X-ray blood irradiator calibration device and calibration method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG INSTITUTE OF QUALITY SCIENCES
- Filing Date
- 2025-07-29
- Publication Date
- 2026-06-02
Smart Images
Figure CN120643771B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of medical device technology, specifically an X-ray blood irradiation instrument calibration device and calibration method. Background Technology
[0002] Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious complication with a mortality rate as high as 90%. Blood irradiation is a commonly used clinical method for processing blood and blood components, using X-rays to inactivate immune-active T lymphocytes in the blood. The accuracy of the X-ray irradiation dose and the dose uniformity of the entire radiation field directly affect the inactivation effect and thus the quality of transfusion. Therefore, accurate measurement of irradiation dose and dose uniformity by X-ray blood irradiators is crucial. However, due to the need for rotation during irradiation, the small measurement chamber leading to difficulties in dynamic irradiation field measurement, and challenges in data transmission and signal loss, current methods often rely on chemical dosimeters and film for measurement. This results in excessively large errors in irradiation dose and dose uniformity, and even inconsistencies between methods used by different manufacturers, making it impossible to achieve consistency across different devices.
[0003] Current technologies still have several problems: Ionization chamber measurement methods cannot solve the problems of dynamic irradiation field dose measurement, signal transmission, and excessively large host units; film dosimetry measurements lack repeatability, meaning the results are unreliable; chemical dosimeters suffer from poor mechanical stability, large positioning errors, high angle dependence, insufficient spatial resolution, and high sensitivity to temperature and humidity, and data readout depends on EPR spectrometers, resulting in irradiation dose measurement errors exceeding 10%. Furthermore, EPR spectrometers are expensive, leading to high costs. Therefore, existing technologies cannot accurately measure the irradiation dose and dose uniformity of X-ray blood irradiators. Summary of the Invention
[0004] To address the aforementioned problems in the existing technology, this application provides an X-ray blood irradiator calibration device and calibration method, solving the problem that existing X-ray blood irradiators cannot accurately measure irradiation dose and irradiation dose uniformity.
[0005] To achieve the above objectives, this application adopts the following technical solution: The first aspect provides a method for calibrating an X-ray blood irradiator, comprising the following steps:
[0006] After selecting and placing the blood equivalent phantom according to the target irradiation container, establish a connection between the detector and the blood equivalent phantom.
[0007] Move the detector to the reference point, set the nominal dose value for irradiation, read the absorbed dose value at the reference point and calculate the indication error. The reference point is the geometric center of the blood equivalent phantom.
[0008] Additionally, the moving detector sequentially acquires the absorbed dose values at the measurement points, selects a typical irradiation program, reads the absorbed dose values at each measurement point after irradiation, and calculates the uniformity of the absorbed dose of the target irradiation container. There are a total of 15 measurement points.
[0009] If the X-ray blood irradiator is a multi-container X-ray blood irradiator, then the corresponding blood equivalent phantom is placed inside the irradiation container, and the reference point of each irradiation container is used as the measurement point. After irradiation, the values are read based on the detector and the consistency of the absorbed dose values between each irradiation container is calculated.
[0010] When the X-ray blood irradiator is a multi-irradiation container X-ray blood irradiator, the calibration method also includes the following steps:
[0011] The corresponding blood equivalent phantoms were inserted into the irradiation containers respectively. The reference point of each irradiation container was used as the measurement point. After irradiation, the values were read by the detector and the consistency of the absorbed dose values between each irradiation container was calculated.
[0012] Determine whether it meets the consistency criteria; if it does, complete the calibration.
[0013] If it does not meet the requirements, adjust the irradiation parameters corresponding to each irradiation container and repeat the above steps until the consistency reaches the standard. The calibration of the X-ray blood irradiator is then complete.
[0014] The consistency of absorbed dose values among the irradiation containers is calculated based on the following formula:
[0015]
[0016] Where C represents the consistency of absorbed dose between irradiation containers, and D max D represents the maximum absorbed dose value of the irradiation container. min This is the minimum absorbed dose value for the irradiation container.
[0017] The process of reading the absorbed dose value at the reference point and calculating the indication error includes:
[0018] Set the nominal dose value to D0, and after irradiation is completed, read the absorbed dose D;
[0019] The error in the indicated value of the absorbed dose at the reference point is calculated using the following formula:
[0020]
[0021] Where ΔD is the absorbed dose error at the reference point; D0 is the nominal absorbed dose value at the reference point; and D is the absorbed dose value at the reference point.
[0022] The formula for calculating the uniformity of absorbed dose to the target irradiation container is as follows:
[0023]
[0024] Where Ci represents the uniformity of absorbed dose at each measurement point, i = 1, 2, ..., n; Di represents the absorbed dose value at each measurement point; and D represents the absorbed dose value at the reference point.
[0025] The maximum absolute value is taken as the uniformity of the irradiation container.
[0026] The second aspect provides an X-ray blood irradiator calibration apparatus, applicable to the X-ray blood irradiator calibration method as described in the first aspect, comprising:
[0027] The detector is equipped with a crystal probe and is connected to the detector host via a connecting cable. The connecting cable integrates a miniature photomultiplier tube, and the inner ring of the detector is equipped with a rotatable bearing for connecting to a blood equivalent phantom.
[0028] The detector host integrates a wireless transmission module and a wired transmission module, which are connected to the terminal software.
[0029] Blood equivalent phantoms include a first type of blood equivalent phantom for calibration of vertically placed irradiation containers and a second type of blood equivalent phantom for calibration of horizontally placed irradiation containers.
[0030] Among them, the first type of blood equivalent phantom is cylindrical, with five cylinders that penetrate the phantom at equal distances from the center and around the perimeter. The upper, middle and lower three points inside the cylinders are measurement points, for a total of 15 measurement points.
[0031] Among them, the second type of blood equivalent phantom is a transverse cylindrical shape with three through holes in the middle of its side, and the three points in the middle through hole are used as measurement points. Three through holes are also opened on each of the two sides, and the middle point of the through hole on each side is used as a measurement point, for a total of 15 measurement points.
[0032] The beneficial effects of this application are:
[0033] This application provides a calibration device and method for an X-ray blood irradiator, which can realize the measurement of dynamic blood irradiation dose and solve the problem that X-ray blood irradiators cannot measure irradiation dose;
[0034] A scintillator detector with high energy response and small size was developed based on LySo crystal. A radiation-resistant, small-volume signal receiver and offline data processing software were also developed, forming a measurement system suitable for X-ray blood irradiation instrument irradiation dose measurement. A calibration method for X-ray blood irradiation devices was proposed to solve the problem that existing X-ray blood irradiation instruments cannot accurately measure irradiation dose and irradiation dose uniformity.
[0035] Compared to existing coarse measurement methods, data transmission can be achieved without drilling holes in the measurement chamber, with a signal transmission loss rate of no more than 3%; the measurement results can be reproduced, making it more suitable for repeated measurements.
[0036] The selection of measurement points in the measurement method, combined with the rotational characteristics of blood irradiation, can cover both the maximum and minimum dose points, and can effectively evaluate the uniformity of blood irradiation dose. By introducing consistency parameters between blood cups in a multi-blood-cup irradiation device and proposing an evaluation method, the performance of different devices can be evaluated more comprehensively. Attached Figure Description
[0037] Figure 1 This is a schematic diagram of the calibration method for the X-ray blood irradiator in this application;
[0038] Figure 2 This is a schematic diagram of the X-ray blood irradiation calibration device of this application;
[0039] Figure 3 This is a schematic diagram of the structure of the first type of blood equivalent phantom of the X-ray blood irradiation calibration device of this application;
[0040] Figure 4 This is a top view of the first type of blood equivalent phantom of the X-ray blood irradiation calibration device of this application.
[0041] Figure 5 This is a schematic diagram showing the layout of the first type of blood equivalent phantom in the X-ray blood irradiation calibration device of this application.
[0042] Figure 6 This is a three-dimensional structural diagram of the second type of blood equivalent phantom of the X-ray blood irradiation calibration device of this application;
[0043] Figure 7 This is a schematic diagram showing the layout of the second type of blood equivalent phantom in the X-ray blood irradiation calibration device of this application.
[0044] Figure 8 This is a schematic diagram of another layout of the second type of blood equivalent phantom in the X-ray blood irradiation calibration device of this application;
[0045] In the diagram, 1—detector, 10—crystal probe, 2—detector host, 3—blood equivalent phantom, 31—first type of blood equivalent phantom, 32—second type of blood equivalent phantom, 4—connecting line. Detailed Implementation
[0046] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.
[0047] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0048] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0049] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0050] Example 1
[0051] like Figure 2 The X-ray blood irradiation calibration device shown includes: a detector 1, a detector host 2, a connecting cable 4 for connecting the detector 1 and the detector host 2, and a blood equivalent phantom 3.
[0052] Detector 1 uses a LySo crystal. Compared to the ionization chamber probe, detector 1 has a sensitive volume of less than 0.1 cm³. It is connected to the detector host 2 via an optical fiber (with an integrated miniature photomultiplier tube). The detector host 2 can store 50,000 measurement points, enabling the acquisition and integration of electrical signals from these points. It also integrates wireless and wired transmission modules, allowing communication with terminal software to ultimately achieve dose point acquisition and data analysis. Furthermore, the host is encased in lead to reduce radiation damage to electronic components in high-dose-rate radiation fields. The connecting cable 4 is wrapped in soft rubber and fixed to the designated measurement position on the blood equivalent phantom 3 via an inner rotatable bearing, thus achieving synchronous rotation of detector 1 and the blood equivalent phantom 3. This solves the problems of small measurement chamber, high irradiation chamber dose rate, dynamic irradiation dose measurement, and signal transmission loss.
[0053] To fix the probe in the blood equivalent phantom 3, the measurement points must first be determined. This technical solution mainly includes two types of blood equivalent phantoms 3. For example... Figure 3 , Figure 4 As shown, the equivalent phantom for the first type of blood is cylindrical with a cylindrical hole penetrating the top, suitable for detector size 1. It has a central opening and four equally spaced holes around the perimeter, with the center of each hole 10mm from the edge of the phantom. The center of the central hole's axial position serves as a reference point for radiation dose measurement. Within the cylinder with five openings, three points (top, middle, and bottom) are selected, for a total of 15 points, as measurement locations for dose distribution uniformity. The top and bottom measurement points are both 2cm from the surface. See the detailed point layout scheme below. Figure 5 There are 15 measurement points in the figure, of which the number "2" is the reference point.
[0054] like Figure 6 As shown, the second type of blood equivalent phantom 32 is a transverse cylindrical shape. Holes are drilled along the side of this type of phantom, with three through holes drilled in the middle, top, middle, and bottom of each side. The center of the top and bottom through holes is 10mm from the edge of the phantom. Three measurement points are selected for each of these three through holes, with the top and bottom points each 2cm from the surface. A total of 9 measurement points are selected for the three middle through holes. Three through holes are also drilled on each of the two sides (with the center of the through holes 10mm from the edge of the phantom), with the middle position of the through holes selected as the measurement point for each side, resulting in 6 measurement points. In summary, a total of 15 measurement points are selected. The specific point layout scheme is shown in [reference needed]. Figure 7 , Figure 8 There are 15 measurement points in the figure, of which the number "5" is the reference point.
[0055] Example 2
[0056] like Figure 1The X-ray blood irradiator calibration method shown is applied to the X-ray blood irradiator calibration device as shown in Example 1, and includes the following steps:
[0057] S1. After selecting and placing the blood equivalent phantom according to the irradiation container, establish a connection between the detector and the blood equivalent phantom.
[0058] The first type of cylindrical blood equivalent phantom is suitable for measuring dose distribution in the longitudinal depth direction and can well simulate the irradiation of blood in a relatively vertically placed cylindrical container. Through the design of the central hole and peripheral holes, the dose distribution at different positions in the longitudinal direction and around the periphery of the phantom can be comprehensively reflected. In particular, the reference point is set at the axial center of the central hole, which facilitates the benchmark measurement of dose and is very suitable for the calibration of conventional vertically placed irradiation containers.
[0059] The second type of transverse cylindrical blood equivalent phantom is suitable for simulating scenarios where blood is irradiated in a transversely placed container, and can focus on measuring the dose at different positions in the transverse direction. Through multiple through holes and measurement points on the side, the dose distribution in different directions such as up / down and left / right during transverse irradiation can be accurately obtained, compensating for the shortcomings of the first type of phantom in transverse measurement, and making it more suitable for calibrating transversely placed irradiation containers. The phantom is selected based on the placement of the blood container corresponding to the X-ray blood irradiator being calibrated. If the blood container is placed vertically during irradiation, the first type of phantom is preferred; if it is placed transversely, the second type of phantom is used.
[0060] S2. Move the detector to the reference point, set the nominal dose value for irradiation, read the absorbed dose value of the reference point and calculate the indication error. The reference point is the geometric center point of the blood equivalent phantom.
[0061] Measurement of reference point absorbed dose indication error: Place a matching blood equivalent phantom inside a sample container of a specific size and model, and select the geometric center point of the blood equivalent phantom as the reference point. Place the detector at the reference point in the blood equivalent phantom, set a typical irradiation program, and set the nominal dose value to D0. After irradiation, read the absorbed dose D, and calculate the indication error of the reference point absorbed dose according to the following formula:
[0062]
[0063] in, D is the absorbed dose error at the reference point; D0 is the nominal absorbed dose at the reference point, and D is the measured absorbed dose at the reference point.
[0064] S3. The moving detector sequentially acquires the absorbed dose values at the measurement points. After irradiating with a typical irradiation program, the absorbed dose values at each measurement point are read, and the uniformity of the absorbed dose of the target irradiation container is calculated. There are a total of 15 measurement points.
[0065] Measurement of absorbed dose uniformity: A sample container of a specific size and model was selected, and a matching blood equivalent phantom was placed inside. The detector was placed on a straight line parallel to the central axis, 1 cm from the phantom surface. The distance from the uppermost measurement point to the top surface of the phantom and the distance from the lowermost measurement point to the bottom surface of the phantom were both 2 cm. A total of 15 measurement points were established. A typical irradiation program was selected, and irradiation was performed. After irradiation, the absorbed dose values at each point were read. The absorbed dose uniformity at each point was calculated using the following formula, and the value with the largest absolute value was taken as the uniformity of the device:
[0066]
[0067] Where Ci represents the uniformity of absorbed dose at each measurement point, i = 1, 2, ..., n; Di represents the measured absorbed dose at each measurement point; and D represents the measured absorbed dose at the reference point.
[0068] S4. If the X-ray blood irradiator is a multi-irradiation container X-ray blood irradiator, then the corresponding blood equivalent phantom is placed inside the irradiation container, and the reference point of each irradiation container is used as the measurement point. After irradiation, the values are read based on the detector and the consistency of the absorbed dose values between each irradiation container is calculated.
[0069] When measuring blood using a multi-cup X-ray blood irradiator, the consistency of absorbed dose between the cups also needs to be considered. A blood equivalent phantom is placed in each blood cup, and the remaining blood cups are filled with corresponding blood equivalent phantoms. A reference point for each blood cup is selected as the measurement point. A typical irradiation program is chosen and irradiation is performed. After irradiation, the consistency of absorbed dose between the blood cups is calculated using the following formula:
[0070]
[0071] Where C represents the consistency of absorbed dose between blood cups.
[0072] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.
[0073] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0074] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A calibration method for an X-ray blood irradiator, characterized in that, Includes the following steps: After selecting and placing the blood equivalent phantom according to the target irradiation container, the detector is connected to the blood equivalent phantom. The blood equivalent phantom includes a first type of blood equivalent phantom for vertically placed irradiation container calibration or a second type of blood equivalent phantom for horizontally placed irradiation container calibration. The first type of blood equivalent phantom is cylindrical, with five cylinders vertically equidistant from the center and around the perimeter, penetrating the phantom. The top, middle, and bottom three points inside the cylinders are measurement points, for a total of 15 measurement points. The second type of blood equivalent phantom is horizontally cylindrical, with three through holes (top, middle, and bottom) in the middle of its side, and the top, middle, and bottom three points of the middle through hole are used as measurement points. Three through holes (top, middle, and bottom) are also opened on each of the two sides, and the middle point of the side through holes is used as a measurement point, for a total of 15 measurement points. Move the detector to a reference point, set the nominal dose value for irradiation, read the absorbed dose value of the reference point and calculate the indication error. The reference point is the geometric center point of the blood equivalent phantom. Furthermore, the detector is moved to sequentially acquire the absorbed dose values at measurement points, and after irradiation using a typical irradiation program, the absorbed dose values at each measurement point are read to calculate the uniformity of the absorbed dose of the target irradiation container. If the X-ray blood irradiator is a multi-container X-ray blood irradiator, then the corresponding blood equivalent phantom is placed inside each irradiation container. The reference point of each irradiation container is used as the measurement point. After irradiation, the values are read from the detector, and the consistency of the absorbed dose values between each irradiation container is calculated. The consistency of the absorbed dose values is calculated based on the following formula: ； Where C represents the consistency of absorbed dose between irradiation containers. This represents the maximum absorbed dose value of the irradiation container. This is the minimum absorbed dose value for the irradiation container.
2. The X-ray blood irradiator calibration method as described in claim 1, characterized in that, Reading the absorbed dose value at the reference point and calculating the indication error includes: Set the nominal dose value to D0, and after irradiation is completed, read the absorbed dose D; The error in the indicated value of the absorbed dose at the reference point is calculated using the following formula: ； in, Absorbed dose error at the reference point; is the nominal absorbed dose value at the reference point, and D is the absorbed dose value at the reference point.
3. The X-ray blood irradiator calibration method as described in claim 1, characterized in that, The formula for calculating the uniformity of absorbed dose of the target irradiation container is as follows: ； Where Ci represents the uniformity of absorbed dose at each measurement point, i=1,2,......,n; Di represents the absorbed dose value at each measurement point; and D represents the absorbed dose value at the reference point. The maximum absolute value is taken as the uniformity of the irradiation container.
4. An X-ray blood irradiator calibration device, applicable to the X-ray blood irradiator calibration method as described in any one of claims 1-3, characterized in that, include: The detector is equipped with a crystal probe and is connected to the detector host via a connecting line. The connecting line integrates a miniature photomultiplier tube. The inner ring of the detector is equipped with a rotatable bearing for connecting to a blood equivalent phantom. The detector host integrates a wireless transmission module and a wired transmission module, which are connected to the terminal software. Blood equivalent phantoms, including a first type of blood equivalent phantom for calibration of vertically placed irradiation containers or a second type of blood equivalent phantom for calibration of horizontally placed irradiation containers.
5. The X-ray blood irradiator calibration device as described in claim 4, characterized in that, The detector host is covered with a lead layer on the outside.