Real-time monitoring and evaluation method for X-ray quality

Abstract

The invention relates to the technical field of radiotherapy, and discloses an X-ray quality real-time monitoring and evaluation method, and the method comprises the steps: irradiating a first irradiation target object and a second irradiation target object through a preset energy gear X-ray, acquiring a first target electric signal corresponding to the first irradiation target object and a second target electric signal corresponding to the second irradiation target object; and dividing the smaller value of the first target electric signal and the second target electric signal by the larger value of the first target electric signal and the second target electric signal to obtain comparison target data for representing the X-ray quality. The X-ray quality real-time monitoring method can overcome the technical problem that the quality of the ray beam cannot be controlled in real time, the X-ray quality can be monitored in real time, whether the X-ray meets the requirement of radiotherapy or not can be found in time, and the safety of radiotherapy is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of radiotherapy technology, and more specifically, to a method for real-time monitoring and evaluation of X-ray quality. Background Technology

[0002] Medical linear accelerators are core medical devices in the radiotherapy industry. During treatment, extremely high requirements are placed on the precision and characteristics of their radiation beams. For high-energy photon beams (X-rays), radiation quality is typically characterized by TPR20.10, which is the ratio of absorbed dose at depths of 20cm and 10cm in a water phantom, assuming all other conditions are the same (source-skin distance 100cm, radiation field size 10cm×10cm). Radiation physicists or technicians conduct routine quality control on the accelerator periodically to ensure the precision and characteristics of the radiation beam meet requirements, preventing the beam's precision and characteristics from directly affecting the accurate execution of the treatment plan and patient safety. However, routine quality control before radiotherapy is insufficient to determine the beam quality in real time during actual treatment. Furthermore, daily quality control of the accelerator requires additional time, wasting significant human and material resources.

[0003] In related technologies, the inability to perform real-time quality control of the radiation beam during radiotherapy is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for real-time monitoring and evaluation of X-ray quality. This real-time monitoring method overcomes the technical problem of not being able to control the quality of X-ray beams in real time. This method can monitor the X-ray quality in real time, promptly detect whether the X-rays meet the requirements for radiotherapy, and greatly improve the safety of radiotherapy.

[0005] The real-time monitoring method for X-ray quality of the present invention includes:

[0006] S100: Irradiate a first irradiated target and a second irradiated target with X-rays of a predetermined energy level, and obtain a first target electrical signal corresponding to the first irradiated target and a second target electrical signal corresponding to the second irradiated target, wherein the first irradiated target and the second irradiated target have different physical properties.

[0007] S200: Divide the larger value of the first target electrical signal and the second target electrical signal by the smaller value of the first target electrical signal and the second target electrical signal to obtain the contrast target data used to characterize the X-ray quality.

[0008] Optionally, in step S100, the physical characteristic is the thickness dimension.

[0009] Optionally, in step S100, the physical property is the atomic number.

[0010] Optionally, in step S200, the comparison target data is calibrated to obtain calibration comparison target data, which satisfies the following piecewise function calibration formula:

[0011]

[0012] in,

[0013] y represents the calibration comparison target data;

[0014] x represents the target data for comparison;

[0015] a0, a1, ..., a n : This is the energy segmentation point, which divides the entire energy range into n consecutive regions;

[0016] k1, ..., k n and b1, ...,b n All are constants.

[0017] Optionally, the predetermined energy level X-ray has multiple energy levels.

[0018] The X-ray quality evaluation method of the present invention includes:

[0019] The above-mentioned real-time monitoring method for X-ray quality;

[0020] S300: Determine whether the comparison target data is within the standard range parameters. If the comparison target data is within the standard range parameters, then the predetermined energy level X-ray meets the treatment requirements.

[0021] If the target data for comparison is not within the standard range parameter, then the smaller value of the target data for comparison and the standard range parameter is further divided by the larger value of the target data for comparison and the standard range parameter to obtain the first ratio, and the first threshold is set.

[0022] If the first ratio is less than or equal to the first threshold, then the predetermined energy level X-ray meets the treatment requirements;

[0023] If the first ratio is greater than the first threshold, the predetermined energy level X-ray does not meet the treatment requirements, resulting in radiation quality interlock and stopping beam output;

[0024] The standard range parameter corresponds to the predetermined energy level X-ray.

[0025] Optionally, in step S300, the standard range parameter is the ratio of the absorbed dose of the water phantom at a depth of 20 cm underwater to the absorbed dose of the water phantom at a depth of 10 cm underwater.

[0026] Optionally, at least two of the first irradiated targets are provided;

[0027] The minimum value of the first target electrical signal corresponding to the at least two first irradiated targets is divided by the maximum value of the first target electrical signal corresponding to the at least two first irradiated targets to obtain a second ratio, and a second threshold is set.

[0028] If the second ratio is less than or equal to the second threshold, then the predetermined energy level X-ray meets the treatment requirements;

[0029] If the second ratio is greater than the second threshold, then the predetermined energy level X-ray does not meet the treatment requirements.

[0030] Optionally, at least two second irradiated targets are provided;

[0031] The minimum value of the second target electrical signal corresponding to the at least two second irradiated targets is divided by the maximum value of the first target electrical signal corresponding to the at least two first irradiated targets to obtain a third ratio, and a third threshold is set.

[0032] If the third ratio is less than or equal to the third threshold, then the predetermined energy level X-ray meets the treatment requirements;

[0033] If the third ratio is greater than the third threshold, then the predetermined energy level X-ray does not meet the treatment requirements.

[0034] Optionally, the first irradiated target and the second irradiated target are located in the non-treatment zone of the predetermined energy level X-ray. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the real-time monitoring and evaluation method for X-ray quality in an embodiment of the present invention. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The method for real-time monitoring and evaluation of X-ray quality according to embodiments of the present invention is described below with reference to the accompanying drawings. Figure 1 As shown, the real-time monitoring method for X-ray quality according to an embodiment of the present invention includes:

[0038] S100: Irradiate a first irradiated target and a second irradiated target with X-rays of a predetermined energy level, and obtain a first target electrical signal corresponding to the first irradiated target and a second target electrical signal corresponding to the second irradiated target, wherein the first irradiated target and the second irradiated target have different physical properties.

[0039] S200: Divide the smaller value of the first target electrical signal and the second target electrical signal by the larger value of the first target electrical signal and the second target electrical signal to obtain the contrast target data used to characterize the X-ray quality;

[0040] According to the real-time monitoring method for X-ray quality in a specific embodiment of the present invention, the method can monitor the X-ray quality in real time, thereby enabling timely detection of whether the X-rays meet the requirements for radiotherapy, and greatly improving the safety of radiotherapy.

[0041] like Figure 1 As shown, in order to make the technical solution of this application easier to understand, the technical solution of this application will be described in more detail below with specific embodiments of the real-time monitoring method of X-ray quality.

[0042] It should be noted that the treatment area and non-treatment area in this technical solution do not overlap. X-rays from the non-treatment area may be blocked by the first or second electrode, or the first or second electrode may weaken the quality of the X-rays. However, the treatment area is primarily for treating patients; that is, the X-rays must not be blocked or weakened to ensure the X-rays meet the treatment requirements.

[0043] In some specific embodiments, such as Figure 1 As shown, in step S100, a first irradiation target and a second irradiation target are irradiated with X-rays at a predetermined energy level. Under the irradiation of the X-rays at the predetermined energy level, the first and second irradiation targets generate corresponding electrical signals, which may include current or voltage. The first target electrical signal corresponding to the first irradiation target and the second target electrical signal corresponding to the second irradiation target are obtained. The first and second irradiation targets have different physical properties.

[0044] It should be noted that a predetermined energy level X-ray can be understood as the energy level of the X-ray being set in advance.

[0045] In some specific embodiments, the same physical characteristics of the first irradiated target and the second irradiated target are not the same, which can be understood as the first irradiated target and the second irradiated target having different thicknesses.

[0046] In some specific embodiments, the physical properties of the first irradiated target and the second irradiated target are different, and the atomic numbers of the first irradiated target and the second irradiated target are different.

[0047] It should be noted that when X-rays pass through the first and second irradiated objects, the intensity attenuation of the X-rays follows the Lambert-Beer law. That is, the thickness of the irradiated object or its atomic number will affect the X-ray intensity, resulting in different attenuations. Specifically, for materials of the same thickness, a higher atomic number leads to greater attenuation of X-rays. For materials with the same atomic number, greater thickness leads to greater attenuation of X-rays.

[0048] In some specific embodiments, the predetermined energy level X-ray has multiple energy levels.

[0049] In some specific embodiments, in step S200, the smaller value of the first target electrical signal and the second target electrical signal is divided by the larger value of the first target electrical signal and the second target electrical signal to obtain comparison target data. Specifically, the physical characteristics of the first irradiated target and the second irradiated target are different, causing the data of the first target electrical signal and the second target electrical signal to be different. Dividing the smaller value of the two by the larger value can obtain the comparison target data.

[0050] In some specific embodiments, in step S200, calibration comparison target data is obtained by calibrating the comparison target data, and the calibration comparison target data satisfies the following piecewise function calibration formula:

[0051]

[0052] in,

[0053] y represents the calibration comparison target data;

[0054] x represents the target data for comparison;

[0055] a0, a1, ..., a n : This is the energy segmentation point, which divides the entire energy range into n consecutive regions; k1, ..., k n and b1, ..., b n All are constants.

[0056] In step S300, the comparison target data is replaced with the calibration comparison target data.

[0057] Specifically, X-rays generate a large number of secondary electrons during the irradiation of a target, which in turn affects the electrical signals generated by the target. In other words, a large number of secondary electrons interfere with the electrical signals, making them nonlinear and thus affecting X-ray monitoring.

[0058] To address the impact of secondary electrons, the comparison target data needs to be calibrated to obtain calibrated comparison target data. Specifically, comparison target data can be obtained under X-ray irradiation at a predetermined energy level. Substituting the comparison target data into the piecewise function calibration formula yields the calibrated X-ray quality. Where a0, a1, ..., a n : This is the dividing point of the interval. This dividing point divides the entire input range into n consecutive regions; k1, ..., k n and b1, ...,b n All are constants.

[0059] k n and b n With the constant determined, two target objects of different thicknesses or atomic numbers are irradiated with X-rays at predetermined energy levels of two different energy levels. The ratio of the electrical signals corresponding to the two target objects can be obtained, i.e., the comparison target data. Then, the ratio of the absorbed dose (TPR) at 20 cm and 10 cm underwater is measured using the two different predetermined energy levels of X-rays to obtain the standard range parameter. Finally, the standard range parameter and the comparison target data are substituted into the calibration formula f. n (x)=k n x+b n The constant k can be determined. n and constant b n The value.

[0060] For example, the ratio of the currents irradiated by two targets with X-rays at two different energy levels is represented by x1 and x2, respectively. The ratio of the absorbed dose of a water phantom irradiated at two different energy levels at 20 cm and 10 cm underwater is represented by y1 and y2. Substitute x1 and y1, x2 and y2 into the calibration formula f, respectively. n (x)=k n x+b n Thus, the constant k can be determined. n and constant b n The value.

[0061] In some specific embodiments, the standard range parameter is the ratio of the absorbed dose of the water phantom at a depth of 20 cm underwater to the absorbed dose of the water phantom at a depth of 10 cm underwater. The X-ray quality can be represented by the characteristic that materials of different thicknesses or atomic numbers attenuate X-rays differently. Since the X-ray quality is the ratio of the absorbed dose at a depth of 20 cm underwater to the absorbed dose at a depth of 10 cm underwater (TPR 20.10), a thin sheet of material with a thicker thickness or a higher atomic number can represent 20 cm underwater, while a thin sheet of material with a thinner thickness or a lower atomic number can represent 10 cm underwater.

[0062] In some specific embodiments, such as Figure 1 As shown, in step S300, it is determined whether the comparison target data is within the standard range parameters. If the comparison target data is within the standard range parameters, the predetermined energy level X-ray meets the treatment requirements. The standard range parameters correspond to the predetermined energy level X-ray.

[0063] In some specific embodiments, such as Figure 1 As shown, in step S300, if the target data is not within the standard range parameters, the smaller value between the target data and the standard range parameters is further divided by the larger value between the target data and the standard range parameters to obtain a first ratio, and a first threshold is set. If the first ratio is less than or equal to the first threshold, the predetermined energy level X-ray meets the treatment requirements. The first threshold can be understood as allowing a certain redundancy in the X-ray energy level parameters, that is, the X-ray quality meets the treatment requirements within a certain range.

[0064] Furthermore, during radiotherapy, the first threshold can be set according to each patient's individual circumstances to ensure that each patient can obtain the best treatment results.

[0065] In some specific embodiments, if the target data being compared is not within the standard range parameters, the smaller value between the target data and the standard range parameters is divided by the larger value between the target data and the standard range parameters to obtain a first ratio, and a first threshold is set. If the first ratio is greater than the first threshold, then the predetermined energy level X-ray does not meet the treatment requirements.

[0066] In actual radiotherapy, if the radiation quality data exceeds the set first threshold, it is determined that the predetermined energy level of X-rays has not met the requirements for treating the patient. This can immediately trigger a radiation quality interlock, stop the accelerator beam output, and ensure the patient's safety.

[0067] The real-time X-ray quality monitoring method in this invention is applied to actual radiotherapy. This method can monitor X-ray quality in real time, ensuring patient safety during treatment. If equipment malfunctions or the X-ray quality momentarily fails to meet radiotherapy requirements during treatment, this method can immediately determine that the X-ray quality does not meet the requirements and trigger a quality interlock to stop the accelerator beam output, ensuring patient safety. Furthermore, traditional water-phantom X-ray quality monitoring methods are time-consuming and cannot monitor X-ray quality in real time during patient treatment. Compared to traditional methods, this method can monitor X-ray quality in real time.

[0068] In some specific embodiments, at least two first irradiation targets are provided. The minimum value of the first target electrical signals corresponding to the at least two first irradiation targets is divided by the maximum value of the first target electrical signals corresponding to the at least two first irradiation targets to obtain a second ratio, and a second threshold is set. If the second ratio is less than or equal to the second threshold, the predetermined energy level X-ray meets the treatment requirements; if the second ratio is greater than the second threshold, the predetermined energy level X-ray does not meet the treatment requirements. Specifically, when the thickness or atomic number of the two first irradiation targets is the same, the electrical signals generated by the two first irradiation targets are comparable. If the electrical signal of one of the two first irradiation targets changes abruptly or there is no electrical signal, it can be determined that the predetermined energy level X-ray does not meet the treatment requirements. Further, if the electrical signals generated by the two first irradiation targets are not significantly different, the maximum value of the two electrical signals divided by the minimum value of the two electrical signals can be greater than the second threshold, in which case the predetermined energy level X-ray does not meet the treatment requirements.

[0069] In some specific embodiments, at least two second irradiation targets are set. The minimum value of the second target electrical signal corresponding to the at least two second irradiation targets is divided by the maximum value of the first target electrical signal corresponding to the at least two first irradiation targets to obtain a third ratio. A third threshold is set. If the third ratio is less than or equal to the third threshold, the predetermined energy level X-ray meets the treatment requirements. If the third ratio is greater than the third threshold, the predetermined energy level X-ray does not meet the treatment requirements. The principle and technical effect of setting multiple second irradiation targets are the same as those of setting multiple first irradiation targets, and will not be repeated here.

[0070] In some specific embodiments, the first and second irradiated targets are located in the non-treatment zone of X-rays at a predetermined energy level, and the first and second irradiated targets do not affect the actual treatment.

[0071] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0073] In this invention, unless otherwise explicitly 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0075] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A method for real-time monitoring of X-ray quality, characterized in that, include: S100: Irradiate a first irradiated target and a second irradiated target with X-rays of a predetermined energy level, and obtain a first target electrical signal corresponding to the first irradiated target and a second target electrical signal corresponding to the second irradiated target, wherein the first irradiated target and the second irradiated target have different physical properties. S200: Divide the smaller value of the first target electrical signal and the second target electrical signal by the larger value of the first target electrical signal and the second target electrical signal to obtain the contrast target data used to characterize the X-ray quality.

2. The real-time monitoring method for X-ray quality according to claim 1, characterized in that, In step S100, the physical characteristic is the thickness dimension.

3. The real-time monitoring method for X-ray quality according to claim 1, characterized in that, In step S100, the physical property is the atomic number.

4. The method for real-time monitoring of X-ray quality according to any one of claims 1 to 3, characterized in that, In step S200, the comparison target data is calibrated to obtain calibration comparison target data, which satisfies the following piecewise function calibration formula: in, y represents the calibration comparison target data; x represents the target data for comparison; a0, a1, ..., a n : This is the energy segmentation point, which divides the entire energy range into n consecutive regions; k1, ..., k n and b1, ...,b n All are constants.

5. The method for real-time monitoring of X-ray quality according to any one of claims 1 to 3, characterized in that, The predetermined energy level X-ray has multiple different energy levels.

6. A method for evaluating the quality of X-rays, characterized in that, include: The method for real-time monitoring of X-ray quality according to any one of claims 1 to 5; S300: Determine whether the comparison target data is within the standard range parameters. If the comparison target data is within the standard range parameters, then the predetermined energy level X-ray meets the treatment requirements. If the target data for comparison is not within the standard range parameter, then the smaller value of the target data for comparison and the standard range parameter is further divided by the larger value of the target data for comparison and the standard range parameter to obtain the first ratio, and the first threshold is set. If the first ratio is less than or equal to the first threshold, then the predetermined energy level X-ray meets the treatment requirements; If the first ratio is greater than the first threshold, the predetermined energy level X-ray does not meet the treatment requirements, resulting in radiation quality interlock and stopping beam output; The standard range parameter corresponds to the predetermined energy level X-ray.

7. The method for evaluating X-ray quality according to claim 6, characterized in that, In step S300, the standard range parameter is the ratio of the absorbed dose of the water phantom at a depth of 20 cm underwater to the absorbed dose of the water phantom at a depth of 10 cm underwater.

8. The method for evaluating X-ray quality according to claim 6 or 7, characterized in that, At least two of the first irradiated targets are provided; The minimum value of the first target electrical signal corresponding to the at least two first irradiated targets is divided by the maximum value of the first target electrical signal corresponding to the at least two first irradiated targets to obtain a second ratio, and a second threshold is set. If the second ratio is less than or equal to the second threshold, then the predetermined energy level X-ray meets the treatment requirements; If the second ratio is greater than the second threshold, then the predetermined energy level X-ray does not meet the treatment requirements.

9. The method for evaluating X-ray quality according to claim 6 or 7, characterized in that, At least two second irradiated targets are provided; The minimum value of the second target electrical signal corresponding to the at least two second irradiated targets is divided by the maximum value of the first target electrical signal corresponding to the at least two first irradiated targets to obtain a third ratio, and a third threshold is set. If the third ratio is less than or equal to the third threshold, then the predetermined energy level X-ray meets the treatment requirements; If the third ratio is greater than the third threshold, then the predetermined energy level X-ray does not meet the treatment requirements.

10. The method for evaluating X-ray quality according to claim 6 or 7, characterized in that, The first and second irradiated targets are located in the non-treatment zone of the predetermined energy level X-ray.

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