System and method for assessing whole-body dose and treatment room environment dose for bnct

Abstract

The application provides a system and method for evaluating BNCT whole-body dose and treatment room environment dose, the system comprising: an acquisition module configured to acquire image data and biological data to further acquire a BNCT whole-body treatment theoretical dose; a characteristic plane module configured to select a measurement characteristic plane along a neutron beam central axis direction based on the BNCT whole-body treatment theoretical dose; a dose measurement module configured to determine a measurement point and acquire a neutron reaction rate and a gamma absorbed dose of the measurement point; an evaluation factor module configured to correspondingly acquire a neutron evaluation factor and a gamma dose evaluation factor based on the neutron reaction rate and the gamma absorbed dose of the measurement point; and an evaluation module configured to evaluate the BNCT whole-body treatment theoretical dose based on the neutron evaluation factor and the gamma dose evaluation factor of the measurement point to acquire a BNCT whole-body treatment evaluation dose. The application constructs a panoramic dose evaluation and quality control closed loop covering "whole-body dose + environment dose", and fills the technical gap of BNCT panoramic dose evaluation.

Description

Technical Field

[0001] This application belongs to the field of radiation technology and relates to a system and method for assessing the whole-body dose and treatment room environmental dose of BNCT. Background Technology

[0002] Boron neutron capture therapy (BNCT) is a binary targeted radiotherapy technique that uses a non-radioactive isotope boron-10 (BNCT) to deliver a neutron to the brain. 10 B) The drug is selectively delivered to tumor cells and irradiated with thermal or ultrathermal neutrons, causing... 10 B occurred 10 B(n,α) 7 Li nuclear reaction, releasing alpha particles with high linear energy transfer (LET) and 7 Li recoil nuclei; due to their range of only about 5-10 μm, they can kill tumor cells while reducing damage to surrounding normal tissues.

[0003] With the development of accelerator neutron source technology, blast radiotherapy (BNCT) is gradually entering clinical applications in hospitals. However, its dosimetric characteristics are quite complex: in addition to scattering and absorption in human tissues, neutrons also produce secondary gamma rays. Therefore, the total dose received by the patient is composed of the dose contribution of neutrons in different energy regions and the absorbed dose of gamma rays. Due to the significant differences between neutrons and gamma rays in energy distribution, transport characteristics, and biological effects, BNCT forms a complex mixed radiation field, making its dose assessment more complex than that of traditional radiotherapy. Therefore, how to assess the overall dose of BNCT is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides a system and method for assessing the systemic dose of BNCT and the environmental dose in the treatment room, which addresses the technical problem of how to correlate and assess the systemic therapeutic dose of BNCT with its environmental impact.

[0005] In a first aspect, this application provides a system for assessing the systemic dose of BNCT, the system comprising:

[0006] The acquisition module is configured to acquire image data and biological data to obtain the theoretical dose of BNCT systemic therapy based on the image data and biological data;

[0007] The feature plane module is configured to select at least one measurement feature plane perpendicular to the neutron beam central axis along the direction of the neutron beam central axis, based on the theoretical dose of the BNCT whole-body treatment.

[0008] The dose measurement module is configured to determine at least one measurement point on the intersection of the measurement feature plane and the body surface, and to acquire the neutron reaction rate and γ absorbed dose of the at least one measurement point;

[0009] The evaluation factor module is configured to obtain neutron evaluation factors and γ dose evaluation factors for each of the measurement points based on the neutron reaction rate and the γ absorbed dose at each of the measurement points.

[0010] The evaluation module is configured to evaluate the theoretical dose of the BNCT systemic treatment based on the neutron evaluation factor and the gamma dose evaluation factor at each of the measurement points, so as to obtain the BNCT systemic treatment evaluation dose.

[0011] In one implementation of the first aspect,

[0012] The feature plane module extracts the percentage depth dose distribution curve along the central axis of the neutron beam from the theoretical dose of the BNCT whole-body treatment to determine key dose feature nodes; the key dose feature nodes include at least the steep drop region with the largest absolute value of the dose gradient and the distal dose plateau region;

[0013] The feature plane module selects at least one feature plane perpendicular to the neutron beam central axis based on the depth position corresponding to the key dose feature node;

[0014] The feature plane module selects the measurement feature plane based on the dose space distribution parameters of the feature plane.

[0015] In one implementation of the first aspect,

[0016] The evaluation factor module extracts the theoretical neutron flux corresponding to each measurement point from the theoretical dose of the BNCT systemic treatment;

[0017] The evaluation factor module queries and obtains the corresponding macroscopic neutron reaction cross section based on at least one neutron detector deployed at each measurement point;

[0018] The evaluation factor module calculates at least one neutron reference reaction rate at each measurement point based on the neutron macroscopic reaction cross section, the theoretical neutron flux, and the volume of the neutron detector.

[0019] The evaluation factor module obtains the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the corresponding neutron reaction rate.

[0020] In one implementation of the first aspect,

[0021] The evaluation factor module extracts the theoretical neutron flux distribution of each measurement characteristic plane from the theoretical dose of the BNCT systemic therapy, and divides the theoretical neutron flux distribution into energy regions to obtain the sub-energy region theoretical neutron flux distribution of each measurement characteristic plane; wherein, the sub-energy region theoretical neutron flux distribution includes the theoretical neutron flux distribution of the thermal neutron region, the theoretical neutron flux distribution of the hyperthermal neutron region, and the theoretical neutron flux distribution of the fast neutron region;

[0022] The evaluation factor module obtains the theoretical neutron flux of the thermal neutron region, the theoretical neutron flux of the hyperthermal neutron region, and the theoretical neutron flux of the fast neutron region at each measurement point based on the theoretical distribution of neutron flux in the energy division region of each measurement feature plane.

[0023] The evaluation factor module obtains the macroscopic neutron reaction cross sections in the thermal neutron region, the ultrathermal neutron region, and the fast neutron region based on the corresponding queries of various neutron detectors deployed at each measurement point.

[0024] For each type of neutron detector, the evaluation factor module multiplies the theoretical neutron flux in the thermal neutron region, the theoretical neutron flux in the ultrathermal neutron region, and the theoretical neutron flux in the fast neutron region by the macroscopic neutron reaction cross section of the corresponding energy region, sums them, and then multiplies them by the volume of the neutron detector to obtain the corresponding neutron reference reaction rate.

[0025] The evaluation factor module obtains the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the neutron reaction rate.

[0026] In one implementation of the first aspect,

[0027] The evaluation module extracts the theoretical neutron equivalent dose value and the theoretical γ absorption dose value of all voxel points in each of the measurement feature planes from the theoretical dose of the BNCT systemic treatment.

[0028] The evaluation module determines the neutron evaluation field and the gamma dose evaluation field corresponding to each voxel point based on each of the neutron evaluation factors and the gamma dose evaluation factors, respectively.

[0029] The evaluation module evaluates the theoretical neutron equivalent dose value of the corresponding voxel point based on each neutron evaluation field to obtain the neutron equivalent evaluation dose of each voxel point.

[0030] The evaluation module evaluates the theoretical dose value of γ absorption at the corresponding voxel point based on each γ dose evaluation field to obtain the γ absorption evaluation dose value at each voxel point.

[0031] The evaluation module obtains the BNCT systemic treatment evaluation dose based on the neutron equivalent evaluation dose and the γ absorption evaluation dose value of each voxel point.

[0032] In one implementation of the first aspect,

[0033] The evaluation module acquires body surface partitions and associates each body surface partition with the nearest measurement point, so that the neutron evaluation factor and the gamma dose evaluation factor of the measurement point are respectively used as the neutron evaluation field and the gamma dose evaluation field of each voxel point in the corresponding body surface partition.

[0034] In one implementation of the first aspect,

[0035] The evaluation module performs spatial interpolation on the neutron evaluation factor and the gamma dose evaluation factor based on the spatial coordinates of each measurement point to obtain the neutron evaluation field and the gamma dose evaluation field corresponding to each voxel point.

[0036] In one implementation of the first aspect, the system further includes an output module:

[0037] The output module is configured to determine whether the neutron assessment factor and / or the gamma dose assessment factor are in an abnormal range; if so, an abnormality prompt message is output; if not, the BNCT systemic treatment assessment dose is output; and / or to obtain a heatmap showing the difference between the theoretical dose distribution and the assessed dose distribution of BNCT systemic treatment, wherein the heatmap uses different color levels to indicate the magnitude of the assessment difference; if the magnitude of the assessment difference exceeds a preset range, an abnormality prompt message is output; if not, the BNCT systemic treatment assessment dose is output.

[0038] Secondly, this application provides a method for assessing the systemic dose of BNCT, wherein the method utilizes the systemic dose assessment system of BNCT as described in the first aspect to obtain the systemic treatment assessment dose of BNCT.

[0039] Secondly, this application provides a method for assessing environmental doses in a treatment room, the method comprising:

[0040] The system described in the first aspect is used to obtain the BNCT systemic treatment assessment dose;

[0041] The BNCT systemic treatment assessment dose is used as a radiation source term to obtain the environmental assessment dose based on the radiation source term and environmental set parameters.

[0042] As described above, the system and method for evaluating the systemic dose and treatment room environmental dose of BNCT described in this application have the following beneficial effects:

[0043] This application integrates "lightweight experimental calibration, whole-body dose assessment and quality control closed-loop feedback" for BNCT whole-body dose and environmental dose assessment, realizing a paradigm shift from "local target area calculation" to "panoramic dose verification".

[0044] First, this application breaks through the limitation of "disconnect between planned calculation and actual irradiation" in traditional BNCT dose assessment. Based on the spatial interpolation or partitioning mechanism of multi-measurement point data, the dose of each body element can be assessed and calibrated, thus providing a basis for the quantitative verification of the irradiation dose of each part of the body.

[0045] Secondly, this application overcomes the bottleneck of BNCT in rapidly obtaining whole-body dose distribution in complex anatomical environments. It can quickly reconstruct the whole-body dose field through a small number of measurement points, which greatly reduces the threshold for clinical implementation and makes whole-body dose assessment feasible for routine clinical applications.

[0046] Furthermore, this application establishes a complete physical quality control chain of "measurement-calculation-verification", which can determine the reliability of the calibration process and trigger alarms when abnormalities occur, thereby providing a quantifiable quality control standard for whole-body dose assessment of BNCT and making up for the lack of standardized verification procedures in the field of BNCT.

[0047] Finally, this application not only completed the assessment of the patient's whole-body dose, but also extended the assessment scope to the treatment room environment, thereby providing a quantitative basis for radiation protection optimization and occupational exposure management, filling the technical gap in BNCT environmental dose assessment. Attached Figure Description

[0048] Figure 1 A schematic diagram of the architecture of the BNCT whole-body dose assessment system described in an embodiment of this application is shown.

[0049] Figure 2 A schematic diagram illustrating the workflow of the evaluation factor module described in an embodiment of this application is shown.

[0050] Figure 3 A schematic diagram illustrating the workflow of the evaluation module described in an embodiment of this application is shown.

[0051] Figure 4 A schematic flowchart of the BNCT systemic dose assessment system described in an embodiment of this application is shown. Detailed Implementation

[0052] The following specific examples illustrate the implementation methods of this application. Those skilled in the art can understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0053] It should be noted that the following description, in conjunction with the accompanying drawings, illustrates several embodiments of this application. Other embodiments may also be used, and changes may be made to the corresponding steps and their combinations without departing from the spirit and scope of this application. The following detailed description should not be considered limiting, and the scope of protection of this application is defined by the claims.

[0054] Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. The terms “comprising,” “including,” and “including” indicate the presence of the stated feature, operation, item, and / or combination thereof, but do not exclude the presence or addition of one or more other features, operations, items, and / or combinations thereof. The terms “or” and “and / or” should be interpreted inclusively.

[0055] In recent years, with the maturation and commercialization of accelerator neutron source technology, bio-neutron therapy (BNCT) has gradually moved from nuclear reactor platforms to hospital settings, becoming an important means of treating recurrent head and neck malignancies, gliomas, and other diseases. Compared with traditional photon radiotherapy and proton and heavy ion therapy, BNCT has unique biological targeting advantages, but its dosimetric characteristics are also more complex. The interaction between neutrons and human tissues includes not only scattering and absorption but also the generation of complex secondary gamma rays. These gamma rays have different attenuation patterns in tissues than neutrons and have extremely strong penetrating power. Therefore, the total dose of BNCT is composed of the neutron equivalent dose (including thermal neutrons, hyperthermal neutrons, and fast neutrons) and the absorbed dose of high-energy gamma rays. This complex mixed energy field characteristic makes dose assessment in BNCT far more challenging than in traditional radiotherapy that relies solely on Monte Carlo (MC) simulations.

[0056] Currently, clinical practice primarily relies on the Monte Carlo algorithm within Treatment Planning Systems (TPS) for dose calculation and optimization in BNCT. Existing technologies have the following technical limitations and shortcomings in assessing systemic and treatment room environmental doses for BNCT:

[0057] (1) Limited scope of assessment, lacking a whole-body perspective. Current BNCT dose assessment mainly focuses on the tumor target area and adjacent organs at risk, and the calculation boundary is usually limited to the irradiation field. For the lower body of patients far from the neutron beam irradiation area, existing systems often assume that its dose contribution is negligible, or only make a rough estimate based on empirical formulas. However, due to the strong penetrating characteristics of secondary gamma rays, this localized assessment method cannot accurately quantify the cumulative radiation risk throughout the body.

[0058] (2) Lack of environmental dose assessment and standardized monitoring methods. In the clinical application of existing BNCT equipment, there is a lack of systematic assessment methods for the radiation dose levels of the treatment room environment (such as the operating position, outside the shielded door, and adjacent machine room). Current radiation protection design mainly relies on static shielding calculations and fails to fully consider the dynamic effects of neutron scattering caused by the patient's body, secondary radiation from activation products, and equipment leakage radiation during actual treatment.

[0059] (3) The measurement methods are cumbersome and inefficient, and cannot quickly reconstruct the three-dimensional dose distribution. Existing methods for measuring the whole-body dose in BNCT require setting up multiple measurement points (usually more than 6) and performing offline energy spectrum analysis using a high-purity germanium detector. The operation is cumbersome and time-consuming, making it difficult to integrate into daily clinical workflows. At the same time, the limited number of measurement points can only provide discrete dose data and cannot reconstruct the three-dimensional dose distribution;

[0060] (4) The BNCT field has not yet established a complete quality control system and lacks systematic verification methods for specific dose distribution. The accuracy of the calculation results is difficult to quantify and evaluate, which restricts the standardization and promotion of BNCT technology.

[0061] Therefore, as an emerging radiotherapy technology, BNCT still has significant technological gaps in areas such as whole-body dose assessment, treatment room environmental dose monitoring, and the establishment of a closed-loop quality control system, and cannot meet the clinical need for comprehensive dose assessment of "patient whole body + treatment room environment".

[0062] To at least address the aforementioned technical issues, this application proposes a system and method for assessing the systemic dose and environmental dose in BNCT treatment. This system and method can comprehensively assess the systemic and environmental doses during BNCT treatment and is a standardized method that is clinically operable, providing technical support for the clinical safety and standardized development of BNCT.

[0063] Figure 1 A schematic diagram of the architecture of the BNCT whole-body dose assessment system described in an embodiment of this application is shown. Figure 1 As shown, the BNCT whole-body dose assessment system includes an acquisition module 10, a characteristic plane module 20, a dose measurement module 30, an assessment factor module 40, and an assessment module 50.

[0064] The acquisition module 10 is configured to acquire image data and biological data to obtain the theoretical dose of BNCT systemic treatment based on the image data and biological data.

[0065] In some embodiments, the acquisition module 10 acquires image data obtained in advance through a positioning CT scan. This image data enables the acquisition of tissue density and anatomical structure information for dose calculation. The CT scan should cover at least the patient's head to the groin to ensure geometric integrity for subsequent whole-body dose assessment. Scan parameters may use conventional radiotherapy positioning standards, such as slice thickness of 1-3 mm and a matrix of 512×512.

[0066] In some embodiments, PET-CT is used to scan the irradiated subject, and the ratio of boron uptake of tumor to normal tissue is extracted from the scanned images as biological data; or stored boron uptake ratio data is retrieved from existing medical imaging databases or clinical case files as biological data.

[0067] Furthermore, the acquired medical imaging data and patient-related biological data are imported into the BNCT treatment planning system (TPS). The imaging data is used to create a three-dimensional anatomical model of the patient and delineate the tumor target area and organs at risk, while the biological data is used to characterize the distribution of boron drugs in different tissues and related dosimetric parameters. Based on this, the TPS uses the Monte Carlo (MC) algorithm to simulate the transport and interaction of neutrons and secondary gamma rays in human tissues, calculating the neutron flux, energy spectrum, and dose components in different tissue regions. Combined with boron concentration, tissue composition, and corresponding biological weighting factors, three-dimensional dose reconstruction is performed. Finally, a treatment plan that meets the requirements of target area dose coverage and normal tissue dose constraints is formulated, obtaining the whole-body neutron flux and dose distribution, including the target area, adjacent organs at risk, and other body regions—that is, the theoretical dose for whole-body BNCT treatment. The delineation of organs at risk should be determined according to the treatment site; for example, for head and neck BNCT, it should at least include the brainstem, optic nerve, and parotid gland.

[0068] Please continue reading. Figure 1 As shown, the feature plane module 20 is configured to select at least one measurement feature plane perpendicular to the neutron beam central axis along the direction of the neutron beam central axis, based on the theoretical dose of the BNCT systemic therapy.

[0069] In some embodiments, the feature plane module 20 extracts the percentage depth dose distribution curve along the central axis of the neutron beam from the theoretical dose of the BNCT whole-body treatment to determine key dose feature nodes; selects at least one feature plane perpendicular to the central axis of the neutron beam based on the depth position corresponding to the key dose feature node; and filters the measurement feature plane based on the dose spatial distribution parameters of the feature plane.

[0070] In some embodiments, the key dose feature nodes include at least a steeply descent region with the largest absolute value of the dose gradient and a distal dose plateau region. The steeply descent region with the largest absolute value of the dose gradient indicates the most drastic dose change with depth; this region is most sensitive to TPS modeling errors and is a key area of ​​focus for dose validation. The distal dose plateau region is a deep region where dose attenuation tends to level off, used to evaluate the integration accuracy of TPS under low dose rate conditions.

[0071] Furthermore, at the depth location corresponding to the key dose feature node, a cross section perpendicular to the central axis is selected as the feature plane.

[0072] For example, in a head and neck BNCT top-facing irradiation scenario, along the central axis, the depth position corresponding to the steep drop area often falls on the neck and chest level, while the depth position corresponding to the distal plateau area usually corresponds to the abdomen, knee level, and ankle level. Therefore, the depth position corresponding to the key dose feature node can be selected as the neck plane, chest plane, abdominal plane, knee plane, and ankle plane as feature planes.

[0073] In some embodiments, representative planes are selected as characteristic planes based on the dose spatial distribution parameters of the characteristic plane, such as off-axis ratio curves, isodose line distributions, and dose gradient distributions within the area covered by the plane.

[0074] For example, for a characteristic plane, its off-axis ratio curve, isodose line distribution, and dose gradient distribution within the plane's coverage area are extracted as corresponding dose spatial distribution parameters. The off-axis ratio curve is used to evaluate the radial dose homogeneity and effective measurement range of the plane. If the edge dose drops prematurely to a lower level than the central dose, it indicates that the effective measurement area of ​​the plane is narrow and should not be prioritized. The isodose line distribution is used to evaluate the relative positional relationship between different dose levels within the plane and the intersection line with the body surface. If a high-priority isodose line (such as the 50% isodose line) forms a continuous and sufficiently long arc with the intersection line with the body surface, it indicates that the plane has sufficient space for point placement and good dose variation coverage. The dose gradient distribution within the plane's coverage area is used to evaluate the richness of dose spatial variation within the plane. If there is a significant and continuous dose gradient variation region within the plane, it indicates that the plane has high validation representativeness; conversely, if the gradient distribution is uniform and gentle, the dosimetric representativeness of the plane is insufficient, and its priority is low.

[0075] In some embodiments, thresholds can be set for the above-mentioned indicators, and feature planes that do not meet the thresholds can be eliminated. This allows for a comprehensive consideration of these indicators, and prioritizes the selection of planes with a wide effective measurement range, sufficient isodose lines forming sufficient arc segments on the body surface, and significant spatial changes in dose gradient as subsequent measurement feature planes.

[0076] It is important to note that the measurement characteristic plane should include at least one characteristic plane located in the distal dose plateau region.

[0077] Please continue reading. Figure 1 As shown, the dose measurement module 30 is configured to determine at least one measurement point on the intersection line of the measurement feature plane and the body surface, and acquire the neutron response rate and γ absorbed dose at the at least one measurement point. In some embodiments, the intersection line of the measurement feature plane and the body surface refers to the spatial curve formed by the intersection of the feature plane (two-dimensional geometric plane) and the three-dimensional body surface contour (skin surface) of the patient. Determining the measurement point on the intersection line ensures that the subsequently acquired measurement data strictly corresponds to the theoretical dose within the feature plane in spatial geometry, that is, the measured value is compared with the calculated value only in a two-dimensional plane, avoiding additional errors introduced by spatial misalignment.

[0078] Furthermore, when determining at least one measurement point on the intersection line of the measurement feature plane and the body surface, priority should be given to selecting intersection line segments that are flat areas of skin, far from the chest, abdomen, and joint areas, and maintain a sufficient safe distance from the edge of the fixation device, and then selecting the measurement point from these segments. In practice, the selection of measurement points should be both safe and feasible. For example, the measurement point should be located in an area with gentle changes in the curvature of the body surface, ensuring that there is no air gap between the sensitive surface of the detector placed at the measurement point and the skin surface, thus guaranteeing the coupling efficiency and measurement accuracy of the detector. The measurement point should also be far from areas with significant respiratory movement and joints (such as the shoulder, elbow, and knee) to avoid the detector's position deviating from the measurement feature plane due to breathing or minor limb movements, thereby causing spatial mismatch between measurement and calculated data. In addition, the measurement point should avoid the coverage areas or mechanical locking positions of patient fixation devices such as thermoplastic films, vacuum bags, and head, neck, and shoulder frames, ensuring that the detector can be installed without obstruction and without interfering with the patient's fixed position during treatment.

[0079] It should be noted that the above measurement point selection principle only describes the process of determining the measurement points. It does not perform any physical "selection" or "marking" operation on the irradiated object. Instead, it directly receives the determined measurement point location data for subsequent processing.

[0080] Once measurement points are identified on the body surface, data can be obtained during the detector retrieval phase by reading data from pre-deployed detectors. For example, measured neutron reaction rates and gamma absorbed dose data at key locations can be obtained from pre-deployed detectors at each measurement point. This measured data will serve as "anchor points" for subsequent whole-body dose assessment, used to calibrate the deviation between the theoretical calculated TPS value and the patient's actual radiation dose, thereby assessing and verifying individualized doses after treatment and accurately quantifying the cumulative whole-body radiation risk.

[0081] In some embodiments, at least one neutron reaction rate corresponding to each of the measurement points can be obtained from at least one neutron detector pre-placed at each measurement point, and the γ absorbed dose corresponding to the measurement point can be obtained based on the placed γ dosimeter.

[0082] For example, the neutron reaction rate can be obtained by pre-placed activation foil, such as gold foil, indium foil, or nickel foil, at the measurement point. The activation foil is sensitive to neutrons; upon neutron irradiation, it produces a radioactive nuclide with a specific half-life, releasing characteristic gamma rays, which can be measured and analyzed using a gamma spectrometer. The size and thickness of the activation foil can be selected according to actual needs to balance detection sensitivity and self-shielding effect.

[0083] It should be noted that for the same measurement point, multiple neutron detectors with different energy response characteristics, such as activated foils, can be pre-deployed simultaneously. The nuclear reaction cross-sections of each detector vary with neutron energy, thus resulting in different response sensitivities to different energy regions, such as thermal neutrons, hyperthermal neutrons, and fast neutrons. In this case, the neutron reaction rate of each detector at the measurement point should be obtained separately to characterize the local neutron field from different energy ranges. Furthermore, by combining the known reaction cross-sections of each detector, the neutron energy spectrum at the measurement point or the neutron flux distribution in different energy regions can be estimated.

[0084] In some embodiments, the gamma absorbed dose at the measurement point is obtained by a gamma-ray dosimeter that is sensitive to gamma rays and is placed at the measurement point, such as a thermoluminescent dosimeter (TLD), an optically luminescent dosimeter (OSL), or a semiconductor detector.

[0085] Furthermore, measured data were obtained by reading the aforementioned detector. The recovered activated foil was placed on a gamma-ray spectrometer (such as a high-purity germanium detector) for energy spectrum measurement. By analyzing the area of ​​the characteristic gamma-ray peaks, combined with the detector efficiency calibration curve and decay correction, the neutron reaction rate R of the activated foil at that measurement point during irradiation was calculated. meas Simultaneously, the gamma dosimeter is fed into the corresponding reader for measurement, and based on its dose response curve, the measurement signal is converted into the gamma absorbed dose Dγmeas at the measurement point.

[0086] When multiple neutron detectors with different energy response characteristics are simultaneously deployed at the same measurement point, the neutron reaction rate of the j-th type of neutron detector at that measurement point is obtained. .

[0087] It should be noted that the above process of obtaining neutron reaction rate and gamma absorbed dose is a numerical processing of the electrical signals (energy spectrum peak area, dosimeter reading) of the pre-deployed detectors, and does not involve any physical intervention on the living human body.

[0088] Please continue reading. Figure 1 As shown, the evaluation factor module 40 is configured to acquire neutron evaluation factors and γ-dose evaluation factors for each measurement point based on the neutron response rate and the γ-absorbed dose at each measurement point. In some embodiments, the evaluation factor module 40 can acquire the theoretical γ-absorbed dose value at the same location as each measurement point within the measurement characteristic plane based on the theoretical dose of BNCT systemic therapy. And calculate its value compared with the γ absorbed dose obtained by actual measurement in step S2. The ratio of the two values ​​is used as the γ dose assessment factor N for the corresponding measurement point. γ .

[0089] Figure 2 A schematic diagram illustrating the workflow of the evaluation factor module described in an embodiment of this application is shown. Figure 2 As shown, the workflow of the evaluation factor module 40 includes steps S41 to S44.

[0090] S41. Extract the theoretical neutron flux corresponding to each measurement point from the theoretical dose of the BNCT systemic treatment.

[0091] S42. Based on at least one neutron detector deployed at each of the measurement points, obtain the corresponding macroscopic neutron reaction cross section.

[0092] S43. Based on the macroscopic neutron reaction cross section, the theoretical neutron flux, and the volume of the neutron detector, calculate at least one neutron reference reaction rate at each measurement point.

[0093] S44. Obtain the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the neutron reaction rate.

[0094] In some embodiments, after obtaining the theoretical dose for BNCT systemic therapy, the corresponding theoretical neutron flux can be obtained based on selected measurement points. Then, for each measurement point, it is necessary to know the reaction rate that the neutron detector "should" measure at that location under the calculated theoretical neutron flux conditions, i.e., the neutron reference reaction rate R. sim Furthermore, based on the measured R values ​​at each measurement point...meas With the obtained neutron reference reaction rate R sim Calculations are performed to obtain the neutron evaluation factor for each of the measurement points.

[0095] Similarly, if multiple detectors are pre-positioned at the same measurement point, the neutron reference response rates of all detectors should also be obtained. Furthermore, based on the neutron reaction rate of the j-th detector at each measurement point... The neutron reference reaction rate of the j-th detector was obtained. Calculations are performed to obtain the neutron evaluation factor for each of the measurement points.

[0096] In some embodiments, when multiple neutron detectors are pre-deployed at the measurement point, the workflow of the evaluation factor module includes steps S100 to S104.

[0097] S100. Extract the theoretical neutron flux distribution of each of the measured characteristic planes from the theoretical dose of the BNCT systemic treatment, and divide the theoretical neutron flux distribution into energy regions to obtain the theoretical neutron flux distribution of each of the measured characteristic planes in different energy regions.

[0098] S101. Based on the theoretical distribution of neutron flux in the energy division region of each of the measurement characteristic planes, obtain the theoretical neutron flux in the thermal neutron region, the theoretical neutron flux in the ultrathermal neutron region, and the theoretical neutron flux in the fast neutron region of each measurement point.

[0099] S102. Based on the various neutron detectors deployed at each measurement point, query and obtain the macroscopic neutron reaction cross section in the thermal neutron region, ultrathermal neutron region, and fast neutron region.

[0100] S103. For each type of neutron detector, the theoretical neutron flux of the thermal neutron region, the theoretical neutron flux of the ultrathermal neutron region, and the theoretical neutron flux of the fast neutron region are multiplied by the macroscopic neutron reaction cross section of the corresponding energy region and summed, and then multiplied by the volume of the neutron detector to obtain the corresponding neutron reference reaction rate.

[0101] S104. Obtain the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the neutron reaction rate.

[0102] The theoretical distribution of neutron flux in the energy division region includes the theoretical distribution of neutron flux in the thermal neutron region, the theoretical distribution of neutron flux in the ultrathermal neutron region, and the theoretical distribution of neutron flux in the fast neutron region.

[0103] In some embodiments, the theoretical neutron flux distribution at each characteristic plane is derived from the TPS and divided into three energy regions according to neutron energy: thermal neutron region (E < 0.5 eV), ultrathermal neutron region (0.5 eV ≤ E < 10 keV), and fast neutron region (E ≥ 10 keV), thereby obtaining the theoretical neutron flux distribution of each energy region within each characteristic plane. The neutron flux value of each energy region is expressed as the number of neutrons per unit area per unit time (n / cm² / s).

[0104] After extracting the theoretical distribution of neutron flux in the energy division region of each of the aforementioned measurement characteristic planes, the theoretical neutron flux in the energy division region of each measurement point can be obtained based on this theoretical distribution, including the theoretical neutron flux Φ in the thermal neutron region. th Theoretical neutron flux Φ in the superheated neutron region epi Theoretical neutron flux Φ in the fast neutron region fast For the j-th type of neutron detector placed at a measurement point, the corresponding neutron reference response rate is... As shown in equation (1).

[0105]

[0106] in, , , V represents the macroscopic cross-section of the j-th detector in each energy region (thermal neutron, ultrathermal neutron, fast neutron); j Let be the volume of the j-th type of activated foil.

[0107] Among them, for the macroscopic section, there are = N A × ρ × σ / M. Where N A ρ is Avogadro's constant; ρ is the material density (commonly measured in g / cm³). 3 M represents the molar mass of the material (commonly expressed in g / mol); the microscopic cross-section σ can be obtained from public kernel databases such as ENDF / B and JENDL.

[0108] Furthermore, when obtaining the neutron reference rate Then, the neutron reaction rate of the j-th detector can be obtained from the actual measurements at each measurement point. Neutron reference reaction rate with the j-th detector The neutron evaluation factor of the energy region at each measurement point is calculated and obtained.

[0109] For example, if multiple activated foils (such as gold foil, manganese foil, and aluminum foil, m ≥ 3) are simultaneously deployed as neutron detectors at a measurement point, since different activated foils have different response sensitivities to neutrons in different energy regions, the individual normalization factor for each energy region can be obtained by solving the following set of equations:

[0110]

[0111] Wherein, the left side of the equation represents the neutron reaction rate corresponding to the m types of detectors at the measurement point. In the right side of the equation , , , , , All are known, only N th N epi N fast The value is unknown. When m ≥ 3, the system of equations can be solved, yielding the neutron assessment factor N in the thermal neutron region. th Neutron assessment factor N in the superheated neutron region epi And fast neutron region neutron assessment factor N fast .

[0112] In some embodiments, if only a single type of neutron detector is used at a measurement point, then there should be only one neutron reference response rate. Neutron reaction rate At this point, it is impossible to distinguish individual deviations in each energy region; therefore, the neutron reference reaction rate must be used. Neutron reaction rate Calculate and obtain the neutron evaluation factor N total As shown in equation (2).

[0113]

[0114] This embodiment assumes that the TPS calculation deviation trend is consistent across different energy regions, thus making it a feasible simplification when measurement conditions are limited.

[0115] It should be noted that when only one type of neutron detector is placed at a measurement point, the corresponding neutron reference response rate is... The calculation is still performed using equation (1).

[0116] Please continue reading. Figure 1 As shown, the evaluation module 50 is configured to evaluate the theoretical dose of the BNCT systemic treatment based on the neutron evaluation factor and the γ dose evaluation factor at each of the measurement points, so as to obtain the BNCT systemic treatment evaluation dose.

[0117] In some embodiments, for each measurement point selected by the feature plane module 20, the corresponding γ dose evaluation factor N is obtained through the evaluation factor module 40. γ And the neutron evaluation factor N in the energy division region th N epiN fast or total N total At this point, the theoretical dose of BNCT systemic treatment obtained from the theoretical calculation of module 10 is evaluated using assessment factors to obtain the assessment dose of BNCT systemic treatment.

[0118] Figure 3 A schematic diagram illustrating the workflow of the evaluation module described in an embodiment of this application is shown. Figure 3 As shown, the workflow of the evaluation module 50 specifically includes steps S50 to S54.

[0119] S50. Extract the theoretical neutron equivalent dose value and the theoretical γ absorption dose value of all voxel points in each of the measurement characteristic planes from the theoretical dose of the BNCT systemic treatment.

[0120] S51. Based on each of the neutron evaluation factors and the γ dose evaluation factors, determine the neutron evaluation field and the γ dose evaluation field corresponding to each of the voxel points.

[0121] S52. Evaluate the theoretical neutron equivalent dose value of the corresponding voxel point based on each of the neutron evaluation fields to obtain the neutron equivalent evaluation dose of each voxel point.

[0122] S53. Evaluate the theoretical dose value of γ absorption at the corresponding voxel point based on each of the γ dose evaluation fields to obtain the γ absorption evaluation dose value of each voxel point.

[0123] S54. Obtain the BNCT systemic treatment assessment dose based on the neutron equivalent assessment dose and the γ absorption assessment dose value of each voxel point.

[0124] In some embodiments, the evaluation module 50 can extend the neutron evaluation factor and the gamma dose evaluation factor to all voxel points throughout the patient's body through spatial interpolation or partition assignment, and obtain the neutron evaluation field N corresponding to the energy region of each voxel point (x,y,z). th (x,y,z), N epi (x,y,z), N fast (x,y,z) or total N total (x,y,z), and N γ (x,y,z).

[0125] Then, using the neutron evaluation field N th (x,y,z), N epi (x,y,z), N fast (x,y,z) or total N total (x,y,z) represents the theoretical neutron equivalent dose value for the corresponding voxel point (x,y,z). An evaluation was performed to obtain the neutron equivalent assessment dose for each of the stated voxel points (x, y, z). As shown in equation (3).

[0126]

[0127] in, Including the neutron evaluation field N in the energy division region th (x,y,z), N epi (x,y,z), N fast (x,y,z), or total N total (x,y,z).

[0128] Simultaneously, the field N was assessed using gamma dose. γ The theoretical γ-absorbed dose value for the corresponding voxel point (x,y,z) An evaluation was performed to obtain the γ-absorbance assessment dose values ​​for each of the stated voxel points (x, y, z). As shown in equation (4).

[0129]

[0130] Finally, the neutron equivalent of the i-th voxel is used to assess the dose. Compared with γ absorption assessment dose value After multiplying by their respective RBE weights, the total bioequivalent dose of the i-th voxel point in the whole body is obtained, as shown in Equation (5).

[0131]

[0132] In some embodiments, the evaluation module 50 determines the neutron evaluation field and the gamma dose evaluation field corresponding to each voxel point based on each of the neutron evaluation factors and the gamma dose evaluation factors, including: obtaining body surface partitions and corresponding each body surface partition with the nearest measurement point, so that the neutron evaluation factor and the gamma dose evaluation factor of the measurement point are respectively used as the neutron evaluation field and the gamma dose evaluation field of each voxel point in the corresponding body surface partition.

[0133] Specifically, for each voxel point (x, y, z), based on the spatial relationship between the voxel point and each measurement point, the neutron evaluation field and the gamma dose evaluation field of each voxel point throughout the body can be obtained through partition assignment. For example, the patient's body surface is divided into several body surface partitions, and each partition is associated with the nearest measurement point. Each region is represented by a nearest measurement point, and all voxel points within that region use the neutron evaluation factor and gamma dose evaluation factor of that measurement point as their neutron evaluation field and gamma dose evaluation field, respectively.

[0134] In some embodiments, the evaluation module 50 determines the neutron evaluation field and the γ dose evaluation field corresponding to each voxel point based on each of the neutron evaluation factors and the γ dose evaluation factors, respectively, by: performing spatial interpolation on the neutron evaluation factors and the γ dose evaluation factors based on the spatial coordinates of each measurement point, so as to obtain the neutron evaluation field and the γ dose evaluation field corresponding to each voxel point.

[0135] For each voxel (x, y, z), based on the spatial relationship between the voxel and each measurement point, the neutron evaluation field and the gamma dose evaluation field for each voxel throughout the body can be obtained through spatial interpolation. For example, based on the neutron evaluation factor, gamma dose evaluation factor, and their spatial coordinates at each measurement point, these discrete measurement results are used as spatial constraint points. Linear interpolation and inverse distance weighting are then employed to estimate the neutron evaluation factor and gamma dose evaluation factor at other locations throughout the body where no detectors are deployed. Voxels closer to a measurement point are generally more significantly affected by the factors at that measurement point. By performing interpolation calculations on all voxel points throughout the body, the discrete normalized factors at a finite number of measurement points can be extended into a three-dimensional neutron evaluation field and gamma dose evaluation field that continuously vary with spatial position.

[0136] In some embodiments, the system provided in this application further includes an output module for quality control evaluation, forming a closed loop of "planning-measurement-calibration-evaluation". In the prior art, BNCT dose calculation lacks quantitative evaluation methods for the evaluation and verification process itself, making it impossible to determine whether the evaluation and verification results are within a reasonable range. This application evaluates the reasonableness by analyzing the distribution characteristics of the neutron evaluation factor and the gamma dose evaluation factor, and triggers an alarm when an anomaly occurs.

[0137] The output module is configured to determine whether the neutron evaluation factor and / or the gamma dose evaluation factor are in an abnormal range; if so, an abnormality prompt message is output; if not, the BNCT systemic treatment evaluation dose is output; and / or to obtain a heatmap showing the difference between the theoretical dose distribution and the evaluation dose distribution of BNCT systemic treatment, wherein the heatmap uses different color levels to indicate the magnitude of the evaluation difference; if the magnitude of the evaluation difference exceeds a preset range, an abnormality prompt message is output; if not, the BNCT systemic treatment evaluation dose is output.

[0138] In some embodiments, under normal circumstances, due to the high accuracy of the Monte Carlo algorithm of TPS, the neutron assessment factor and the gamma dose assessment factor should fluctuate within a reasonable range, for example, between 0.8 and 1.2. If the neutron assessment factor and the gamma dose assessment factor are within this range, it indicates that the theoretical calculation deviation of TPS is small, the assessment of S4 is of a fine-tuning nature, and the assessment result is reliable. If there is a significant deviation from 1 (e.g., N < 0.8 or N > 1.2), it indicates that there is a large systematic deviation in the theoretical calculation of TPS. Possible reasons include: the patient's position does not match the assumptions made during TPS modeling, abnormal boron concentration distribution, collimator position offset, etc. In this case, an abnormality prompt message needs to be output to remind the patient to re-examine the treatment parameters or TPS model.

[0139] In some embodiments, the dose difference or relative deviation at each spatial location is calculated by comparing the theoretical dose distribution of BNCT systemic treatment with the dose distribution of BNCT systemic treatment obtained after evaluation based on measured data, and a difference heatmap is generated accordingly to visually display the dose evaluation difference range in different regions of the body using different color levels. When the evaluation difference range corresponding to any voxel, target region, or preset statistical indicator exceeds a preset threshold, it is determined that there is an abnormal deviation between the theoretical dose and the evaluated dose, and a corresponding abnormal prompt message is output; if the evaluation differences are all within the preset allowable range, it is considered that the theoretical dose and the measured evaluation correction result have good consistency, and the BNCT systemic treatment evaluation dose distribution is output.

[0140] Figure 4 A schematic flowchart of a systemic method for assessing the whole-body dose of BNCT according to another embodiment of this application is shown. Figure 4 As shown, firstly, image and biological data are acquired, and the theoretical dose for BNCT systemic treatment is calculated using TPS. Then, a measurement characteristic plane and measurement points are selected, and the theoretical neutron equivalent dose and theoretical gamma absorption dose values ​​for all voxel points within the measurement characteristic plane are obtained. Next, the neutron reaction rate and gamma absorption dose at the measurement points are acquired. Simultaneously, the neutron reference reaction rate for each measurement point is obtained based on the theoretical distribution of neutron flux in the energy division region, and a neutron evaluation factor for each measurement point is obtained based on the neutron reference reaction rate and neutron reaction rate. Similarly, the gamma dose evaluation factor for each measurement point is obtained based on the measured gamma absorption dose and the theoretical gamma absorption dose value in the off-axis dose field data. Then, the theoretical gamma absorption dose value for each voxel point within the measurement characteristic plane is evaluated based on the gamma dose evaluation factor to obtain the gamma absorption evaluation dose value, and the theoretical neutron equivalent dose value for each voxel point within the measurement characteristic plane is evaluated based on the neutron evaluation factor to obtain the neutron equivalent evaluation dose. In addition, the systemic treatment assessment dose of the BNCT is output based on the neutron assessment factor and / or the gamma dose assessment factor.

[0141] This application also provides a method for assessing the systemic dose of BNCT, which uses the BNCT systemic dose assessment system described in the above embodiments to obtain the BNCT systemic treatment assessment dose. The method directly outputs calibrated dose distribution data and a dose assessment report, which are data information.

[0142] This application also provides a method for assessing environmental dose in a treatment room. The method includes the following steps: obtaining a BNCT systemic treatment assessment dose; using the BNCT systemic treatment assessment dose as a radiation source term, and obtaining an environmental assessment dose based on the radiation source term and environmental geometric parameters.

[0143] In some embodiments, treatment room environmental dose assessment is typically estimated using standard source terms or uniform phantoms, which cannot reflect the actual radiation output of a specific patient under specific treatment conditions. This method uses the BNCT whole-body treatment assessment dose as the radiation source term and combines it with the geometric parameters of the treatment room environment for extrapolation, thereby achieving personalized assessment of treatment room environmental dose.

[0144] Specifically, the BNCT whole-body dose assessment system provided in the above embodiments can be used to obtain the BNCT whole-body treatment assessment dose as a radiation source item. The assessed whole-body three-dimensional dose distribution D... total (x, y, z) represents the neutron and gamma doses of each voxel within the patient's body. This distribution reflects the actual radiation intensity and spatial distribution characteristics of the patient as a radiation source during this treatment, including:¹ within the patient's body 0 B(n,α) 7 The scattering distribution within the patient's body includes the transient gamma rays generated by the Li reaction, the 2.22 MeV secondary gamma rays generated by hydrogen neutron capture, and the primary gamma rays leaking from the beam shaping component. Therefore, compared to the assumptions of using a standard source term or a uniform phantom in traditional methods, using the BNCT whole-body treatment assessment dose as the radiation source term more accurately reflects the true radiation output of an individual patient.

[0145] In some embodiments, obtaining the environmental assessment dose of the treatment room based on the radiation source term and environmental geometric parameters includes: obtaining a target location within the treatment room, the target location including an unshielded location and a shielded location; obtaining the distance and direction of the target location relative to the radiation source term; when the target location is an unshielded location, obtaining the radiation dose at the target location based on the radiation dose in the direction and the distance; when the target location is a shielded location, obtaining the radiation dose at the target location based on the radiation dose in the direction, the distance, and the exponential attenuation factor of the shielding material.

[0146] For example, based on the radiation source term and combined with the geometric parameters of the treatment room environment (such as the distance and obstruction relationship between the patient's position and the operating position, the accompanying person's position, and the shielding wall), the dose level at each key location in the treatment room is obtained. The specific method is as follows:

[0147] (1) Obtain the target location within the treatment room, which includes unshielded locations and shielded locations. Unshielded locations refer to places within the treatment room that are not shielded, including but not limited to operating positions (the location of the staff's control console) and accompanying positions (the location of the patient's family members or observers); shielded locations refer to places outside the shielding wall of the treatment room, including but not limited to corridors outside the shielding wall, adjacent rooms, and external environmental monitoring points.

[0148] (2) For unshielded positions such as the operating position and the accompanying position, the dose level mainly depends on the distance from the patient's body surface. Taking the assessed gamma dose distribution on the patient's body surface as the source term, each local position on the patient's body surface is regarded as a series of point radiation sources. For any unshielded position in the treatment room, its dose rate is estimated by the inverse square law of distance attenuation: that is, the dose rate at this position is equal to the dose rate on the body surface in the corresponding direction multiplied by the square of the ratio of the reference distance to the distance (the distance between the target position and the radiation source point). In addition, if the difference in dose rate in different directions on the patient's body surface during irradiation is considered, an angle correction factor can be further introduced. According to the angle between the calculation point and the normal of the patient's body surface, the corresponding dose rate value of the body surface in the corresponding direction is called to participate in the calculation. Among them, the reference distance refers to the distance between the reference point outside the body surface (the position of the actual output dose rate) and the radiation source point (or equivalent point source), which is usually set to 0.3m.

[0149] (3) For the location outside the shielding wall, i.e., the shielding position, based on the above-mentioned distance attenuation, the attenuation effect of the shielding material on γ-rays is further considered. In fact, when γ-rays penetrate shielding materials such as concrete, boron-containing polyethylene, and lead, their intensity attenuates exponentially, and the degree of attenuation depends on the product of the linear attenuation coefficient and the thickness of the material. Therefore, when calculating the γ-ray dose at the shielding position, the dose rate obtained by the inverse square distance attenuation is multiplied by the exponential attenuation factor of each layer of shielding material. Furthermore, if the shielding wall is composed of multiple layers of different materials, the attenuation factors of each layer are multiplied sequentially to obtain the final dose rate after penetration of the shield.

[0150] (4) After obtaining the dose rates of the shielded and unshielded positions, the corresponding γ dose can be calculated based on the irradiation time or the time the operator stays at the corresponding position.

[0151] In summary, this application integrates "lightweight experimental calibration, whole-body dose assessment and quality control closed-loop feedback" for BNCT whole-body dose and environmental dose assessment, realizing a paradigm shift from "local target area calculation" to "panoramic dose verification".

[0152] First, this application breaks through the limitation of "disconnect between planned calculation and actual irradiation" in traditional BNCT dose assessment. Based on the spatial interpolation or partitioning mechanism of multi-measurement point data, the dose of each body element can be assessed and calibrated, providing a basis for the quantitative verification of the irradiation dose of each part of the body.

[0153] Secondly, this application overcomes the bottleneck of BNCT in rapidly obtaining whole-body dose distribution in complex anatomical environments. It can quickly reconstruct the whole-body dose field through a small number of measurement points, which greatly reduces the threshold for clinical implementation and makes whole-body dose assessment feasible for routine clinical applications.

[0154] Furthermore, this application establishes a complete physical quality control chain of "measurement-calculation-verification", which can determine the reliability of the calibration process and trigger alarms when abnormalities occur, thereby providing a quantifiable quality control standard for whole-body dose assessment of BNCT and making up for the lack of standardized verification procedures in the field of BNCT.

[0155] Finally, this application not only completed the assessment of the patient's whole-body dose, but also extended the assessment scope to the treatment room environment, thereby providing a quantitative basis for radiation protection optimization and occupational exposure management, filling the technical gap in BNCT environmental dose assessment.

[0156] The scope of protection of the BNCT systemic dose and treatment room environmental dose assessment method of this application embodiment is not limited to the execution order of the steps listed in this embodiment; each step can be executed according to the corresponding data acquisition and processing conditions without changing the data dependency relationship between the steps.

[0157] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0158] The above embodiments are used to illustrate the principles and effects of this application, and are not intended to limit this application. Equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application shall still be covered by the claims of this application.

Claims

1. A system for assessing the systemic dose of BNCT, characterized in that, The system includes: The acquisition module is configured to acquire image data and biological data to obtain the theoretical dose of BNCT systemic therapy based on the image data and biological data; The feature plane module is configured to select at least one measurement feature plane perpendicular to the neutron beam central axis along the direction of the neutron beam central axis, based on the theoretical dose of the BNCT whole-body treatment. The dose measurement module is configured to determine at least one measurement point on the intersection of the measurement feature plane and the body surface, and to acquire the neutron reaction rate and γ absorbed dose of the at least one measurement point; The evaluation factor module is configured to obtain neutron evaluation factors and γ dose evaluation factors for each of the measurement points based on the neutron reaction rate and the γ absorbed dose at each of the measurement points. The evaluation module is configured to evaluate the theoretical dose of the BNCT systemic treatment based on the neutron evaluation factor and the gamma dose evaluation factor at each of the measurement points, so as to obtain the BNCT systemic treatment evaluation dose.

2. The BNCT systemic dose assessment system according to claim 1, characterized in that, Also includes: The feature plane module extracts the percentage depth dose distribution curve along the central axis of the neutron beam from the theoretical dose of the BNCT whole-body treatment to determine key dose feature nodes; the key dose feature nodes include at least the steep drop region with the largest absolute value of the dose gradient and the distal dose plateau region; The feature plane module selects at least one feature plane perpendicular to the neutron beam central axis based on the depth position corresponding to the key dose feature node; The feature plane module selects the measurement feature plane based on the dose space distribution parameters of the feature plane.

3. The BNCT systemic dose assessment system according to claim 1, characterized in that, Also includes: The evaluation factor module extracts the theoretical neutron flux corresponding to each measurement point from the theoretical dose of the BNCT systemic treatment; The evaluation factor module queries and obtains the corresponding macroscopic neutron reaction cross section based on at least one neutron detector deployed at each measurement point; The evaluation factor module calculates at least one neutron reference reaction rate at each measurement point based on the neutron macroscopic reaction cross section, the theoretical neutron flux, and the volume of the neutron detector. The evaluation factor module obtains the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the corresponding neutron reaction rate.

4. The BNCT systemic dose assessment system according to claim 1, characterized in that, Also includes: The evaluation factor module extracts the theoretical neutron flux distribution of each measurement characteristic plane from the theoretical dose of the BNCT systemic therapy, and divides the theoretical neutron flux distribution into energy regions to obtain the sub-energy region theoretical neutron flux distribution of each measurement characteristic plane; wherein, the sub-energy region theoretical neutron flux distribution includes the theoretical neutron flux distribution of the thermal neutron region, the theoretical neutron flux distribution of the hyperthermal neutron region, and the theoretical neutron flux distribution of the fast neutron region; The evaluation factor module obtains the theoretical neutron flux of the thermal neutron region, the theoretical neutron flux of the hyperthermal neutron region, and the theoretical neutron flux of the fast neutron region at each measurement point based on the theoretical distribution of neutron flux in the energy division region of each measurement feature plane. The evaluation factor module obtains the macroscopic neutron reaction cross sections in the thermal neutron region, the ultrathermal neutron region, and the fast neutron region based on the corresponding queries of various neutron detectors deployed at each measurement point. For each type of neutron detector, the evaluation factor module multiplies the theoretical neutron flux in the thermal neutron region, the theoretical neutron flux in the ultrathermal neutron region, and the theoretical neutron flux in the fast neutron region by the macroscopic neutron reaction cross section of the corresponding energy region, sums them, and then multiplies them by the volume of the neutron detector to obtain the corresponding neutron reference reaction rate. The evaluation factor module obtains the neutron evaluation factor for each measurement point based on the neutron reference reaction rate and the neutron reaction rate.

5. The BNCT systemic dose assessment system according to claim 1, characterized in that, Also includes: The evaluation module extracts the theoretical neutron equivalent dose value and the theoretical γ absorption dose value of all voxel points in each of the measurement feature planes from the theoretical dose of the BNCT systemic treatment. The evaluation module determines the neutron evaluation field and the gamma dose evaluation field corresponding to each voxel point based on each of the neutron evaluation factors and the gamma dose evaluation factors, respectively. The evaluation module evaluates the theoretical neutron equivalent dose value of the corresponding voxel point based on each neutron evaluation field to obtain the neutron equivalent evaluation dose of each voxel point. The evaluation module evaluates the theoretical dose value of γ absorption at the corresponding voxel point based on each γ dose evaluation field to obtain the γ absorption evaluation dose value at each voxel point. The evaluation module obtains the BNCT systemic treatment evaluation dose based on the neutron equivalent evaluation dose and the γ absorption evaluation dose value of each voxel point.

6. The BNCT systemic dose assessment system according to claim 5, characterized in that, Also includes: The evaluation module acquires body surface partitions and associates each body surface partition with the nearest measurement point, so that the neutron evaluation factor and the gamma dose evaluation factor of the measurement point are respectively used as the neutron evaluation field and the gamma dose evaluation field of each voxel point in the corresponding body surface partition.

7. The BNCT systemic dose assessment system according to claim 5, characterized in that, Also includes: The evaluation module performs spatial interpolation on the neutron evaluation factor and the gamma dose evaluation factor based on the spatial coordinates of each measurement point to obtain the neutron evaluation field and the gamma dose evaluation field corresponding to each voxel point.

8. The BNCT systemic dose assessment system according to claim 1, characterized in that, The system also includes an output module: The output module is configured to determine whether the neutron evaluation factor and / or the gamma dose evaluation factor are in an abnormal range; If yes, an error message is output; otherwise, the BNCT systemic treatment assessment dose is output; and / or a heatmap showing the difference between the theoretical dose distribution and the assessed dose distribution of BNCT systemic treatment is obtained, wherein the heatmap uses different color levels to indicate the magnitude of the assessment difference; if the magnitude of the assessment difference exceeds a preset range, an error message is output; otherwise, the BNCT systemic treatment assessment dose is output.

9. A method for assessing the systemic dose of BNCT, characterized in that, The method utilizes the BNCT systemic dose assessment system as described in any one of claims 1 to 8 to obtain the BNCT systemic treatment assessment dose.

10. A method for assessing environmental dosage in a treatment room, characterized in that, The method includes: The system according to any one of claims 1 to 8 is used to obtain the BNCT systemic treatment assessment dose; The BNCT systemic treatment assessment dose is used as a radiation source term to obtain the treatment room environmental assessment dose based on the radiation source term and environmental geometric parameters.

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