Asymmetric dual-mode ionization system and method

Abstract

Embodiments of the present disclosure relate to an asymmetric dual-mode ionization system and method. The asymmetric dual-mode ionization chamber measurement system may include a first high voltage plate, a second high voltage plate, and a readout plate. The first high voltage plate may be positioned a first active volume from the readout plate. The second high voltage plate may be positioned a second active volume from the readout plate. A high voltage potential may be coupled to the first high voltage plate during a first mode and to the second high voltage plate during a second mode. Ion pairs generated by radiation fluxes passing through the first active volume during the first mode and through the second active volume during the second mode may be measured at the readout plate to determine a radiation rate of the ionizing radiation. The asymmetric dual-mode ionization chamber measurement system may advantageously measure different radiation fluxes having significantly different ranges of radiation rate fluxes.

Description

Background Art

[0001] Radiation therapy (RT) uses ionizing radiation to control or kill tumors, or to prevent tumors from recurring after other medical procedures. In cancerous tumors, ionizing radiation can damage the DNA of cancerous tissue, causing cell death. Common types of radiation therapy include radiotherapy and radiosurgery. Radiation therapy is usually delivered in relatively small doses, five days a week, for four to six weeks. Radiosurgery is usually delivered in relatively large doses in one to five treatments. The number and frequency of treatments are usually called fractionation schemes. Conventional radiation therapy modalities usually deliver a dose rate of 0.6-180 centigrays / second (cGy / sec). An emerging radiation therapy modality, called flash therapy, is usually delivered in a single treatment at a high dose rate of 40-120Gy / sec over a few seconds or less.

[0002] Now refer to Figure 1 , shows an exemplary radiotherapy system. Radiotherapy system 100 may include a particle source and accelerator or energy source 110 (hereinafter referred to as a particle or energy source), a beam transport system 120, a beam applicator 130, an ionization chamber measurement system 140, and a patient positioning system 150. Radiotherapy system 100 typically also includes many other components, such as vacuum components, power supply components, cooling components, mechanical support components, gantry components, etc., which are not necessary for understanding the corresponding aspects of the present technology and are therefore not described in detail herein.

[0003] In one embodiment, the particle or energy source 110 may include a proton, electron, or other particle source and a particle accelerator to accelerate a stream of protons, electrons, or other particles. In another embodiment, the particle or energy source 110 may include a photon, x-ray, gamma ray, or other energy source to generate a stream of photons, x-rays, gamma rays, or other energy. The particle or energy stream may be output from the particle or energy source 110 to a beam delivery system 120. In one embodiment, the beam delivery system 120 may include various bending magnets, focusing magnets, etc. to guide the particles along the beam delivery system 120. In one embodiment, the beam applicator 130 may be configured to scan the particle stream within the target area to deliver a specific amount of dose to a specific area within the target. In another embodiment, the beam applicator 130 may be a multi-leaf collimator configured to scan the energy stream within the target area. In other embodiments, the beam applicator 130 may be any other device for directing the particle or energy stream to the target area. Ionization chamber measurement system 140 may be configured to measure radiation rate, flux, beam fluence, etc. of the particle stream before it is directed to a target area of ​​a patient. Patient positioning system 150 may include a table, chair, etc. that moves in one or more directions to position a patient.

[0004] In one embodiment, the ionization chamber measurement system 140 measures charge based on the number of ion pairs (e.g., electrons and positively charged atoms) generated by incident radiation as the particle stream passes through the chamber. Conventional technology ionization chambers may include two electrodes, a high voltage source that applies a high voltage potential between the two electrodes, and circuitry that measures the current generated by the ion pairs as the ionizing radiation of the particle stream passes through the gas in the chamber. Conventional technology ionization chambers are calibrated to indicate the radiation rate, flux, beam fluence, etc. based on the measured current for a particle stream with a given range of rates, fluxes, fluences, etc. However, radiotherapy systems 100 are currently designed to deliver particles or energy fluxes for different treatment modalities with significantly different ranges of radiation rates, fluxes, beam fluences, etc. For example, the radiotherapy system 100 can be used for a first treatment modality, such as conventional radiotherapy, delivering a dose rate of 0.6-180 cGy / sec. The radiotherapy system 100 can also be used for a second treatment modality, such as flash radiotherapy, delivering a dose rate of 40-120 Gy / sec. However, implementing two very different treatment modalities currently requires swapping the ionization chamber measurement system 140. Following the swap, a lengthy calibration process is required. Consequently, switching between two different treatment modalities (e.g., conventional radiation therapy and flash radiation therapy) requires shutting down the treatment room for several hours. Therefore, there is a need to improve the availability of the radiotherapy system 100 when switching between different treatment modalities. Summary of the Invention

[0005] The present technology can be best understood by referring to the following description and accompanying drawings, which are used to illustrate embodiments of the present technology for an asymmetric dual-mode ionization system.

[0006] In one embodiment, an ionization chamber measurement system may include a high voltage source, a readout board, a first high voltage board, a second high voltage board, a switch matrix, and an ion charge measurement circuit. The high voltage source may be configured to generate a high voltage potential. The first high voltage board may be configured to form a first active volume between the first high voltage board and the readout board. The second high voltage board may be configured to form a second active volume between the second high voltage board and the readout board. The switch matrix may be configured to couple the high voltage potential to the first high voltage board during a first mode and to couple the high voltage potential to the second high voltage board during a second mode. The ion charge measurement circuit may be coupled to the readout board. The radiation flow may be configured to pass through the first active volume and the second active volume. The ion charge measurement circuit may be configured to measure ions generated by the radiation flow passing through the first active volume during the first mode and to measure ions generated by the radiation flow passing through the second active volume during the second mode.

[0007] In another embodiment, a dual-mode ionization measurement method may include receiving an indication of a first mode or a second mode. In the first mode, a high voltage potential may be coupled to a first high voltage plate of the ionization chamber. The first high voltage plate may be spaced apart from a readout plate by a first gap. When the first mode is indicated, ionizing radiation may pass through the first gap of the ionization chamber. The ion charge generated by the ionizing radiation passing through the first gap may be measured on the readout plate in the first mode. In the second mode, a high voltage potential may be coupled to a second high voltage plate of the ionization chamber. The second high voltage plate may be spaced apart from the readout plate by a second gap. When the second mode is indicated, ionizing radiation may pass through the second gap of the ionization chamber. The ion charge generated by the ionizing radiation passing through the second gap may be measured on the readout plate in the second mode. The measurement result of the radiation rate of the ionizing radiation may be determined based on the measured ion charge and the state of the ionization mode signal.

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the present technology are illustrated by way of example and not limitation in the figures of the accompanying drawings and in which like reference numerals refer to like elements and in which:

[0010] Figure 1 An exemplary particle therapy system is shown.

[0011] Figure 2A and Figure 2B An asymmetric dual-mode ionization system according to aspects of the present technique is shown.

[0012] Figure 3 A dual-mode ionization measurement method according to aspects of the present technique is shown. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to embodiments of the present technology, examples of which are illustrated in the accompanying drawings. Although the present technology will be described in conjunction with these embodiments, it will be understood that the description is not intended to limit the present technology to these embodiments. On the contrary, the present invention is intended to cover alternatives, modifications and equivalents that may be included within the scope of the present invention as defined by the appended claims. Further, in the following detailed description of the present technology, many specific details are set forth in order to provide a thorough understanding of the present technology. However, it will be understood that the present technology can be practiced without these specific details. In other cases, well-known methods, procedures, components and circuits are not described in detail so as not to unnecessarily obscure aspects of the present technology.

[0014] Some of the following embodiments of the present technology are presented in terms of routines, modules, logic blocks, and other symbolic representations of operations on data within one or more electronic devices. Descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Routines, modules, logic blocks, and / or the like are herein and generally considered to be self-consistent sequences of processes or instructions leading to desired results. These processes are those involving physical manipulations of physical quantities. Typically, although not necessarily, these physical manipulations take the form of electrical or magnetic signals capable of being stored, transferred, compared, and otherwise manipulated in an electronic device. For convenience, and in accordance with common usage, with reference to embodiments of the present technology, these signals are referred to as data,

[0015] However, it should be remembered that these terms are to be interpreted as referring to physical operations and quantities and are merely convenient labels and will be further interpreted according to terminology commonly used in the art. Unless otherwise expressly stated as apparent from the following discussion, it should be understood that discussions utilizing the present technology, discussions using terms such as "receiving" and / or similar terms refer to the actions and processes of electronic devices, such as electronic computing devices, that operate and transform data. Data is represented as physical (e.g., electronic) quantities within the logic circuits, registers, memories, and / or the like of the electronic device and is converted into other data similarly represented as physical quantities within the electronic device.

[0016] In this application, the use of disjunctives is intended to include conjunctions. The use of definite or indefinite articles is not intended to indicate cardinality. In particular, a reference to a "said" object or an "an" object is intended to also represent one of a possible plurality of such objects. The use of the terms "comprise," "comprises," "includes," "contains," etc. specifies the presence of the elements, but does not exclude the presence or addition of one or more other elements and / or groups thereof. It should also be understood that although the terms first, second, etc. can be used in this article to describe various elements, such elements should not be limited by these terms. These terms are used in this article to distinguish one element from another. For example, a first element can be referred to as a second element, and similarly, a second element can be referred to as a first element, without departing from the scope of the embodiment. It should also be understood that when an element is referred to as "coupled" to another element, the element can be directly or indirectly connected to the other element, or there can be an intermediate element. In contrast, when an element is referred to as "directly connected" to another element, there is no intermediate element. It should also be understood that the term "and or" includes any and all combinations of one or more related elements. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0017] Now refer to Figure 2A and Figure 2B, shows an asymmetric dual-mode ionization system according to aspects of the present technology. The asymmetric dual-mode ionization system may include a high voltage source 210, a switch matrix 220, an ionization chamber 230, a first high voltage board 240, a second high voltage board 250, a readout board 260, and an ion charge measurement circuit 270. The asymmetric dual-mode ionization system may be configured as follows: Figure 2A In the first mode shown and as Figure 2B The second mode is shown.

[0018] The ionization chamber 230 can be configured to pass ionizing radiation through the gas within the ionization chamber 230. The ionizing radiation can be, but is not limited to, a stream of protons, electrons, photons, or other similar radiation streams. In one embodiment, the ionization chamber 230 is open to the atmosphere. In other embodiments, the ionization chamber 230 can be sealed and filled with one or more specific gases and maintained at a predetermined pressure and temperature. In one embodiment, the first high-voltage plate 240, the second high-voltage plate 250, and the readout plate 260 can be housed within the structure of the ionization chamber 230. In another embodiment, the first high-voltage plate 240, the second high-voltage plate 250, and the readout plate 260 can comprise the ionization chamber 230 itself. The first high-voltage plate 240 can be configured to form a first active volume between the first high-voltage plate 240 and the readout plate 250. The second high-voltage plate 260 can be configured to form a second active volume between the second high-voltage plate 260 and the readout plate 250. In one embodiment, the readout plate 250 can be arranged between the first high-voltage plate 240 and the second high-voltage plate 250, wherein the first high-voltage plate 240 and the readout plate 250 are separated by a first predetermined gap (gap 1), and the second high-voltage plate 260 and the readout plate 250 are separated by a second predetermined gap (gap 2). The first predetermined gap (gap 1) can be greater than the second predetermined gap (gap 2). The structure of the readout plate 260 and the first high-voltage plate 240 and the second high-voltage plate 250 in the ionization chamber 230 is also referred to as a double-stack dual-mode ionization chamber in this article. In one embodiment, the first high-voltage plate 240, the second high-voltage plate 250 and the readout plate 260 can be metal plates. In another embodiment, the first high-voltage plate 240, the second high-voltage plate 250 and the readout plate 260 can be formed by a conductive layer (including but not limited to a polyimide layer) provided on an isolation substrate. The first high-voltage plate 240, the second high-voltage plate 250 and the readout plate 260 can have a given size and shape, including but not limited to circular, square or rectangular. In an exemplary embodiment, the first high voltage plate 240 and the second high voltage plate 250 may be spaced apart from the readout plate 260 by a first predetermined gap and a second predetermined gap (Gap 1, Gap 2) within a range of 0.1 millimeters (mm) to 10 centimeters (cm). In other embodiments, the predetermined gap may be less than 0.1 millimeters (mm) or greater than 10 centimeters (cm).

[0019] The ionizing radiation 280 can be configured to pass through the first active volume and the second active volume. For example, the ionizing radiation 280 can pass through the first high-voltage plate 240, the first active volume, the readout plate 260, the second active volume, and then through the second high-voltage plate 250. For higher radiation rates, more ion pairs will be generated in a given volume compared to lower radiation rates (e.g., gas amplification). Therefore, for lower radiation rates, the first active volume or the first predetermined gap (Gap 2) can be larger so that the number of ion pairs generated by the lower radiation rate is within a given range. Similarly, for higher radiation rates, the second active volume or the second predetermined gap (Gap 2) can be smaller so that the number of ion pairs generated by the higher radiation rate will be within the same given range.

[0020] The switch matrix 220 can be configured to couple the high-voltage power supply 210 to the first high-voltage board 240 during a first mode. In a second mode, the switch matrix 220 can be configured to couple the high-voltage power supply 210 to the second high-voltage board 250 during the second mode. For example, the switch matrix 220 can include a first switch configured to couple the high-voltage potential from the high-voltage power supply 210 to the first high-voltage board 240 during the first mode and to the second high-voltage board 250 during the second mode. A second switch of the switch matrix 220 can couple a ground potential to the first high-voltage board 240 during the second mode and to the second high-voltage board 250 during the first mode. The switching can be automatic and activated by an appropriate ionization mode control signal 290. In an exemplary embodiment, the high voltage potential from the high voltage power supply 210 applied to the first high voltage plate 240 during the first mode and to the second high voltage plate 250 during the second mode can generate an electric field strength in the range of 100 to 1000 volts per millimeter (V / mm) in the first active volume and the second active volume during the respective first and second modes. As the ionizing radiation 280 passes through the first active volume or the second active volume during the respective first and second modes, ion pairs (e.g., electrons and charged particles) are generated in the respective active volume between the respective high voltage plates 240, 250 and the readout plate 260. The free electrons and charged particles are accelerated toward the respective high voltage plates 240, 250 and the readout plate where they are collected by the respective plates.

[0021] In one embodiment, the first mode can be characterized by a first radiation rate, and the second mode can be characterized by a second radiation rate, wherein the second radiation rate is an order of magnitude greater than the first radiation rate or greater. In one embodiment, the first mode can be a conventional radiotherapy treatment modality, such as, but not limited to, proton radiotherapy. The second mode can be a second radiotherapy treatment modality, such as, but not limited to, flash proton radiotherapy. The first active volume or the first predetermined gap can be determined based on the radiation rate (e.g., dose rate) of ionizing radiation in the first mode, and the second active volume or the second predetermined gap can be determined based on the radiation rate (e.g., dose rate) of ionizing radiation in the second mode.

[0022] Ion charge measurement circuit 270 may be coupled to readout plate 260 and configured to measure ions generated by ionizing radiation 280 passing through a first active volume during a first mode and to measure ions generated by ionizing radiation 280 passing through a second active volume during a second mode. For example, in the first mode, ion charge measurement circuit 270 may measure a current generated between readout plate 260 and ground. In the second mode, ion charge measurement circuit 270 may measure a current generated between readout plate 260 and ground. In the first mode, a relatively low ionizing radiation rate (e.g., a dose rate) amplifies a relatively small number of ion pairs from the gas in a given volume. Thus, in a large active volume in the first mode, ion pairs are generated corresponding to the ionizing radiation rate, and the resulting current can be measured by ion charge measurement circuit 270. The measured current can be calibrated to indicate the ionizing radiation rate, beam flux, beam fluence, etc. in the first mode. Similarly, in a small active volume in the second mode, ion pairs are generated corresponding to the ionizing radiation, and the resulting current can be measured by ion charge measurement circuit 270. The measured current can be calibrated to indicate the ionizing radiation rate, beam flux, beam fluence, etc. in the first mode and the second mode. For example, the measured current can be correlated to indicate the dose rate for both conventional proton radiotherapy and flash proton radiotherapy modalities without requiring changes to the ionization chamber 230 and / or the ion charge measurement circuit 270. Thus, calibration can advantageously be performed once or periodically, rather than each time the mode is changed, because no changes to the ionization chamber 230 and / or the ion charge measurement circuit 270 are required.

[0023] Reference Figure 3, a dual-mode ionization measurement method according to aspects of the present technology is shown. The dual-mode ionization measurement method can begin in 310 by receiving an indication of a first mode or a second mode. In one embodiment, an ionization mode control signal indicating a first radiotherapy mode or a second radiotherapy mode can be received. For example, the ionization mode control signal can indicate a conventional proton radiotherapy modality or a flash proton radiotherapy modality. In another example, the ionization mode control signal can indicate a conventional electron radiotherapy modality or a flash electron radiotherapy modality. In yet another example, the ionization mode control signal can indicate a conventional photon radiotherapy modality or a flash photon radiotherapy modality.

[0024] In 320, when the first mode is indicated, a high voltage potential may be coupled to the first high voltage plate. In one embodiment, when the ionization mode control signal indicates the first radiotherapy mode, the high voltage potential may be coupled to the first high voltage plate of the ionization chamber, wherein the first high voltage plate is separated from the readout plate by a first gap. In an exemplary embodiment, the high voltage potential may generate an electric field strength in the range of 100 V / mm to 1000 V / mm across the first gap. In 330, when the first mode is indicated, ionizing radiation having a first rate range may pass through the ionization chamber. For example, when the ionization mode control signal indicates a conventional proton radiotherapy modality, a particle flux for the conventional proton radiotherapy modality may allow proton radiation of 0.6-180 cGy / sec to pass through the ionization chamber. In one embodiment, free electrons and ions are generated by the ionizing radiation across the first gap. The free electrons and charged particles are collected by the corresponding first high voltage plate and the readout plate. In 340, when the first mode is indicated, the ion charge generated between the first high voltage plate and the readout plate may be measured. In one embodiment, a current may be measured between a readout plate and ground when ionizing radiation having a first range of rates passes through the ionization chamber in a first mode.

[0025] Alternatively, in 350, when the second mode is indicated, a high voltage potential may be coupled to the second high voltage plate. In one embodiment, when the ionization mode control signal indicates the second radiotherapy mode, the high voltage potential may be coupled to the second high voltage plate of the ionization chamber, wherein the second high voltage plate is separated from the readout plate by a second gap. In an exemplary embodiment, the high voltage potential may generate an electric field strength in the range of 100 to 1000 V / mm across the second gap. In 360, when the second mode is indicated, ionizing radiation having a second rate range may be passed through the ionization chamber. For example, when the ionization mode control signal indicates flash proton radiotherapy modality, the particle flux for the flash proton radiotherapy modality may be 40-120 Gy / sec of proton radiation passing through the ionization chamber. In one embodiment, free electrons and charged particles are generated by the ionizing radiation passing through the second gap. The free electrons and charged particles are collected by the corresponding second high voltage plate and readout plate. In 370, when the second mode is indicated, the ion charge generated between the second high voltage plate and the readout plate may be measured. In one embodiment, a current between the readout plate and ground may be measured when ionizing radiation having a second range of rates passes through the ionization chamber in the second mode.

[0026] At 380, a measurement result of the rate, flux density, beam fluence, etc. of ionizing radiation determined based on the measured ion charge and the corresponding first mode or second mode can be output. In one embodiment, the measured current for a given mode can be calibrated to indicate the ionizing radiation rate, flux density, beam fluence, etc. Thus, for example, the measured current can be correlated to indicate the dose rate for both conventional proton radiotherapy and flash proton radiotherapy modalities without having to change each time the mode changes.

[0027] Reference again Figure 1 The dual-mode ionization chamber measurement system 200 and the method 300 can be used in the ionization chamber measurement system 150 of the radiotherapy system 100. For example, the dual-mode ionization chamber measurement system 200 can be used to measure the dose rate, etc., of the proton, electron, or photon radiation flux of the radiotherapy system 100, and the radiotherapy system 100 can be switched between conventional radiotherapy modalities and flash radiotherapy modalities without the need for recalibration after each mode switch.

[0028] Particle or energy therapy systems are just one possible application for dual-mode ionization chamber measurement systems according to aspects of the present technology. Other possible applications may include nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), accelerator magnets for high energy physics (HEP) research, and nuclear fusion systems. Dual-mode ionization chamber measurement systems according to aspects of the present technology can also be used in any other device and method where it is necessary to measure particle or energy flows with significantly different ranges of radiation rates, fluxes, beam fluences, etc.

[0029] The foregoing descriptions of specific embodiments of the present technology have been presented for purposes of illustration and description. The descriptions are not intended to be comprehensive or to limit the technology to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings. The embodiments are chosen and described to best explain the principles of the technology and its practical application, so as to enable others skilled in the art to best utilize the technology and various embodiments with various modifications as suited to the specific purposes contemplated herein. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. An asymmetric dual-mode ionization chamber measurement system, comprising: a high voltage source configured to generate a high voltage potential; Ionization chamber, including; Readout plate; a first high voltage plate arranged to form a first active volume between the first high voltage plate and the readout plate, wherein a radiation flow is configured to pass through the first active volume; as well as a second high voltage plate arranged to form a second active volume between the second high voltage plate and the readout plate, and wherein the radiation flow is configured to pass through the second active volume; a switch matrix configured to couple the high voltage potential to the first high voltage board during a first mode and to couple the high voltage potential to the second high voltage board during a second mode; as well as Ion charge measurement circuitry is coupled to the readout board and is configured to measure ions generated by the radiation flux through the first active volume during the first mode and to measure ions generated by the radiation flux through the second active volume during the second mode.

2. The asymmetric dual-mode ionization chamber measurement system according to claim 1, wherein: The rate range of the radiation flow in the second mode is greater than the rate range of the radiation flow in the first mode; and The first active volume is larger than the second active volume.

3. The asymmetric dual-mode ionization chamber measurement system according to claim 1, wherein: The radiation flow includes a proton radiation flow; The first mode comprises a conventional proton radiation therapy modality; and The second mode includes a flash proton radiation therapy modality.

4. The asymmetric dual-mode ionization chamber measurement system according to claim 1, wherein: The radiation flow includes an electron radiation flow; The first mode comprises a conventional electron radiation therapy modality; and The second mode includes a flash electron radiation therapy modality.

5. The asymmetric dual-mode ionization chamber measurement system according to claim 1, wherein: The radiation flow includes a photon radiation flow; The first mode comprises a conventional photon radiation therapy modality; and The second mode comprises a flash photon radiation therapy modality.

6. The asymmetric dual-mode ionization chamber measurement system according to claim 1, wherein the switch matrix comprises: a first switch configured to couple the high voltage potential to the first high voltage board during the first mode and to couple the high voltage potential to the second high voltage board during the second mode; as well as A second switch is configured to couple a ground potential to the second high-voltage board during the first mode and to couple the ground potential to the first high-voltage board during the second mode.

7. The asymmetric dual-mode ionization chamber measurement system of claim 1 , wherein the ion charge measurement circuit comprises a current measurement circuit configured to measure a current generated by ions flowing between the readout plate and a ground potential during the first mode and a current generated by the ions flowing between the readout plate and the ground potential during the second mode.

8. The asymmetric dual-mode ionization chamber measurement system of claim 1 , wherein the high voltage potential produces an electric field strength of between 100 V / mm and 1000 V / mm across the first active volume during the first mode, and produces an electric field strength of between 100 V / mm and 1000 V / mm across the second active volume during the second mode.

9. An asymmetric dual-mode ionization measurement method, comprising: receiving an indication of a first mode or a second mode; coupling a high voltage potential to a first high voltage plate of the ionization chamber when the first mode is indicated, wherein the first high voltage plate is spaced apart from a readout plate by a first gap; coupling the high voltage potential to a second high voltage plate of the ionization chamber when the second mode is indicated, wherein the second high voltage plate is spaced apart from the readout plate by a second gap; passing ionizing radiation having a first density range through the ionization chamber when the first mode is indicated; passing ionizing radiation having a second density range through the ionization chamber when the second mode is indicated; as well as measuring ion charge on the readout plate when an ionization mode control signal is in a first state, wherein the ion charge is generated by the ionizing radiation passing through the ionization chamber; measuring the ion charge on the readout plate when the ionization mode control signal is in a second state, wherein the ion charge is generated by the ionizing radiation passing through the ionization chamber; as well as A measurement result of the radiation rate of the ionizing radiation determined according to the measured ion charge and the state of the ionization mode signal is output.

10. The asymmetric dual-mode ionization measurement method according to claim 9, wherein: The ionizing radiation includes proton radiation; The first mode comprises a conventional proton radiation therapy modality; and The second mode includes a flash proton radiation therapy modality.

11. The asymmetric dual-mode ionization measurement method according to claim 9, wherein: The ionizing radiation includes electron radiation; The first mode comprises a conventional electron radiation therapy modality; and The second mode includes a flash electron radiation therapy modality.

12. The asymmetric dual-mode ionization measurement method according to claim 9, wherein: The ionizing radiation includes photon radiation; The first mode comprises a conventional photon radiation therapy modality; and The second mode comprises a flash photon radiation therapy modality.

13. The asymmetric dual-mode ionization measurement method according to claim 9, further comprising: coupling a ground potential to the second high voltage plate of the ionization chamber when the first mode is indicated; as well as When the second mode is indicated, the ground potential is coupled to a first high voltage plate of the ionization chamber.

14. A radiotherapy system comprising: particle or energy source; a beam delivery system coupled to the particle or energy source; a beam applicator coupled to the beam delivery system; as well as an ionization chamber measurement system coupled to the beam applicator, wherein the ionization chamber measurement system comprises; a high voltage source configured to generate a high voltage potential; a readout plate, wherein the readout plate is coupled to an ion charge measurement circuit; a first high voltage plate arranged to form a first active volume between the first high voltage plate and the readout plate, wherein the particle radiation stream is configured to pass through the first active volume; a second high voltage plate arranged to form a second active volume between the second high voltage plate and the readout plate, and wherein the particle radiation stream is configured to pass through the second active volume; a switch matrix configured to couple the high voltage potential to the first high voltage board during a first mode and to couple the high voltage potential to the second high voltage board during a second mode; as well as The ion charge measurement circuit is coupled to the readout board and is configured to measure ions generated by ionizing radiation passing through the first active volume during the first mode and to measure ions generated by ionizing radiation passing through the second active volume during the second mode.

15. The radiotherapy system of claim 14, wherein: The particle or energy sources include proton sources and accelerators; The first mode comprises a conventional proton radiation therapy modality; and The second mode includes a flash proton radiation therapy modality.

16. The radiation therapy system of claim 14, wherein: The particle or energy sources include electron sources and accelerators; The first mode comprises a conventional electron radiation therapy modality; and The second mode includes a flash electron radiation therapy modality.

17. The radiation therapy system of claim 14, wherein: The particle or energy source includes a photon source; The first mode comprises a conventional photon radiation therapy modality; and The second mode comprises a flash photon radiation therapy modality.

18. The radiation therapy system of claim 14, wherein the switch matrix comprises: a first switch configured to couple the high voltage potential to the first high voltage board during the first mode and to couple the high voltage potential to the second high voltage board during the second mode; as well as A second switch is configured to couple a ground potential to the second high-voltage board during the first mode and to couple the ground potential to the first high-voltage board during the second mode.

19. The radiation therapy system of claim 14, wherein the ion charge measurement circuit comprises a current measurement circuit.

20. The radiation therapy system of claim 14, wherein the readout board, the first high voltage board, and the second high voltage board comprise conductive plates.

21. The radiation therapy system of claim 14, wherein the readout board, the first high voltage board, and the second high voltage board comprise boards of a conductive layer on an isolated substrate.

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