Boron neutron capture therapy system and irradiation dose correction method

Abstract

The present application relates to a boron neutron capture therapy system and an irradiation dose correction method, the boron neutron capture therapy system including a neutron beam irradiation module, a blood boron concentration detection device, a treatment planning module, an irradiation dose correction module, and a control module, wherein the neutron beam irradiation module generates a neutron beam, the blood boron concentration detection device detects an actual blood boron concentration of an irradiated subject, the treatment planning module generates a predetermined treatment plan, the irradiation dose correction module obtains a corrected irradiation dose based on the actual blood boron concentration, and the control module retrieves the predetermined treatment plan from the treatment planning module and controls the irradiation time of the neutron beam irradiation module based on the corrected irradiation dose so that the irradiation dose received by a patient reaches a target dose, thereby reducing an error in the irradiation dose due to a change in blood boron concentration during actual irradiation.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a radiation therapy system, particularly to a boron neutron capture therapy system. Another aspect of the present invention relates to an exposure dose correction method, particularly to an exposure dose correction method for a boron neutron capture therapy system. [Background technology]

[0002] With the development of atomic science, radiation therapy using cobalt-60, linear accelerators, electron beams, etc. has become one of the main means of cancer treatment. However, conventional photon or electron therapy not only kills tumor cells due to the limitations of the physical conditions of the radiation itself, but also damages many normal tissues along the beam path. In addition, tumor cells have different degrees of sensitivity to radiation, so conventional radiation therapy is not very effective in treating malignant tumors with high radiation resistance (e.g., glioblastoma multiforme, melanoma).

[0003] To reduce radiation damage to normal tissues surrounding tumors, the concept of targeted therapy in chemotherapy has been applied to radiotherapy, and for tumor cells with high radiation resistance, radiotherapy with high relative biological effectiveness (RBE), such as proton therapy, heavy ion therapy, and neutron capture therapy, is currently being actively developed. Among these, boron neutron capture therapy, a type of neutron capture therapy, provides a better cancer treatment option than conventional radiotherapy by specifically collecting boron-containing drugs in tumor cells, which, combined with highly precise neutron beam control, provides a better cancer treatment option than conventional radiotherapy.

[0004] Boron Neutron Capture Therapy (BNCT) is a treatment that uses boron ( 10 B) Utilizing the property that the contained drug has a large capture cross section for thermal neutrons, 10 B(n,α) 7 Li neutron capture and fission reactions4 He and 7 Two types of heavy charged particles of Li are generated. The two types of heavy charged particles have an average energy of approximately 2.33 MeV, a high linear energy transfer (LET), and a short range. The linear energy transfer and range of the alpha particles are 150 keV / μm and 8 μm, respectively. 7 In the case of Li heavy charged particles, the energy is 175 keV / μm and 5 μm, and the total range of the two types of particles is approximately the size of a single cell, so radiation damage to the living body is limited to the cellular level. By selectively concentrating boron-containing drugs in tumor cells and combining them with an appropriate neutron source, the goal of locally killing tumor cells can be achieved without causing significant damage to normal tissues.

[0005] During boron neutron capture therapy (BNCT), the neutron beam used to irradiate the patient is highly radiant. Therefore, precise control of the radiation dose is essential to achieve a high therapeutic effect while minimizing radiation damage to the patient. Therefore, the accuracy of treatment planning is crucial. Currently, boron-containing drugs, such as BPA, used in BNCT are generally expensive. To reduce treatment costs and simplify the treatment process, treatment planning involves estimating the radiation dose using a simulation calculation based on a predetermined blood boron concentration. During the actual treatment process, the patient is continuously injected with the BNC. Before the patient enters the irradiation chamber for treatment, blood samples are extracted to measure the patient's actual blood boron concentration. The BNC is then continuously infused throughout the treatment process to maintain the normal blood boron concentration.

[0006] The accuracy of the neutron beam irradiation dose is very important in practical treatment. Too high an irradiation dose can potentially damage the irradiated subject, while too low an irradiation dose can 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 subject. In actual treatment processes, a predetermined treatment plan is usually obtained by simulation and calculation based on a predetermined boron concentration. However, different irradiated subjects have different metabolic conditions, and different drugs and injection methods cause differences in the range of blood boron concentration values ​​of the irradiated subject. Therefore, there is a difference between the predetermined blood boron concentration and the irradiated subject's actual blood boron concentration, and there is an error in the predetermined treatment plan formulated based on the predetermined blood boron concentration. There is a need to provide a boron neutron capture therapy system and an irradiation dose correction method that can correct the predetermined treatment plan to ensure therapeutic effectiveness. Summary of the Invention

[0007] Therefore, in order to address the above technical issues, it is necessary to provide a boron neutron capture therapy system and an irradiation dose correction method that can guarantee therapeutic effects.

[0008] A neutron capture therapy system according to one aspect of the present invention includes a neutron beam irradiation module, a blood boron concentration detection device, a treatment planning module, an exposure dose correction module, and a control module, wherein the neutron beam irradiation module generates a neutron beam, the blood boron concentration detection device detects the actual blood boron concentration of the irradiated subject, the treatment planning module generates a predetermined treatment plan, the exposure dose correction module obtains a corrected exposure dose based on the actual blood boron concentration, and the control module calls up the predetermined treatment plan from the treatment planning module and controls the irradiation time of the neutron beam irradiation module based on the corrected exposure dose so that the exposure dose received by the patient reaches a target dose.

[0009] Furthermore, the treatment planning module simulates and calculates based on a predetermined blood boron concentration to obtain the predetermined treatment plan.

[0010] Furthermore, the exposure dose correction module corrects the target dose rate based on the actual blood boron concentration to obtain the corrected exposure dose.

[0011] Furthermore, the boron neutron capture therapy system further includes a neutron dose detection device that detects the cumulative neutron count in real time to obtain the irradiation dose.

[0012] Furthermore, the neutron dose detection device is a BF3 proportional counter.

[0013] Furthermore, the predetermined cumulative neutron count N preset is calculated using the following equation 1: N preset =R BF3,cal ×T preset (1) In the formula, R BF3,cal is the theoretical counting rate of the neutron dose detector, and B preset is the predetermined boron concentration, and T preset is the default boron concentration B preset is the predetermined irradiation time corresponding to T preset is calculated using Equation 2 below:

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[0014] Furthermore, the corrected cumulative neutron count N update is calculated using Equation 4 below:

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[0015] Another aspect of the present invention provides a method for correcting an irradiation dose in a boron neutron capture therapy system, which includes the steps of generating a predetermined treatment plan by combining a predetermined boron concentration and medical image data of an 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 a target dose.

[0016] Furthermore, the exposure dose correction method further includes a step of determining a target dose based on medical image data of the object to be irradiated.

[0017] Furthermore, the exposure dose correction method further includes the step of obtaining a predetermined exposure dose.

[0018] Furthermore, the step of acquiring the corrected irradiation dose is specifically performed by correcting a predetermined target dose rate of the predetermined treatment plan based on an actually measured boron concentration to acquire a corrected target dose rate, and then calculating the corrected irradiation dose based on the corrected target dose rate.

[0019] Furthermore, the predetermined cumulative neutron count N preset is calculated using the following equation 1: N preset =R BF3,cal ×T preset (1) In the formula, R BF3,cal is the theoretical counting rate of the neutron dose detector, and B preset is the predetermined boron concentration, and T preset is the default boron concentration B preset is the predetermined irradiation time corresponding to T preset is calculated using Equation 2 below:

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[0020] Furthermore, the corrected cumulative neutron count N update is calculated using Equation 4 below:

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[0021] Furthermore, the exposure dose correction method further includes a neutron dose detection device that detects the exposure dose in real time, and when the neutron dose detection device detects that the exposure dose has reached the corrected exposure dose, the control module controls the neutron beam irradiation module to stop the irradiation.

[0022] Furthermore, the neutron dose detection device obtains the exposure dose by detecting the cumulative neutron count in real time, and is specifically a BF3 proportional counter.

[0023] In one embodiment of the present invention, an irradiation dose correction method for a boron neutron capture therapy system generates a predetermined treatment plan based on a predetermined blood boron concentration, corrects the predetermined target dose rate of the predetermined treatment plan based on the actual blood boron concentration to obtain the corrected target dose rate, calculates and obtains the corrected neutron dose based on the corrected target dose rate, and controls the irradiation treatment time of the neutron irradiation module. This eliminates the need to inject a boron-containing drug into the patient when formulating the predetermined treatment plan, and eliminates the need to obtain blood boron concentration detection results before irradiation, thereby saving treatment costs and simplifying the treatment process. The irradiation dose is corrected based on the actual blood boron concentration during the treatment process, reducing the error between the actual irradiation dose and the target dose caused by changes in blood boron concentration during actual irradiation. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a block diagram of a boron neutron capture therapy system in one embodiment of the present invention. [Figure 2] 1 is a schematic diagram of the layout of a boron neutron capture therapy system in one embodiment of the present invention. [Figure 3] FIG. 2 is a schematic diagram of a beam shaper in one embodiment of the present invention. [Figure 4] 1 is a flowchart of an exposure dose correction method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] In order to clarify the purpose, technical means and advantages of the present application, the present application will be described in detail below with reference to the drawings and examples. Note that the specific examples described herein are only for the purpose of interpreting the present application and are not intended to limit the present application.

[0026] 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 mounting module 7. Specifically, the neutron beam irradiation module 1 generates a neutron beam suitable for treatment and includes a neutron generator 11, a beam shaper 12, and a collimator 13. The neutron generator 11 generates a neutron beam, the beam shaper 12 adjusts the beam quality of the neutron beam generated by the neutron generator 11 to reduce unnecessary dose deposition, the collimator 13 collects the neutron beam so that the neutron beam has high targetability during treatment, and the neutron dose detection device 3 detects the neutron beam generated by the neutron beam irradiation module 1. The blood boron concentration detection device 4 detects the neutron dose of the irradiated subject S, the blood boron concentration detection device 4 detects the actual blood boron concentration of the irradiated subject S, the treatment planning module 5 generates a predetermined treatment plan, the irradiation dose correction module obtains a corrected irradiation dose based on the actual blood boron concentration detected by the blood boron concentration detection device 4, the control module 6 calls up the predetermined treatment plan for the current irradiated subject S from the treatment planning module 5 and controls the neutron beam irradiation module 1 to perform irradiation treatment based on the corrected irradiation dose, and the placement module 7 places the irradiated subject S.

[0027] The main principle of boron neutron capture therapy is as follows: the irradiated body S is doped with boron ( B- 10) After the boron-containing drug is administered or injected, the boron-containing drug selectively accumulates in tumor cells, and then the boron ( B- 10) Utilizing the property that the contained drug has a large capture cross section for thermal neutrons, 10 B(n,α) 7 Li neutron capture and fission reactions 4 He and 7Two types of heavy charged particles of Li are generated, with an average energy of approximately 2.33 MeV, a high linear energy transfer (LET), and a short range. The total range of the two particles is equivalent to the size of a single cell, so the radiation damage to the living body is limited to the cellular level, and the goal of locally killing tumor cells can be achieved without causing significant damage to normal tissue.

[0028] 2, in the embodiment disclosed herein, the neutron generator 11 includes an accelerator 111 and a target 112. The accelerator 111 accelerates charged particles (e.g., protons, deuterons, etc.) to generate a charged particle beam such as a proton beam, and the charged particle beam is irradiated onto the target 112, which interacts with the target 112 to generate a neutron beam (neutron beam). The target 112 is preferably a metal target 112. An appropriate nuclear reaction is selected based on the required neutron yield and energy, the energy and current magnitude of the accelerated charged particles that can be provided, the physical and chemical properties of the metal target 112, etc. Well-studied nuclear reactions include: 7 Li(p,n) 7 Be and 9 Be(p,n) 9 B, and both of these reactions are endothermic. In an embodiment of the present invention, a target 112 made of lithium metal is used. However, as is well known to those skilled in the art, the target 112 may be made of a metal material other than lithium or beryllium, such as tantalum (Ta) or tungsten (W). The target 112 may be disk-shaped, have another solid shape, or be in a liquid state (liquid metal). The accelerator may be a linear accelerator, a cyclotron, a synchrotron, or a synchrocyclotron. In another embodiment, the neutron generator may be a nuclear reactor without an accelerator or target.

[0029] Whether the neutron source for boron neutron capture therapy is a nuclear reactor or a nuclear reaction between accelerated charged particles and the target 112, the generated beam actually contains a mixed radiation field, i.e., neutrons and photons ranging from low to high energy. For boron neutron capture therapy of deep-seated tumors, the higher the content of other radiation, except for epithermal neutrons, the greater the proportion of non-selective dose deposition in normal tissues. Therefore, it is necessary to minimize the content of these radiations that cause unnecessary dose deposition. The beam shaper 12 adjusts the beam quality of the neutron beam generated by the neutron generator 11 to reduce unnecessary dose deposition, and the collimator 13 focuses the neutron beam, ensuring high targetability during treatment.

[0030] 3, the beam shaper 12 includes a reflector 121, a moderator 122, a thermal neutron absorber 123, a radiation shield 124, and a beam outlet 125. The moderator 122 adjusts the fast neutron energy (>40 keV) emitted from the neutron generator 11 to the epithermal neutron energy range (0.5 eV to 40 keV) and can reduce the content of thermal neutrons (<0.5 eV) as much as possible. The moderator 122 is made of a material that has a large cross section with fast neutrons and a small cross section with epithermal neutrons. In a preferred embodiment, the moderator 122 is made of at least one of D2O, AlF3, Fluental (registered trademark), CaF2, Li2CO3, MgF2, and Al2O3. The reflector 121 surrounds the moderator 122. The reflector 121 is made of a material with a high neutron reflecting ability, and reflects the neutrons that have passed through the moderator 122 and diffused to the surrounding area back into the neutron beam, improving the utilization rate of the neutrons. In a preferred embodiment, the reflector 121 is made of at least one of Pb and Ni. In the neutron beam transport path, a thermal neutron absorber 123 is installed at the rear of the moderator 122, and absorbs the thermal neutrons that have passed through the moderator 122 to reduce the content of thermal neutrons in the neutron beam. The thermal neutron absorber is made of a material with a large cross section that interacts with thermal neutrons. In a preferred embodiment, the thermal neutron absorber 123 is made of Li. -6 In another embodiment, the material of the moderator 122 is Li.-6 Therefore, it is not necessary to install the thermal neutron absorber 123 alone, and the moderator 122 may be the thermal neutron absorber 123, and the radiation shielding body 124 blocks neutrons and photons leaking from portions other than the beam exit 125, and the material of the radiation shielding body 124 includes at least one of a photon shielding material and a neutron shielding material, and in a preferred embodiment, the material of the radiation shielding body 124 includes lead (Pb) as a photon shielding material and polyethylene (PE) as a neutron shielding material.

[0031] A collimator 13 is installed behind the beam exit 125, and the epithermal neutron beam emitted from the collimator 13 is irradiated onto the subject S, passes through the superficial normal tissue of the subject S, and is then slowed down to thermal neutrons, reaching the tumor cells and achieving the therapeutic objective.

[0032] As can be understood, the beam shaper 12 may have other structures as long as it can obtain an epithermal neutron beam that meets treatment requirements, and the present invention does not require the collimator 13, and the beam is directly irradiated onto the irradiated object S after emerging from the beam exit 125 of the beam shaper 12. For ease of explanation, when the collimator 13 is installed, the exit of the collimator 13 may be interpreted as the beam exit 125.

[0033] The device for acquiring the three-dimensional medical image may be an imaging device such as CT, MRI, PET, or ultrasound, and in the present invention, preferably, a CT device image acquisition module 2 is used to acquire medical image data of the irradiated body S using electronic computed tomography (CT). The medical image data of the irradiated body S includes a coordinate matrix in a medical image coordinate system of a medical image voxel model of the irradiation target site (lesion, i.e., tumor cells) and a CT value matrix.

[0034] The neutron dose detection device 3 includes a detector that receives neutrons and outputs a signal, a signal processing unit that processes the signal output from the detector, a counter that counts the signals output from the signal processing unit to obtain a counting rate, a conversion unit that converts the counting rate recorded by the counter into a neutron flux rate or a neutron dose rate, a calculation unit that integrates and calculates the neutron flux rate or the neutron dose rate to obtain a neutron dose, and a display that displays the neutron dose. In this technical means, the neutron dose detected by the neutron dose detection device 3 is the exposure dose received by the irradiated object S.

[0035] The detector may be placed within the beam shaper 12, within the collimator 13, or at any position close to the beam shaper 12, as long as it can detect the neutron dose of the neutron beam at the detector position.

[0036] Detectors that can realize real-time detection of neutron dose of neutron beams include ionization chambers and scintillation probes, and those based on ionization chamber structures include He -3 These include proportional counters, BF3 proportional counters, fission chambers, and boron ionization chambers. Scintillation probes can be made of organic or inorganic materials. When detecting thermal neutrons, the scintillation probe is often doped with elements with high thermal neutron capture cross sections, such as Li or B. Certain elements in the two detectors undergo capture or fission reactions with the neutrons entering the detector, releasing heavy charged particles and fission fragments, generating a large number of ion pairs within the ionization chamber or scintillation probe. These charges are collected to form electrical signals, which are then subjected to noise reduction, conversion, and separation processing by a signal processing unit, and the electrical signals are converted into pulse signals. The magnitude of the voltage pulses is analyzed to distinguish between neutron pulse signals and gamma pulse signals. The separated neutron pulse signals are continuously recorded by a counter to obtain the neutron counting rate (n / s). The conversion unit calculates and converts the counting rate using internal software, programs, etc., to obtain the neutron flux rate (cm). -2 s -1) is obtained, and the neutron flux rate is further calculated and converted to obtain the neutron dose rate (Gy / s), and finally, the integration unit integrates the neutron dose rate to obtain the real-time neutron dose.

[0037] Below, a fission chamber, a scintillator detector, and a BF3 proportional counter will be briefly described as examples.

[0038] As the neutron beam passes through the fission chamber, it interacts with the gas molecules inside the chamber or with the walls of the chamber, producing electrons and positively charged ions, called ion pairs. A high voltage electric field is applied within the fission chamber, causing the electrons to migrate toward the central anode wire and the positively charged ions to migrate toward the surrounding cathode walls, producing a measurable electrical signal.

[0039] A material such as an optical fiber in a scintillation probe generates visible light after absorbing energy, and uses ionizing radiation to excite electrons in a crystal or molecule to an excited state. When the electrons return to the ground state, the emitted fluorescence is collected and detected as a neutron beam. The scintillation probe emits visible light after interacting with the neutron beam, and a photomultiplier tube converts the visible light into an electrical signal for output.

[0040] The BF3 proportional counter is placed in the beam shaping body and is irradiated with the neutron beam, and a nuclear reaction occurs between the B element in the BF3 proportional counter and the neutrons. 10 B(n,α) 7 Li, and the alpha particles and 7The Li-ion particles are driven by a voltage and collected by a high-voltage electrode to generate an electric signal. The electric signal is transmitted to a signal processing unit via a coaxial cable, where it is amplified and filtered to form a pulse signal. The processed pulse signal is transmitted to a counter for pulse counting to obtain the counting rate (n / s), which can be used to measure the intensity of the neutron beam, i.e., the neutron dose, in real time.

[0041] In one embodiment of the present invention, the neutron dose is preferably detected using a BF3 proportional counter. Naturally, the type of detector is not limited to this, and any type of detector may be used as long as it can detect the neutron dose in real time.

[0042] Before neutron beam irradiation therapy is performed on the irradiated subject S, the actual blood boron concentration in the subject's body must be detected using a blood boron concentration detection device 4, and the predetermined irradiation dose must be corrected based on the actual blood boron concentration. The detection of boron concentration can be achieved by inductively coupled plasma spectroscopy, high-resolution alpha autoradiography, charged ion spectroscopy, neutron capture camera, nuclear magnetic resonance and magnetic resonance imaging, positron emission tomography, prompt gamma spectrometry, etc., and devices related to the above detection methods are called boron concentration detection devices.

[0043] The mounting module 7 includes a mounting table that supports the irradiation target S, and a driving unit that drives the mounting table to move it to the irradiation position.

[0044] As shown in FIG. 4, the irradiation dose correction method for the boron neutron capture therapy system 100 in one embodiment of the present invention includes the following steps S1 to S4.

[0045] In step S1, a default treatment plan is generated; A predetermined treatment plan is generated by combining a predetermined blood boron concentration and medical image data of the irradiated body, and the predetermined treatment plan is a predetermined irradiation time T preset , including predetermined irradiation parameters such as a predetermined target dose rate.

[0046] Medical personnel determine the target dose D by combining the patient's physical characteristic parameters, medical image data of the patient, and their own experience. ROI,prescribed (also called prescription dose) and set the target dose D ROI,prescribed is the neutron dose that the irradiated object should actually receive.

[0047] In other embodiments, any of the above parameters, including some or more unmentioned parameters, may be understood to be predefined illumination parameters.

[0048] In step S2, a predetermined irradiation dose of a predetermined treatment plan is obtained; In this embodiment, the cumulative neutron count is used as a monitoring parameter for the exposure dose of the BNCT online monitoring system, and the exposure dose is corrected by calculating and correcting the cumulative neutron count. When the cumulative neutron count reaches the target value, the exposure dose reaches the target dose.

[0049] Default cumulative neutron count N preset is calculated using the following equation 1: N preset =R BF3,cal ×T preset (1) In the formula, R BF3,cal is the theoretical counting rate of the neutron dose detector 3, and T preset is the standard blood boron concentration B preset is the predetermined irradiation time corresponding to the

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[0050] In step S3, irradiation treatment is performed on the irradiated body S based on a predetermined treatment plan, and the actual boron concentration and corrected irradiation dose are obtained during the irradiation process. In one embodiment of the present invention, the exposure dose is corrected based on the actual boron concentration to obtain the corrected exposure dose. In this embodiment, the corrected cumulative neutron count N update The blood boron concentration of the irradiated subject is detected by the blood boron concentration detector 4, and the actual blood boron concentration B update After obtaining the actual blood boron concentration B update Corrected cumulative neutron count N corresponding to update Calculate

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[0051] In step S4, irradiation control is carried out based on the corrected irradiation dose.

[0052] Based on the corrected exposure dose, it is determined whether the exposure dose received by the irradiated body S reaches the target dose, and the cumulative neutron count detected by the neutron dose detection device 3 is calculated as the corrected cumulative neutron count N update When the target dose D is reached, the irradiation dose received by the irradiated object is ROI,prescribed , the control module 6 controls the neutron beam irradiation module 1 to stop the irradiation and terminate the treatment.

[0053] As can be seen, during treatment, if the system does not always obtain actual boron concentration information, when the neutron dose detected by the neutron dose detection device 3 reaches the predetermined target dose, the irradiation dose received by the irradiated subject will be the prescribed dose D. ROI,prescribed , the control module 6 controls the neutron beam irradiation module 1 to stop the irradiation and terminate the treatment.

[0054] In one embodiment of the present invention, during the actual irradiation process, the neutron beam irradiation dose is detected in real time by the neutron dose detection device 3, and the irradiation is stopped when the neutron irradiation dose reaches the corrected irradiation dose or the predetermined target dose. In another embodiment, irradiation control can be realized by monitoring the irradiation time. Specifically, the required target irradiation time is obtained by calculation based on the corrected irradiation dose or the predetermined 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 the irradiation and end the treatment. That is, step S4 may be a step of performing irradiation control based on the target irradiation time.

[0055] The target irradiation time T is calculated using the following equation 6:

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[0056] In one embodiment of the present invention, before performing irradiation treatment, the actual blood boron concentration of the irradiated subject is detected using a blood boron concentration detection device 4, and the corrected irradiation time is calculated based on the actual blood boron concentration of the irradiated subject before performing irradiation treatment on the irradiated subject. In another embodiment, if the actual irradiation parameters change during the irradiation process, the target irradiation parameters need to be adjusted periodically or in real time according to the specific situation to maximize the therapeutic effect. During neutron beam irradiation treatment of the irradiated subject S, a boron agent needs to be continuously supplied to the irradiated subject S, and it is difficult to always maintain the irradiated subject's internal boron concentration at the same level throughout the entire irradiation process. As shown in Equation 5, the target dose rate changes with changes in blood boron concentration, while the prescribed dose, i.e., the target dose, remains unchanged. If the blood boron concentration changes, the irradiation dose and target irradiation time need to be further corrected to ensure that the neutron dose actually received by the irradiated subject matches the prescribed dose and ensure the therapeutic effect.

[0057] Accordingly, one embodiment of the present invention may further include step S5, which detects the blood boron concentration of the irradiated subject in real time or periodically during the actual irradiation process, corrects the exposure dose or target exposure time in real time or periodically based on the detected blood boron concentration, and repeats steps S3 to S4 until the neutron dose detected by the neutron dose detection device 3 reaches the target dose or the actual exposure time is equal to the corrected target exposure time. Meanwhile, the parameters of the neutron beam generated by the neutron irradiation module may also change, and the neutron dose detection device 3 can monitor the beam parameters of the neutron beam in real time. If the beam parameters of the neutron beam change, the target exposure time can also be appropriately corrected to ensure that the neutron dose actually received by the irradiated subject matches the prescribed dose.

[0058] There are various methods for detecting the blood boron concentration of an irradiated subject in real time. In one embodiment of the present invention, an example will be described in which the boron concentration in the body of an irradiated subject S is estimated by detecting gamma rays emitted from the irradiated subject S. A neutron beam enters the body of the irradiated subject and reacts with boron, generating gamma rays. By measuring the amount of gamma rays, the amount of boron that reacted with the neutron beam can be estimated, thereby estimating the boron concentration in the body of the irradiated subject S. Specifically, the boron concentration detection device measures boron concentration by detecting gamma rays (478 keV) generated by the reaction between neutrons and boron, and is a boron distribution measurement system (PG (Prompt-γ)-SPECT) that can measure boron concentration distribution by measuring gamma rays of a unit energy. The boron concentration detection device includes a gamma ray detection unit and a boron concentration calculation unit. The gamma ray detection unit detects information about gamma rays emitted from within the body of the irradiated subject S, and the boron concentration calculation unit calculates the boron concentration within the body of the irradiated subject S based on the information about the gamma rays detected by the gamma ray detection unit, and a scintillator and various other gamma ray detection devices may be used as the gamma ray detection unit. In this embodiment, the gamma ray detection unit is placed near the tumor of the irradiated subject S, for example, at a position about 30 cm away from the tumor of the irradiated subject S.

[0059] The boron neutron capture therapy system 100 of the present invention obtains a predetermined target dose by performing simulation based on a predetermined blood boron concentration to obtain a predetermined treatment plan, and then calculates and obtains a corrected irradiation dose based on the dose rate corresponding to the actual blood boron concentration, and controls the neutron irradiation module based on this to carry out irradiation treatment. This eliminates the need to inject boron-containing drugs into the patient when formulating the predetermined treatment plan, and eliminates the need to obtain blood boron concentration detection results before irradiation, thereby saving treatment costs and simplifying the treatment process. The target irradiation dose is corrected based on the actual blood boron concentration during the treatment process, and reduces errors in the irradiation dose caused by changes in blood boron concentration during actual irradiation.

[0060] Although the steps in the flowcharts according to the above-described embodiments are displayed in order according to the arrows, it should be understood that these steps are not necessarily performed in the order indicated by the arrows. Unless explicitly stated otherwise in this specification, the execution of these steps is not limited to a strict order, and these steps may be performed in other orders. Furthermore, at least some of the steps in the flowcharts according to the above-described embodiments may include multiple steps or multiple stages, and these steps or stages may not necessarily be performed at the same time but may be performed at different times. These steps or stages may not necessarily be performed sequentially, but may be performed in order or alternately with other steps or at least some of the steps or stages in other steps.

[0061] The technical features of the above embodiments can be combined in any manner, and for the sake of brevity, 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, any combination should be considered to be within the scope of the present specification.

[0062] The above examples merely illustrate some embodiments of the present application, and although the descriptions are specific and detailed, they should not be understood as limiting the scope of the claims of the present application. Furthermore, those skilled in the art may make several modifications and improvements without departing from the concept of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application should be determined based on the scope of the appended claims. [Explanation of symbols]

[0063] 100 Boron Neutron Capture Therapy System 1. Neutron beam irradiation module 11 Neutron Generator 111 Accelerator 112 Target 12 Beam shaper 121 Reflector 122 Reducer 123 Thermal Neutron Absorber 124 Radiation Shield 125 Beam Exit 13 Collimator 2. Image Acquisition Module 3 Neutron dose detection device 4. Blood boron concentration detector 5 Treatment Planning Module 6 Control Module 7 Mounting module 8. Exposure Dose Correction Module S Irradiated object

Claims

1. The system includes a neutron beam irradiation module, a blood boron concentration detection device, a treatment planning module, an irradiation dose correction module, and a control module; the neutron beam irradiation module generates a neutron beam; the blood boron concentration detection device detects the actual blood boron concentration of the irradiated subject; the treatment planning module generates a pre-defined treatment plan; the exposure dose correction module obtains a corrected exposure dose based on the actual blood boron concentration; The control module calls the predetermined treatment plan from the treatment planning module and controls 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 a target dose.

2. 10. The boron neutron capture therapy system of claim 1, wherein the treatment planning module simulates and calculates based on a predetermined blood boron concentration to obtain the predetermined treatment plan.

3. 3. The boron neutron capture therapy system according to claim 2, wherein the exposure dose correction module obtains the corrected exposure dose by correcting a target dose rate based on the actual blood boron concentration.

4. 4. The boron neutron capture therapy system according to claim 3, further comprising a neutron dose detection device that detects cumulative neutron counts in real time to obtain an irradiation dose.

5. The neutron dose detection device is a BF ３ 5. The boron neutron capture therapy system of claim 4, wherein the boron neutron capture therapy system is a proportional counter.

6. Default cumulative neutron count N ｐｒｅｓｅｔ is calculated using the following equation 1: N ｐｒｅｓｅｔ =R ＢＦ３，ｃａｌ ×T ｐｒｅｓｅｔ (1) In the formula, R ＢＦ３，ｃａｌ is the theoretical counting rate of the neutron dose detector, and B ｐｒｅｓｅｔ is the predetermined boron concentration, and T ｐｒｅｓｅｔ is the default boron concentration B ｐｒｅｓｅｔ is the predetermined irradiation time corresponding to T ｐｒｅｓｅｔ is calculated using the following equation 2: [Equation 1] In the formula, D ＲＯＩ，ｐｒｅｓｃｒｉｂｅｄ is the target dose, [Equation 2] is the predetermined target dose rate, [Equation 3] is calculated using the following equation 3: [Equation 4] 6. The boron neutron capture therapy system of claim 5, wherein a, b, and c are fitting coefficients obtained by function fitting using a plurality of predetermined boron concentration values ​​and their corresponding simulated dose rates.

7. Corrected cumulative neutron count N ｕｐｄａｔｅ is calculated using the following equation 4: [Equation 5] In the formula, B ｕｐｄａｔｅ is the actual blood boron concentration, and T ｕｐｄａｔｅ is the actual blood boron concentration B ｕｐｄａｔｅ is the planned irradiation time corresponding to [Equation 6] is the actual blood boron concentration B ｕｐｄａｔｅ is the corrected target dose rate corresponding to [Equation 7] is calculated using the following equation 5: [Equation 8] 5. The boron neutron capture therapy system of claim 4, wherein a, b, and c are fitting coefficients obtained by function fitting using a plurality of predetermined boron concentration values ​​and their corresponding simulated dose rates.

8. generating a predetermined treatment plan by combining the predetermined boron concentration and medical image data of the irradiated object; obtaining a corrected exposure 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 a target dose.

9. 9. The method for correcting an exposure dose according to claim 8, further comprising the step of determining a target dose based on medical image data of an irradiated object.

10. The method of claim 9 , further comprising the step of obtaining a predetermined exposure dose.

11. 11. The irradiation dose correction method according to claim 10, wherein the step of acquiring the corrected irradiation dose is specifically performed by correcting a predetermined target dose rate of the predetermined treatment plan based on an actually measured boron concentration value to acquire a corrected target dose rate, and then performing calculation based on the corrected target dose rate to acquire the corrected irradiation dose.

12. Default cumulative neutron count N ｐｒｅｓｅｔ is calculated using the following equation 1: N ｐｒｅｓｅｔ =R ＢＦ３，ｃａｌ ×T ｐｒｅｓｅｔ (1) In the formula, R ＢＦ３，ｃａｌ is the theoretical counting rate of the neutron dose detector, and B ｐｒｅｓｅｔ is the predetermined boron concentration, and T ｐｒｅｓｅｔ is the default boron concentration B ｐｒｅｓｅｔ is the predetermined irradiation time corresponding to T ｐｒｅｓｅｔ is calculated using the following equation 2: [Equation 9] D ＲＯＩ，ｐｒｅｓｃｒｉｂｅｄ is the target dose, [Equation 10] is the predetermined target dose rate, [0011] is calculated using the following equation 3: [0012] 11. The method for correcting an exposure dose according to claim 10, wherein a, b, and c are fitting coefficients obtained by function fitting using a plurality of predetermined boron concentration values ​​and their corresponding simulated dose rates.

13. The corrected cumulative neutron count N ｕｐｄａｔｅ is calculated using the following equation 4: [0013] In the formula, B ｕｐｄａｔｅ is the actual blood boron concentration, and T ｕｐｄａｔｅ is the actual blood boron concentration B ｕｐｄａｔｅ is the planned irradiation time corresponding to [0014] is the actual blood boron concentration B ｕｐｄａｔｅ is the corrected target dose rate corresponding to [Equation 15] is calculated using the following equation 5: [0016] 12. The method for correcting an exposure dose according to claim 11, wherein a, b, and c are fitting coefficients obtained by function fitting using a plurality of predetermined boron concentration values ​​and their corresponding simulated dose rates.

14. 12. The exposure dose correction method according to claim 11, further comprising a neutron dose detection device that detects the exposure dose in real time, wherein when the neutron dose detection device detects that the exposure dose has reached the correction exposure dose, the control module controls the neutron beam irradiation module to stop the irradiation.

15. The neutron dose detection device is a BF ３ 15. The method for correcting exposure dose according to claim 14, characterized in that the counter is a proportional counter.

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