 3D contour data and grayscale value distribution of the tumor, and repeats the above volume, density and dose calculation steps to obtain the real-time ablation dose. ; Dose comparison and control module, real-time ablation dose Initial ablation dose In contrast, When the power of the ablation device is reduced, The preset upper limit of the dosage is the floating ratio; when When the power of the ablation device is increased, The floating ratio is the preset lower limit of the dose.

9. The tumor ablation dose control system according to claim 8, characterized in that: The ablation device control module includes a power setting submodule, which sets the power conversion efficiency of the ablation device according to the energy conversion efficiency of the ablation device. , through the formula Calculate initial power ,in is the preset initial ablation time; According to the heat dissipation characteristics of the ablation needle, set the initial coolant flow rate , the flow rate and power satisfy the relationship , c is the heat dissipation coefficient.

10. The tumor ablation dose control system according to claim 8, characterized in that: The imaging and parameter acquisition module: According to the contour data through the formula Calculation of tumor volume ,in is the cross-sectional area of ​​the i-th layer, is the distance between two adjacent layers of cross sections, and n is the number of layers; By combining the gray value distribution of CT images with the formula Calculate the mean tumor density ,in is the density value corresponding to the jth pixel, and m is the total number of selected pixels; The method of selecting pixel points is: take the geometric center of the tumor as the center and r as the radius to draw a circle, select the pixel points in the circle to participate in the calculation, and r is calculated based on the maximum diameter R of the tumor through the formula Sure.

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