A method and device for predicting dose based on radiotherapy

Abstract

The present invention discloses a dose prediction method and device based on radiotherapy, including: obtaining the original integrated dose volume histogram of the structure to be predicted, and obtaining the reference dose distribution and the actual dose distribution according to the preset measurement plane; obtaining the projection weight distribution of the structure to be predicted on the preset measurement plane according to the preset measurement plane and the control point parameters; calculating and obtaining the reference dose volume histogram based on projection and the actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution; calculating the dose difference value of the reference dose volume histogram based on projection and the actual dose volume histogram, and calculating and obtaining the predicted integrated dose volume histogram according to the dose difference value, thereby completing the prediction of the dose. The present invention solves the technical problem of the need to perform complex modeling and model testing processes in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of medical software, and in particular to a dose prediction method and device based on radiotherapy. Background Art

[0002] Due to the complexity of radiotherapy, in order to ensure medical safety and to ensure that the plan used for treatment meets clinical requirements and to ensure the consistency of the executed treatment plan with the planned design, a pre-treatment dose verification is required before the treatment plan is used for actual patient treatment. Dose verification is to compare the dose distribution measured during the actual execution of the plan with the dose distribution calculated by the plan, and to evaluate the effect of the actual execution of the plan by evaluating the difference between the measured value and the calculated value. Generally, an ionization chamber matrix, a semiconductor matrix, and an electronic portal imaging device (EPID) are used as pre-treatment IMRT plan dose measurement tools.

[0003] Common dose distribution comparison and analysis methods include dose difference test, distance-to-agreement, gamma analysis and three-dimensional dose reconstruction comparison. The first three methods are for comparison of direct measurement results. The treatment plan needs to be transplanted to the measurement device for calculation to obtain the dose distribution of the measurement plane. The general measurement device is a uniform cube, cylinder or polygon, not the shape of the human body or the actual human body being treated. Because there are differences between the measurement device and the actual human body, the difference results obtained are inconsistent with the actual human body dose difference results. Therefore, the biggest disadvantage of direct comparison is that it cannot intuitively reflect the data required by the clinic, such as the integrated dose volume histogram and average dose of different anatomical structures. The three-dimensional dose reconstruction comparison method can obtain the results closest to the treatment, but on the one hand, it has high requirements for the measurement device to complete accurate reconstruction, such as high resolution to ensure complete capture of accurate flux distribution; fast data acquisition speed is required to ensure that the acquisition process can obtain complete plan execution information in real time. On the other hand, it requires complex modeling and model testing processes, and the quality of the modeling results will directly affect the final results.

[0004] Therefore, there is an urgent need for a dose prediction method and device that can avoid the modeling and model testing process. Summary of the invention

[0005] The present invention provides a dose prediction method and device based on radiotherapy to solve the technical problem of requiring complex modeling and model testing processes in the prior art.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a dose prediction method based on radiotherapy, comprising:

[0007] Obtaining the original integrated dose volume histogram of the structure to be predicted, and obtaining the reference dose distribution and the actual dose distribution according to the preset measurement plane;

[0008] According to the preset measurement plane and the control point parameters, the projection weight distribution of the structure to be predicted on the preset measurement plane is obtained; wherein the control point parameters are obtained by a medical linear accelerator;

[0009] Calculate and obtain a projection-based reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution;

[0010] The dose difference value is calculated for the projection-based reference dose volume histogram and the actual dose volume histogram, and a predicted integrated dose volume histogram is calculated and obtained according to the dose difference value, thereby completing the prediction of the dose.

[0011] It can be understood that, compared with the prior art, the present invention can obtain the original integrated dose volume histogram of the structure to be predicted through the existing dose distribution comparison and analysis method, and obtain the reference dose distribution and the actual dose distribution according to the measurement plane, and obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the control point parameters, thereby ensuring that the calculated reference dose volume histogram and the actual dose volume histogram can be based on the projection weight, thereby improving the accuracy of the dose volume histogram, and accurately calculating the predicted integrated dose volume histogram through the dose difference value between the reference and actual dose volume histograms, thereby avoiding the existing process of complex modeling and model testing, and improving the efficiency of dose prediction.

[0012] As a preferred solution, the control point parameters include: the total number of control points of the medical linear accelerator, the arm angle of each control point and the ratio of the number of beam jumps of each control point.

[0013] It can be understood that the control point parameters are determined by data such as the arm angle of the execution control point of the medical linear accelerator, which can ensure accurate calculation of the projection weight distribution without using complex data required for modeling.

[0014] As a preferred solution, the projection weight distribution of the structure to be predicted on the preset measurement plane is obtained according to the preset measurement plane and the control point parameters, specifically:

[0015] The preset measurement plane is divided into a plurality of measurement points, and according to the straight line determined by each measurement point and the beam source of the linear accelerator, the trajectory length of the straight line corresponding to each measurement point passing through the structure to be predicted is obtained respectively, and according to each measurement point, the trajectory length corresponding to each measurement point, the total number of control points and the ratio of the beam hop number of each control point, the projection weight distribution of each measurement point is calculated and obtained respectively.

[0016] It can be understood that by dividing the preset measurement plane, the trajectory length corresponding to each measurement point is obtained by matching the obtained measurement points with the straight line determined by the beam source of the linear accelerator, and according to the execution control point parameters of the linear accelerator, the structural projection weight distribution of the structure to be predicted on the measurement plane can be accurately obtained, thereby simplifying the prediction calculation process.

[0017] As a preferred solution, after obtaining the original integrated dose volume histogram of the structure to be predicted, the method further includes:

[0018] According to the preset volume value and the preset dose value of the structure to be predicted, the volume value and the dose value of the original integrated dose volume histogram are normalized respectively, so as to obtain a normalized original integrated dose volume histogram.

[0019] It can be understood that by normalizing the volume value and dose value of the integrated dose-volume histogram respectively through the preset volume value and the preset dose value of the structure to be predicted, the normalized original integrated dose-volume histogram can avoid errors in the calculation process caused by data of different magnitudes, thereby improving the accuracy of the calculation.

[0020] As a preferred solution, the step of calculating and obtaining a projection-based reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution is specifically as follows:

[0021] Obtaining and adding the projection weights of the measurement points that are greater than 0 in the projection weight distribution to obtain a total weight of the measurement points;

[0022] According to a preset dose value, respectively normalizing the reference dose distribution and the actual dose distribution;

[0023] According to the dose value interval in the original integrated dose volume histogram, the projection weights of the measurement points in the normalized reference dose distribution and the normalized actual dose distribution that are greater than the dose value interval are added respectively, so as to obtain a first weight sum and a second weight sum of each dose value interval respectively; wherein the first weight sum is the weight sum of the reference dose distribution, and the second weight sum is the weight sum of the actual dose distribution;

[0024] The first weight sum and the second weight sum are normalized according to the total weight of the measurement points, and a projection-based reference dose volume histogram and an actual dose reference histogram are obtained according to the normalized first weight sum and the second weight sum.

[0025] It can be understood that the total weight of the measurement points whose added projection weights are greater than zero is obtained by statistics on the projection weight distribution, and the projection weights of the measurement points corresponding to the dose value interval are added through the normalized reference dose distribution and the normalized actual dose distribution, thereby obtaining the first weight sum and the second weight sum, and the first weight sum and the second weight sum are normalized respectively through the total weight of the measurement points, so as to accurately obtain the projection-based reference dose volume histogram and the actual dose reference histogram.

[0026] As a preferred solution, the calculation of the dose difference value between the reference dose volume histogram based on the projection and the actual dose volume histogram, and the calculation to obtain the predicted integrated dose volume histogram according to the dose difference value, is specifically as follows:

[0027] According to the first weight sum and the second weight sum, calculating the difference between the dose values ​​corresponding to when the first weight sum and the second weight sum are the same as each other, as the dose difference value;

[0028] The predicted dose value is calculated based on the dose difference value and the original integrated dose-volume histogram, and the weight sum when the first weight sum is the same as the second weight sum is used as the predicted volume value, so as to calculate and obtain the predicted integrated dose-volume histogram.

[0029] It can be understood that by calculating the difference between the dose values ​​corresponding to the first weight sum and the second weight sum when they are the same as the dose difference value, the dose difference value between the reference dose volume histogram and the actual dose reference histogram can be accurately calculated, and the predicted dose value is calculated by the dose difference value, and the predicted integral dose volume histogram is accurately calculated by taking the weight sum when the first weight sum and the second weight sum are the same as the predicted volume value, thereby improving the calculation efficiency of the overall predicted integral dose volume histogram.

[0030] As a preferred solution, after the calculation to obtain the predicted integrated dose volume histogram, the method further includes:

[0031] According to the preset volume value and the preset dose value of the structure to be predicted, the predicted volume value and the predicted dose value are restored respectively, so as to obtain a predicted integrated dose volume histogram restored to an absolute value.

[0032] It can be understood that by using the preset volume value and the preset dose value of the structure to be predicted, the predicted volume value and the predicted dose value are restored respectively, and then the predicted integrated dose volume histogram restored to the absolute value is accurately obtained, which simplifies the complexity of the intermediate calculation, avoids the modeling process, and improves the calculation efficiency and accuracy.

[0033] Accordingly, the present invention also provides a dose prediction device based on radiotherapy, comprising: an acquisition module, a projection weight module, a histogram module and a prediction module;

[0034] The acquisition module is used to acquire the original integrated dose volume histogram of the structure to be predicted, and acquire the reference dose distribution and the actual dose distribution according to the preset measurement plane;

[0035] The projection weight module is used to obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the preset measurement plane and the control point parameters; wherein the control point parameters are obtained by a medical linear accelerator;

[0036] The histogram module is used to calculate and obtain a reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution;

[0037] The prediction module is used to calculate the dose difference value between the reference dose volume histogram based on the projection and the actual dose volume histogram, and calculate and obtain the predicted integrated dose volume histogram according to the dose difference value, so as to complete the prediction of the dose.

[0038] As a preferred solution, it also includes: a normalization module;

[0039] The normalization module is used to perform normalization operations on the volume value and the dose value of the original integrated dose volume histogram according to the preset volume value and the preset dose value of the structure to be predicted, so as to obtain a normalized original integrated dose volume histogram.

[0040] As a preferred solution, it also includes: a restoration module;

[0041] The restoration module is used to restore the predicted volume value and the predicted dose value according to the preset volume value and the preset dose value of the structure to be predicted, so as to obtain a predicted integrated dose volume histogram restored to an absolute value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : A flow chart of the steps of a dose prediction method based on radiotherapy provided by an embodiment of the present invention;

[0043] Figure 2 : A schematic diagram of a beam source of a Chinese linear accelerator in a method for predicting dose based on radiotherapy provided in an embodiment of the present invention;

[0044] Figure 3 : A flow chart of calculation steps for obtaining a projection dose volume histogram in a dose prediction method based on radiotherapy provided by an embodiment of the present invention;

[0045] Figure 4 : A flow chart of the calculation steps of predicting the integrated dose volume histogram in a dose prediction method based on radiotherapy provided in an embodiment of the present invention;

[0046] Figure 5 : A schematic structural diagram of a dose prediction device based on radiotherapy provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] 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.

[0048] Embodiment 1

[0049] Please refer to Figure 1 , a dose prediction method based on radiotherapy provided by an embodiment of the present invention, comprising the following steps S101-S104:

[0050] S101: Obtain an original integrated dose volume histogram of the structure to be predicted, and obtain a reference dose distribution and an actual dose distribution according to a preset measurement plane.

[0051] As a preferred solution, after obtaining the original integrated dose volume histogram of the structure to be predicted, the method further includes:

[0052] According to the preset volume value and the preset dose value of the structure to be predicted, the volume value and the dose value of the original integrated dose volume histogram are normalized respectively, so as to obtain a normalized original integrated dose volume histogram.

[0053] In this embodiment, preferably, the normalized original integrated dose volume histogram DVH of the anatomical structure S to be predicted to be analyzed in the original treatment plan is derived through a radiotherapy planning system (TPS) or a third-party independent dose verification software. planThe anatomical structures to be predicted include but are not limited to the irradiation target area, brain stem and spinal cord. In this embodiment, the normalized original integrated dose volume histogram is obtained by calculating the volume value V of the original integrated dose volume histogram. plan Divide by the volume value V of the anatomical structure S to be predicted plan，max , and the dose value D of the original integrated dose volume histogram plan Divide by the maximum dose value D in the original treatment plan plan，max , to obtain the normalized original integrated dose volume histogram.

[0054] It can be understood that by normalizing the volume value and dose value of the integrated dose-volume histogram respectively through the preset volume value and the preset dose value of the structure to be predicted, the normalized original integrated dose-volume histogram can avoid errors in the calculation process caused by data of different magnitudes, thereby improving the accuracy of the calculation.

[0055] Furthermore, in this embodiment, the reference dose distribution and the actual dose distribution are obtained by transplanting the target treatment plan to the phantom of the electronic portal imaging system (EPID) through the radiotherapy planning system or the third-party independent dose verification software, and calculating the reference dose distribution D of the EPID measurement plane under ideal conditions. ref , and execute the target treatment plan, and obtain the actual dose distribution D of the medical linear accelerator executing the plan through EPID measurement eva .

[0056] S102: According to the preset measurement plane and control point parameters, obtaining a projection weight distribution of the structure to be predicted on the preset measurement plane; wherein the control point parameters are obtained by a medical linear accelerator.

[0057] It should be noted that a medical linear accelerator is an accelerator that uses microwave electromagnetic fields to accelerate electrons and has a linear motion track. It is a medical device used for radiotherapy of tumors or other lesions in patients. It can generate high-energy X-rays and electron beams, and has the characteristics of high dose rate, short irradiation time, large irradiation field, good dose uniformity and stability, and small penumbra. The control point parameters are obtained based on the plan file of the radiotherapy plan in the medical linear accelerator (generally using a standardized Dicom file), or can be obtained based on the log file when the medical linear accelerator is executed. The control point parameter content describes the specific accelerator equipment parameters when the medical linear accelerator executes the treatment plan.

[0058] As a preferred solution, the control point parameters include: the total number of control points of the medical linear accelerator, the gantry angle of each control point and the ratio of the number of beam jumps of each control point.

[0059] It is understandable that the control point parameters are determined by the arm angle and other data of the execution control point of the medical linear accelerator, which can ensure the accurate calculation of the projection weight distribution, and does not need to use the complex data required for modeling. At the same time, the control point parameters are the total number of control points for the medical linear accelerator to execute the treatment plan, the arm (Gantry) angle of each control point (the arm angle is used to determine the position of the accelerator source, and the medical linear accelerator rotates around the isocenter when executing the plan), and the ratio of the number of beam jumps at each control point.

[0060] Specifically, the preset measurement plane is divided into a number of measurement points, and according to the straight line determined by each measurement point and the beam source of the linear accelerator, the trajectory length of each measurement point corresponding to the straight line passing through the structure to be predicted is obtained respectively, and according to each measurement point, the trajectory length corresponding to each measurement point, the total number of control points and the ratio of the number of beam jumps of each control point, the projection weight distribution of each measurement point is calculated and obtained respectively. The specific calculation formula is as follows:

[0061] Where (i, j) is the measurement point in the i-th row and j-th column of the measurement plane, C is the total number of planned control points, PM p is the ratio of the number of hops (Monitor Unit, MU) of the pth control point to the total MU, and L is the length of the path of the straight line from the source to the measurement point (i, j) passing through the anatomical structure S, as Figure 2 shown.

[0062] It can be understood that by dividing the preset measurement plane, the trajectory length corresponding to each measurement point is obtained by matching the obtained measurement points with the straight line determined by the beam source of the linear accelerator, and according to the execution control point parameters of the linear accelerator, the structural projection weight distribution of the structure to be predicted on the measurement plane can be accurately obtained, thereby simplifying the prediction calculation process.

[0063] S103: Calculate and obtain a projection-based reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution.

[0064] As a preferred option, see Figure 3 Step S103 specifically includes the following steps S201-S204:

[0065] S201: Obtain and add the projection weights of the measurement points greater than 0 in the projection weight distribution to obtain the total weight of the measurement points. The specific calculation formula is as follows:

[0066] N=∑ ij W ij , where W ij>0, N is the total weight of the measurement points.

[0067] S202: performing normalization operations on the reference dose distribution and the actual dose distribution respectively according to preset dose values.

[0068] In this embodiment, preferably, the reference dose distribution D ref The maximum dose value is taken as the dose normalization value D max Taking the reference dose distribution as an example, the reference dose distribution D ref The dose value D ij Normalize to D ij '=D ij / D max , thus obtaining the normalized reference dose distribution D ref '. Similarly, for the actual dose distribution D eva The normalization operation, the actual dose distribution D eva The dose values ​​in the ij '=D ij / D max , thus obtaining the normalized actual dose distribution D eva '.

[0069] S203: According to the dose value interval in the original integrated dose volume histogram, the projection weights of the measurement points in the normalized reference dose distribution and the normalized actual dose distribution that are greater than the dose value interval are added respectively to obtain a first weight sum and a second weight sum for each dose value interval respectively; wherein the first weight sum is the weight sum of the reference dose distribution, and the second weight sum is the weight sum of the actual dose distribution.

[0070] In this embodiment, preferably, according to the original integrated dose volume histogram DVH plan Dose interval D plan is the statistical dose value interval, and the statistically normalized reference dose distribution D ref 'The medium dose is greater than the D of the kth dose interval plan，k The first weight sum N corresponding to each measurement point k1 , and the actual dose distribution D after statistical normalization eva 'The medium dose is greater than the D of the kth dose interval plan，k The second weight sum N corresponding to each measurement point k2 .

[0071] S204: Normalizing the first weight sum and the second weight sum according to the total weight of the measurement points, and obtaining a projection-based reference dose volume histogram and an actual dose reference histogram according to the normalized first weight sum and the second weight sum.

[0072] In this embodiment, according to the total weight of the measurement points, N k '=N k / N respectively normalizes the first weight sum and the second weight sum, thereby obtaining a projection-based reference dose volume histogram and an actual dose reference histogram.

[0073] It can be understood that the total weight of the measurement points whose added projection weights are greater than zero is obtained by statistics on the projection weight distribution, and the projection weights of the measurement points corresponding to the dose value interval are added by the normalized reference dose distribution and the normalized actual dose distribution, thereby obtaining the first weight sum and the second weight sum, and the first weight sum and the second weight sum are normalized by the total weight of the measurement points, so as to accurately obtain the reference dose volume histogram DVH based on the projection. ref and actual dose reference histogram DVH eva .

[0074] S104: Calculating the dose difference value between the projection-based reference dose volume histogram and the actual dose volume histogram, and calculating and obtaining the predicted integrated dose volume histogram according to the dose difference value, thereby completing the dose prediction.

[0075] As a preferred option, see Figure 4 Step S104 specifically includes the following steps S301-S302:

[0076] S301: Calculate, according to the first weight sum and the second weight sum, a difference between the dose values ​​corresponding to when the first weight sum and the second weight sum are the same, as a dose difference value.

[0077] In this embodiment, by using the projection-based reference dose volume histogram DVH ref and actual dose volume histogram DVH eva Compare and calculate the same N k 'DVH ref With DVH eva The dose difference value PD k .

[0078] S302: Calculate and obtain a predicted dose value according to the dose difference value and the original integrated dose-volume histogram, and use the weight sum when the first weight sum is the same as the second weight sum as the predicted volume value, thereby calculating and obtaining a predicted integrated dose-volume histogram.

[0079] In this embodiment, according to the dose interval D in the original integrated dose volume histogram plan，kand the dose difference value PD k , through D pre，k =D plan，k +PD k Calculate the predicted dose value D pre，k , and DVH ref and DVH eva The corresponding N k 'As the predicted volume value V pre，k , so according to the predicted dose value D pre，k and the predicted volume value V pre，k To obtain the predicted integrated dose volume histogram.

[0080] It can be understood that by calculating the difference between the dose values ​​corresponding to the first weight sum and the second weight sum being the same as the dose difference value, the dose difference value between the reference dose volume histogram and the actual dose reference histogram can be accurately calculated, and the predicted dose value is calculated by the dose difference value, and the predicted integral dose volume histogram is accurately calculated by taking the weight sum when the first weight sum and the second weight sum are the same as the predicted volume value, thereby improving the calculation efficiency of the overall predicted integral dose volume histogram.

[0081] As a preferred solution, after the calculation to obtain the predicted integrated dose volume histogram, the method further includes:

[0082] According to the preset volume value and the preset dose value of the structure to be predicted, the predicted volume value and the predicted dose value are restored respectively, so as to obtain a predicted integrated dose volume histogram restored to an absolute value.

[0083] In this embodiment, the volume value V of the anatomical structure S to be predicted in step S101 is plan，max and the maximum dose value D in the original treatment plan plan，max , to predict the volume value V pre and the predicted dose value D pre Specifically, by predicting the volume value V pre Multiply by the volume value V of the anatomical structure S to be predicted plan，max , and by predicting the dose value D pre Multiply by the maximum dose value D in the original treatment plan plan，max , thus obtaining the predicted integrated dose volume histogram restored to absolute value.

[0084] It can be understood that by using the preset volume value and the preset dose value of the structure to be predicted, the predicted volume value and the predicted dose value are restored respectively, and then the predicted integrated dose volume histogram restored to the absolute value is accurately obtained, which simplifies the complexity of the intermediate calculation, avoids the modeling process, and improves the calculation efficiency and accuracy.

[0085] As a preferred solution of this embodiment, the above steps may be repeated to calculate and obtain the predicted integrated dose volume histogram for other anatomical structures to be analyzed, thereby obtaining dose predictions for other anatomical structures.

[0086] Implementing this embodiment has the following effects:

[0087] Compared with the prior art, the embodiment of the present invention can obtain the original integrated dose volume histogram of the structure to be predicted under the original treatment plan through the existing dose distribution comparison and analysis method, and obtain the reference dose distribution and the actual dose distribution according to the measurement plane, and obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the control point parameters, so as to ensure that the calculated reference dose volume histogram and the actual dose volume histogram can be based on the projection weight, thereby improving the accuracy of the dose volume histogram, and accurately calculating the predicted integrated dose volume histogram through the dose difference value between the reference and actual dose volume histograms, avoiding the existing process of complex modeling and model testing, and improving the efficiency of dose prediction.

[0088] Embodiment 2

[0089] Accordingly, see Figure 5 The present invention also provides a dose prediction device based on radiotherapy, including: an acquisition module 401, a projection weight module 402, a histogram module 403 and a prediction module 404.

[0090] The acquisition module 401 is used to acquire the original integrated dose volume histogram of the structure to be predicted, and acquire the reference dose distribution and the actual dose distribution according to a preset measurement plane.

[0091] As a preferred embodiment, the embodiment of the present invention also includes: a normalization module 4011; the normalization module 4011 is used to normalize the volume value and dose value of the original integrated dose volume histogram according to the preset volume value and preset dose value of the structure to be predicted, so as to obtain a normalized original integrated dose volume histogram.

[0092] The projection weight module 402 is used to obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the preset measurement plane and control point parameters; wherein the control point parameters are obtained by a medical linear accelerator.

[0093] As a preferred solution, the control point parameters include: the total number of control points of the medical linear accelerator, the arm angle of each control point and the ratio of the number of beam jumps of each control point.

[0094] As a preferred solution, the projection weight module 402 is specifically used to: divide the preset measurement plane into a number of measurement points, and obtain the trajectory length of the straight line corresponding to each measurement point passing through the structure to be predicted according to the straight line determined by each measurement point and the beam source of the linear accelerator, and calculate the projection weight distribution of each measurement point according to each measurement point, the trajectory length corresponding to each measurement point, the total number of control points and the ratio of the beam jump number of each control point.

[0095] The histogram module 403 is used to calculate and obtain a reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution.

[0096] As a preferred embodiment, the histogram module 403 is specifically used to: obtain and add the projection weights of the measurement points greater than 0 in the projection weight distribution to obtain the total weight of the measurement points; according to the preset dose value, respectively normalize the reference dose distribution and the actual dose distribution; according to the dose value interval in the original integrated dose volume histogram, respectively add the projection weights of the measurement points greater than the dose value interval in the normalized reference dose distribution and the normalized actual dose distribution to obtain the first weight sum and the second weight sum of each dose value interval; wherein the first weight sum is the weight sum of the reference dose distribution, and the second weight sum is the weight sum of the actual dose distribution; according to the total weight of the measurement points, respectively normalize the first weight sum and the second weight sum, and obtain the projection-based reference dose volume histogram and the actual dose reference histogram according to the normalized first weight sum and the second weight sum.

[0097] The prediction module 404 is used to calculate the dose difference value between the reference dose volume histogram based on the projection and the actual dose volume histogram, and calculate and obtain the predicted integrated dose volume histogram according to the dose difference value, so as to complete the prediction of the dose.

[0098] As a preferred embodiment, the prediction module 404 is specifically used to: calculate the difference between the dose values ​​corresponding to when the first weight sum and the second weight sum are the same, as a dose difference value, based on the first weight sum and the second weight sum; calculate and obtain the predicted dose value based on the dose difference value and the original integrated dose-volume histogram, and use the weight sum when the first weight sum and the second weight sum are the same as the predicted volume value, thereby calculating and obtaining the predicted integrated dose-volume histogram.

[0099] As a preferred solution, it also includes: a restoration module 4041; the restoration module 4041 is used to restore the predicted volume value and the predicted dose value according to the preset volume value and the preset dose value of the structure to be predicted, so as to obtain a predicted integrated dose volume histogram restored to an absolute value.

[0100] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0101] Implementing the above embodiments has the following effects:

[0102] Compared with the prior art, the embodiment of the present invention can obtain the original integrated dose volume histogram of the structure to be predicted through the existing dose distribution comparison and analysis method, and obtain the reference dose distribution and the actual dose distribution according to the measurement plane, and obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the control point parameters, thereby ensuring that the calculated reference dose volume histogram and the actual dose volume histogram can be based on the projection weight, thereby improving the accuracy of the dose volume histogram, and accurately calculating the predicted integrated dose volume histogram through the dose difference value between the reference and actual dose volume histograms, thereby avoiding the existing process of complex modeling and model testing, and improving the efficiency of dose prediction.

[0103] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dose prediction method based on radiotherapy, characterized in that: include: Obtaining the original integrated dose volume histogram of the structure to be predicted, and obtaining the reference dose distribution and the actual dose distribution according to the preset measurement plane; According to the preset measurement plane and the control point parameters, the projection weight distribution of the structure to be predicted on the preset measurement plane is obtained; wherein the control point parameters are obtained by a medical linear accelerator; Calculate and obtain a projection-based reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution; The dose difference value is calculated for the projection-based reference dose volume histogram and the actual dose volume histogram, and a predicted integrated dose volume histogram is calculated and obtained according to the dose difference value, thereby completing the prediction of the dose.

2. A method for predicting dose based on radiotherapy according to claim 1, characterized in that: The control point parameters include: the total number of control points of the medical linear accelerator, the arm angle of each control point and the ratio of the number of beam jumps of each control point.

3. A method for predicting dose based on radiotherapy according to claim 2, characterized in that: The step of obtaining the projection weight distribution of the structure to be predicted on the preset measurement plane according to the preset measurement plane and the control point parameters is specifically as follows: The preset measurement plane is divided into a plurality of measurement points, and according to the straight line determined by each measurement point and the beam source of the linear accelerator, the trajectory length of the straight line corresponding to each measurement point passing through the structure to be predicted is obtained respectively, and according to each measurement point, the trajectory length corresponding to each measurement point, the total number of control points and the ratio of the beam hop number of each control point, the projection weight distribution of each measurement point is calculated and obtained respectively.

4. A method for predicting dose based on radiotherapy according to claim 3, characterized in that: After obtaining the original integrated dose volume histogram of the structure to be predicted, the method further includes: According to the preset volume value and the preset dose value of the structure to be predicted, the volume value and the dose value of the original integrated dose volume histogram are normalized respectively, so as to obtain a normalized original integrated dose volume histogram.

5. A method for predicting dose based on radiotherapy according to claim 4, characterized in that: The step of calculating and obtaining a projection-based reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution is specifically as follows: Obtaining and adding the projection weights of the measurement points greater than 0 in the projection weight distribution to obtain a total weight of the measurement points; According to a preset dose value, respectively normalizing the reference dose distribution and the actual dose distribution; According to the dose value interval in the original integrated dose volume histogram, the projection weights of the measurement points in the normalized reference dose distribution and the normalized actual dose distribution that are greater than the dose value interval are added respectively, so as to obtain a first weight sum and a second weight sum of each dose value interval respectively; wherein the first weight sum is the weight sum of the reference dose distribution, and the second weight sum is the weight sum of the actual dose distribution; The first weight sum and the second weight sum are normalized according to the total weight of the measurement points, and a projection-based reference dose volume histogram and an actual dose reference histogram are obtained according to the normalized first weight sum and the second weight sum.

6. A method for predicting dose based on radiotherapy according to claim 5, characterized in that: The step of calculating the dose difference value between the reference dose volume histogram based on the projection and the actual dose volume histogram, and obtaining the predicted integrated dose volume histogram by calculation according to the dose difference value, is specifically as follows: According to the first weight sum and the second weight sum, calculating the difference between the dose values ​​corresponding to when the first weight sum and the second weight sum are the same as each other, as the dose difference value; The predicted dose value is calculated based on the dose difference value and the original integrated dose-volume histogram, and the weight sum when the first weight sum is the same as the second weight sum is used as the predicted volume value, so as to calculate and obtain the predicted integrated dose-volume histogram.

7. A method for predicting dose based on radiotherapy according to claim 6, characterized in that: After the calculation to obtain the predicted integrated dose volume histogram, the method further includes: According to the preset volume value and the preset dose value of the structure to be predicted, the predicted volume value and the predicted dose value are restored respectively, so as to obtain a predicted integrated dose volume histogram restored to an absolute value.

8. A dose prediction device based on radiotherapy, characterized in that: include: Acquisition module, projection weight module, histogram module and prediction module; The acquisition module is used to acquire the original integrated dose volume histogram of the structure to be predicted, and acquire the reference dose distribution and the actual dose distribution according to the preset measurement plane; The projection weight module is used to obtain the projection weight distribution of the structure to be predicted on the preset measurement plane according to the preset measurement plane and the control point parameters; wherein the control point parameters are obtained by a medical linear accelerator; The histogram module is used to calculate and obtain a reference dose volume histogram and an actual dose volume histogram according to the projection weight distribution, the original integrated dose volume histogram, the reference dose distribution and the actual dose distribution; The prediction module is used to calculate the dose difference value between the reference dose volume histogram based on the projection and the actual dose volume histogram, and calculate and obtain the predicted integrated dose volume histogram according to the dose difference value, so as to complete the prediction of the dose.

9. A dose prediction device based on radiotherapy as claimed in claim 8, characterized in that: Also includes: Normalization module; The normalization module is used to perform normalization operations on the volume value and the dose value of the original integrated dose volume histogram according to the preset volume value and the preset dose value of the structure to be predicted, so as to obtain a normalized original integrated dose volume histogram.

10. The dose prediction device based on radiotherapy according to claim 8, characterized in that: Also includes: Restore module; The restoration module is used to obtain a predicted integrated dose volume histogram restored to an absolute value according to a preset volume value and a preset dose value of the structure to be predicted.

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