Neutron capture therapy device and operation step of monitoring system thereof

Abstract

To provide a neutron capture therapy device and an operation step of a monitoring system thereof.SOLUTION: A neutron capture therapy device includes a neutron beam irradiation system, a detection system, and a monitoring system. The neutron beam irradiation system generates neutron beams for performing neutron capture therapy for a patient. The detection system detects irradiation parameters in the process of neutron beam irradiation therapy. The monitoring system controls an entire neutron beam irradiation process. The monitoring system includes a storage part for storing the irradiation parameters, a control part for performing a therapeutic plan on the basis of the irradiation parameters stored in the storage part, and a correction part for correcting part of the irradiation parameters stored in the storage part. Fundamental coincidence between a dosage of the neutron beams with which the patient is irradiated, and an irradiation dosage of preset neutron beams is secured, and accuracy of the dosage of the neutron beams with which the patient is irradiated is improved.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to the field of radiation irradiation, and in particular to a neutron capture therapy device and its monitoring system. Concerning the operational steps. [Background technology]

[0002] With the development of atomic science, radiation such as cobalt-60, linear accelerators, and electron beams Radiation therapy has already become one of the main means of cancer treatment. However, conventional photon or electron therapy The physical limitations of radiation itself limit the number of tumor cells killed and the number of cells in the beam path. Damages many normal tissues. Different tumor cells have different degrees of sensitivity to radiation. Unlike conventional radiation therapy, it is difficult to treat highly radioresistant malignant tumors (e.g., glial cell tumors). Glioblastoma multiforme, melanoma )) is not very effective in treating them.

[0003] Chemotherapy is used to reduce radiation damage to the normal tissue surrounding the tumor. The concept of targeted therapy in apy is used in radiation therapy and to target highly radioresistant tumors. Currently, there are several biologically effective treatments for cancer cells, including proton therapy, heavy particle therapy, and neutron capture therapy. relative biological effectiveness, RBE ) are being actively developed. Of these, neutron capture therapy is one of the above two. For example, in boron neutron capture therapy, a boron-containing drug is administered to tumor By combining this with highly precise control of the neutron beam, it is possible to achieve a level of therapeutic efficacy that is superior to conventional radiation therapy. It offers better cancer treatment options compared to traditional cancer treatments.

[0004] Neutron beam radiation that delivers radiation therapy to patients during boron neutron capture therapy Because of the intensity of the radiation, the dose delivered to the patient must be precisely controlled. In some cases, preset exposure parameters such as neutron exposure dose may be inaccurate and may cause The problem of inaccurate dose detection still exists.

[0005] In addition, during the actual irradiation process, due to operator or doctor error, the control panel may be touched by mistake. It is possible that the user may accidentally enter commands incorrectly or change related commands and exposure parameters. This increases medical risks. Summary of the Invention

[0006] In order to solve the above problems, according to one aspect of the present invention, a neutron beam is delivered to a patient at a precise dose. Neutron capture therapy devices that can irradiate neutrons generate neutron beams for neutron irradiation therapy. The neutron beam irradiation system consists of a neutron beam irradiator and a neutron irradiation treatment device that detects irradiation parameters during the neutron irradiation treatment process. The system includes a detection system for detecting the neutrons and a monitoring system for controlling the entire neutron beam irradiation process. The monitoring system includes a storage unit for storing the irradiation parameters, A control unit that executes a treatment plan based on irradiation parameters, and a part of the information stored in the storage unit The correction unit corrects the irradiation parameters.

[0007] Further, the exposure parameters include a remaining exposure time, and the correction unit is Correct the shot time.

[0008] Furthermore, the corrected remaining irradiation time t r Calculate

number

number

number

[0009] Further, the irradiation parameters include a neutron dose rate, and the correction unit is Correct the rate.

[0010] Furthermore, the corrected neutron dose rate Ir is calculated using the following equation (2-5):

number

[0011] Further, the irradiation parameters include a boron concentration, and the correction unit corrects the boron concentration. do.

[0012] Further, the irradiation parameters include preset irradiation parameters, real-time irradiation parameters, and the like. and the modified irradiation parameters, and the monitoring system monitors the preset irradiation parameters. an input unit for inputting the real-time radiation parameters detected by the detection system; A reading unit for reading the parameters and a calculation unit for calculating the irradiation parameters stored in the memory unit. and a calculation unit that determines whether or not it is necessary to correct the irradiation parameters based on the calculation results of the calculation unit. and a display unit that displays at least the remaining irradiation time in real time. include.

[0013] Furthermore, before the preset exposure parameters are modified, the memory unit stores the preset exposure parameters. The parameters are stored, and the remaining irradiation time displayed on the display unit is compared with the preset irradiation time. The difference between the time when the exposure was actually performed and the time when the preset exposure parameters were modified. The memory unit stores the most recently modified irradiation parameters, and the display unit displays the most recently modified irradiation parameters. The remaining exposure time is the revised remaining exposure time.

[0014] Furthermore, the calculation unit calculates real-time irradiation parameters and preset irradiation parameters. If the difference value between the real-time irradiation parameter and the real-time irradiation parameter is greater than the first threshold value or the real-time irradiation parameter is greater than the second threshold value, If the difference is greater than the first threshold or less than the third threshold, the determination unit modifies the irradiation parameters. Give the command that needs to be corrected.

[0015] According to another aspect of the present invention, the operation steps of the monitoring system for the neutron capture therapy device include: Step S1 in which the input unit inputs preset irradiation parameters, and step S2 in which the memory unit stores the irradiation parameters A step S2 of storing the irradiation parameters in the storage unit, and the control unit Step S3 of executing a treatment plan based on the data; and Step S4 of reading the real-time irradiation parameters stored in the memory unit; Calculate the stored irradiation parameters and the real-time irradiation parameters read by the reading unit. Step S5: determining whether the determination unit has a value stored in the storage unit based on the calculation result of the calculation unit; A step S6 of determining whether or not the irradiation parameters need to be corrected; When it is determined that the irradiation parameters stored in the memory need to be modified, the modifying unit The most recent set of irradiation parameters in the storage unit is modified, and the judgment unit determines the most recent set of irradiation parameters. When it is determined that the set of irradiation parameters does not need to be corrected, the correction unit performs a correction operation. Step S7 in which the display unit displays the most recent set of irradiation parameters stored in the memory unit. and step S8 of displaying the remaining irradiation time in real time based on the data.

[0016] The monitoring system for the neutron capture therapy apparatus according to the present invention includes a treatment plan stored in a memory unit. A correction unit is provided to correct the irradiation parameters for performing the above-mentioned procedure. The dose of the neutron beam that is generated basically coincides with the preset dose of the neutron beam. This ensures that the neutron beam is delivered to the patient at a high dose, improving the accuracy of the dose. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a neutron beam irradiation system of a neutron capture therapy apparatus according to the present invention. [Diagram 2] 1 is a schematic diagram of a beam shaper of a neutron capture therapy device according to the present invention. [Diagram 3] 1 is a schematic diagram of a neutron beam irradiation system and a detection system of a neutron capture therapy device according to the present invention. [Figure 4] 1 is a schematic diagram of a neutron dose detection device of a neutron capture therapy device according to a first embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of a neutron dose detection device of a neutron capture therapy device according to a second embodiment of the present invention. [Figure 6] 1 is a schematic diagram of a monitoring system for a neutron capture therapy device according to the present invention. [Figure 7] 1 is a schematic diagram of a neutron capture therapy device in which an erroneous operation prevention system according to the present invention is combined with a display unit and an input unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The objectives, technical means and technical effects of the present invention will be more clearly understood, and based on them, those skilled in the art will be able to In order to enable the reader to practice the invention, the following description will be given with reference to the drawings and examples. will be explained in further detail.

[0019] In the following description, the terms "first," "second," etc. may be used to describe various elements herein. Although these elements may be used to illustrate the invention, they are not limited to these terms and are not intended to be limiting. The terms are merely used to distinguish the objects being described and have no sequential or technical meaning. It has no taste.

[0020] Radiation therapy is a common means of treating cancer, while boron neutron capture therapy is a In recent years, it has been increasingly used as an effective treatment method. A neutron beam with a preset neutron dose is irradiated onto a target, e.g., a patient S, to generate boron neutrons. Boron Neutron Capture Therapy (BNCT) The neutron capture therapy device that performs the neutron capture therapy consists of a neutron beam irradiation system, a detection system, and a monitoring system. The neutron beam irradiation system 1 includes: A neutron beam suitable for administering neutron irradiation therapy to a patient S is generated and detected by a detection system. The system detects and monitors irradiation parameters such as neutron dose during neutron beam irradiation treatment. The vision system 3 controls the entire neutron beam irradiation process, and the calibration system presets The neutron dose is calibrated, and the system for preventing misoperation prevents personnel from giving erroneous commands to the monitoring system 3. Prevents users from entering information.

[0021] Boron neutron capture therapy is a method to 10 B) The drug contains a large blocking effect on thermal neutrons. Taking advantage of the surface characteristic, 10 B(n,α) 7 Li neutron capture and fission reactions the law of nature 4 He and 7 Li, two kinds of heavy charged particles are generated, and the two kinds of heavy charged particles have an average energy of The energy transfer coefficient is about 2.33 MeV, and the linear energy transfer coefficient is about 2.33 MeV. These have the characteristics of a high LET and a short range. 4 Linear energy of He particles The energy deposition and range are 150 keV / μm and 8 μm, respectively. 7 Li heavy charged particles The linear energy deposition and range of the two heavy ions are 175 keV / μm and 5 μm, respectively. The total range of the charged particles is equivalent to the size of one cell, so radiation damage to living organisms is measured in terms of cell levels. The boron-containing drug can selectively collect in tumor cells, and the neutron beam can be limited to the tumor cells. After the neutron enters the body of patient S, it reacts with the boron in the body of patient S and 4 He and 7 Li It generates two kinds of heavy charged particles, 4 He and 7 Two types of heavy charged particles of Li have a large effect on normal tissue. It kills tumor cells locally, without causing any serious damage.

[0022] As shown in FIG. 1, the neutron beam irradiation system 1 includes a neutron beam generating module 11. and a beam adjustment module that adjusts the neutron beam generated by the neutron beam generation module 11. Includes 12 Joules.

[0023] The neutron beam generating module 11 generates a neutron beam that is irradiated to the patient S, and An accelerator 111 for accelerating a particle beam and a neutron beam generating device for generating a neutron beam by reacting with the charged particle beam. A target 112 is disposed between the accelerator 111 and the target 112, and a charged particle beam is generated. The charged particle beam transport unit 113 transports the charged particle beam. The charged particle beam is transported to a target 112, one end of which is connected to an accelerator 111 and the other end of which is connected to a The charged particle beam transport unit 113 is connected to the target 112. A beam control device such as a charged particle scanner (not shown) is installed. The adjustment unit controls the traveling direction and beam diameter of the charged particle beam. scans the charged particle beam and adjusts the irradiation position of the charged particle beam on the target 112 Control.

[0024] The accelerator 111 may be a cyclotron, a synchrotron, a synchrocyclotron, or a linear accelerator. The target 112 may be a lithium (Li) target. and a beryllium (Be) target, and the charged particle beam is Accelerated to an energy level that overcomes the nuclear Coulomb repulsion and targets 112 and 7 Li (p,n) 7 The Be nuclear reaction is carried out to generate a neutron beam, and the nuclear reaction that has been generally studied is as follows: 7 Li(p,n) 7 Be and 9 Be(p,n) 9 B. Typically, the target 112 is A target layer and an oxidation prevention layer that is located on one side of the target layer and prevents the target layer from being oxidized. layer, the oxidation prevention layer being made of Al or stainless steel.

[0025] In the embodiment of the present invention, charged particles are accelerated by an accelerator 111 and are coupled to a target 112. A nuclear reaction provides a neutron source, and in other embodiments, a nuclear reactor, a DT neutron generator, a D However, the neutron source may be a neutron source such as a neutron generator. Whether it be accelerating particles and reacting them with the target 112 to provide a neutron source, or Whether it is a neutron source provided by a DT neutron generator, a DD neutron generator, etc., It also produces a mixed radiation field, i.e. the beam produced is a fast neutron beam, an epithermal neutral The boron neutron capture therapy process includes epithermal neutrons, thermal neutrons, and gamma rays. The higher the content of other radiation other than neutrons (collectively referred to as radiation contamination), the greater the risk of developing a normal The proportion of non-selective dose deposition in tissues increases, causing these unnecessary dose depositions. The radiation that is absorbed should be reduced as much as possible.

[0026] The International Atomic Energy Agency (IAEA) has issued a 2015 Recommendation for neutron sources used in clinical boron neutron capture therapy. In this paper, we propose five proposals for the quality elements of air beams. These proposals are It can be used to compare the advantages and disadvantages of different neutron sources, and also to select neutron generation pathways and beam These five proposals can be used as a reference when designing the shaping body 121. As shown below.

[0027] Epithermal neutron flux>1×10 9 n / cm 2 s Fast neutron contamination<2×10- 13 Gy-cm 2 / n Photon contamination<2×10 -13 Gy-cm 2 / n Ratio of thermal to epithermal neutron flux utron flux ratio<0.05 Epithermal neutron current to flux ratio>0.7 Note: The epithermal neutron energy range is from 0.5 eV to 40 keV, and the thermal neutron energy range is from The energy range is less than 0.5 eV, and the fast neutron energy range is greater than 40 keV. stomach.

[0028] As shown in FIGS. 2 and 3, the beam adjustment module 12 adjusts the beam to be ultimately irradiated onto the patient S. The aim is to minimize radiation contamination caused by the radiation and to deliver epithermal neutrons to treat patient S. The neutron beam is generated by the neutron beam generating module 11 so as to be focused on the area that needs to be irradiated. The beam conditioning module 12 moderates and shields the neutron beam. and a beam shaper 121 for focusing the epithermal neutrons onto the part of the patient S that needs to be irradiated. Specifically, the beam shaper 121 includes a collimator 122. The moderator 1211 can moderate the generated neutron beam to the epithermal neutron energy region, and the deviated neutron The reflector 121 guides the neutrons to the moderator 1211 to improve the beam intensity of the epithermal neutrons. 2) Absorption of thermal neutrons causes excess dose deposition in superficial normal tissue during treatment. The thermal neutron absorber 1213 prevents the radiation from leaking and blocks the neutrons and photons from escaping. and a radiation shield 1214 to reduce dose deposition in tissue. It does not contain a neutron absorber, but absorbs thermal neutrons by materials contained in the moderator or reflector. Alternatively, it may be understood that the moderator and the thermal neutron absorber are integrally installed. In other embodiments, the radiation shielding portion is not included and may be made of the same material as the reflector. Alternatively, it may be understood that the reflector and the radiation shielding portion are integrally installed.

[0029] The decelerator 1211 may be formed by laminating a plurality of different materials. The material is selected depending on factors such as the energy of the charged particle beam, e.g., the accelerator 11 The proton beam from 1 has an energy of 30 MeV and uses a beryllium target. In this case, the material of the decelerator 1211 is lead, iron, aluminum, or calcium fluoride. The energy of the proton beam from the accelerator 111 is 11 MeV, and the beryllium terbium When a get is used, the material of the moderator 1211 is heavy water (D2O) or lead fluoride, etc. In a preferred embodiment, the moderator 1211 is made of MgF2 and a weight percentage of MgF2. The reflector 1212 is made of Pb and is thermally neutral. The secondary absorber 1213 is 6 The radiation shielding portion 1214 is made of photon shielding and The photon shielding part is made of lead (Pb) and the neutron shielding part is made of polyethylene. The shape of the decelerator 1211 may be a bicone shape as shown in FIG. 3, the reflector 1212 may be cylindrical, and the decelerator 1211 may be disposed around the reflector 1212. and its shape adaptively changes according to the shape of the decelerator 1211.

[0030] Then, as shown in Figure 3, the detection system measures the neutron dose of the neutron beam in real time. a neutron dose detector 21 for detecting the temperature of the target 112; 22, a displacement detection device 23 for detecting whether the patient S is displaced during the treatment process, and a patient and a boron concentration detection device (not shown) for detecting the boron concentration in the body of S.

[0031] As shown in FIG. 4, the neutron dose detection device 21 is a detector that receives neutrons and outputs a signal. a signal processing unit 212 for processing a signal output from the detector 211; a counter 213 for counting the signal output from the signal processing unit 212 to obtain a count rate; The counting rate recorded in the counter 213 is converted into a neutron flux rate or a neutron dose rate. and a conversion unit 214 for integrating the neutron flux rate or the neutron dose rate to obtain the neutron dose. The detector includes an integration unit 215 for acquiring the neutron dose and a display 218 for displaying the neutron dose. 211, signal processing unit 212 and counter 213 constitute the count rate channel 20. do.

[0032] The detector 211 may be disposed in the beam shaper 121 and may be disposed in the collimator 122. The detector 21 may be located at any position close to the beam shaper 121. It is sufficient to be able to detect the neutron dose of the neutron beam at position 1.

[0033] The detector 211 that can detect the neutron dose of a neutron beam in real time is , ionization chamber and scintillation probe, and based on the ionization chamber structure, He -30% total number tube, BF30% total number tube, fission ionization chamber, boron ionization chamber, scintillation The probe may be made of organic or inorganic materials and may be used for thermal neutron detection. The probes are often doped with elements with high thermal neutron capture cross section, such as Li or B. Some elements in the detector react with neutrons entering the detector by capture or fission, becoming heavily charged. It releases particles and fission fragments, creating a large number of ion pairs in the ionization chamber or scintillation probe. These charges are collected to form an electrical signal, which is then processed by the signal processing unit 212. The electrical signal is converted into a pulse signal, and the magnitude of the voltage pulse is reduced, converted, and separated. The neutron pulse signal and the gamma pulse signal are resolved by analyzing the length of the separated neutrons. The neutron pulse signal is continuously recorded by the counter 213 to obtain the neutron counting rate (n / s). The conversion unit 214 calculates the counting rate by internal software, programs, etc. Calculate and convert to neutron flux rate (cm -2 s -1 ) and further increase the neutron flux rate. The neutron dose rate (Gy / s) is obtained by calculating and converting it into the integral unit. , and integrate the neutron dose rate to obtain the real-time neutron dose.

[0034] Hereafter, fission chamber, scintillation probe The following is a brief explanation of the BF3 detector and the scintillator detector. Reveal.

[0035] When the neutron beam passes through the fission chamber, it ignites the gas molecules or fission products inside the chamber. The ionization chamber walls react with the ions to generate electrons and positively charged ions, which are then The charged ions are called ion pairs. A high voltage electric field is applied inside the fission chamber, so the charged ions The electrons move toward the central anode wire, and the positively charged ions move toward the surrounding cathode walls. This generates an electrical signal that can be measured.

[0036] Materials such as optical fibers in scintillation probes can absorb energy and then decay. It uses ionizing radiation to excite electrons in a crystal or molecule to an excited state, so that the electrons When it returns to the ground state, the emitted fluorescence is collected and then detected as a neutron beam. Scintillation probes emit visible light after interacting with a neutron beam, producing photoelectrons. A multiplier tube is used to convert visible light into an electrical signal and output it.

[0037] The BF3 detector is disposed in the beam shaper 121 and is irradiated with the neutron beam. Nuclear reaction occurs between B element and neutrons in the detector 10 B(n,α) 7 Li is produced by nuclear reaction Alpha particles and 7 The Li particles are driven by a voltage and collected by a high-voltage electrode, The electrical signal is transmitted to the signal processing unit 212 via a coaxial cable. , the signal is amplified and filtered to form a pulse signal. The pulse signal is transmitted to the counter 213, where the pulses are counted, and the counting rate (n / s) is The intensity of the neutron beam, i.e., the neutron dose, is measured in real time based on the count rate. It is possible.

[0038] The temperature detection device 22 is a thermocouple and has two types of components different from each other. The two ends of a conductor (called a thermocouple wire or hot electrode) are joined together to form a circuit, and the When the temperatures are different, an electromotive force is generated in the circuit. This phenomenon is called the thermoelectric effect. Such an electromotive force is called a thermoelectric force. Thermocouples use this principle to measure temperature. One end that directly measures the temperature of the medium is called the working junction (also called the temperature measuring junction), and the other end The cold junction is called the cold junction (also called the compensation junction), and the cold junction is connected to the display instrument or the auxiliary instrument. The thermocouple is then turned on and the display instrument displays the thermoelectric voltage generated by the thermocouple. As known, the temperature detection device 22 may be any detector 21 capable of detecting temperature, such as a resistance thermometer. It may be 1.

[0039] The displacement detection device 23 is an infrared signal detector. The infrared detector detects infrared radiation emitted from the human body. It works by detecting infrared radiation. Infrared detectors collect external infrared radiation and The infrared light is then collected by an infrared sensor, which typically uses a pyroelectric element. When the temperature changes due to infrared radiation, the device releases an electric charge to the outside and issues an alarm after detection processing. Such a detector 211 is intended to detect radiation in the human body. Therefore, radiation sensitive elements are highly sensitive to infrared radiation with wavelengths of around 10 μm. Of course, as is well known to those skilled in the art, the displacement detection device 23 may be The detector may be any detector that detects a change in the displacement of an irradiated object, such as a displacement sensor. A position sensor is a device that detects the movement of an object based on the change in the displacement of the object relative to a reference object. As is further known to those skilled in the art, the displacement detection device 23 determines whether or not the irradiation Not only can it detect the displacement of the object, but it can also fix the support member and / or the object to be irradiated. Or, by detecting the displacement of a treatment table, etc., it is possible to indirectly know the displacement of the target to be irradiated. .

[0040] During the process of neutron beam irradiation therapy for patient S, The boron concentration is detected by inductively coupled plasma spectroscopy, high resolution alpha-audio Radiography, charged ion spectroscopy, neutron capture camera, nuclear magnetic resonance and magnetic resonance imaging This can be achieved by using a variety of detection methods, including shadowing, positron emission tomography, and prompt gamma ray spectrometry. The device involved in this law is called a boron concentration detection device.

[0041] In the present invention, the boron concentration in the body of patient S is measured by detecting gamma rays emitted by patient S. As an example, let us consider the case where a neutron beam enters the patient's body and reacts with boron. Afterwards, gamma rays are generated and the amount of boron reacting with the neutron beam is determined by measuring the amount of gamma rays. By estimating the boron concentration in the body of patient S, it is possible to estimate the boron concentration in the body of patient S. The apparatus is a neutron beam irradiation system 1 that is used in the process of administering neutron beam irradiation therapy to a patient S. The boron concentration in the body of patient S is measured in real time.

[0042] The boron concentration detector detects gamma rays (478kev) generated by the reaction of neutrons with boron. The boron concentration is measured by detecting A boron distribution measurement system (PG(Prompt- The boron concentration detection device is a gamma ray detection unit and The gamma ray detector measures the gamma rays emitted from the body of the patient S. The boron concentration calculation unit calculates the concentration of boron based on the information about the gamma rays detected by the gamma ray detection unit. The boron concentration in the body of patient S is calculated, and the gamma ray detection part is a scintillator and various other In this embodiment, the gamma ray detection unit detects the tumor of the patient S. The imaging device is placed near the tumor of patient S, for example, at a position about 30 cm away from the tumor.

[0043] The detector 211 of the neutron dose detection device 21 for detecting the neutron dose of the neutron beam is Between two consecutively incident neutrons, which belong to the pulse detector and can be resolved by the detector 211 The shortest time interval between the neutrons is defined as the pulse resolution time τ(s). Within a time τ after the injection, the detector 211 can accurately record the other injected neutrons. Since the time τ cannot be detected, it is also called dead time.

[0044] The neutron detection sensitivity of detector 211 is the ratio of the total output of detector 211 to the corresponding total input. For the detector 211 of the neutron dose detection device 21 of the present invention, the input object The physical quantity is a neutron beam, and the output physical quantity is typically an optical or electrical signal. The higher the ratio of the input current to the corresponding total input current, the more sensitive the detector 211 is to detecting neutrons. The higher the neutron detection sensitivity, the shorter the corresponding pulse resolution time τ of the detector 211. To reduce statistical errors, low flux beams are usually The high flux beam is detected by the detector 211, which has high neutron detection sensitivity. The light is detected by a detector 211 with a low intensity.

[0045] Different embodiments will be described in detail below, and the same components will be simplified in different embodiments. The same numbers are used for the sake of clarity, and similar parts are designated by the same reference numerals in the different embodiments. They are differentiated by the same number or by the slash "'" or "''".

[0046] In the first embodiment shown in FIG. 4, the neutron dose detection device 21 has one count rate channel. 20, to accurately detect the neutron dose of neutron beams with different fluxes. In the second embodiment shown in FIG. 5, the neutron dose detection device 21′ includes at least two detectors. 2. The neutron detection sensitivity of the detector 211' of each count rate channel 20' are different from each other, and furthermore, the neutron dose detection device 21' detects the current power or The count rate channel 20' selects an appropriate count rate channel 20' based on the neutron beam flux. Specifically, in the second embodiment, the neutron dose detection The device 21' has at least two count rate channels 20' and at least two count rate channels A count rate channel selection unit that selects one appropriate count rate channel 20' from the 216 and the count rate channel 20' selected by the count rate channel selection unit 216. A conversion unit 214 that converts the counting rates recorded by and an integration unit 21 that integrates the neutron flux rate or neutron dose rate to obtain the neutron dose. Includes 5 and.

[0047] The two count rate channels 20' are respectively referred to as a first count rate channel 201 and a second count rate channel 202. The first count rate channel 201 receives neutrons and outputs a signal. a first detector 2011 for detecting a signal output from the first detector 2011; The signal processing unit 2012 outputs a signal and a first counter 2013 for counting neutrons, and a second count rate channel 202 for counting neutrons. a second detector 2021 that receives the light and outputs a signal; a second signal processing unit 2022 for processing the signal; and a second counter 2023 for counting the output signal. The set 216 selects an appropriate neutron beam flux based on the current power or neutron beam flux of the accelerator 111. The count rate channel selection unit 21 selects the count rate channel 20, and the conversion unit 214 converts the count rate channel The count rate recorded by the count rate channel 20 selected by 6 is referred to as the neutron flux rate or neutral The neutron flux rate or neutron dose rate is converted to a neutron dose rate by an integration unit 215. to obtain the neutron dose.

[0048] Typically, the neutron flux that can be produced when the accelerator is at maximum power is called the maximum neutron flux. The real-time neutron flux detected is defined as the maximum neutron flux. If the neutron flux is smaller than half the normal, the neutron flux is considered to be small and the detected rear If the real-time neutron flux is more than half the maximum neutron flux, the neutron flux Lux is thought to be large.

[0049] The neutron detection sensitivity of the first detector 2011 is a first sensitivity, and the neutron detection sensitivity of the second detector 2021 is a first sensitivity. The neutron detection sensitivity of the first sensitivity is the second sensitivity, and the first sensitivity is smaller than the second sensitivity. In the first detector 2011, a large amount of neutron absorbing material such as B4C or Cd will be wrapped around it. Or because it is filled with low pressure operating gas or designed to be small in size, the neutron detection sensitivity is When the neutron flux is large, the first detector 2011 detects the neutrons in a pulse. The count rate loss due to the solution time can be reduced. Compared to the 2011 vessel, it is either wrapped in a small amount of neutron absorbing material or not wrapped in any material at all. or is filled with high pressure operating gas or designed to be large in size, the second sensitivity is If the sensitivity is greater than the first sensitivity and the neutron flux is small, the second detector 2021 detects the neutrons. By doing so, it is possible to reduce statistical errors in the count rate due to low count rates.

[0050] Correspondingly, the neutron detection sensitivity of the first count rate channel 201 is 10 times that of the second count rate channel. The neutron detection sensitivity of the accelerator 111 is smaller than that of the accelerator 202. Select the appropriate count rate channel 20' based on the current power or neutron flux, e.g. For example, if the maximum beam intensity of the accelerator 111 is 10 mA, the beam intensity of the accelerator 111 If the current is greater than 5 mA, a first count in a first count rate channel 201 having a first sensitivity is activated. The counting rate recorded by the counter 2013 is selected and transmitted to the conversion unit 214 for use in dose calculation. If the beam intensity of the accelerator 111 is less than 5 mA, a second count rate having a second sensitivity is obtained. The count rate recorded by the second counter 2023 of the channel 202 is selected and input to the conversion unit 2 The count rate channel selection unit selects the accurate count rate. The neutron radiation dose is calculated by selecting the neutron radiation dose and transmitting it to the conversion unit 214. Get the quantity.

[0051] The neutron dose detection device 21 has at least two first counting rates having different neutron detection sensitivities. A count rate channel 201 and a second count rate channel 202 are provided, and a count rate channel selection unit By selecting the correct counting rate according to the actual situation, the neutron dose can be calculated by the This avoids the loss of count rate due to pulse resolution time, and is suitable for low count rates. This can avoid statistical errors caused by the neutron radiation, improving the accuracy of real-time neutron dose detection. , and further improves the accuracy of the neutron dose of the neutron beam irradiated to the patient S.

[0052] In other embodiments, the count rate channels 20, 20' may be configured in any number as desired. This may be done.

[0053] In the above-mentioned embodiments, the power, neutron flux, etc. of the accelerator 111 are In another embodiment, the count rate channel 20 is selected based on the detector 211 and A count rate channel 20' may be selected based on the distance to the neutron source, e.g., detector 2 If 11 is placed closer to the neutron source, a second count rate channel with a second sensitivity When 202 is selected and the detector 211 is placed at a position away from the neutron source, the first sensitivity 2. Select the first count rate channel 201 having a detector.

[0054] The detectors 211 of the neutron dose detection device 21 are all pulse detectors. In addition, the pulse detector has a problem of time resolution. 2 generates a signal pulse, which is followed by one τ time interval, and the detector 211 detects this interval time. All other signal pulses further generated within the In this case, if the time interval between any two signal pulses is less than τ, the second pulse is recorded. Therefore, there is a deviation in the count rate recorded by the counter 213 that needs to be corrected. The conversion unit 214 converts the corrected count rate C k Combined with dose conversion coefficients based on This allows accurate neutron flux rate and neutron dose rate D to be measured in real time. t (Gy / s).

[0055] As shown again in FIG. 4 and FIG. 5, the neutron dose detection device 21 further includes a count rate correction function. The count rate correction unit 217 further includes a count rate correction calculator. The count rate correction coefficient calculation unit and the pulse resolution time calculation unit are included.

[0056] The counting rate correction calculation unit calculates the corrected counting rate C using the following formula (1-1): k Calculate

number

[0057] The counting rate correction coefficient calculation unit calculates the counting rate correction coefficient K using the following formula (1-2):

number

[0058] For the neutrons that enter the detector 211, the number of neutrons that react within a unit time is m, and If the number of pulses actually recorded by the counter 213 during the time is n, the counter is in operation. The time that the counter is unable to record is nτ, and the total number of neutrons that enter the counter but are not recorded during this time is mn τ, that is, the loss coefficient is mn, and we obtain equation (1-3).

number

[0059] Substituting equation (1-3) into equation (1-2) gives equation (1-4).

number

[0060] As can be seen from the above formula, if the pulse resolution time τ is known, the counter 213 records The count rate correction coefficient can be calculated by combining the number of pulses and formula (1-4), and the count rate The corrected count rate can be calculated by substituting the correction coefficient into equation (1-1).

[0061] The common methods for calculating the pulse resolution time are the two-ray source method and the reactor power method. Both methods require calculations at two natural neutron sources or nuclear reactors, which is expensive. In an embodiment of the invention, the pulse resolution time is calculated by a monitoring system of a neutron capture therapy device. and reduce costs by fully utilizing existing equipment and resources.

[0062] Specifically, first, the accelerator 111 is operated in a low flux state. In this case, neutrons are The first neutron beam flux is I1, and at this time, counter 2 The count rate recorded by 13 is C1, which is in a low flux state, so theoretically, There is no signal pulse that cannot be recorded by the detector 211 due to the influence of the pulse resolution time. Next, the accelerator 111 is operated in a high flux state, in this case the neutron beam flux The second neutron beam flux I2 is recorded by counter 213. The count rate is C2, and in this case the count rate is affected by the pulse resolution time, so The signal pulse is not recorded, and the pulse resolution time calculation unit calculates the pulse based on the following formula (1-5): Calculate the loop decomposition time τ.

number

[0063] If the position of the detector 211 does not change, the pulse resolution time is calculated every time the device is operated. However, after the detector 211 has been in operation for a long time, the performance parameters may change and the This causes changes in the pulse resolution time, so the pulse resolution time must be calculated periodically.

[0064] The count rate correction unit 217 can calculate the pulse resolution time of the detector 211, In addition, the count rate correction coefficient is calculated based on the pulse resolution time. This allows the error in the counting rate to be corrected, further improving the accuracy of real-time neutron dose detection. This will improve the accuracy of the neutron dose of the neutron beam delivered to the patient S. To make.

[0065] Before radiation therapy can be performed, it is necessary to transport the radiation to the patient S through simulations, calculations, etc. A certain total neutron dose, neutron flux rate or neutron dose rate or current during the exposure period and the required Obtain the irradiation parameters such as irradiation time and irradiation angle, and for ease of explanation, In another embodiment, the above parameters are collectively referred to as preset exposure parameters. Any parameters, including some or more of the unmentioned parameters, may be preset. These may be understood as irradiation parameters, and are the preset neutron dose (Gy), the pre-set Reset neutron flux rate (cm -2 s -1 ), preset neutron dose rate (Gys -1 ), preset current (A) and preset exposure time (s). Several factors change depending on the temperature, so the detection system determines the temperature based on the relevant parameters detected. The exposure parameters must be adjusted periodically based on the exposure conditions. The adjusted irradiation parameters are called real-time irradiation parameters and the adjusted irradiation parameters are called corrected irradiation parameters. The adjusted exposure parameters are called preset exposure parameters. Alternatively, the irradiation parameters may be modified.

[0066] As shown in FIG. 6, the monitoring system 3 includes an input unit for inputting preset irradiation parameters. a power supply unit 31, a memory unit 32 for storing irradiation parameters, and a power supply unit 33 for supplying the irradiation parameters stored in the memory unit 32. A control unit 33 executes a treatment plan based on the meter, and a detection system detects real-time A reading unit 34 for reading real-time irradiation parameters and a memory unit 32 for storing real-time irradiation parameters. 3, a calculation unit for calculating the parameters and the preset / corrected irradiation parameters; 5, and judges whether it is necessary to correct the irradiation parameters based on the calculation results of the calculation unit 35. When the judgment unit 36 ​​judges that the irradiation parameters need to be corrected, a correction unit 37 for correcting a part of the irradiation parameters in the memory unit 32; and a display unit 38 for displaying the remaining irradiation time and other irradiation parameters in real time. .

[0067] Before the preset irradiation parameters are modified, the irradiation parameters stored in the memory unit 32 are preset irradiation parameters, and the irradiation parameters corrected by the correction unit 37 are also preset. The remaining irradiation time displayed on the display unit 38 is the preset irradiation parameter. The irradiation parameters displayed on the display unit 38 are the difference between the time between the actual irradiation time and the real-time irradiation time. After the preset irradiation parameters are corrected, the memory unit 32 The irradiation parameters stored in the memory are the corrected irradiation parameters, and the corrector 37 corrects them again. The irradiation parameters to be corrected are also the corrected irradiation parameters, and the remaining parameters displayed on the display unit 38 are The irradiation time is the corrected remaining irradiation time, and is displayed on the display unit 38 as the irradiation parameter. The data are the modified exposure parameters and, of course, the preset exposure parameters. and the corrected irradiation parameters can be displayed simultaneously.

[0068] In other embodiments, the input unit 31, the storage unit 32, etc. may not be included.

[0069] The monitoring system 3 and the detection system are electrically connected to each other, so that the detection system detects The collected and related information can be transmitted to the monitoring system 3, and the neutron dose measurement in the detection system can be performed. The display 218 of the output device 21 and the display unit 38 of the monitoring system 3 are the same device. Often, it is just a single display panel.

[0070] The operation process of the monitoring system 3 will be specifically described as follows with reference to FIG. 6. will be done.

[0071] In S1, the input unit 31 inputs preset irradiation parameters, e.g., preset neutron flux, Preset neutron dose rate or preset neutron dose rate or preset current, preset neutron dose and pulse Enter preset exposure parameters such as reset exposure time and preset boron concentration, In S2, the memory unit 32 stores the irradiation parameters. In S3, the control unit 33 generates a treatment plan based on the irradiation parameters stored in the memory unit 32. Run In S4, the reading unit 34 reads the real-time irradiation parameters detected by the detection system. Take, In S5, the calculation unit 35 calculates the irradiation parameters stored in the memory unit 32 and the reading unit 34. Calculate the real-time irradiation parameters taken, In S6, the judgment unit 36 ​​judges whether the reference value stored in the memory unit is 0 based on the calculation result of the calculation unit 35. Determine whether the morphism parameters need to be modified; In S7, the judgment unit 36 ​​determines whether the irradiation parameters stored in the memory unit 32 need to be corrected. If it is determined that the irradiation parameters are corrected, the correction unit 37 corrects the most recent irradiation parameters in the memory unit 32. death, The judgment unit 36 ​​judges that it is not necessary to modify the irradiation parameters stored in the memory unit 32. In this case, the correction unit 37 does not perform the correction operation. In S8, the display unit 38 displays the remaining illumination based on the illumination parameters stored in the memory unit 32. The exposure time or remaining exposure time and other exposure parameters are displayed in real time.

[0072] In the operation process of the monitoring system 3, the reading unit 34 reads the real-time irradiation parameters Read the real-time irradiation parameters periodically, for example, once every 5 minutes. The correlation calculation is performed by transmitting the correlation data to the calculation unit 35. A difference value between the standard irradiation parameter and the preset irradiation parameter is greater than a first threshold value or If the real-time irradiation parameter is greater than the second threshold or less than the third threshold, The decision unit 36 ​​issues a command that the irradiation parameters need to be corrected, and then the correction unit 3 The memory unit 32 corrects the irradiation parameters stored in the memory unit 32, and the judgment unit 36 ​​corrects the irradiation parameters. In this case, the correction unit 37 writes in the memory unit 32 a command that the meter does not need to be corrected. The stored irradiation parameters are not modified. For example, the calculation unit 35 calculates that the neutron The difference between the dose rate and the preset neutron dose rate or the real-time neutron flux rate and the preset Difference value between set neutron flux rate or real-time boron concentration and preset boron concentration The difference between the exposure time and the exposure time remaining or the corrected exposure time and the remaining exposure time (preset exposure time and exposure time) The difference between the actual time of irradiation and the time when the irradiation was actually performed or the previous corrected remaining irradiation time is greater than the preset first threshold value, or the calculation unit 35 compares the real Real-time neutron dose rate or real-time neutron flux rate or real-time boron concentration The second threshold is reset or the third threshold is reset. This is the case.

[0073] Before the preset irradiation parameters are modified, the memory unit 32 stores the preset irradiation parameters. The display 38 displays the remaining exposure time and other preset exposure parameters in real time. After the preset irradiation parameters are modified, the memory unit 32 stores the most recent The set of modified exposure parameters is stored, and the display 38 displays the modified remaining exposure time. and the most recent set of other modified exposure parameters in real time. In addition to the irradiation time, the display unit 38 can also display which irradiation parameters are selected according to actual needs. It may further display whether all irradiation parameters can be selected, or some of them. The irradiation parameters may be displayed. Typically, the display 38 displays the remaining irradiation time, real-time Displays information such as exposure dose and boron concentration.

[0074] In the embodiment of the present invention, the calculation unit 35 calculates the rear radiation amount detected by the neutron dose detection device 21. The real-time neutron dose Dr and the preset neutron dose D total By combining these, the corrected remaining exposure time t r where t0 is is the preset exposure time, and t is the real-time exposure time detected by the detection system, i.e. That is, the time at which irradiation was performed,

number

number

[0075] If P is less than 97%, the following formulas (2-2) and (2-3) are used to correct the The remaining exposure time t r Calculate.

number

number

[0076] In this case, the correction unit 37 determines whether the preset irradiation time stored in the memory unit 32 or the corrected irradiation time is All that is required is to modify the remaining exposure time.

[0077] If P is 97% or more, the correction unit 37 prevents the patient S from absorbing excess neutrons. To prevent this, the neutron dose rate is changed to a first neutron dose rate that is less than the preset neutron dose rate. The first neutron dose rate is adjusted and the exposure time is increased accordingly. The neutron dose rate is preferably set to a preset neutron dose rate I d The first neutron dose rate is adjusted to 1 / 5 of I d / 5, the following formula (2 -4) to obtain the corrected remaining exposure time t r Calculate.

number

[0078] In this case, the correction unit 37 corrects the remaining exposure time and the preset neutron beam in the memory unit 32. The dose rate corrected remaining exposure time t r and needs to be corrected to the corrected neutron dose rate. The control unit 33 then executes the treatment plan based on the modified irradiation parameters. In this state, patient S absorbs excess neutrons under irradiation of a neutron beam with a high neutron dose rate. To prevent this, the neutron dose rate can be set to 1 / 3, 1 / 4, or 1 / 2 the preset neutron dose rate. The correction unit 37 may adjust the P ratio to other multiples such as 1 / 6 or 1 / 7. If it is 95% or more, or if it is other ratios, adjust the neutron dose rate. The specific ratio may be preset according to the actual situation. Of course, Based on the value of P calculated by the calculation unit 35, the neutron dose rate is calculated from the preset neutron dose rate. The preset neutron dose rate is used without determining whether it is necessary to adjust to a smaller first neutron dose rate. The percentage of the real-time neutron dose and the preset neutron dose is After determining the conditions under which the neutron dose rate needs to be corrected, one threshold is manually set. The input unit 31 inputs and stores the detected real-time neutron beam in the memory unit 32. If the amount is equal to or greater than the threshold, the decision unit 36 ​​decides that the irradiation parameters need to be modified. Then, the correction unit 37 is activated to correct the neutron dose rate to a first value smaller than the preset neutron dose rate. It may be adjusted for neutron dose rate.

[0079] In the above embodiment, if P is less than 97%, the calculation unit 35 performs real-time neutral The irradiation of the preset neutron dose is completed while maintaining the neutron dose rate unchanged. and in another embodiment, the exposure time is kept constant. By varying the neutron dose rate or boron concentration, the pre-set exposure time can be The purpose of completing the irradiation of the neutron dose rate can be achieved, and the neutron dose rate can be changed. The method involves varying the power of the accelerator, the thickness of the target layer of the target 112, etc. Calculate the corrected neutron dose rate Ir using the following equation (2-5):

number

[0080] The neutron dose rate is calculated by converting the neutron flux rate into a conversion factor. Since the neutron dose rate is obtained by integrating the neutron count rate, correcting the neutron dose rate is This is equivalent to correcting the Lux rate and neutron counting rate.

[0081] In this embodiment, when P is 97% or more, patient S is exposed to a high neutron dose rate. To prevent excessive neutron absorption under the irradiation of the electron beam, the neutron beam is still The dose rate is adjusted to 1 / 5 of the preset neutron dose rate, and the corrected dose rate is calculated using equation (2-4). The remaining exposure time t r Calculate.

[0082] The time during which irradiation is actually performed reaches the preset irradiation time or When the neutron dose reaches the preset neutron dose, the control unit instructs the neutron capture therapy device to stop irradiation. Send the command.

[0083] The monitoring system 3 includes a memory unit 32 for storing irradiation parameters for executing a treatment plan. By installing a correction unit 37 that corrects the data, the neutron beam irradiated to the patient S is Ensure that the neutron dose is essentially consistent with the preset neutron dose and that the patient S is This will further improve the accuracy of neutron dose measurements from neutron beams and provide real-time neutron dose measurements. If the percentage between and the preset neutron dose is 97% or more, patient S is exposed to a high neutron dose rate. In order to prevent excessive neutron absorption under neutron beam irradiation, It is also possible to adjust the neutrons irradiated to the patient S to a lower value and lengthen the irradiation time accordingly. It serves to improve the accuracy of the neutron dose of the beam.

[0084] In the above-mentioned embodiment, the real-time data obtained from the neutron dose detection device 21 is Determine whether the preset exposure parameters need to be modified based on the time neutron dose. Based on these real-time and preset exposure parameters, In another embodiment, the temperature sensing device 22, Based on the real-time irradiation parameters detected by the displacement detection device 23 or the boron concentration detection device, Determine whether the preset parameters need to be modified and whether these detection devices Calculates corrected exposure parameters based on the real-time exposure parameters detected by the device. For example, the boron concentration in the body of the patient S may be preset by a boron concentration detection device. If the boron concentration does not match or is not within the preset interval, correction is performed. The positive portion 37 modifies the remaining irradiation time or modifies the transport rate of boron into the patient's body. Usually, when radiation therapy is nearing the end, the boron concentration in the patient S is corrected in a short period of time. In this case, the usual choice is to modify the remaining exposure time.

[0085] The accuracy of the neutron beam irradiation dose is very important during practical treatment, and the irradiation dose is large. Too little radiation dose will cause potential damage to the patient S, and too little radiation dose will reduce the quality of treatment. Calculation error of the reset neutron dose calculation part and real-time irradiation pattern during the actual irradiation process Any deviation between the measured parameters and the preset exposure parameters will result in inaccuracies in the neutron exposure dose. In order to achieve this, irradiation parameters are modified in real time during the actual irradiation process. In addition, the calculation of preset irradiation parameters is also very important. To ensure that the neutron exposure dose administered is more accurate, a calibration system is It is necessary to calibrate the preset neutron dose of the neutron beam. When the patient S is positioned, the real-time neutron dose rate is measured, and the boron concentration in the patient is measured. , the effects of factors such as neutron flux must be taken into account.

[0086] The calibration coefficients used by the calibration system include the neutron calibration coefficient K1 and the boron calibration coefficient K2. , the neutron calibration factor K1 is the positioning calibration factor K p and neutron beam intensity calibration factor K iRegarding The boron calibration factor K2 is the boron concentration calibration factor K b and boron self-shielding effect calibration coefficient K s Related to.

[0087] Deviations between the real-time neutron dose rate and the preset neutron dose rate will ultimately result in patient The positioning calibration factor K p and neutral Child beam intensity calibration factor K i is introduced to correct the neutron exposure dose.

[0088] The self-shielding effect is the difference in the amount of neutron radiation irradiated to the tumor site when the boron concentration is different. Specifically, the higher the boron concentration in the body of patient S, This reduces the penetration ability of the neutron beam and shortens the track of the neutron beam on the tumor. The neutron beam reacts with boron in a shallower track, and conversely, the neutron beam reacts with boron in a shallower track. The tumor is irradiated over a longer track, and the neutron beam is concentrated in the deeper track. Specifically, a first boron concentration value in the patient's body is obtained by a boron concentration detection device. a first track when the neutron beam is irradiated to the tumor site; obtain a first boron calibration factor and measure a second boron concentration in the patient's body by a boron concentration detection device; A concentration value is obtained, and a second track is provided when the neutron beam is applied to the tumor site, and calibration is performed. The positive system obtains a second boron calibration factor, and the first boron concentration value is the first track is smaller than the second track, and the first boron calibration The factor is smaller than the second boron calibration factor. Therefore, when calculating neutron exposure doses Consider the effect of self-shielding on the actual neutron beam irradiation and the irradiation track Therefore, the boron concentration calibration factor K b and boron self-shielding effect calibration factor K s Introduced The neutron exposure dose is calibrated using this.

[0089] Specifically, the neutron calibration is performed using the formulas (3-1), (3-2), and (3-3), respectively. Positive coefficient K1, Positioning calibration coefficient K p and neutron beam intensity calibration factor K i Calculate the correlation equation is as follows:

number

number

number

[0090] Here, D is the dose actually used in the treatment, i.e., the dose measured by the neutron dose detector 21. Real-time neutron dose D r and D0 is the preset neutron dose that is not calibrated, I is the actual neutron beam intensity measured in real time by the neutron dose detector 21. is the neutron dose rate, I0 is the theoretical beam intensity, i.e., the preset neutral density input from the input section 31. is the child dose rate.

[0091] Using equations (3-4), (3-5) and (3-6), respectively, the boron calibration coefficient K2, Boron concentration calibration factor K b and boron self-shielding effect calibration factor K s The correlation equation is as follows: That is correct.

number

number

number

[0092] Here, B is the actual boron concentration in the body of patient S, i.e., the concentration detected by the boron concentration detection device. The real-time boron concentration measured B0 is the set value of the boron concentration in the treatment plan, i.e., the plan input from the input unit 31. is the reset boron concentration, φ B is the thermal neutron flux in the body of patient S when the boron concentration distribution is B, φ B0 is the thermal neutron flux in the body of patient S when the boron concentration distribution is B0. do.

[0093] Calculate the uncalibrated preset neutron dose D0 using the following equation (3-7).

number

[0094] The calibrated preset neutron dose D in the treatment plan is calculated using the following formula (3-8): to tal Calculate.

number

[0095] Here, D B is the dose at 1 ppm boron concentration in Gy, B con is the actual measured boron concentration in ppm, D fis the fast neutron dose in Gy, D th is the thermal neutron dose in Gy, RBE n is the relative biological effectiveness of neutrons, D r is the gamma radiation dose in Gy, RBE r is the gamma relative biological effectiveness.

[0096] During the actual treatment, the calibration system uses preset neutrons in a pre-established treatment plan. The dose is calibrated to prevent administering an inaccurate neutron dose to patient S.

[0097] The calibration system measures the positioning deviation of the patient S, the real-time neutron dose rate deviation, and the real-time The neutron dose is calculated by taking into consideration the effect of factors such as the concentration of boron on the preset neutron dose. Calibration factor K1 and boron calibration factor K2 are introduced to calibrate the preset neutron dose and the patient S This ensures the accuracy of the neutron dose of the neutron beam irradiated to the target at the source.

[0098] During actual treatment, after the input unit 31 has completed inputting the preset irradiation parameters, the operator The input unit 3 starts the neutron capture therapy device and performs radiation treatment. 1 The input function is locked and the relevant exposure parameters cannot be re-entered. During the irradiation process, incorrect parameters and commands may be input due to incorrect touch or incorrect operation. However, this is not an ideal situation during the treatment process. If it does not match, the irradiation will be stopped or continued according to the abnormal condition. The parameters can be corrected or the instructions can be changed in a timely manner. However, the operating interface can be easily configured to operate in real time. In this way, after irradiation has started, irradiation parameters and control commands can still be input through the input unit 31. Thus, precise irradiation parameters and instructions can be entered during the irradiation process. It is possible to guarantee real-time input, but this prevents errors during the irradiation process. This may result in the input of incorrect parameters, commands, or repeated input of operating commands; There is a risk that this could affect the irradiation results.

[0099] As shown in FIG. 7, the neutron capture therapy device has an operation interface. The interface includes the input unit 31, the display unit 38, a confirmation button 51 for confirming that information is correct, and a start irradiation button. 52, an irradiation pause button 53, an irradiation cancel button 54, and a report generation button 55. The operator activates the information error confirmation button 51 to confirm that all information is error-free. The monitoring system 3 then transmits a signal to the monitoring system 3 to confirm that there are no errors in all the information. Only after receiving a signal that confirms that there is no contamination can the neutron capture therapy device be started to perform neutron beam irradiation. The monitoring system 3 ensures that all information is correct. After receiving the confirmation signal, the irradiation start button 52 is activated to start the neutron capture therapy. Neutron capture therapy equipment is equipped with sufficient conditions to start the device and irradiate the neutron beam. After the irradiation is started, the irradiation of the neutron beam is temporarily stopped by pressing the irradiation pause button 53. The neutron beam irradiation can be canceled by pressing the cancel button 54. Once complete, activate the generate report button 55 to automatically generate a report related to the radiation treatment. The neutron beam irradiation can be temporarily suspended, i.e. all irradiation parameters and commands can be reset. The irradiation parameters are kept unchanged, and the original irradiation parameters are restored by activating the irradiation start button 52 again. The neutron beam is irradiated according to the meter and command, and the neutron beam irradiation is canceled. That is, all irradiation parameters and instructions are cleared, and the irradiation is performed when the neutron beam is irradiated again. Input the irradiation parameters and commands again, and press the confirmation button 51 for confirming that the information is correct and the irradiation start button 52. It is necessary to start the tanks 52 in order.

[0100] The misoperation prevention system comprehensively considers two factors: operability and safety. The double confirmation section and foolproof section ensure safe and accurate irradiation. At the same time, the system has poor real-time operability. The operator can easily access all the information. The confirmation unit is started twice to transmit a signal to the neutron capture therapy device that the confirmation is correct. The neutron capture therapy device could not be started to execute the irradiation treatment plan before the operation started. That is, the irradiation start button 52 cannot be activated. The input section 31 allows the user to modify and enter irradiation parameters and instructions, and a report generation button 55 is also included. It will be clicked.

[0101] In an embodiment of the present invention, the second confirmation unit is configured to confirm that the information in the operation interface is correct. The doctor must first confirm the treatment plan by clicking the confirmation button 51. The operator must check twice to ensure that the information is correct and that there are no errors. By clicking the Confirm button 51, the user can confirm that the information is correct. Once the data is entered into the visual system 3, the device can be started and the treatment plan can be executed. This reduces the risk of introducing incorrect control commands due to incorrect operation. For example, Before performing radiation therapy on patient S, Parameters (e.g., exposure dose, collimator number) must be verified and all information After verifying that the information is correct, click the "Confirm Information is Correct" button 51 on the operation interface. Only after clicking the button can the start irradiation function be activated; otherwise, the doctor will not be able to start irradiation. Even if the start button 52 is clicked, the device will refuse to start irradiating the neutron beam, and Gives a presentation of unconfirmed information.

[0102] In the embodiment of the present invention, the foolproof part is a start button 52 for starting the irradiation. After the start button 52 is activated to start the treatment plan, the input function of the input unit 31 is locked. You cannot re-enter any information. In particular, you must enter the relevant instructions and and irradiation parameters are inputted by the input unit 31, and the relevant irradiation parameters and instructions are sent to the monitoring system. When inputting the data into program 3, the operator can check whether the relevant exposure parameters and instructions are incorrect. After checking and confirming that there are no errors, activate the information error confirmation button 51, and then enter The input section 31 is locked, and the relevant irradiation parameters and instructions can be modified or In this way, erroneous input is prevented and the input unit 31 is unlocked. Only then can the relevant irradiation parameters and instructions be entered again. After clicking the irradiation pause button 53 or the irradiation cancel button 54, the irradiation The treatment is stopped, and the input unit 31 for inputting related information is unlocked. In this case, the relevant information can be modified and added by the input unit 31. After completing the shooting treatment, the input section will be automatically unlocked. This prevents erroneous input. For example, medical personnel can After confirming that the S information, irradiation parameters, and other information are correct, Click the Confirm Information Errors button 51, then click the Start Irradiation button 52, and After this, the system starts the radiation treatment, in which case the input section 31 for inputting the relevant information is is locked and you cannot enter any information.

[0103] Before completing the radiation treatment, the report generation button 55 is also locked. , the report generation button 55 is automatically unlocked, i.e., activates the treatment report generation function. It is possible.

[0104] The foolproof part is not limited to the irradiation start button 52 in the above example, but may be any other important button. The button and parameter input window are also applied, and the function can be confirmed twice and the button can be used to The implementation carrier of the proof may be software or hardware. For example, the foolproof part may be a key or dial switch on a control panel. Often, some operations cannot be performed before the key or switch is turned on, and Only after turning on or switching on the relevant operation can the associated operation be performed.

[0105] In an embodiment of the present invention, commands and irradiation parameters are input in the form of a touch screen. In other embodiments, the input may be made using a key (eg, a mechanical key).

[0106] The anti-misoperation system performs parameter setting and control command input functions when necessary. Not only can it guarantee the accuracy of the data, but also can prevent the input of incorrect parameters due to incorrect operation or other reasons. This can reduce the need to repeatedly input commands, thereby reducing the risk of device malfunction.

[0107] The neutron dose detector 21 of the neutron capture therapy apparatus according to the present invention has different neutron detection sensitivities. At least two count rate channels, a first count rate channel 201 and a second count rate channel 202, are included. A count rate channel selection unit 216 is provided, and the count rate channel selection unit 216 is implemented. Pulse resolution is achieved by calculating the neutron dose by selecting the correct counting rate according to the actual situation. It can avoid the loss error of count rate due to time, and the statistical error due to low count rate. This can avoid the need for a high-quality neutron radiation treatment, improve the accuracy of real-time neutron dose detection, and further improve patient safety. Improve the accuracy of the neutron dose of the neutron beam irradiated to S, and also improve the neutron dose detection device. The device 21 calculates the pulse resolution time of the detector 211 and calculates the pulse resolution time based on the pulse resolution time. Correct the count rate error due to pulse resolution time by calculating the count rate correction factor. A count rate correction unit 217 capable of detecting neutron dose in real time was also installed. This will further improve the accuracy and ultimately the accuracy of the neutron dose of the neutron beam irradiated to the patient S. Further improve the degree.

[0108] The neutron capture therapy device according to the present invention further includes a monitoring system 3. periodically corrects irradiation parameters for executing the treatment plan stored in the memory unit 32. By installing the correction unit 37, the neutron dose of the neutron beam irradiated to the patient S is ensure that the neutron dose irradiated to the patient S is essentially consistent with the preset neutron dose. The accuracy of the neutron dose in the neutron beam has been further improved, and the real-time neutron dose and the preset If the percentage of the neutron dose from the patient S is 97% or more, the patient S is exposed to neutrons from the high neutron dose rate. The neutron dose rate is adjusted low to prevent excessive neutron absorption during irradiation of the beam. The irradiation time can be increased accordingly, and the amount of radiation in the neutron beam irradiated to the patient S can be reduced. This serves to improve the accuracy of the proton dose.

[0109] The neutron capture therapy device according to the present invention further includes a calibration system. Factors such as the positioning deviation of the operator S, real-time neutron dose rate deviation, and real-time boron concentration The neutron calibration coefficient K1 and boron concentration are determined by taking into consideration the effect of the element on the preset neutron dose. The basic calibration coefficient K2 is introduced to calibrate the preset neutron dose and the neutron beam irradiated to the patient S. This ensures the accuracy of the neutron dose at the source.

[0110] As described above, the neutron capture therapy device according to the present invention can deliver a neutron beam with an accurate irradiation dose to a patient. Reduce the risk of equipment malfunction due to incorrect operation while ensuring the operability of the equipment. It is possible.

[0111] The neutron capture therapy device according to the present invention is The present invention is not limited to the above-mentioned configuration. The material, shape and position of the member may be changed based on the present invention. Any obvious changes, substitutions or modifications made thereto are within the scope of the present invention. do.

Claims

1. The system includes a neutron beam irradiation system that generates a neutron beam, a detection system that detects real-time irradiation parameters including real-time neutron dose, and a monitoring system that controls the entire neutron beam irradiation process. The neutron beam irradiation system includes a neutron beam generation module that generates the neutron beam, and a beam adjustment module that adjusts the neutron beam generated by the neutron beam generation module, the beam adjustment module including a beam shaping body and a collimator, The detection system is a neutron dose detection device that detects the real-time neutron dose of the neutron beam in real time, and includes a detector that receives neutrons from the neutron beam and outputs a signal, wherein the detector is located in the beam shaping body or the collimator. The neutron capture therapy apparatus is characterized in that the monitoring system includes a storage unit for storing irradiation parameters including total neutron dose, remaining irradiation time, and neutron dose rate; a correction unit for periodically correcting the remaining irradiation time or neutron dose rate stored in the storage unit based on the difference between the total neutron dose stored in the storage unit and the real-time neutron dose detected by the detection system; and a control unit for executing a treatment plan based on the most recent irradiation parameters stored in the storage unit.

2. The neutron capture therapy apparatus according to claim 1, characterized in that the modification unit modifies the remaining irradiation time.

3. Using the following formulas (2-2) and (2-3), calculate the corrected remaining irradiation time t r, [Math 1] （２－２） [Math 2] （２－３） Here, t is the time during which the irradiation was performed. [Math 3] The neutron capture therapy apparatus according to claim 2, characterized in that D is the average neutron dose value within the t-time period, Dr is the real-time neutron dose detected by the detection system, and D total is the preset total neutron dose.

4. The neutron capture therapy apparatus according to claim 1, characterized in that the modification unit modifies the neutron dose rate.

5. The corrected neutron dose rate Ir is calculated using the following formula (2-5): [Math 4] （２－５） The neutron capture therapy apparatus according to claim 4, wherein t is the time during which irradiation was performed, t0 is the preset remaining irradiation time, Dr is the real-time neutron dose detected by the detection system, and Dtotal is the preset total neutron dose.

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