An orthogonal strip CZT detector module and method for particle therapy range and dose monitoring

Abstract

The application discloses a kind of orthogonal strip CZT detector module and method for particle therapy range and dose monitoring, orthogonal strip CZT detector module includes orthogonal strip CZT detector, signal front-end electronics circuit, channel compression circuit;Anode electrode and cathode electrode in orthogonal strip CZT detector are long strip and mutually orthogonal setting;Channel compression circuit reduces the channel number of signal output.According to user demand, the present application can realize the switching of single probe measurement mode and coincidence measurement mode, the method for monitoring the secondary particle intensity generated by the interaction of primary beam particles and human tissue in particle beam therapy field, the position and dose of particle primary beam irradiation target body or human body are calculated by secondary particle counting rule, so as to realize the monitoring of particle beam range and dose, the present application reduces the channel number of readout electronics and reduces the complexity of data acquisition, modular design meets the characteristics of economy and miniaturization.

Description

Technical Field

[0001] This invention belongs to the field of radiotherapy technology, and in particular relates to an orthogonal bar CZT detector module and method for monitoring the range and dose of particle therapy. Background Technology

[0002] Particle therapy, due to its superior physical dose distribution and lower toxicity to normal tissues, has become an important development direction in the field of tumor radiotherapy, with proton therapy (PT) and carbon ion radiotherapy (CIRT) being the most representative. Proton therapy relies on the Bragg peak characteristic, depositing a relatively low dose in normal tissues during the incident phase, while forming a sharp dose peak at the end of the target area. Therefore, it can significantly reduce the radiation dose to organs at risk while ensuring tumor control, making it particularly suitable for pediatric tumors, skull base tumors, and lesions near vital organs. In recent years, it has gained widespread clinical application globally, driving the development of dosimetry, planning systems, and image-guided technologies. In contrast, carbon ion therapy, in addition to having a similar Bragg peak dose distribution, also has a higher relative biological effect (RBE) and a steeper dose gradient, offering potential advantages for the treatment of radioresistant and recurrent tumors, and is considered one of the most advanced and promising tumor radiotherapy methods currently available. In particle therapy, range and dose monitoring are crucial for the safety and effectiveness of treatment. However, existing monitoring technologies are limited by the spatial resolution of detectors, and the detectors are large and expensive, making them difficult to widely adopt in clinical practice.

[0003] During particle therapy, proton beams and carbon ion beams interact with human tissue, generating secondary particles such as electrons, neutrons, protons, gamma rays, and positron-emitting nuclides (¹¹C, ¹⁵O, ¹⁰C, ¹³N, etc.). While a small number of these smaller particles deposit energy within the body and cannot escape, most escape and are captured by detectors. Cadmium zinc telluride (CZT) detectors are radiation detectors based on semiconductor materials. CZT detectors offer advantages such as high energy resolution, high spatial resolution, and low noise, making them widely used in medical imaging, radiation monitoring, and astrophysical research. When radiation interacts with a CZT crystal, it ionizes the crystal, generating electron-hole pairs. With an applied bias voltage, the electrons and holes drift towards the anode and cathode, respectively, and are ultimately collected to form an electrical signal.

[0004] Currently, commonly used electrode structures include planar, pixel, and strip types. The determination of the electrode structure revolves around the characteristics of the detector electrodes, and different electrode structures have a significant impact on the function of the CZT detector. With the diversification of CZT detector electrode structures, the high channel number makes the front-end readout electronics increasingly complex. Application-specific integrated circuits (ASICs) for high-channel CZT detectors have been developed. ASICs typically include charge-sensitive amplifiers (CSAs), shaping amplifiers, peak hold circuits, analog-to-digital converters, etc. Although they have advantages such as high sensitivity, high integration, and low power consumption, their disadvantages are also quite obvious: poor versatility, limited energy dynamic range, complex design, and high cost, which restricts the flexible use of CZT detectors. Summary of the Invention

[0005] In view of the problems and defects existing in the above-mentioned background technology, the present invention aims to provide an orthogonal bar CZT detector module and method for particle therapy dose monitoring.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An orthogonal bar CZT detector module for monitoring the range and dose of particle therapy includes:

[0008] Orthogonal bar CZT detector: used to receive secondary particles generated during particle therapy. After the secondary particles interact with the detector crystal, energy is deposited and an electrical signal is generated. The orthogonal bar CZT detector includes a CZT crystal, several anode electrodes disposed on the upper surface of the CZT crystal, and several cathode electrodes disposed on the lower surface of the CZT crystal. The anode electrodes and cathode electrodes are both elongated and orthogonally arranged.

[0009] Signal front-end electronics circuit: including a preamplifier circuit and a filter shaping circuit, wherein the preamplifier circuit is used to amplify the electrical signal and convert the electrical signal into a voltage signal; the filter shaping circuit is used to further amplify the voltage signal and shape it into a quasi-Gaussian pulse signal;

[0010] Channel compression circuit: It uses a resistor voltage divider network to combine pulse signals from multiple channels and compress the signals according to weights to reduce the number of signal output channels;

[0011] Shielded enclosure: The CZT detector, signal front-end electronics circuit and channel compression circuit are all housed in a shielded enclosure to provide electromagnetic shielding.

[0012] Preferably, the preamplifier circuit includes several charge-sensitive preamplifiers, and the output terminal of each anode / cathode is connected to one of the charge-sensitive preamplifiers; the filter shaping circuit is integrated from several individual channel circuits, and each individual channel is connected to the output terminal of one charge-sensitive preamplifier. Each individual channel circuit includes a differentiating circuit and a two-stage amplification circuit.

[0013] Preferably, the channel compression circuit is divided into two circuits to process the anode electrode signal and the cathode electrode signal respectively. The anode / cathode signals input to each circuit enter a resistor divider network. Each channel in the resistor divider network corresponds to two resistors. The signals from several channels are combined into two paths and then amplified by a single-stage amplifier circuit before being output. A total of four signals are output from the anode and cathode electrodes. The resistance value in each channel is selected according to the following formula:

[0014] ;

[0015] ;

[0016] in, This represents the maximum resistance value in the channel. This represents the total number of channels. For channel number, It is the ratio of the maximum resistance to the minimum resistance. For channel Medium resistance The resistance value, For channel Medium resistance The resistance value.

[0017] The present invention further provides a method for monitoring the range and dose of particle therapy based on an orthogonal bar CZT detector module, which supports single-probe measurement mode and coincidence measurement mode.

[0018] Preferably, the single-probe measurement mode includes the following steps: During particle therapy, a single orthogonal strip CZT detector module is placed on the side parallel to the particle beam, ensuring that the anode electrodes of the orthogonal strip CZT detector are laterally distributed along the beam direction. The orthogonal strip CZT detector module collects electrical signals and performs preprocessing and channel compression. A data acquisition module is used to acquire the four-channel electrode signals after channel compression and transmits the acquired data to a host computer. The host computer processes the event data, including filtering the acquired events and calculating the energy and three-dimensional position of each event. Several mutually orthogonal cathode and anode electrodes divide the orthogonal strip CZT detector into several regions. The secondary particle count of each region is counted according to its position and the count is corrected. The particle range distribution is obtained based on the secondary particle count, and the cumulative machine jump count is calculated based on the total secondary particle count. The relative dose is calculated based on the cumulative machine jump count to obtain the range and dose distribution during particle therapy.

[0019] Preferably, the coincidence measurement mode includes the following steps: During particle therapy, two orthogonal strip CZT detector modules are placed on both sides parallel to the particle beam, with the two detector modules facing each other to ensure that the anode electrodes of the orthogonal strip CZT detectors are laterally distributed along the beam direction. The orthogonal strip CZT detector modules collect electrical signals and perform preprocessing and channel compression. A data acquisition module is used to acquire the eight-channel electrode signals after channel compression and transmit the acquired data to a host computer. The host computer processes the event data, including filtering the acquired events, calculating the energy and three-dimensional position of each event, recording the timestamp of each event for the judgment of coincidence events, setting a coincidence time window of 10 ns, setting an energy window of 480 keV to 540 keV, and saving events that meet the above two conditions. Using an image reconstruction algorithm, the range and dose distribution during particle therapy are obtained.

[0020] Preferably, the formula for calculating the energy and three-dimensional position of each event is as follows:

[0021] ;

[0022] ;

[0023] ;

[0024] ;

[0025] ;

[0026] in, , The amplitudes of the two anode signals output from the orthogonal bar CZT detector module after channel compression are given. , The amplitudes of the two cathode signals output from the orthogonal bar CZT detector module after channel compression are given. The location of the event in the direction of the anode electrode. This represents the location of the event in the direction of the cathode electrode. The relative energy of the anode electrode. The relative energy of the cathode electrode. This represents the depth position of the event relative to the detector. For the thickness of the detector, This is a correction factor.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) This invention provides an orthogonal bar CZT detector module for particle therapy dose monitoring, which has the characteristics of reasonable circuit optimization, compact internal structure and small space occupation. It can be used for monitoring at the beam site with a portable data acquisition module and host computer, making the monitoring more flexible and meeting the needs of many application scenarios.

[0029] (2) In this invention, the orthogonal strip CZT detector is used for beam monitoring. The CZT detector has the advantages of high energy resolution, room temperature operation capability and good detection efficiency. Moreover, the strip electrode structure not only gives the CZT detector the characteristic of charge unipolar induction, but also provides accurate position (three-dimensional) positioning capability.

[0030] (3) In this invention, a channel compression circuit suitable for orthogonal bar CZT detectors was designed. With minimal impact on overall performance, the original multi-channel signal can be significantly reduced, reducing the pressure on the data acquisition module and making miniaturization and portability possible. At the same time, the channel can be restored based on the compressed signal position after compression, providing a new idea for the three-dimensional position calculation of orthogonal bar CZT detectors.

[0031] (4) This invention establishes a correlation between the count of the orthogonal bar CZT detector and the particle range and particle therapy dose. With the detector position unchanged, the range of different energy particle beams irradiating human tissue is related to the secondary particle count characteristics measured by the detector. At the same time, the detector count can be used to calculate the machine jump count, thereby monitoring the particle therapy dose;

[0032] (5) This invention proposes two measurement modes: a single-probe measurement mode and a coincidence measurement mode. The former requires less space, has better real-time performance, and achieves range measurement accuracy on the order of mm. In terms of dosage, the relative dose can be calculated based on the relationship between the cumulative machine jump count and the total count, with a dose measurement accuracy of 5%. The coincidence measurement mode can monitor beam range deviation and dose distribution changes after image reconstruction. Considering the deviation between the positron-emitting nuclide and the range, as well as the influence of the biological scouring effect, the range verification error can be guaranteed to be within 2 mm. The reconstruction results can be compared with the dose distribution of the treatment planning system to further verify the dose. The two measurement modes make the monitoring methods more diversified, and the results can be used for comparison and correction to further improve the accuracy of the monitoring system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the orthogonal strip CZT detector module of the present invention;

[0034] Figure 2 This is a flowchart illustrating the operation of the orthogonal bar CZT detector module of the present invention.

[0035] Figure 3 The weighted potential distribution of the anode and cathode of the orthogonal bar CZT detector;

[0036] Figure 4 This is a schematic diagram of a channel compression circuit;

[0037] Figure 5 (a) shows the count distribution curve in the direction of the anode electrode. Figure 5 (b) is a scatter plot of the two-dimensional positions of the cathode and anode;

[0038] Figure 6 This is a schematic diagram of the single-probe measurement mode and the coincidence measurement mode of the present invention;

[0039] Figure 7 This is a schematic diagram of the single-probe measurement mode and the coincident measurement mode processing method of the present invention;

[0040] Figure 8 (a) Range at different energies and Approximate linear relationship graph Figure 8 (b) is a graph showing the relationship between cumulative count and cumulative machine jumps under different energies. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, an orthogonal bar CZT detector module for monitoring the range and dose of particle therapy includes: an orthogonal bar CZT detector, a signal front-end electronic circuit, a channel compression circuit, and a shielded enclosure. The signal front-end electronic circuit includes a preamplifier circuit and a filter shaping circuit.

[0044] The orthogonal strip CZT detector, used for signal acquisition, consists of a CZT crystal, several anode electrodes, and several cathode electrodes disposed on the surface of the CZT crystal. The anode and cathode electrode structures form an orthogonal strip shape. The electrode material is a high-work-efficiency material such as gold or titanium, and the shape is elongated. The width of the anode electrode strips can be designed to be several hundred micrometers or hundreds of micrometers depending on the required monitoring accuracy. Due to the significant sharing of hole charge, the width of the cathode electrode strips is preferably in the millimeter range. In this embodiment, the anode electrode is 16.4 mm long and 0.9 mm wide, with a 0.1 mm gap between adjacent anode electrodes. There are a total of 32 anode and cathode electrodes (16 anodes + 16 cathodes), distributed orthogonally on the upper and lower surfaces, forming 32 signal channels. Figure 2 The electrode structure distribution of the orthogonal bar CZT detector is shown. In use, the cathode electrode of the orthogonal bar CZT detector is connected to a negative high voltage, and the anode electrode is grounded, so that an electric field is generated inside the detector to collect charge carriers that drift through the electric field.

[0045] Orthogonal bar electrode structures exhibit unipolar charge induction. The concept of weighted potential is introduced here to explain this unipolar induction. Weighted potential, a tool introduced by the Shockley-Ramo theorem for calculating induced charge, states that the total charge on an electrode is proportional to the change in weighted potential as the charge travels from its origin to its destination. The distribution of the weighted potential can be calculated in simulations. In unipolar CZT detectors, the anode weighted potential is very low near the cathode, rapidly increasing to 1 (maximum value 1) in the region close to the anode. This characteristic makes the detector output signal primarily dependent on electron collection, reducing reliance on hole collection. The weighted potential distribution of the anode electrode in an orthogonal bar CZT detector is shown below. Figure 3 As shown in the figure, the weighted potential distribution of the orthogonal strip electrode structure satisfies this characteristic very well.

[0046] The signal front-end electronics circuitry performs preliminary processing on the electrical signals acquired by the quadrature bar CZT detector. The preamplifier circuit mainly consists of 32 charge-sensitive preamplifiers (model MA-01C), which are characterized by high sensitivity and low noise. Powered by ±12V, they are matched one-to-one with the electrodes of the quadrature bar CZT detector to amplify the electrical signals and convert them into voltage signals. The voltage signal is then input to a multi-channel filtering and shaping circuit. This circuit integrates multiple channels into a single unit, with each individual channel connected to the output of the charge-sensitive preamplifier. Powered by ±6V, each channel includes a differentiating circuit and a two-stage amplification circuit. This reduces signal baseline jitter, shapes the signal waveform, and shortens the fall time, further amplifying and shaping the voltage signal into a quasi-Gaussian pulse signal.

[0047] The channel compression circuit is a self-designed readout circuit suitable for orthogonal strip CZT detectors. The schematic diagram of the channel compression circuit is shown below. Figure 4 As shown. The channel compression circuit principle is similar to the Symmetric Charge Division Circuit (SCDC). It consists of two circuits that process the cathode and anode electrode signals separately. Each circuit receives 16 channels of input signals, which enter an Impedance Bridge Circuit (IBC). After a single-stage amplification circuit, it outputs two signals, thus achieving the channel compression function. Taking the anode channel compression circuit as an example (the cathode channel compression circuit is similar), the 16 anode signals enter a resistor divider network. Each channel corresponds to two resistors (Ra and Rb). The resistor values ​​are selected according to the following formula:

[0048] ;

[0049] ;

[0050] In the formula, This represents the maximum resistance value in the channel. This represents the total number of channels. For channel number, It is the ratio of the maximum resistance to the minimum resistance. For channel Medium resistance The resistance value, For channel Medium resistance The resistance values ​​are determined. In the entire resistor network, the maximum resistance is chosen to be 1000Ω, and the minimum resistance is chosen to be 62.5Ω. Because the resistor divider network causes signal attenuation, an amplifier stage is added before the output signal to flexibly adjust the overall gain of the channel compression circuit in order to match the threshold of the subsequent acquisition system. All Ra resistors are connected together, and all Rb resistors are connected together, outputting... and The overall system was reduced from 16 channels to 2 channels, thus achieving channel compression. Similarly, the cathode channel compression circuit output... and .

[0051] The orthogonal bar CZT detector module of this invention can calculate the energy of each monitored event and its three-dimensional position within the orthogonal bar CZT detector based on the four signals output from the channel compression circuit. The formulas for calculating the relative position of the event within the orthogonal bar CZT detector and the formulas for calculating the energy are as follows:

[0052] ;

[0053] ;

[0054] ;

[0055] ;

[0056] ;

[0057] In the formula, , The amplitudes of the two anode signals output from the orthogonal bar CZT detector module after channel compression are given. , The amplitudes of the two cathode signals output from the orthogonal bar CZT detector module after channel compression are given. The location of the event in the direction of the anode electrode. This represents the location of the event in the direction of the cathode electrode. The relative energy of the anode electrode. The relative energy of the cathode electrode. This represents the depth position of the event relative to the detector. For the thickness of the detector, This is a correction factor. It should be noted that... , , , These are the amplitude values ​​at the highest points of the four signal amplitudes. When calculating the position... and The relative positions of the detectors in the anode and cathode directions are obtained through event reconstruction. and directional count distribution, such as Figure 5 As shown in (a), the figure clearly distinguishes 16 counting peaks, corresponding to the 16 electrodes of the detector. The positions of these 16 electrodes relative to the interior of the detector are known, as shown in (a). Figure 5 As shown in (b), by combining the cathode and anode signals, the two-dimensional location of the interaction of each event within the detector can be determined. For information in the depth direction, the ratio of the cathode and anode signals can be used.

[0058] The channel compression circuit can compress the original 32-channel signal into 4-channel signals (2 anodes and 2 cathodes). At the same time, it provides a method for determining the three-dimensional position of the particle incident detector, which helps to improve the accuracy of monitoring the distribution of secondary particles generated during particle therapy.

[0059] The CZT detector, signal front-end electronics, and channel compression circuit are all housed within a shielded enclosure, which provides electromagnetic shielding to ensure the detector and circuitry operate normally in complex environments. The orthogonal strip CZT detector is positioned at the very front of the enclosure to capture secondary particles. The signal front-end electronics and channel compression circuit are secured with screws, and the signal ports within the circuits are connected using ribbon cables. All of these design features aim to achieve miniaturization, portability, and flexibility for the module.

[0060] This invention proposes an orthogonal bar CZT detector module for monitoring the range and dose of particle therapy. It allows switching between single-probe measurement mode and coincidence measurement mode according to user needs. Schematic diagrams of the single-probe measurement mode and coincidence measurement mode are shown below. Figure 6 As shown, in single-probe measurement mode, one orthogonal bar CZT detector is set up, which is connected to the data acquisition module. The data acquisition module is connected to the host computer outside the treatment room via a network cable. In coincidence measurement mode, two orthogonal bar CZT detectors are set up, both of which are connected to the data acquisition module, which is connected to the host computer outside the treatment room via a network cable. The orthogonal bar CZT detector module used in both measurement modes is the same.

[0061] The data acquisition module uses an 8-channel synchronous acquisition card, with each channel having a sampling rate of 125MHz, 12-bit resolution, and a voltage threshold of -1V to 1V. The trigger mode can be selected as internal or external trigger, and the working mode can be selected as integral sampling, peak sampling, or waveform sampling. This acquisition module has the advantages of low power consumption, portability, and high cost performance. It can meet the normal use of single-probe measurement mode and compliant measurement mode, and the channels can be expanded when there are additional requirements.

[0062] In actual use, the orthogonal bar CZT detector module needs to be placed on the side parallel to the particle beam to ensure that the anode electrode of the orthogonal bar CZT detector is distributed laterally along the beam direction. The acquisition module is placed inside the treatment room along with the orthogonal bar CZT detector module. After data acquisition, the data is processed by connecting to the host computer outside the treatment room via a network cable.

[0063] Data processing flowchart as follows Figure 7 As shown. In single-probe measurement mode, the four signals from the orthogonal bar CZT detector module enter the acquisition module. The acquisition module performs preliminary signal processing, and events exceeding the self-trigger threshold are saved. Each saved event consists of four waveform signals composed of 255 sampling points. These events are uploaded to the host computer for further processing. First, the events are filtered to select valid events, excluding events with excessive or insufficient energy, waveform stacking, or high baseline noise. Then, the waveform signals are peak-finding, and all valid events are saved as the corresponding peak values ​​of the four signals. The peak value of each event is calculated according to the aforementioned formula. , , Location. The above calculations , The position refers to the relative position of the anode and cathode electrode strips inside the detector. After correction and restoration, the position of the valid event can be obtained. The orthogonal cathode and anode divide the detector into 16×16 regions. The count of each region is counted according to the position. However, due to the influence of electrode differences, charge sharing events, statistical fluctuations, etc., the secondary particle count distribution needs to be corrected. This paper uses local statistics, interpolation, and smoothing methods to correct the count and obtain a more accurate count.

[0064] In particle therapy, the Monitor Unit (MU) is a crucial parameter, used in radiotherapy to measure the accelerator's output dose, and can be measured by the ionization chamber within the treatment head. However, the number of secondary particles measured per MU varies depending on the energy level. Based on the relationship between the total detected count and the MU, a relationship between particle range and energy (within a certain energy range) can be established. Figure 8 As shown in (a), the figure illustrates the range and The relationship between the total count and the machine hop count (MU), representing the count per unit machine hop count (MU), and the secondary particle count distribution can further verify the range. For relatively stable beam conditions, the cumulative secondary particle count per unit time is approximately linearly related to the cumulative machine hop count (MU), such as... Figure 8 As shown in (b), the cumulative machine jump count can be calculated based on the detector count, and a correction factor can be introduced to perform a preliminary calculation of the dose.

[0065] In the coincidence measurement mode, the signal preprocessing in the data acquisition module is similar to that in the single-probe measurement mode. Signals from two modules enter the data acquisition module, and a total of eight signals are saved and uploaded to the host computer. Similarly, events are filtered, and the energy and three-dimensional position of each event are calculated. The timestamp (threshold time) of each event is recorded for subsequent coincidence event judgment. A coincidence time window of 10ns and an energy window of 480keV to 540keV are set. Events that meet the above two conditions are saved. Using an image reconstruction algorithm, the range and dose distribution during particle therapy are obtained.

[0066] During the monitoring process, regardless of whether it is single-probe measurement mode or composite measurement mode, the data is packaged and uploaded after each beam exit for the above processing to obtain real-time preliminary results. The short monitoring time may lead to large errors and uncertainties in the results. Subsequent uploaded data will be further optimized and corrected to obtain more accurate results.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An orthogonal bar CZT detector module for monitoring the range and dose of particle therapy, characterized in that, include: Orthogonal strip CZT detector: used to detect radiation and generate electrical signals, including a CZT crystal, several anode electrodes disposed on the upper surface of the CZT crystal, and several cathode electrodes disposed on the lower surface of the CZT crystal, wherein the anode electrodes and cathode electrodes are both elongated strips and orthogonally arranged to each other; Signal front-end electronics circuit: including a preamplifier circuit and a filter shaping circuit, wherein the preamplifier circuit is used to amplify the electrical signal and convert the electrical signal into a voltage signal; The filtering and shaping circuit is used to further amplify the voltage signal and shape it into a quasi-Gaussian pulse signal. Channel compression circuit: This circuit uses a resistor divider network to combine pulse signals from multiple channels and compress the signals according to weights, thereby reducing the number of output signal channels. The channel compression circuit consists of two parts, processing the anode and cathode signals respectively. The anode / cathode signals input to each part enter the resistor divider network. Each channel in the resistor divider network corresponds to two resistors. The signals from multiple channels are combined into two paths and then amplified by a single stage before being output. A total of four signals are output from the anode and cathode electrodes. The resistance value in each channel is selected according to the following formula: ； ； in, This represents the maximum resistance value in the channel. This represents the total number of channels. For channel number, It is the ratio of the maximum resistance to the minimum resistance. For channel Medium resistance The resistance value, For channel Medium resistance The resistance value; Shielded enclosure: The CZT detector, signal front-end electronics circuit and channel compression circuit are all housed in a shielded enclosure to provide electromagnetic shielding.

2. The orthogonal strip CZT detector module according to claim 1, characterized in that, The preamplifier circuit includes several charge-sensitive preamplifiers, with each anode / cathode output terminal corresponding to one of the charge-sensitive preamplifiers; the filter shaping circuit is integrated from several individual channel circuits, with each individual channel corresponding to the output terminal of one charge-sensitive preamplifier, and each individual channel circuit includes a differentiating circuit and a two-stage amplification circuit.

3. A method for monitoring the range and dose of particle therapy based on an orthogonal bar CZT detector module as described in claim 1 or 2, characterized in that, Supports single-probe measurement mode and coincident measurement mode.

4. The method for monitoring the range and dose of particle therapy according to claim 3, characterized in that, The single-probe measurement mode includes the following steps: During particle therapy, a single orthogonal strip CZT detector module is placed on the side parallel to the particle beam, ensuring that the anode electrodes of the orthogonal strip CZT detector are laterally distributed along the beam direction. The orthogonal strip CZT detector module collects electrical signals and performs preprocessing and channel compression. The data acquisition module is used to acquire the four-channel electrode signals after channel compression, and the acquired data is transmitted to the host computer. The host computer processes the event data, including filtering the acquired events and calculating the energy and three-dimensional position of each event. A number of mutually orthogonal cathode and anode electrodes divide the orthogonal strip CZT detector into several regions. The secondary particle count of each region is counted according to its position and the count is corrected. The particle range distribution is obtained by counting secondary particles, and the cumulative machine jump count is calculated by counting the total number of secondary particles. The relative dose is then calculated from the cumulative machine jump count to obtain the range and dose distribution during particle therapy.

5. The method for monitoring the range and dose of particle therapy according to claim 3, characterized in that, The conformity measurement mode includes the following steps: During particle therapy, two orthogonal strip CZT detector modules are placed on opposite sides parallel to the particle beam, ensuring that the anode electrodes of the orthogonal strip CZT detectors are laterally distributed along the beam direction. The orthogonal strip CZT detector modules collect electrical signals and perform preprocessing and channel compression. A data acquisition module collects the eight-channel electrode signals after channel compression and transmits the collected data to a host computer. The host computer processes the event data, including filtering the collected events, calculating the energy and three-dimensional position of each event, and recording the timestamp of each event for event matching. A matching time window of 10 ns and an energy window of 480 keV to 540 keV are set, and events that meet both conditions are saved. An image reconstruction algorithm is used to obtain the range and dose distribution during particle therapy.

6. The method for monitoring the range and dose of particle therapy according to claim 4 or 5, characterized in that, The formula for calculating the energy and three-dimensional position of each event is as follows: ； ； ； ； ； in, , The amplitudes of the two anode signals output from the orthogonal bar CZT detector module after channel compression are given. , The amplitudes of the two cathode signals output from the orthogonal bar CZT detector module after channel compression are given. The location of the event in the direction of the anode electrode. This represents the location of the event in the direction of the cathode electrode. The relative energy of the anode electrode. The relative energy of the cathode electrode. This represents the depth position of the event relative to the detector. For the thickness of the detector, This is a correction factor.

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