External irradiation in vitro cell absorbed dose detection method and system

Abstract

The present invention relates to the technical field of radiobiology, and provides an external irradiation in vitro cell absorbed dose detection method and system. By using the geometric model of in vitro cells, the conversion coefficient between the absorbed dose of the cell layer and the absorbed dose of air is calculated in advance. When evaluating the absorbed dose of in vitro cells, it is only necessary to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer by an ionization chamber, and then use the conversion coefficient between the absorbed dose of the cell layer and the absorbed dose of air to obtain the absorbed dose of the cell layer. Compared with the traditional method, the present invention greatly improves the test efficiency of the absorbed dose of in vitro cells and further improves the test accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of radiobiology, and relates to a method and a system for detecting the absorbed dose of ex vivo cells under external irradiation. Background Art

[0002] The quantitative detection of the absorbed dose can not only predict the biological effects of radiation, but also be used in the dose optimization process in the research and development of radioactive therapeutic drugs, which is of great significance for optimizing the therapeutic effect, evaluating the safety of treatment, and individualizing the adjustment of the dose. At present, the main method for quantitatively detecting the absorbed dose of cells is to measure the absorbed dose of the cell culture medium in the cell dish by using an ionization chamber dose meter, and approximate the absorbed dose of the cells with the absorbed dose value of the cell culture medium. The basic process of measuring the absorbed dose by an ionization chamber is as follows: by measuring the ionization charge of the secondary particles generated during the interaction of ionizing radiation with matter, the absorbed dose is calculated; that is, measuring the absorbed dose by an ionization chamber can be divided into two steps: first, measuring the ionization charge generated by ionizing radiation, and then using the average ionization energy of air to calculate and convert it into the energy deposited by ionizing radiation, that is, the absorbed dose. And the kinetic energy of the electrons consumed for generating a pair of positive and negative particles in air is basically a constant for all electrons, that is, the average ionization energy is W / e = 33.97 J / C.

[0003] However, the disadvantages of using an ionization chamber dose meter for quantitatively detecting the absorbed dose of cells are as follows: 1) Due to the influence of factors such as the type of radiation particles, the energy of the particles, the amount of cell culture medium, and the stacking thickness of cells in the culture medium, it can only approximately reflect the actual absorbed dose of cells and there is a large uncertainty; 2) Since the energy response is a key factor affecting the measurement accuracy of directly measuring the absorbed dose of cell culture medium by an ionization chamber, and the dose calibration procedure is complex, it is difficult to obtain an accurate dose calibration factor; 3) For external neutron irradiation, using an ionization chamber to directly measure the absorbed dose of cell culture medium requires applying multiple correction factors, which further leads to a greater difference between the absorbed dose of cell culture medium and the true cell dose value.

[0004] Therefore, there is an urgent need for a detection scheme for the absorbed dose of ex vivo cells under external irradiation with high measurement efficiency. Summary of the Invention

[0005] The present invention provides a method and a system for detecting the absorbed dose of ex vivo cells under external irradiation to solve at least one problem existing in the prior art.

[0006] To achieve the above object, in a first aspect, a method for detecting the absorbed dose of ex vivo cells under external irradiation provided by the present invention includes obtaining the type of irradiation particles and the irradiation distance, and selecting the type of ionization chamber and the type of filling gas of the ionization chamber according to the type of irradiation particles.

[0007] According to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas in the ionization chamber, use the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer; determine the air absorbed dose according to the absorbed dose in the cavity gas;

[0008] Based on the air absorbed dose and the pre-acquired conversion coefficient between the cell layer absorbed dose and the air absorbed dose, obtain the cell layer absorbed dose; the conversion coefficient between the cell layer absorbed dose and the air absorbed dose is obtained by a preset in vitro cell geometric model using a particle transport simulation program.

[0009] Further, preferably, the method for obtaining the conversion coefficient between the cell layer absorbed dose and the air absorbed dose by a preset in vitro cell geometric model using a particle transport simulation program includes,

[0010] Establish an in vitro cell geometric model; the in vitro cell geometric model includes a cell culture dish, a cell layer, and a cell culture medium layer;

[0011] Using a particle transport simulation program, obtain the absorbed dose of the cell layer in the cell culture dish according to the particle type, particle energy, and irradiation distance through the in vitro cell geometric model; use the particle transport simulation program to obtain the air absorbed dose according to the particle type, particle energy, and irradiation distance;

[0012] According to the absorbed dose of the cell layer in the cell culture dish and the air absorbed dose, obtain the conversion coefficient between the cell layer absorbed dose and the air absorbed dose.

[0013] Further, preferably, in the process of using the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas in the ionization chamber,

[0014] When the type of irradiated particles is photons or electrons, the type of ionization chamber is a graphite cavity ionization chamber;

[0015] When the filling gas of the graphite cavity ionization chamber is air, the absorbed dose measured by the ionization chamber in the cavity gas at the irradiation position of the cell layer is equal to the air absorbed dose;

[0016] When the filling gas of the graphite cavity ionization chamber is gas g, determine the air absorbed dose D according to the absorbed dose in the cavity gas a Determined by the following formula,

[0017] D a =D mg× S w,g

[0018] Among them, D mg is the absorbed dose in the cavity gas g obtained by ionization chamber measurement; S w,g is the ratio of the average mass collision stopping power of the graphite w of the cavity ionization chamber wall material to the gas g in the cavity;

[0019] S w,g = , (s / ρ) w is the mass collision stopping power of graphite for secondary electrons of photons or for electrons; (s / ρ) g is the mass collision stopping power of the cavity gas for secondary electrons of photons or for electrons.

[0020] Furthermore, preferably, in the process of measuring the absorbed dose in the cavity gas at the irradiation position of the cell layer by using an ionization chamber according to the type of irradiation particle, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber,

[0021] when the type of irradiation particle is neutron, the type of ionization chamber is a tissue equivalent ionization chamber;

[0022] Determine the air absorbed dose D a according to the following formula:

[0023] D a =D mg ×(K a / K g )

[0024] Among them, D mg is the absorbed dose in the cavity gas g obtained by tissue equivalent ionization chamber measurement; K a and K g are the specific kinetic energy of neutrons in air and the specific kinetic energy of neutrons in the gas g in the ionization chamber cavity, respectively.

[0025] Furthermore, preferably, in the process of measuring the absorbed dose in the cavity gas at the irradiation position of the cell layer by using an ionization chamber according to the type of irradiation particle, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber,

[0026] when the irradiation particles contain both neutrons and photons at the same time;

[0027] Use a tissue equivalent ionization chamber to obtain the absorbed dose of neutrons in the cavity gas; use a hydrogen-free ionization chamber to obtain the absorbed dose of photons in the cavity gas;

[0028] Determine the air absorbed dose of neutrons based on the absorbed dose of neutrons in the cavity gas, and determine the air absorbed dose of photons based on the absorbed dose of photons in the cavity gas.

[0029] Furthermore, preferably, the hydrogen-free ionization chamber is a graphite-carbon dioxide ionization chamber or a graphite-argon ionization chamber.

[0030] Furthermore, preferably, in the process of obtaining the absorbed dose of the cell layer based on the air absorbed dose and the conversion coefficient of the pre-acquired absorbed dose of the cell layer to the air absorbed dose,

[0031] When the particle source is neutrons, photons or electrons, the absorbed dose of the cell layer is obtained by the following formula:

[0032] D cell =D a× R(S, E, F) × A ;

[0033] where D cell is the absorbed dose of the cell layer; D a is the air absorbed dose value measured by the ionization chamber; R(S,E,F) is the corresponding conversion coefficient of the absorbed dose of the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A);

[0034] When the particle source contains both neutrons and photons, the absorbed dose of neutrons in the cell layer is obtained by the following formula:

[0035] D cell =D a，N× R(S, E, F) × A ;

[0036] The absorbed dose of photons in the cell layer is obtained by the following formula:

[0037] D cell =D a，P× R(S, E, F) × A ;

[0038] where D cell is the absorbed dose of the cell layer; D a，N is the neutron air absorbed dose value measured by the ionization chamber; D a，P is the photon air absorbed dose value measured by the ionization chamber; R(S,E,F) is the corresponding conversion coefficient of the absorbed dose of the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A).

[0039] Further, preferably, the cell layer in the in vitro cell geometric model is composed of tissue equivalent materials.

[0040] To solve the above problems, in a second aspect, the present invention also protects an external irradiation in vitro cell absorbed dose detection system for implementing the above-mentioned external irradiation in vitro cell absorbed dose detection method. The system includes:

[0041] An irradiation data acquisition unit for acquiring the type of irradiation particles and the irradiation distance, and selecting the type of ionization chamber and the type of filling gas of the ionization chamber according to the type of irradiation particles;

[0042] A measurement unit for measuring the absorbed dose in the cavity gas at the irradiation position of the cell layer using an ionization chamber according to the type of irradiation particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber; and determining the air absorbed dose according to the absorbed dose in the cavity gas;

[0043] An absorbed dose acquisition unit for obtaining the cell layer absorbed dose based on the air absorbed dose and a pre-acquired conversion coefficient between the cell layer absorbed dose and the air absorbed dose; the conversion coefficient between the cell layer absorbed dose and the air absorbed dose is obtained by using a particle transport simulation program through a preset in vitro cell geometric model.

[0044] To solve the above problems, in a third aspect, the present invention also provides an electronic device, which includes:

[0045] At least one processor; and,

[0046] A memory communicatively connected to the at least one processor; wherein,

[0047] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the steps in the above-mentioned external irradiation in vitro cell absorbed dose detection method.

[0048] The beneficial effects of the external irradiation in vitro cell absorbed dose detection method, system, and electronic device of the present invention are as follows. By using a particle transport simulation program, the effects of particle type, energy level, and the thickness of the cell culture medium and cell layer on the cell absorbed dose are comprehensively considered. First, the conversion coefficient between the in vitro cell absorbed dose and the air absorbed dose is determined under different irradiation conditions. Then, the air absorbed dose is directly measured using an ionization chamber, and the measurement result of the air absorbed dose is converted into the absorbed dose of in vitro cells through the previously obtained conversion coefficient between the cell layer absorbed dose and the air absorbed dose. Compared with the traditional method of directly measuring the absorbed dose of the cell culture medium using an ionization chamber, the present invention not only simplifies the measurement process but also significantly improves the accuracy of measuring the absorbed dose of in vitro cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic flowchart of the external irradiation in vitro cell absorbed dose detection method provided by an embodiment of the present invention;

[0050] Figure 2 It is a schematic structural diagram of the in vitro cell geometric model provided by an embodiment of the present invention;

[0051] Figure 3 It is a schematic principle diagram of the external irradiation in vitro cell absorbed dose detection system provided by an embodiment of the present invention;

[0052] Figure 4 It is a schematic internal structure diagram of the electronic device for implementing the external irradiation in vitro cell absorbed dose detection method provided by an embodiment of the present invention;

[0053] The realization, functional features, and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] Refer to Figure 1 As shown, it is a schematic flowchart of the external irradiation in vitro cell absorbed dose detection method provided by an embodiment of the present invention. This method can be executed by a device, and the device can be implemented by software and / or hardware.

[0056] In this embodiment, the external irradiation in vitro cell absorbed dose detection method includes steps S110 to S130.

[0057] S110. Obtain the irradiation particle type and irradiation distance, and select the type of ionization chamber and the type of filling gas of the ionization chamber according to the irradiation particle type.

[0058] It should be noted that the type of irradiation particles includes any one of neutrons, photons, and electrons; or the type of irradiation particles is a combination of neutrons and photons.

[0059] When the type of irradiation particles is photons or electrons, the type of ionization chamber is a graphite cavity ionization chamber. When the type of irradiation particles is neutrons, the type of ionization chamber is a tissue equivalent ionization chamber. When the irradiation particles contain both neutrons and photons, the tissue equivalent ionization chamber is used to obtain the absorbed dose of neutrons in the cavity gas, and the hydrogen-free ionization chamber is used to obtain the absorbed dose of photons in the cavity gas.

[0060] Specifically, the wall material and cavity gas of the tissue equivalent ionization chamber are designed to be equivalent to the tissue to be detected to ensure the accuracy and reliability of the measurement results. For example, the tissue equivalent ionization chamber is designed to have a response to neutrons and γ radiation similar to that of human soft tissue, making it more accurate in measuring the absorbed dose in human tissue. Specifically, the wall material of the tissue equivalent ionization chamber is a tissue equivalent material (usually composed of materials containing C, H, N, and O atoms with different mass percentages), and the gas filled is also a tissue equivalent gas. Its density can be different from that of the wall material, but it has the same atomic composition. Therefore, in order to ensure that under neutron irradiation conditions, the measurement results can truly reflect the energy deposition of neutrons in biological tissue, a tissue equivalent ionization chamber is selected to measure the absorbed dose of neutrons in the cavity gas.

[0061] In a specific embodiment, based on improving the superior performance in measuring the absorbed dose of photons in the cavity gas, the hydrogen-free ionization chamber is selected as a graphite-carbon dioxide ionization chamber or a graphite-argon ionization chamber. The absorbed dose of photons in the cavity gas refers to the measure of the energy absorbed by gas molecules when photons interact with gas molecules. The measurement of the absorbed dose of photons in the cavity gas is crucial for determining the energy distribution and dose distribution of photon beams in treatment or experiments. Specifically, the graphite-carbon dioxide ionization chamber and the graphite-argon ionization chamber are sensitive and stable to photon beams. These ionization chambers can accurately measure the energy absorption of photons in the gas medium, thus providing basic data for the precise quantification of the absorbed dose of isolated cells. Through these data, using the conversion coefficient of the absorbed dose of the cell layer obtained by the present invention to the absorbed dose of air, the precise calculation of the absorbed dose of isolated cells can be achieved. The tissue equivalent ionization chamber is often paired with a hydrogen-free ionization chamber that is less sensitive to neutrons but sensitive to γ radiation to form a dual ionization chamber detector for measuring the absorbed dose of the cavity gas in a mixed radiation field scenario.

[0062] S120. According to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas in the ionization chamber, measure the absorbed dose in the cavity gas at the irradiation position of the cell layer using the ionization chamber; determine the air absorbed dose based on the absorbed dose in the cavity gas.

[0063] S130. Based on the air absorbed dose and the pre-obtained conversion coefficient between the cell layer absorbed dose and the air absorbed dose, obtain the cell layer absorbed dose; the conversion coefficient between the cell layer absorbed dose and the air absorbed dose is obtained using a particle transport simulation program through a preset in vitro cell geometric model.

[0064] Example 1

[0065] The method for obtaining the conversion coefficient between the cell layer absorbed dose and the air absorbed dose using a particle transport simulation program through a preset in vitro cell geometric model includes:

[0066] S101. Establish an in vitro cell geometric model; the in vitro cell geometric model includes a cell culture dish, a cell layer, and a cell culture medium layer.

[0067] Figure 2 It is a schematic structural diagram of the in vitro cell geometric model provided by an embodiment of the present invention; as Figure 2 shown, the in vitro cell geometric model includes a cell culture dish, a cell layer, and a cell culture medium layer; the outer diameter of the cell culture container is R cm, the inner diameter is r cm, the thickness of the cell layer is H1 cm, and the thickness of the cell culture medium layer is H2 cm; the cell layer medium is composed of tissue equivalent materials. Among them, the density of the cell layer is ρ c g / cm 3 , then the mass M of the cell layer c = ρ c ×πr 2 ×H1 (g).

[0068] The thickness of the cell culture medium and the cell layer will mainly affect the degree of particle scattering, thereby affecting the magnitude of the absorbed dose of the cell layer.

[0069] S102. Use a particle transport simulation program to obtain the absorbed dose D

[0070] of the cell layer in the cell culture dish according to the particle type, particle energy, and irradiation distance through the in vitro cell geometric model; use a particle transport simulation program to obtain the air absorbed dose according to the particle type, particle energy, and irradiation distance. ca (S, E, F).

[0071] Specifically, the attributes of the particle source are represented by P(S, E, A), where P represents a certain particle source; S represents the particle type, E is the energy of the particles emitted by the particle source, and A represents the emission intensity of the particle source. The spatial position coordinates of the particle source P(S, E, A) are represented as O(a, b, c), where a, b, and c respectively represent the coordinate values of point O in the X, Y, and Z directions of the three-dimensional rectangular coordinate system. The spatial position where the cell culture dish is placed is represented as N(aˊ, bˊ, cˊ), and aˊ, bˊ, cˊ respectively represent the coordinate values of point N in the X, Y, and Z directions of the three-dimensional rectangular coordinate system.

[0072] It should be noted that when the particle irradiation source is a rectangular plane source, assuming the length of the rectangle is K cm and the width is Y cm, then X > R, Y > R, X > (H1 + H2), and Y > (H1 + H2); if the particle irradiation source is a circular plane photon source, assuming the diameter of the circle is Rˊ cm, then Rˊ > R and Rˊ > (H1 + H2).

[0073] Using the particle transport simulation program, calculate the deposited energy E of the particles emitted by the particle source P(S, E, A) located at O(a, b, c) in the cell layer of the cell culture dish at the position N(aˊ, bˊ, cˊ). c (S, E, F), where F is the distance between point O(a, b, c) and point P(aˊ, bˊ, cˊ).

[0074] Furthermore, based on the deposited energy E of the cell layer in the cell culture dish at the position N(aˊ, bˊ, cˊ). c (S, E, F), calculate the absorbed dose D of a single particle in the cell layer. c (S, E, F):

[0075] D c (S, E, F) = E c (S, E, F) × 1.602 × 10 -10 / M c (Gy) .

[0076] Among them, M c is the mass of the cell layer.

[0077] In the second part, use the particle transport simulation program to obtain the air absorbed dose D ca (S, E, F) according to the particle type, particle energy, and irradiation distance.

[0078] Using the particle transport program, calculate the deposited energy E of the particles emitted by the particle source P(S, E, A) located at O(a, b, c) at the position N(aˊ, bˊ, cˊ) in the air. a(S, E, F); where F is the distance between point O(a, b, c) and point N(a', b', c').

[0079] Furthermore, based on the air deposition energy E at position N(a', b', c'), a calculate the air absorption dose D of a single particle according to (S, E, F) ca (S, E, F):

[0080] D ca (S, E, F) = E a (S, E, F) × 1.602 × 10 -10 / M a (Gy) .

[0081] Wherein, M a is the mass of air.

[0082] S103. Obtain the conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose according to the absorbed dose of the cell layer and the air absorbed dose in the cell culture dish.

[0083] The conversion coefficient R(S, E, F) between the absorbed dose of the cell layer and the air absorbed dose is determined by the following formula:

[0084] R(S, E, F) = D c (S, E, F) / D ca (S, E, F);

[0085] Wherein, R(S, E, F) represents that under the conditions of particle type S, particle energy E, and irradiation distance F, the ratio of the absorbed dose of the cell layer to the air absorbed dose at the same position is R.

[0086] Specifically, for the particle type, due to different particle types, the conversion coefficients between the absorbed dose of the cell layer and the air absorbed dose are different; for the particle energy E, due to different particle energies, the conversion coefficients between the absorbed dose of the cell layer and the air absorbed dose are different. For the irradiation distance, since the irradiation distance affects the magnitude of the conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose, it thus affects the accuracy of measuring the absorbed dose of isolated cells. It solves the problem in the prior art that since the energy response is the key factor affecting the measurement accuracy of directly measuring the absorbed dose of cell culture medium using an ionization chamber, and the dose calibration procedure is complex, it is difficult to obtain accurate dose calibration factors.

[0087] Example 2

[0088] When the type of irradiated particle is photon or electron, the type of ionization chamber is a graphite cavity ionization chamber; when the filling gas of the graphite cavity ionization chamber is air, the ionization chamber measures the absorbed dose D in the cavity gas at the irradiation position of the cell layer. mg is equal to the air absorbed dose D a .

[0089] During measurement, the center of the sensitive volume of the measuring ionization chamber should coincide with the geometric center position of the cell layer in the cell culture dish.

[0090] The absorbed dose of the cell layer is obtained by the following formula:

[0091] D cell =D a× R(S, E, F) × A ;

[0092] where D cell is the absorbed dose of the cell layer; D a is the value of the air absorbed dose measured by the ionization chamber; R(S,E,F) is the conversion coefficient of the absorbed dose of the cell layer to the air absorbed dose obtained in Example 1; A is the emission intensity of the particle source P(S,E,A).

[0093] Example 3

[0094] When the type of irradiated particle is photon or electron, the type of ionization chamber is a graphite cavity ionization chamber. During measurement, the center of the sensitive volume of the measuring ionization chamber should coincide with the geometric center position of the cell layer in the cell culture dish.

[0095] When the filling gas of the graphite cavity ionization chamber is gas g, the air absorbed dose D is determined according to the absorbed dose in the cavity gas a by the following formula,

[0096] D a =D mg× S w,g

[0097] where D mg is the absorbed dose of the cavity gas g measured by the ionization chamber; S w,g is the ratio of the average mass collision stopping power of the graphite w of the cavity ionization chamber wall material to the gas g in the cavity;

[0098] S w,g = , (s / ρ) w is the mass collision stopping power of graphite for secondary electrons of photons or for electrons; (s / ρ) gis the mass collision stopping power of cavity gas for secondary electrons of photons or for electrons.

[0099] According to the air absorbed dose D a , the absorbed dose of the cell layer is obtained by the following formula:

[0100] D cell =D a× R(S, E, F) × A ;

[0101] where D cell is the absorbed dose of the cell layer; D a is the value of the air absorbed dose measured by the ionization chamber; R(S,E,F) is the conversion coefficient of the corresponding absorbed dose of the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A).

[0102] Example 4

[0103] When the irradiation particle type is neutron, the type of the ionization chamber is a tissue-equivalent ionization chamber. During measurement, the center of the sensitive volume of the measurement ionization chamber should coincide with the geometric center position of the cell layer in the cell culture dish.

[0104] The air absorbed dose D is determined according to the absorbed dose in the cavity gas by the following formula a ,

[0105] D a =D mg ×(K a / K g )

[0106] where D mg is the absorbed dose in the cavity gas g measured by the tissue-equivalent ionization chamber; K a and K g are the specific kinetic energy of neutrons in air and the specific kinetic energy of neutrons in the gas g in the ionization chamber cavity, respectively.

[0107] According to the air absorbed dose D a , the absorbed dose of the cell layer is obtained by the following formula:

[0108] D cell =D a× R(S, E, F) × A ;

[0109] where D cell is the absorbed dose of the cell layer; D aThe air absorption dose value obtained by ionization chamber measurement; R(S,E,F) is the conversion coefficient of the corresponding absorbed dose of the cell layer to the air absorption dose; A is the emission intensity of the particle source P(S,E,A).

[0110] Example 5

[0111] When the irradiated particles contain both neutrons and photons; the absorbed dose of neutrons in the cavity gas is obtained using a tissue-equivalent ionization chamber; the absorbed dose of photons in the cavity gas is obtained using a hydrogen-free ionization chamber. During measurement, the center of the sensitive volume of the measurement ionization chamber should coincide with the geometric center of the cell layer in the cell culture dish. The hydrogen-free ionization chamber is a graphite-carbon dioxide ionization chamber or a graphite-argon ionization chamber.

[0112] 1) Determine the air absorption dose D of neutrons according to the absorbed dose of neutrons in the cavity gas g1 through the following formula g1,N :

[0113] D g1,N =

[0114] Wherein, is the sum of the absorbed doses of neutrons and photons in the cavity gas g1 measured by the tissue-equivalent ionization chamber; is the sum of the absorbed doses of neutrons and photons in the cavity gas g2 measured by the "hydrogen-free" ionization chamber; is the ratio of the sensitivity of the "hydrogen-free" ionization chamber to neutrons to the sensitivity to the γ-rays used during calibration.

[0115] According to the air absorption dose D of neutrons g1,N Determine the air absorption dose D a,N

[0116] D a,N = D g1,N ×(K a / K g1 ) ;

[0117] Wherein, K a and K g1 are respectively the specific kinetic energy of neutrons in air and the specific kinetic energy in gas g1.

[0118] According to the air absorption dose D a,N , obtain the absorbed dose of neutrons in the cell layer through the following formula:

[0119] D cell=D a，N× R(S, E, F) × A ;

[0120] Among them, D cell is the absorbed dose of the cell layer; D a,N is the value of the air absorbed dose obtained by ionization chamber measurement; R(S,E,F) is the conversion coefficient of the corresponding absorbed dose of the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A).

[0121] 2) Determine the air absorbed dose D of photons according to the absorbed dose of the photons in the cavity gas g2 through the following formula g2,p :

[0122] D g2,p =

[0123] Among them, is the sum of the absorbed doses of neutrons and photons in the cavity gas g1 of the tissue-equivalent ionization chamber; is the sum of the absorbed doses of neutrons and photons in the cavity gas g2 of the "hydrogen-free" ionization chamber; is the ratio of the sensitivity of the "hydrogen-free" ionization chamber to neutrons to the sensitivity to the γ-rays used for calibration.

[0124] D a,P = D g2,p ×S w,g2

[0125] Among them, S w,g2 is the ratio of the average mass collision stopping power of the graphite w of the chamber wall material of the "hydrogen-free" ionization chamber to the cavity gas g2, that is, S w,g2 = , where (s / ρ)w is the mass collision stopping power of graphite for secondary electrons of photons; (s / ρ) g2 is the mass collision stopping power of the cavity gas g2 for secondary electrons of photons.

[0126] The photon absorbed dose of the cell layer is obtained through the following formula:

[0127] D cell =D a，P× R(S, E, F) × A ;

[0128] Among them, D cell is the absorbed dose of the cell layer; D a，N is the value of the neutron air absorbed dose obtained by ionization chamber measurement;D a，P The photon air absorption dose value obtained by ionization chamber measurement; R(S,E,F) is the conversion coefficient of the corresponding cell layer absorption dose to the air absorption dose; A is the emission intensity of the particle source P(S,E,A).

[0129] It solves the problem in the prior art that for external neutron irradiation, when using an ionization chamber to directly measure the absorption dose of cell culture medium, multiple correction factors need to be applied, which further leads to a greater difference between the absorption dose of cell culture medium and the true cell dose value.

[0130] In the specific implementation process, the present invention integrates each function on one hardware and sets up a man-machine interaction system. Only manual input is required to obtain the irradiated particle type and irradiation distance, select the type of ionization chamber and the type of filling gas of the ionization chamber according to the irradiated particle type, and input the thickness of the cell culture medium and the cell layer. The data processing module of the hardware automatically calculates the conversion coefficient between the cell layer absorption dose and the air absorption dose, and calculates the cell layer absorption dose. During the whole testing process, the testing system can not only display the test results on the man-machine interaction module, but also export the results to a file, and can analyze and statistically process some test items, that is, it realizes automatic comparison, automatic result output and automatic statistical analysis. It not only solves the problems in the prior art that the detection data of the absorbed dose of ex vivo irradiated cells is large and the detection results take a long time; it further weakens the professional requirements for operators in the detection of the absorbed dose of ex vivo irradiated cells, and greatly improves the accuracy and efficiency of the detection of the absorbed dose of ex vivo irradiated cells.

[0131] As Figure 3 shown, the present invention provides an ex vivo irradiated cell absorbed dose detection system 300, and the present invention can be installed in an electronic device. According to the functions achieved, the ex vivo irradiated cell absorbed dose detection system 300 may include an irradiation data acquisition unit 310, a measurement unit 320, and an absorbed dose acquisition unit 330. The modules in the present invention can also be referred to as units, which refer to a series of computer program segments that can be executed by the processor of an electronic device and can complete fixed functions, and are stored in the memory of the electronic device.

[0132] In this embodiment, the functions of each module / unit are as follows:

[0133] The irradiation data acquisition unit 310 is used to obtain the irradiated particle type and irradiation distance, and select the type of ionization chamber and the type of filling gas of the ionization chamber according to the irradiated particle type;

[0134] A measurement unit 320 is configured to measure the absorbed dose in the cavity gas at the irradiated position of the cell layer by using an ionization chamber according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas in the ionization chamber; and determine the air absorbed dose based on the absorbed dose in the cavity gas.

[0135] An absorbed dose acquisition unit 330 is configured to obtain the absorbed dose of the cell layer based on the air absorbed dose and a pre-acquired conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose; the conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose is obtained by using a preset in vitro cell geometry model based on a particle transport simulation program.

[0136] The external irradiation in vitro cell absorbed dose detection system 300 of the present invention comprehensively considers the effects of particle type, energy level, and the thickness of cell culture medium and cell layer on the cell absorbed dose by using a particle transport simulation program; first determines the conversion coefficient between the in vitro cell absorbed dose and the air absorbed dose under different irradiation conditions. Then, directly measures the air absorbed dose by using an ionization chamber, and converts the measurement result of the air absorbed dose into the absorbed dose of in vitro cells through the previously obtained conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose. Compared with the traditional method of directly measuring the absorbed dose of cell culture medium by using an ionization chamber, the present invention not only simplifies the measurement process, but also significantly improves the accuracy of measuring the absorbed dose of in vitro cells.

[0137] As Figure 4 shown, the present invention provides an electronic device 4 capable of implementing an external irradiation in vitro cell absorbed dose detection method.

[0138] The electronic device 4 may include a processor 40, a memory 41, and a bus, and may further include a computer program stored in the memory 41 and executable on the processor 40, such as an external irradiation in vitro cell absorbed dose detection program 42.

[0139] Among them, the memory 41 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, mobile hard disk, multimedia card, card-type memory (such as SD or DX memory, etc.), magnetic memory, magnetic disk, optical disc, etc. In some embodiments, the memory 41 can be an internal storage unit of the electronic device 3, such as the mobile hard disk of the electronic device 4. In some other embodiments, the memory 31 can also be an external storage device of the electronic device 4, such as a plug-in mobile hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc. equipped on the electronic device 3. Further, the memory 41 can also include both the internal storage unit of the electronic device 4 and the external storage device. The memory 41 can be used not only to store application software installed in the electronic device 4 and various types of data, such as the code of the external irradiation in vitro cell absorption dose detection program, etc., but also to temporarily store the data that has been output or will be output.

[0140] In some embodiments, the processor 40 can be composed of integrated circuits. For example, it can be composed of a single packaged integrated circuit, or can be composed of multiple integrated circuits with the same or different functions, including a combination of one or more central processing units (CPU), microprocessors, digital processing chips, graphics processors, and various control chips, etc. The processor 40 is the control core (Control Unit) of the electronic device, connecting various components of the entire electronic device through various interfaces and lines, and by running or executing programs or modules (such as the external irradiation in vitro cell absorption dose detection program, etc.) stored in the memory 41, and calling the data stored in the memory 41, to execute various functions of the electronic device 4 and process data.

[0141] The bus can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. The bus is set to achieve connection and communication between the memory 41 and at least one processor 40, etc.

[0142] Figure 4 Only the electronic device with components is shown. Those skilled in the art can understand that Figure 4The structure shown does not constitute a limitation on the electronic device 4, and may include fewer or more components than shown, or combine certain components, or have a different component arrangement.

[0143] For example, although not shown, the electronic device 4 may further include a power source (such as a battery) for powering each component. Preferably, the power source may be logically connected to the at least one processor 40 through a power management device, so as to implement functions such as charge management, discharge management, and power consumption management through the power management device. The power source may also include any components such as one or more DC or AC power sources, a recharge device, a power failure detection circuit, a power converter or inverter, and a power status indicator. The electronic device 4 may also include a variety of sensors, a Bluetooth module, a Wi-Fi module, etc., which will not be elaborated here.

[0144] Furthermore, the electronic device 4 may further include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a WI-FI interface, a Bluetooth interface, etc.), which is generally used to establish a communication connection between the electronic device 3 and other electronic devices.

[0145] Optionally, the electronic device 4 may further include a user interface. The user interface may be a display, an input unit (such as a keyboard), and optionally, the user interface may also be a standard wired interface or a wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch liquid crystal display, and an OLED (Organic Light-Emitting Diode) toucher, etc. Among them, the display may also be appropriately referred to as a display screen or a display unit, which is used to display the information processed in the electronic device 4 and to display a visual user interface.

[0146] It should be understood that the embodiments are only for illustration purposes and are not limited by this structure in the scope of the patent application.

[0147] The external irradiation in vitro cell absorbed dose detection program 42 stored in the memory 41 of the electronic device 4 is a combination of multiple instructions. When running in the processor 40, it can achieve: obtaining the irradiation particle type and irradiation distance, and selecting the type of ionization chamber and the type of filling gas of the ionization chamber according to the irradiation particle type; according to the irradiation particle type, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, measuring the absorbed dose in the cavity gas at the cell layer irradiation position by using the ionization chamber; determining the air absorbed dose according to the absorbed dose in the cavity gas; obtaining the cell layer absorbed dose based on the air absorbed dose and a pre-obtained conversion coefficient between the cell layer absorbed dose and the air absorbed dose; wherein, the conversion coefficient between the cell layer absorbed dose and the air absorbed dose is obtained by using a particle transport simulation program based on a preset in vitro cell geometric model.

[0148] Specifically, the specific implementation method of the above instructions by the processor 40 can refer to Figure 1 the description of the relevant steps in the corresponding embodiment, which will not be elaborated here. It should be emphasized that to further ensure the privacy and security of the above external irradiation in vitro cell absorbed dose detection program, the above database available processing data is stored in the nodes of the blockchain where the server cluster is located.

[0149] Furthermore, if the module / unit integrated in the electronic device 4 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory).

[0150] An embodiment of the present invention further provides a computer-readable storage medium. The storage medium can be non-volatile or volatile. The storage medium stores a computer program, and when the computer program is executed by a processor, it realizes: obtaining the type of irradiated particles and the irradiation distance, and selecting the type of ionization chamber and the type of filling gas of the ionization chamber according to the type of irradiated particles; according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, measuring the absorbed dose in the cavity gas at the irradiation position of the cell layer by using the ionization chamber; determining the air absorbed dose according to the absorbed dose in the cavity gas; obtaining the absorbed dose of the cell layer based on the air absorbed dose and a pre-obtained conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose; wherein, the conversion coefficient between the absorbed dose of the cell layer and the air absorbed dose is obtained by using a particle transport simulation program based on a preset in vitro cell geometric model. Specifically, the specific implementation method when the computer program is executed by the processor can refer to the description of the relevant steps in the method for detecting the absorbed dose of in vitro irradiated cells in the embodiment, which will not be elaborated here.

[0151] In several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation.

[0152] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0153] In addition, in each embodiment of the present invention, the functional modules can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of a combination of hardware and software functional modules.

[0154] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms.

[0155] Therefore, from any perspective, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Thus, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claims concerned.

[0156] The blockchain referred to in the present invention is a new application mode of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, and encryption algorithm. Blockchain, in essence, is a decentralized database, a string of data blocks generated by using cryptographic methods. Each data block contains information about a batch of network transactions, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block. The blockchain can include the blockchain underlying platform, the platform product service layer, and the application service layer, etc.

[0157] In addition, it is obvious that the word "including" does not exclude other units or steps, and the singular does not exclude the plural. A plurality of units or devices stated in the apparatus claims can also be implemented by one unit or device through software or hardware. Words such as "second" are used to denote names and do not denote any particular order.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An in vitro cell absorbed dose detection method for external irradiation, characterized in that the method Including: Obtain the type of irradiated particles and the irradiation distance, and select the type of ionization chamber and the type of filling gas of the ionization chamber according to the type of irradiated particles; According to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, use the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer; determine the air absorbed dose according to the absorbed dose in the cavity gas; Based on the air absorbed dose and the pre-obtained conversion coefficient between the cell layer absorbed dose and the air absorbed dose, obtain the cell layer absorbed dose; wherein, the conversion coefficient between the cell layer absorbed dose and the air absorbed dose is obtained by using a particle transport simulation program through a preset in vitro cell geometric model; wherein, the in vitro cell geometric model includes a cell culture dish, a cell layer, and a cell culture solution layer.

2. The ex vivo cell absorbed dose detection method according to claim 1, wherein The method for obtaining the conversion coefficient between the cell layer absorbed dose and the air absorbed dose by using a particle transport simulation program through a preset in vitro cell geometric model includes: Establish an in vitro cell geometric model; Use a particle transport simulation program to obtain the absorbed dose of the cell layer in the cell culture dish according to the particle type, particle energy, and irradiation distance through the in vitro cell geometric model; use the particle transport simulation program to obtain the air absorbed dose according to the particle type, particle energy, and irradiation distance; Obtain the conversion coefficient between the cell layer absorbed dose and the air absorbed dose according to the absorbed dose of the cell layer in the cell culture dish and the air absorbed dose.

3. The ex vivo cell absorbed dose detection method according to claim 1, wherein In the process of using the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, When the type of irradiated particles is photons or electrons, the type of ionization chamber is a graphite cavity ionization chamber; When the filling gas of the graphite cavity ionization chamber is air, the absorbed dose in the cavity gas measured by the ionization chamber at the irradiation position of the cell layer is equal to the air absorbed dose; When the filling gas of the graphite cavity ionization chamber is gas g, the air absorbed dose D is determined according to the absorbed dose in the cavity gas. a It is determined by the following formula: where D mg is the absorbed dose in the cavity gas g obtained by ionization chamber measurement; S w,g is the ratio of the average mass collision stopping power of the graphite w of the cavity ionization chamber wall material to the gas g in the cavity; (s / ρ) w is the mass collision stopping power of graphite for secondary electrons of photons or for electrons; (s / ρ) g is the mass collision stopping power of the cavity gas for secondary electrons of photons or for electrons.

4. The in vitro cell absorbed dose detection method for external irradiation according to claim 1, wherein In the process of using the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, When the type of irradiated particles is neutrons, the type of ionization chamber is a tissue equivalent ionization chamber; Determine the air absorbed dose D based on the absorbed dose in the cavity gas a It is determined by the following formula where D mg is the absorbed dose in the cavity gas g obtained by measurement with a tissue equivalent ionization chamber; K a and K g are the kerma in air and the kerma in the gas g in the ionization chamber cavity for neutrons, respectively.

5. The ex vivo cell absorbed dose detection method according to claim 4, characterized in that In the process of using the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer according to the type of irradiated particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber, When the irradiated particles simultaneously contain neutrons and photons; Use a tissue equivalent ionization chamber to obtain the absorbed dose of neutrons in the cavity gas; use a hydrogen-free ionization chamber to obtain the absorbed dose of photons in the cavity gas; Determine the air absorbed dose of neutrons according to the absorbed dose of neutrons in the cavity gas, and determine the air absorbed dose of photons according to the absorbed dose of photons in the cavity gas.

6. The external irradiation in vitro cell absorbed dose detection method according to claim 5, characterized in that The hydrogen-free ionization chamber is a graphite-carbon dioxide ionization chamber or a graphite-argon ionization chamber.

7. The method for detecting the absorbed dose of ex vivo cells by external irradiation according to claim 1, characterized in that, In the process of obtaining the absorbed dose of the cell layer based on the absorbed dose of air and the pre-acquired conversion coefficient between the absorbed dose of the cell layer and the absorbed dose of air, When the particle source is neutrons, photons or electrons, the absorbed dose of the cell layer is obtained by the following formula: where D cell is the absorbed dose of the cell layer; D a is the value of the air absorbed dose measured by the ionization chamber; R(S,E,F) is the conversion coefficient of the corresponding absorbed dose of the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A); When the particle source contains both neutrons and photons simultaneously, the neutron absorbed dose in the cell layer is obtained through the following formula: The photon absorbed dose in the cell layer is obtained through the following formula: where D cell is the absorbed dose in the cell layer; D a，N is the neutron air absorbed dose value measured by the ionization chamber; D a，P is the photon air absorbed dose value measured by the ionization chamber; R(S,E,F) is the conversion coefficient of the corresponding absorbed dose in the cell layer to the air absorbed dose; A is the emission intensity of the particle source P(S,E,A).

8. The ex vivo cell absorbed dose detection method according to claim 2, wherein The cell layer in the in vitro cell geometric model is composed of tissue equivalent materials.

9. An in vitro cell absorbed dose detection system for external irradiation, characterized in that, A system for implementing the method for detecting the absorbed dose of in vitro irradiated cells according to any one of claims 1 to 8, the system includes, An irradiation data acquisition unit, configured to acquire the type of irradiation particles and the irradiation distance, and select the type of ionization chamber and the type of filling gas of the ionization chamber according to the type of irradiation particles; A measurement unit, configured to use the ionization chamber to measure the absorbed dose in the cavity gas at the irradiation position of the cell layer according to the type of irradiation particles, the type of ionization chamber, the irradiation distance, and the type of filling gas of the ionization chamber; determine the absorbed dose of air according to the absorbed dose in the cavity gas; An absorbed dose acquisition unit, configured to obtain the absorbed dose of the cell layer based on the absorbed dose of air and the pre-acquired conversion coefficient between the absorbed dose of the cell layer and the absorbed dose of air; wherein, the conversion coefficient between the absorbed dose of the cell layer and the absorbed dose of air is obtained by using a particle transport simulation program based on a preset in vitro cell geometric model.

10. An electronic device, characterized in that, The electronic device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the steps in the method for detecting the absorbed dose of in vitro irradiated cells according to any one of claims 1 to 8.

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