Boron neutron capture treatment system and irradiation dose correction method

Abstract

The present application relates to a boron neutron capture treatment system and an irradiation dose correction method. The boron neutron capture treatment system comprises a neutron beam irradiation module for generating a neutron beam, a blood boron concentration detection device for detecting the actual concentration of blood boron in an irradiated body, a treatment planning module for generating a preset treatment plan, an irradiation dose correction module for acquiring a corrected irradiation dose according to the actual concentration of blood boron, and a control module. The control module is configured for retrieving the preset treatment plan from the treatment planning module and controlling the irradiation time of the neutron beam irradiation module according to the corrected irradiation dose, such that an irradiation dose received by a patient reaches a target dose, thereby reducing the error of the irradiation dose caused by a change in the concentration of blood boron during actual irradiation.

Description

Boron neutron capture therapy system and irradiation dose correction method Technical Field

[0001] The present invention relates to a radiotherapy system on the one hand, and in particular to a boron neutron capture therapy system on the other hand, and to a radiation dose correction method on the other hand, and in particular to a radiation dose correction method on the boron neutron capture therapy system on the other hand. Background Art

[0002] With advances in atomic science, such as cobalt-60, linear accelerators, and electron beams, radiation therapy has become a primary method of cancer treatment. However, conventional photon or electron therapy is limited by the physical properties of radiation. While killing tumor cells, it can also damage a significant amount of normal tissue in the beam's path. Furthermore, due to the varying sensitivity of tumor cells to radiation, conventional radiation therapy is often ineffective in treating more radioresistant malignancies, such as glioblastoma multiforme and melanoma.

[0003] To reduce radiation damage to normal tissues surrounding the tumor, the concept of targeted therapy from chemotherapy has been applied to radiotherapy. Furthermore, for highly radioresistant tumor cells, radiation therapy methods with high relative biological effectiveness (RBE), such as proton therapy, heavy particle therapy, and neutron capture therapy, are currently being actively developed. Among these, boron neutron capture therapy, a form of neutron capture therapy, offers a superior cancer treatment option compared to traditional radiotherapy by specifically targeting boron-containing drugs in tumor cells, combined with precise neutron beam control.

[0004] Boron Neutron Capture Therapy (BNCT) is a therapy that uses boron-containing ( 10 B) The drug has a high capture cross section for thermal neutrons. 10 B(n,α) 7 Li neutron capture and nuclear fission reaction production 4 He and 7 The average energy of the two heavily charged particles of Li is about 2.33 MeV, with high linear energy transfer (LET) and short range. The linear energy transfer and range of α particles are 150 keV / μm and 8 μm respectively. 7The Li heavy-charged particles have a range of 175keV / μm and 5μm, respectively. The combined range of these two particles is approximately equivalent to the size of a cell. Therefore, radiation damage to organisms can be limited to the cellular level. When boron-containing drugs selectively accumulate in tumor cells, combined with an appropriate neutron radiation source, they can achieve the goal of locally killing tumor cells without causing excessive damage to normal tissues.

[0005] During boron neutron capture therapy (BNCT), the neutron beam used to irradiate the patient is highly intensive, necessitating precise control of the dose to achieve optimal therapeutic outcomes while minimizing radiation damage. Therefore, accurate treatment planning is crucial. In clinical practice, boron-containing drugs such as BPA, which can be used for BNCT, are generally expensive. To reduce treatment costs and simplify the treatment process, treatment planning uses a pre-set blood boron concentration to simulate and estimate the dose. During treatment, the patient is continuously infused with the boron-containing drug. Blood is drawn before the patient enters the irradiation room for treatment to measure the patient's actual blood boron concentration. During irradiation, the drug is continuously infused to maintain the blood boron concentration.

[0006] The accuracy of the neutron beam irradiation dose is crucial in practical treatment. Too much irradiation dose will cause potential damage to the irradiated body, while too little irradiation dose will reduce the quality of treatment. The neutron beam irradiation dose is determined by the blood boron concentration and the neutron dose of the neutron beam actually irradiated to the irradiated body. In the actual treatment process, a preset treatment plan is usually obtained by simulation calculation based on the preset boron concentration. Due to the different metabolic conditions of different irradiated bodies, different drugs and different injection methods will cause differences in the range of blood boron concentration values ​​of the irradiated body, resulting in a difference between the preset blood boron concentration and the actual blood boron concentration of the irradiated body. Therefore, the preset treatment plan formulated according to the preset blood boron concentration has errors. It is necessary to provide a boron neutron capture therapy system and irradiation dose correction method that can correct the preset treatment plan to ensure the treatment effect.

[0007] Summary of the Invention

[0008] Based on this, it is necessary to provide a boron neutron capture therapy system and irradiation dose correction method that can ensure the treatment effect in response to the above technical problems.

[0009] On the one hand, the present invention provides a neutron capture therapy system, which includes: a neutron beam irradiation module for generating a neutron beam; a blood boron concentration detection device for detecting the actual blood boron concentration of an irradiated body; a treatment plan module for generating a preset treatment plan; an irradiation dose correction module for obtaining a corrected irradiation dose based on the actual blood boron concentration; and a control module for retrieving the preset treatment plan from the treatment plan module and controlling the irradiation time of the neutron beam irradiation module based on the corrected irradiation dose so that the irradiation dose received by the patient reaches the target dose.

[0010] Furthermore, the treatment plan module obtains the preset treatment plan by simulation calculation based on the preset blood boron concentration.

[0011] Furthermore, the irradiation dose correction module corrects the target dose rate according to the actual blood boron concentration to obtain the corrected irradiation dose.

[0012] Furthermore, the boron neutron capture therapy system also includes a neutron dose detection device for real-time detection of cumulative neutron counts to obtain irradiation doses.

[0013] Furthermore, the neutron dose detection device is a BF3 proportional counter.

[0014] Furthermore, the preset cumulative neutron count N preset Formula 1 is used for calculation, which is as follows: N preset =R BF3，cal ×T preset (1)

[0015] Among them, R BF3,cal is the theoretical counting rate of the neutron dose detection device, B preset is the preset boron concentration, T preset is the preset boron concentration B preset The corresponding preset irradiation time, T preset The calculation is performed using the following formula 2:

[0016] Among them, D ROI，prescribed The target dose, To preset the target dose rate, Formula 3 is used for calculation, which is as follows:

[0017] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0018] Furthermore, the cumulative neutron count N is corrected update Calculate using the following formula 4:

[0019] Among them, B update is the actual blood boron concentration, T update is the actual blood boron concentration B update The corresponding planned irradiation time, is the actual blood boron concentration B update The corresponding corrected target dose rate, The calculation is performed using the following formula 5:

[0020] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0021] On the other hand, the present invention also provides a method for correcting the irradiation dose of a boron neutron capture therapy system, which includes: generating a preset treatment plan by combining a preset boron concentration and medical imaging data of the irradiated body; obtaining a corrected irradiation dose based on the actual boron concentration; and controlling the irradiation time based on the corrected irradiation dose so that the irradiation dose received by the patient reaches the target dose.

[0022] Furthermore, the irradiation dose correction method further includes a step of determining a target dose based on medical imaging data of the irradiated body.

[0023] Furthermore, the irradiation dose correction method also includes a step of obtaining a preset irradiation dose.

[0024] Furthermore, obtaining the corrected irradiation dose specifically includes correcting a preset target dose rate in the preset treatment plan according to the actually detected boron concentration value to obtain a corrected target dose rate, and calculating the corrected irradiation dose according to the corrected target dose rate.

[0025] Furthermore, the preset cumulative neutron count N preset Formula 1 is used for calculation, which is as follows: N preset =R BF3，cal ×T preset (1)

[0026] Among them, R BF3,cal is the theoretical counting rate of the neutron dose detection device, B preset is the preset boron concentration, T preset is the preset boron concentration B preset The corresponding preset irradiation time, T preset The calculation is performed using the following formula 2:

[0027] D ROI，prescribed The target dose, To preset the target dose rate, Formula 3 is used for calculation, which is as follows:

[0028] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0029] Furthermore, the corrected cumulative neutron count N update Calculate using the following formula 4:

[0030] Among them, B update is the actual blood boron concentration, T update is the actual blood boron concentration B update The corresponding planned irradiation time, is the actual blood boron concentration B update The corresponding corrected target dose rate, The calculation is performed using the following formula 5:

[0031] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0032] Furthermore, the irradiation dose correction method further includes a neutron dose detection device for detecting the irradiation dose in real time. When the irradiation dose detected by the neutron dose detection device reaches the corrected irradiation dose, the control module controls the neutron beam irradiation module to stop irradiation.

[0033] Furthermore, the neutron dose detection device obtains the irradiation dose by real-time detection of the cumulative neutron count, and is specifically a BF3 proportional counter.

[0034] In an irradiation dose correction method for a boron neutron capture therapy system according to an embodiment of the present invention, a preset treatment plan is generated according to a preset blood boron concentration, and a preset target dose rate in the preset treatment plan is corrected according to the actual blood boron concentration to obtain a corrected target dose rate. A corrected neutron dose is calculated according to the corrected target dose rate to control the irradiation treatment time of the neutron irradiation module. There is no need to inject boron-containing drugs into the irradiated body when formulating the preset treatment plan, and there is no need to wait for the blood boron concentration detection result before implementing irradiation, which saves treatment costs and simplifies the treatment process. During the treatment process, the irradiation dose is corrected according to the actual blood boron concentration, reducing the error between the actual irradiation dose and the target dose caused by the change in blood boron concentration during actual irradiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG1 is a block diagram of a boron neutron capture therapy system according to an embodiment of the present invention;

[0036] FIG2 is a schematic diagram of the layout of a boron neutron capture therapy system according to an embodiment of the present invention;

[0037] FIG3 is a schematic diagram of a beam shaping body according to an embodiment of the present invention;

[0038] FIG4 is a flow chart of an irradiation dose correction method according to an embodiment of the present invention.

[0039] Figure 1: Boron neutron capture therapy system 100, neutron beam irradiation module 1, neutron generation device 11, accelerator 111, target 112, beam shaper 12, reflector 121, retarder 122, thermal neutron absorber 123, radiation shield 124, beam outlet 125, collimator 13, image acquisition module 2, neutron dose detection device 3, blood boron concentration detection device 4, treatment planning module 5, control module 6, loading module 7, irradiation dose correction module 8, irradiated object S. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of this application more clear, the following describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0041] 1 , the boron neutron capture therapy system 100 in this embodiment includes a neutron beam irradiation module 1 , an image acquisition module 2 , a neutron dose detection device 3 , a blood boron concentration detection device 4 , a treatment planning module 5 , an irradiation dose correction module 8 , a control module 6 and a loading module 7 . Specifically, the neutron beam irradiation module 1 is used to generate a neutron beam suitable for treatment, which includes a neutron generator 11, a beam shaper 12 and a collimator 13. The neutron generator 11 is used to generate a neutron beam, the beam shaper 12 is used to adjust the beam quality of the neutron beam generated by the neutron generator 11 and reduce unnecessary dose deposition, and the collimator 13 is used to converge the neutron beam so that the neutron beam has higher targeting during the treatment process; the neutron dose detection device 3 is used to detect the neutron dose of the neutron beam generated by the neutron beam irradiation module 1; the blood boron concentration detection device 4 is used to detect the actual blood boron concentration of the irradiated body S; the treatment plan module 5 is used to generate a preset treatment plan; the irradiation dose correction module obtains a corrected irradiation dose according to the actual blood boron concentration detected by the blood boron concentration detection device 4; the control module 6 calls the preset treatment plan of the current irradiated body S from the treatment plan module 5, and controls the neutron beam irradiation module 1 to perform irradiation treatment according to the corrected irradiation dose; the loading module 7 is used to load the irradiated body S.

[0042] The main principle of boron neutron capture therapy is: the irradiated body S takes or injects boron ( B- 10) drug, the boron-containing drug selectively accumulates in tumor cells, and then utilizes the boron-containing ( B- 10) The drug has a high capture cross section for thermal neutrons. 10 B(n,α)7 Li neutron capture and nuclear fission reaction production 4 He and 7 Li has two heavily charged particles, with an average energy of about 2.33 MeV. They have high linear energy transfer (LET) and short range characteristics. The total range of the two particles is approximately equivalent to the size of a cell. Therefore, the radiation damage caused to the organism can be limited to the cellular level, and can achieve the purpose of locally killing tumor cells without causing too much damage to normal tissues.

[0043] As shown in FIG2 , in the embodiment disclosed in the present application, the neutron generating device 11 includes an accelerator 111 and a target 112. The accelerator 111 is used to accelerate charged particles (such as protons, deuterons, etc.) to generate a charged particle beam such as a proton beam. The charged particle beam irradiates the target 112 and interacts with the target 112 to generate a neutron beam (neutron beam). The target 112 is preferably a metal target 112. The appropriate nuclear reaction is selected based on the required neutron yield and energy, the energy and current of the accelerated charged particles that can be provided, the physical and chemical properties of the metal target 112, and other characteristics. Commonly discussed nuclear reactions include 7 Li(p,n) 7 Be and 9 Be(p,n) 9 B, both reactions are endothermic reactions. In the embodiment of the present invention, a target material 112 made of lithium metal is used. However, it is well known to those skilled in the art that the material of the target material 112 can also be made of metal materials other than lithium and beryllium, such as tantalum (Ta) or tungsten (W); the target material 112 can be in the shape of a circular plate, or other solid shapes, or a liquid (liquid metal); the accelerator can be a linear accelerator, a cyclotron, a synchrotron, or a synchrocyclotron. In other embodiments, the neutron generating device can be a nuclear reactor instead of an accelerator and a target material.

[0044] Regardless of whether the neutron source for boron neutron capture therapy comes from a nuclear reactor or a nuclear reaction between accelerated charged particles and the target material 112, the resulting radiation field is actually a mixed radiation field, meaning that the generated beam contains neutrons and photons ranging from low to high energies. For boron neutron capture therapy of deep-seated tumors, the greater the amount of radiation other than epithermal neutrons, the greater the proportion of non-selective dose deposition in normal tissue. Therefore, the amount of radiation that causes unnecessary dose deposition should be minimized. The beam shaper 12 can adjust the beam quality of the neutron beam generated by the neutron generator 11, reducing unnecessary dose deposition. The collimator 13 is used to focus the neutron beam, ensuring that the neutron beam has a high degree of targeting during treatment.

[0045] As shown in FIG3 , the beam shaping body 12 includes a reflector 121, a retarder 122, a thermal neutron absorber 123, a radiation shield 124, and a beam outlet 125. The retarder 122 can adjust the energy of fast neutrons (>40keV) emitted from the neutron generator 11 to the epithermal neutron energy range (0.5eV-40keV) and reduce the content of thermal neutrons (<0.5eV) as much as possible; the retarder 122 is made of a material with a large cross section for fast neutrons and a small cross section for epithermal neutrons. As a preferred embodiment, the retarder 122 is made of D2O, AlF3, Fluental TM , CaF2, Li2CO3, MgF2 and Al2O3; the reflector 121 surrounds the retarder 122 and reflects the neutrons that diffuse through the retarder 122 back to the neutron beam to improve the utilization rate of the neutrons. It is made of a material with strong neutron reflection ability. As a preferred embodiment, the reflector 121 is made of at least one of Pb or Ni; on the transmission path of the neutron beam, the thermal neutron absorber 123 is arranged at the rear of the retarder 122 to absorb the thermal neutrons that pass through the retarder 122 to reduce the content of thermal neutrons in the neutron beam. It is made of a material with a large cross-section for interacting with thermal neutrons. As a preferred embodiment, the thermal neutron absorber 123 is made of Li -6 In other embodiments, since the material of the retarder 122 contains Li -6 The thermal neutron absorber 123 may not be provided separately, but the retarder 122 may be used as the thermal neutron absorber 123; the radiation shielding body 124 is used to shield neutrons and photons leaking from the part other than the beam outlet 125. The material of the radiation shielding body 124 includes at least one of a photon shielding material and a neutron shielding material. As a preferred embodiment, the material of the radiation shielding body 124 includes a photon shielding material lead (Pb) and a neutron shielding material polyethylene (PE).

[0046] The collimator 13 is disposed at the rear of the beam outlet 125 . The epithermal neutron beam emitted from the collimator 13 is directed toward the irradiated body S. The epithermal neutron beam is slowed down into thermal neutrons after passing through the shallow normal tissue of the irradiated body S and reaches the tumor cells to achieve the purpose of treatment.

[0047] It is understood that the beam shaping body 12 may have other configurations as long as it can produce an epithermal neutron beam that meets treatment requirements. The present invention may also not include the collimator 13, and the beam may directly irradiate the irradiated object S after exiting the beam outlet 125 of the beam shaping body 12. For ease of description, when the collimator 13 is provided, the outlet of the collimator 13 may also be interpreted as the beam outlet 125.

[0048] The device for acquiring three-dimensional medical images can be an imaging device such as CT, MRI, PET, or ultrasound. The present invention preferably uses a CT device image acquisition module 2 to acquire medical image data of the irradiated object S using computed tomography (CT). The medical image data of the irradiated object S includes a coordinate matrix of a medical image voxel model of the irradiated area (lesion, i.e., tumor cells) in a medical image coordinate system and a CT value matrix.

[0049] The neutron dose detection device 3 includes a detector for receiving neutrons and outputting signals, a signal processing unit for processing the signals output from the detector, a counter for counting the signals output from the signal processing unit to obtain a count rate, a conversion unit for converting the count rate recorded by the counter into a neutron flux rate or a neutron dose rate, a calculation unit for integrating the neutron flux rate or the neutron dose rate to obtain the neutron dose, and a display for displaying the neutron dose. In this embodiment, the neutron dose detected by the neutron dose detection device 3 is the irradiation dose received by the irradiated object S.

[0050] The detector can be placed in the beam shaper 12, in the collimator 13, or at any position near the beam shaper 12, as long as the detector is located at a position that can be used to detect the neutron dose of the neutron beam.

[0051] Detectors that can detect the neutron dose of a neutron beam in real time include ionization chambers and scintillation detectors. Among them, He -3 Proportional counters, BF3 proportional counters, fission ionization chambers, boron ionization chambers, and scintillation detectors contain organic or inorganic materials. When detecting thermal neutrons, scintillation detectors often add elements with high thermal neutron capture cross-sections such as Li or B. An element in the two types of detectors undergoes capture or nuclear fission reactions with the neutrons entering the detector, releasing heavily charged particles and nuclear fission fragments, generating a large number of ionization pairs in the ionization chamber or scintillation detector. These charges are collected and formed into electrical signals, which are processed by the signal processing unit for noise reduction, conversion, and separation, and converted into pulse signals. By analyzing the size of the voltage pulses, neutron pulse signals and gamma pulse signals are distinguished. The separated neutron pulse signals are continuously recorded by the counter to obtain the neutron counting rate (n / s). The conversion unit calculates and converts the counting rate through internal software and programs to obtain the neutron flux rate (cm -2 s -1 ), the neutron dose rate (Gy / s) is obtained by further calculation and conversion of the neutron flux rate. Finally, the integration part integrates the neutron dose rate to obtain the real-time neutron dose.

[0052] The following is a brief introduction using the fission chamber, scintillator detector, and BF3 proportional counter as examples.

[0053] When the neutron beam passes through the fission ionization chamber, it interacts with gas molecules or the chamber walls, generating electrons and positively charged ions. These electrons and positively charged ions are called ion pairs. Due to the high voltage applied to the fission ionization chamber, the electrons move toward the central anode filament and the positively charged ions move toward the surrounding cathode walls, generating a measurable electrical signal.

[0054] The optical fiber and other materials within the scintillation detector absorb energy and generate visible light. This ionizing radiation excites electrons in crystals or molecules to an excited state. When the electrons return to their ground state, the resulting fluorescence is collected and used as a neutron beam detector. The visible light emitted by the scintillation detector upon interaction with the neutron beam is converted into an electrical signal using a photomultiplier tube.

[0055] The BF3 proportional counter is placed in the beam shaper to receive neutron beam irradiation. The B element in the BF3 proportional counter undergoes nuclear reaction with neutrons. 10 B(n,alpha) 7 Li, alpha particles produced by nuclear reactions and 7 Driven by voltage, Li-ion particles are collected by high-voltage electrodes, generating an electrical signal. This electrical signal is transmitted via a coaxial cable to a signal processing unit for amplification and filtering, forming a pulse signal. The processed pulse signal is then transmitted to a counter for pulse counting, which generates a count rate (n / s). This count rate can be used to measure the neutron beam intensity, or neutron dose, in real time.

[0056] In one embodiment of the present invention, a BF3 proportional counter is preferably used to detect the neutron dose. Of course, the type of detector is not limited thereto, as long as it can detect the neutron dose in real time.

[0057] Before neutron beam irradiation therapy is performed on the irradiated body S, a blood boron concentration detection device 4 is used to detect the actual blood boron concentration in the irradiated body. The preset irradiation dose is then corrected based on the actual blood boron concentration. Boron concentration detection can be achieved using inductively coupled plasma spectroscopy, high-resolution alpha autoradiography, charged ion spectroscopy, neutron capture cameras, nuclear magnetic resonance and magnetic resonance imaging, positron emission tomography, prompt gamma-ray spectrometry, and other methods. The devices involved in these detection methods are referred to as boron concentration detection devices.

[0058] The mounting module 7 includes a mounting table that supports the irradiated object S and a driving unit that drives the mounting table to move to an irradiation position.

[0059] 4 , a method for correcting the irradiation dose of a boron neutron capture therapy system 100 according to an embodiment of the present invention includes the following steps:

[0060] S1: Generate a preset treatment plan;

[0061] Combine the preset boron concentration and the medical imaging data of the irradiated body to generate a preset treatment plan, which includes the preset irradiation time T preset , preset target dose rate and other preset irradiation parameters.

[0062] Medical staff set the target dose D based on the body characteristics of the irradiated body, the medical imaging data of the irradiated body and their own experience. ROI，prescribed , or called the prescribed dose, target dose D ROI，prescribed That is, the actual neutron dose that the irradiated body needs to receive.

[0063] In other embodiments, some of the above parameters or more unmentioned parameters may be understood as preset irradiation parameters.

[0064] S2: Obtain the preset radiation dose in the preset treatment plan;

[0065] In this embodiment, the cumulative neutron count is used as a monitoring parameter for the BNCT online monitoring system for the irradiation dose. The irradiation dose is corrected by calculating and correcting the cumulative neutron count. When the cumulative neutron count reaches the target value, the irradiation dose reaches the target dose.

[0066] Preset cumulative neutron count N preset Formula 1 can be used for calculation, which is as follows: N preset =R BF3，cal ×T preset (1)

[0067] Among them, R BF3,cal is the theoretical counting rate of the neutron dose detection device 3, T preset is the preset boron concentration B preset The corresponding preset irradiation time is calculated using the following formula 2:

[0068] Preset target dose rate Formula 3 is used for calculation, which is as follows:

[0069] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0070] S3: Perform irradiation treatment on the irradiated body S according to the preset treatment plan, and obtain the actual boron concentration and corrected irradiation dose during the irradiation process;

[0071] In one embodiment of the present invention, the irradiation dose is corrected according to the actual boron concentration to obtain a corrected irradiation dose. In this embodiment, the corrected cumulative neutron count N is obtained. update As a parameter basis for judging whether the target dose has been reached. The blood boron concentration of the irradiated body is detected by the blood boron concentration detection device 4. When the actual blood boron concentration B is obtained update Then, the actual blood boron concentration B is calculated using formula 4. update The corresponding corrected cumulative neutron count N update , Formula 4 is as follows:

[0072] Among them, T update is the actual blood boron concentration B update The corresponding planned irradiation time, is the actual blood boron concentration B update The corresponding corrected target dose rate, The calculation is performed using the following formula 5:

[0073] Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

[0074] S4: Implement irradiation control according to the corrected irradiation dose.

[0075] The irradiation dose received by the irradiated body S is judged to have reached the target dose according to the corrected irradiation dose. When the cumulative neutron count detected by the neutron dose detection device 3 reaches the corrected cumulative neutron count N update When the radiation dose received by the irradiated body reaches the target dose D ROI，prescribed , the control module 6 controls the neutron beam irradiation module 1 to stop irradiation to end the treatment.

[0076] It is understandable that if the system has not obtained the actual boron concentration information during the treatment process, when the neutron dose detected by the neutron dose detection device 3 reaches the preset target dose, it indicates that the radiation dose received by the irradiated body has reached the prescribed dose D ROI，prescribed , the control module 6 controls the neutron beam irradiation module 1 to stop irradiation to end the treatment.

[0077] In one embodiment of the present invention, during the actual irradiation process, the neutron dose detection device 3 detects the irradiation dose of the neutron beam in real time, and stops irradiation when the neutron irradiation dose reaches the corrected irradiation dose or the preset target dose; in other embodiments, irradiation control can be achieved by monitoring the irradiation time. Specifically, the required target irradiation time is calculated based on the corrected irradiation dose or the preset target dose. When the actual irradiation time reaches the target irradiation time, the control module 6 controls the neutron beam irradiation module 1 to stop irradiation to end the treatment, that is, step S4 can be based on the target irradiation time. The irradiation control can be implemented.

[0078] The target irradiation time T is calculated using Formula 6, which is as follows:

[0079] Among them, R BF3,cal is the count rate of the BF3 proportional counter under given reference radiation source conditions, R BF3,QC is the BF3 count rate measured in the daily beam QC, which reflects the BF3 neutron count rate level on the day of irradiation. T1 is the irradiation time corresponding to the blood boron concentration B1, which is calculated using Formulas 7 and 8. Formulas 7 and 8 are as follows:

[0080] In one embodiment of the present invention, before performing irradiation treatment, a blood boron concentration detection device 4 is used to detect the actual blood boron concentration of the irradiated body, and a corrected irradiation time is calculated based on the actual blood boron concentration of the irradiated body before the irradiation treatment is performed; in other embodiments, during the irradiation process, the actual irradiation parameters will change, and it is necessary to adjust the target irradiation parameters periodically or in real time according to the specific situation to maximize the treatment effect. During the neutron beam irradiation treatment of the irradiated body S, it is necessary to continuously supply boron medicine to the irradiated body S. However, during the entire irradiation process, it is difficult to ensure that the boron concentration in the irradiated body remains at the same level. Referring to Formula 5, the target dose rate changes with the change of blood boron concentration, and the prescribed dose, i.e., the target dose, remains unchanged. When the blood boron concentration changes, the irradiation dose and the target irradiation time need to be further corrected to ensure that the neutron dose actually received by the irradiated body remains consistent with the prescribed dose to ensure the treatment effect.

[0081] Correspondingly, an embodiment of the present invention may further include step S5, detecting the blood boron concentration of the irradiated body in real time or periodically during the actual irradiation process, correcting the irradiation dose or target irradiation time in real time or periodically according to the detected blood boron concentration, and repeating steps S3-S4 until the neutron dose detected by the neutron dose detection device 3 reaches the target dose or the actual irradiation time is equal to the corrected target irradiation time; on the other hand, the parameters of the neutron beam generated by the neutron irradiation module may also change. The neutron dose detection device 3 can monitor the beam parameters of the neutron beam in real time. When the beam parameters of the neutron beam change, the target irradiation time can also be appropriately corrected to ensure that the neutron dose actually received by the irradiated body remains consistent with the prescribed dose.

[0082] There are various methods for real-time detection of the blood boron concentration in an irradiated subject. One embodiment of the present invention uses the example of estimating the boron concentration in the irradiated subject S by detecting gamma rays emitted by the irradiated subject S. A neutron beam enters the irradiated subject S and reacts with boron to generate gamma rays. By measuring the amount of gamma rays, the amount of boron reacting with the neutron beam can be estimated, thereby estimating the boron concentration in the irradiated subject S. Specifically, a boron concentration detection device detects gamma rays (478 keV) generated by the reaction between neutrons and boron to measure the boron concentration. A boron distribution measurement system (PG (Prompt-γ)-SPECT) capable of measuring the boron concentration distribution by measuring single-energy gamma rays is used as the boron concentration detection device. The boron concentration detection device includes a gamma ray detection unit and a boron concentration calculation unit. The gamma ray detection unit detects information related to gamma rays emitted from the irradiated subject S. The boron concentration calculation unit calculates the boron concentration in the irradiated subject S based on the information related to the gamma rays detected by the gamma ray detection unit. The gamma ray detection unit can utilize a scintillator or other various gamma ray detection devices. In the present embodiment, the gamma-ray detection unit is arranged near the tumor of the irradiated body S, for example, at a position about 30 cm away from the tumor of the irradiated body S.

[0083] The boron neutron capture therapy system 100 of the present invention simulates a preset treatment plan based on a preset blood boron concentration, thereby obtaining a preset target dose, and then calculates a corrected irradiation dose based on the dose rate corresponding to the actual blood boron concentration. The neutron irradiation module is controlled accordingly to implement irradiation therapy. There is no need to inject boron-containing drugs into the irradiated body when formulating a preset treatment plan, and there is no need to wait for the blood boron concentration to be detected before implementing irradiation, which saves treatment costs and simplifies the treatment process. During the treatment process, the target irradiation dose is corrected according to the actual blood boron concentration, reducing the error of the irradiation dose caused by changes in blood boron concentration during actual irradiation.

[0084] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0085] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A boron neutron capture therapy system, characterized in that: include: a neutron beam irradiation module, for generating a neutron beam; A blood boron concentration detection device for detecting the actual blood boron concentration of the irradiated body; A treatment plan module, used to generate a preset treatment plan; an irradiation dose correction module, which obtains a corrected irradiation dose according to the actual blood boron concentration; and The control module is used to retrieve the preset treatment plan from the treatment plan module and control the irradiation time of the neutron beam irradiation module according to the corrected irradiation dose so that the irradiation dose received by the patient reaches the target dose.

2. The boron neutron capture therapy system according to claim 1, characterized in that: The treatment plan module obtains the preset treatment plan by simulation calculation based on the preset blood boron concentration.

3. The boron neutron capture therapy system according to claim 2, characterized in that: The irradiation dose correction module corrects the target dose rate according to the actual blood boron concentration to obtain the corrected irradiation dose.

4. The boron neutron capture therapy system according to claim 3, characterized in that: The invention also includes a neutron dose detection device for detecting the accumulated neutron count in real time to obtain the irradiation dose.

5. The boron neutron capture therapy system according to claim 4, characterized in that: The neutron dose detection device is a BF3 proportional counter.

6. The boron neutron capture therapy system according to claim 5, characterized in that: Preset cumulative neutron count N preset Formula 1 is used for calculation, which is as follows: N preset =R BF3，cal ×T preset (1) Among them, R BF3,cal is the theoretical counting rate of the neutron dose detection device, B preset is the preset boron concentration, T preset is the preset boron concentration B preset The corresponding preset irradiation time, T preset The calculation is performed using the following formula 2: Among them, D ROI，prescribed The target dose, To preset the target dose rate, Formula 3 is used for calculation, which is as follows: Among them, a, b, and c are fitting coefficients, which are obtained from multiple preset boron concentration values ​​and their corresponding simulations. The dose rate is obtained by function fitting.

7. The boron neutron capture therapy system according to claim 4, characterized in that: Corrected cumulative neutron count N update Calculate using the following formula 4: Among them, B update is the actual blood boron concentration, T update is the actual blood boron concentration B update The corresponding planned irradiation time, is the actual blood boron concentration B update The corresponding corrected target dose rate, The calculation is performed using the following formula 5: Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

8. A method for correcting irradiation dose of a boron neutron capture therapy system, characterized in that: include: Generate a preset treatment plan by combining the preset boron concentration and the medical imaging data of the irradiated body; Obtain corrected irradiation dose based on actual boron concentration; and The irradiation time is controlled according to the corrected irradiation dose so that the irradiation dose received by the patient reaches the target dose.

9. The irradiation dose correction method according to claim 8, characterized in that: The method also includes the step of determining a target dose based on the medical imaging data of the irradiated body.

10. The irradiation dose correction method according to claim 9, characterized in that: The method also includes the step of obtaining a preset irradiation dose.

11. The irradiation dose correction method according to claim 10, characterized in that: The corrected irradiation dose is obtained by correcting the preset target dose rate in the preset treatment plan according to the actually detected boron concentration value to obtain a corrected target dose rate, and calculating the corrected irradiation dose according to the corrected target dose rate.

12. The irradiation dose correction method according to claim 10, characterized in that: Preset cumulative neutron count N preset Formula 1 is used for calculation, which is as follows: N preset =R BF3，cal ×T preset (1) Among them, R BF3,cal is the theoretical counting rate of the neutron dose detection device, B preset is the preset boron concentration, T preset is the preset boron concentration B preset The corresponding preset irradiation time, T preset The calculation is performed using the following formula 2: D ROI，prescribed The target dose, To preset the target dose rate, Formula 3 is used for calculation, which is as follows: Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

13. The irradiation dose correction method according to claim 11, characterized in that: The corrected cumulative neutron count N update Calculate using the following formula 4: Among them, B update is the actual blood boron concentration, T update is the actual blood boron concentration B update The corresponding planned irradiation time, is the actual blood boron concentration B update The corresponding corrected target dose rate, The calculation is performed using the following formula 5: Wherein, a, b, and c are fitting coefficients, which are obtained by function fitting of multiple preset boron concentration values ​​and their corresponding simulated dose rates.

14. A method for correcting radiation dose according to claim 11, characterized in that: It also includes a neutron dose detection device for real-time detection of irradiation dose. When the irradiation dose detected by the neutron dose detection device reaches the corrected irradiation dose, the control module controls the neutron beam irradiation module to stop irradiation.

15. A method for correcting irradiation dose according to claim 14, characterized in that: The neutron dose detection device is a BF3 proportional counter.

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