CN116585624A - A beam focusing transmission system and radiotherapy equipment applied to ultra-high energy electron beams - Google Patents

Abstract

The disclosure relates to a beam focusing transmission system and radiotherapy equipment applied to ultra-high-energy electron beams. The system includes: a transmission module and a focusing module, and the quadrupole iron in the transmission module is used to focus the incoming electron beam in the outgoing direction. Diverge and focus the incoming electron beam in the parallel outgoing direction; the deflection diode in the transmission module is used to deflect the incoming electron beam at a specified angle in the parallel outgoing direction; the focusing module is used to focus on the outgoing direction Focus the electron beams emitted by the transmission module and diverge the electron beams emitted by the transmission module in the parallel exit direction. Different electrons in the electron beams emitted by the focusing module are injected into the target object at different positions and focused on the target object within the target area. According to the system of the embodiment of the present disclosure, the electron beam can be flat-focused to increase the dose deposition peak depth in the target object, and at the same time, the compactness of the entire beam focusing and transmission system is improved.

Description

A beam focusing transmission system and radiotherapy equipment applied to ultra-high energy electron beams

This disclosure claims the priority of the Chinese patent application with the application number 202211461413.0 and the application name "Electron Beam Focusing System and Radiotherapy Equipment" submitted to the China Patent Office on November 21, 2022, the entire contents of which are incorporated by reference in this disclosure middle.

technical field

The present disclosure relates to the field of electron beam processing, in particular to a beam focusing transmission system and radiotherapy equipment applied to ultra-high-energy electron beams.

Background technique

Radiation therapy refers to the use of high-energy ionizing radiation to destroy the biochemical structure of cancer cells to achieve the purpose of inhibiting tumor growth. At present, radiotherapy mainly uses rays such as electrons, photons, and protons. Traditional electron radiotherapy technology mainly uses low-energy electron beams in the energy range of 6MeV to 20MeV. Because of its shallow penetration depth and poor lateral penumbra quality, it is only suitable for treating shallow layers (within 5cm of the human body) such as skin and limbs. Tumor tissue in other parts cannot be used for human deep tumor radiotherapy. In recent years, with the development of new electron accelerator technologies such as laser plasma wake acceleration, it has become possible to use ultra-high-energy electron beams (electron beams in the energy range of 50MeV to 250MeV) to perform radiotherapy on human deep tumors.

However, when ultra-high-energy electron beams are directly and parallelly injected into the human body, high dose deposition will be formed at the entrance and exit of the human body, and it is difficult to form a dose peak in the deep lesion area of the human body, which will reduce the effect of electron radiotherapy, and miniaturized radiotherapy equipment It has become a development trend. Therefore, in order to make the ultra-high-energy electron beam form a dose peak in the deep lesion area of the human body and adapt to the miniaturized radiotherapy equipment, it is very necessary to design a beam focusing transmission system with strong focusing ability and compact structure.

Contents of the invention

In view of this, the present disclosure proposes a beam focusing transmission system and radiotherapy equipment applied to ultra-high-energy electron beams, which can not only reduce the dose deposition formed by ultra-high-energy electron beams at the entrance and exit of the human body, but also enable ultra-high-energy electron beams to The dose peak is formed in the deep lesion area of the human body, which improves the effect of electron radiotherapy and improves the compactness of the whole system, so that it can better adapt to the miniaturization of radiotherapy equipment and is conducive to reducing the spatial scale of the entire radiotherapy equipment.

According to one aspect of the present disclosure, there is provided a beam focusing transmission system applied to ultra-high-energy electron beams, including: a transmission module and a focusing module, wherein the electron beam to be focused enters the transmission module and the focusing module in sequence module; the transmission module includes at least one quadrupole iron and a deflection diode; each quadrupole iron in the transmission module is used to diverge the incoming electron beam in the focused outgoing direction and in the parallel outgoing direction Focusing the incoming electron beam, so that the electron beam emitted by the transmission module is an electron beam that diverges in the focused outgoing direction and focuses in the parallel outgoing direction; wherein, the focusing The outgoing direction is perpendicular to the magnetic field direction of the deflecting dipole iron, and the parallel outgoing direction is parallel to the magnetic field direction of the deflecting dipole iron; the deflecting dipole iron in the transmission module is used in the parallel outgoing direction deflecting the incoming electron beam at a specified angle to change the transmission direction of the incoming electron beam, the transmission direction of the electron beam emitted by the transmission module is different from the transmission direction of the electron beam before entering the transmission module; The focusing module includes a quadrupole iron, and the quadrupole iron in the focusing module is used to focus the electron beam emitted by the transmission module in the focusing outgoing direction and to focus the electron beam current emitted by the transmission module in the parallel outgoing direction. The electron beams emitted by the module are diverged, so that the electron beams emitted by the focusing module are electron beams focused on the focused emission direction and nearly parallel to the parallel emission direction, and the focusing module Different electrons in the emitted electron beam are intended to be injected into the target object at different positions and focused to target regions of interest within the target object.

In a possible implementation manner, the system further includes a control module, and the control module is electrically connected to the quadrupole iron in the transmission module, the deflection diode, and the quadrupole iron in the focusing module, respectively. The control module is used to control the quadrupole iron and the deflection diode in the transmission module according to the focal depth corresponding to the target target area and the initial beam current parameters of the electron beam to be focused And the quadrupole irons in the focusing module respectively generate magnetic induction intensity matched with the target target area, so that the electron beam emitted by the focusing module is focused to the target target area; wherein, the initial beam current parameter Including at least one of the following: electron energy, divergence angle, and beam spot size.

In a possible implementation manner, by controlling the deflection dipole iron to generate a magnetic induction intensity that matches the target target area, the energy selection of electrons with different energies in the incoming electron beam is realized; by controlling the transmission The quadrupole iron in the module and the quadrupole iron in the focusing module respectively generate magnetic induction intensity matching the target target area, so as to control the different electrons in the electron beam emitted by the focusing module when they are injected into the target object The incident position and angle of incidence, and the depth of focus after entering the target object.

In a possible implementation manner, the specified angle includes any angle from 30 degrees to 150 degrees.

In a possible implementation manner, when the transmission module includes at least two quadrupole irons, the deflection diodes in the transmission module are located in any pair of adjacent two quadrupole irons in the transmission module. Between the quadrupole irons, or before at least two quadrupole irons in the transmission module, or behind at least two quadrupole irons in the transmission module.

In a possible implementation manner, the transmission module and the focusing module are arranged outside the beam transmission pipe of the electron beam, wherein the beam transmission pipe is located at the deflection diode and The specified angle is the same as the corner.

In a possible implementation manner, the electron beam current includes an ultra-high-energy electron beam current of 50 MeV to 250 MeV generated by an ultra-high-energy electron source.

According to another aspect of the present disclosure, a radiotherapy device is provided, including: an ultra-high-energy electron source for generating an electron beam; and the above-mentioned beam focusing transmission system.

In a possible implementation manner, the focused beam transmission system is arranged in a mechanical arm of the radiotherapy equipment, and the mechanical arm can rotate around a target object.

According to an embodiment of the present disclosure, the electron beams are diverged and emitted in the focused emission direction through the quadrupole iron in the transmission module and focused and emitted in the parallel emission direction, and the focusing is performed by the quadrupole iron in the focusing module. In the exit direction, the divergent electron beams emitted by the transmission module are changed into strong focused exits, and in the parallel exit direction, the focused electron beams emitted by the transmission module are changed into parallel exits, which can make the electron beams emitted by the focusing module flat at a large angle The formula is strongly focused to the target area of the target object (such as the lesion area inside the patient's body), and because different electrons in the electron beam emitted by the focusing module will shoot into the target object at different positions and focus on the target area in the target object area, which can reduce the dose deposition of the electron beam at the entrance/exit of the target object, and realize the peak dose deposition of the electron beam in the target area, thereby greatly reducing the radiation dose to other normal tissues in the target object and improving the effect of electron radiotherapy At the same time, the deflection diode is used to deflect the electron beam at a specified angle, and the entire beam focusing transmission system can be folded spatially, making the entire beam focusing transmission system more compact and more suitable for miniaturized radiotherapy equipment.

Other features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the specification, serve to explain the principles of the disclosure.

FIG. 1 shows a schematic diagram of a dose peak comparison between a parallel beam and a focused beam according to an embodiment of the present disclosure.

FIG. 2 shows a schematic diagram of a beam focusing delivery system according to an embodiment of the present disclosure.

FIG. 3 shows a schematic diagram of a beam focusing delivery system according to an embodiment of the present disclosure.

Fig. 4a and Fig. 4b show schematic diagrams of the movement trajectory of the electron beam according to an embodiment of the present disclosure.

FIG. 5 shows a schematic diagram of a beam focusing delivery system according to an embodiment of the present disclosure.

Figures 6a, 6b and 6c illustrate dose distribution diagrams of electron beam current deposition in a body of water according to an embodiment of the disclosure.

Detailed ways

Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numbers in the figures indicate functionally identical or similar elements. While various aspects of the embodiments are shown in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments.

In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific implementation manners. It will be understood by those skilled in the art that the present disclosure may be practiced without some of the specific details. In some instances, methods, means, components and circuits that are well known to those skilled in the art have not been described in detail so as to obscure the gist of the present disclosure.

Radiation therapy uses high-energy ionizing radiation such as X-rays, gamma rays, electrons, protons, etc. to destroy the biochemical structure of cancer cells to achieve the purpose of inhibiting tumor growth. Since the above radiation can also damage normal tissue cells, it is necessary to formulate a certain treatment plan to minimize the side effects of radiation on normal tissue.

At present, clinical radiation therapy mainly uses photons, protons or electrons for irradiation. The most widely used technical scheme is the photon scheme. The cost of the photon scheme is reasonable, and the scheme execution efficiency is high, but there are limitations in the dose deposition of organs at risk and the radiobiological effect; the advantages of the proton/heavy ion scheme in dose distribution are better than the former, but Its construction cost is too high, and the treatment efficiency is low. A treatment center can only treat about 1,000 people per year; traditional electron beam radiotherapy mainly uses low-energy electron beams in the range of 6MeV-20MeV output by radio frequency linear accelerators, and the maximum penetration depth is insufficient and poor The quality of the lateral penumbra restricts the application of the above techniques in actual treatment, especially in deep tumor radiotherapy.

Ultra-high-energy electron beams (50MeV-250MeV) overcome the above-mentioned shortcomings of low-energy electron beams, and can deposit deeper doses and sharper lateral penumbras. Recently, many Monte Carlo simulations have compared the therapeutic effects of photons, protons and ultra-high-energy electrons on prostate, brain and other tumors through intensity-modulated radiotherapy (IMRT). Studies have found that the therapeutic effect of ultra-high-energy electron beams is significantly better than that of photon beams, and slightly inferior to that of proton beams. Considering that the construction cost of electron accelerators is generally much lower than that of proton accelerators, radiotherapy devices based on ultra-high-energy electron beams have great potential market value. In recent years, new electron accelerator technologies based on laser plasma coda waves and X-band electron linear accelerators can further reduce the scale of accelerators to desktop scale, making the advantages of ultra-high-energy electron radiotherapy more obvious.

Although ultra-high-energy electron beam radiotherapy technology has certain advantages over X-ray technology, it still produces high dose deposition on the surface of the human body and other normal tissue areas, and thus there is a certain risk of radiation toxicity. As shown in Figure 1, parallel beams (i.e., parallel incident ultra-high-energy electron beams) are difficult to form a dose deposition peak at a deeper target depth, which is not advantageous for the treatment of deep tumors located between 10cm and 20cm in the body, while Focusing the beam (that is, focusing the incident ultra-high-energy electron beam) can form a better dose deposition peak at the target depth; therefore, it is necessary to design a beam focusing transmission system that can strongly focus the ultra-high-energy electron beam to the deep lesion area. On this basis, it is also very necessary to further improve the high compactness of the beam focus transmission system to realize the miniaturization of electronic radiotherapy equipment.

In view of this, the embodiments of the present disclosure provide a beam focusing transmission system applied to ultra-high-energy electron beams, which can be applied to radiotherapy equipment for ultra-high-energy electron beams, and can be adapted to radiotherapy for deep tumors in the human body, especially in vivo Among them, the spatial scale of radiotherapy equipment can be further reduced, and the ultra-high-energy electron beam can be guaranteed to achieve the peak dose deposition in the deep tumor area.

The beam focusing transmission system provided by the embodiments of the present disclosure will be described in detail below with reference to FIG. 2 to FIG. 5 .

FIG. 2 shows a schematic diagram of a beam focusing delivery system according to an embodiment of the present disclosure. The focused beam transmission system can be applied to various electron radiotherapy equipment, for example, radiotherapy equipment using ultra-high-energy electron beam current. As shown in FIG. 2, the beam focusing transmission system includes: a transmission module 201 and a focusing module 202, wherein the electron beam to be focused enters the transmission module 201 and the focusing module 202 in sequence;

The transmission module 201 includes at least one quadrupole iron and deflection diodes; each quadrupole iron in the transmission module is used to diverge the incoming electron beam in the focused outgoing direction and to diverge the incoming electron beam in the parallel outgoing direction. The current is focused, so that the electron beam emitted by the transmission module 201 is an electron beam that diverges in the focused outgoing direction and focuses in a parallel outgoing direction; wherein, the focused outgoing direction is perpendicular to the magnetic field direction of the deflection diode, The parallel outgoing direction is parallel to the magnetic field direction of the deflection diode;

The deflection diode in the transmission module 201 is used to deflect the incoming electron beam at a specified angle in the parallel exit direction to change the transmission direction of the incoming electron beam. The transmission direction of the electron beam emitted by the transmission module is the same as the incoming transmission direction. The transmission direction of the electron beam in front of the module is different;

The focusing module 202 includes a quadrupole iron, and the quadrupole iron in the focusing module is used to focus the electron beams emitted by the transmission module in the focusing outgoing direction and diverge the electron beams emitted by the transmission module in the parallel outgoing direction, so as to The electron beam flow emitted by the focusing module 202 is focused and outgoing in the focused outgoing direction and nearly parallel outgoing in the parallel outgoing direction, and different electrons in the electron beam flow emitted by the focusing module 202 are used to inject at different positions Target the object and focus on the target area of interest within the target object.

Wherein, the electron beam entering the above-mentioned beam focusing transmission system can be an ultra-high-energy electron beam with 50MeV-250MeV generated by an ultra-high-energy electron source. The ultra-high-energy electron source may include accelerators such as a laser plasma accelerator and a high-gradient electron linear accelerator, and the embodiments of the present disclosure do not limit the type of the ultra-high-energy electron source. It is known that when the ultra-high-energy electron beam generated by the ultra-high-energy electron source propagates in the material, due to scattering, the electron beam will diverge in the form of a pencil beam. position and angle) into the lesion area of the human body, the surface layer of the human skin (that is, the entrance and exit of the human body) will deposit excessively high radiation doses. Electrons enter the human body at different positions and focus on the lesion area. Embodiments of the present disclosure can emit electron beams in a flat and strong focusing manner to achieve a peak dose deposition in a deeper position inside the human body.

Among them, by diverging and then focusing the electron beam in the focused outgoing direction, and at the same time focusing and then diverging in the parallel outgoing direction, different electrons in the electron beam emitted by the system can be injected into the human body at different positions and then The peak of dose deposition is formed in the lesion area of the human body, which is conducive to improving the effect of electron radiotherapy. Among them, the dose represents the energy given by the electron radiation to the substance per unit mass. The target object can be understood as the object to be radiotherapy, such as human body, animal, etc., and the target area can be understood as the target area to be radiotherapy, such as the tumor in the human body. Lesion area.

It can be known that, since the magnetic field distribution of a single quadrupole iron will produce focusing and defocusing effects on the electron beam at the same time, and the direction of focusing and defocusing on the electron beam in the magnetic field is opposite, therefore, in a certain It is difficult to achieve strong focusing in two directions of action within the transmission distance, so the embodiment of the present disclosure adopts a "flat focus" method that achieves strong focusing in the focused output direction and approximately parallel output in the parallel output direction.

In practical applications, the magnetic field direction of the deflection dipole iron in the transmission module 201 can be set in advance. Since the focused outgoing direction is parallel to the magnetic field direction of the deflection dipole iron, and the parallel outgoing direction is perpendicular to the magnetic field direction of the deflection dipole iron, so in the deflection After the magnetic field direction of the dipole iron is fixed, the focusing outgoing direction and the parallel outgoing direction are also known and fixed, and then the polarities of the quadrupole irons in the transmission module 201 and the focusing module 202 are also known and fixed. The polarity can include a focusing direction with a focusing effect and a defocusing direction with a defocusing effect, wherein the direction of the magnetic field of the deflected dipole iron is perpendicular to the parallel outgoing direction and parallel to the focused outgoing direction (that is, it is consistent with the lateral focusing direction of the beam. ), it can avoid that the divergent beams generated by the defocusing action of the quadrupole irons in the focusing output direction have different propagation trajectories in the deflection diodes, even if the divergent beams have the same propagation trajectories in the deflection diodes.

Optionally, the polarities of the quadrupole irons in the transmission module 201 may be the same, and the polarities of the quadrupole irons in the focusing module 202 and the polarities of the quadrupole irons in the transmission module 201 may be opposite. Wherein, the polarities of each quadrupole iron in the transmission module 201 are consistent, which means that each quadrupole iron in the transmission module 201 has a defocusing effect on the electron beam current in the focusing and outgoing direction and has a uniform effect on the electron beam current in the parallel outgoing direction. is the focusing effect; and the polarity of the quadrupole iron in the focusing module 202 is opposite to the polarity of the quadrupole iron in the transmission module 201, which means that the quadrupole iron in the focusing module 202 has a focusing effect on the electron beam in the focused outgoing direction And it has a defocusing effect on the electron beam in the parallel exit direction; in this way, the electron beam emitted by the system is a strongly focused exit beam in the focused exit direction, and a parallel exit beam in the parallel exit direction.

Optionally, when more than two quadrupole irons are included in the transmission module 201, there may also be quadrupole irons with opposite polarities in the transmission module 201, that is, the transmission module 201 may include a part that opposes the electron beam in the focused outgoing direction. The current is a quadrupole iron that defocuss and focuses on the electron beam in the parallel exit direction, and partly focuses on the electron beam in the focused exit direction and defocuses the electron beam in the parallel exit direction As for the quadrupole, it is sufficient to ensure that the electron beams emitted by the transmission module 201 diverge in the focused outgoing direction and focus in the parallel outgoing electron beams, which is not limited in this embodiment of the present disclosure.

Exemplarily, in the beam focusing transmission system shown in Figure 3, the transmission module 201 includes a quadrupole iron 2011, a deflection diode 2012, and a quadrupole iron 2013; the focusing module 202 includes a quadrupole iron 2021; wherein, the quadrupole iron 2011 diverges the incoming electron beam in the focusing outgoing direction and focuses the incoming electron beam in the parallel outgoing direction, and the deflection diode 2012 deflects the electron beam emitted by the quadrupole 2011 by a specified angle α, also That is, the transmission direction of the electron beam is changed, wherein the specified angle can include any angle between 30 degrees and 150 degrees, and the quadrupole iron 2013 further deflects the electron beam emitted by the diode iron 2012 in the focused outgoing direction. Diverging and further focusing the electron beams emitted by the deflecting diode 2012 in the parallel outgoing direction; the quadrupole 2021 in the focusing module 202 focuses the electron beams emitted by the quadrupole 2013 in the focused outgoing direction and The electron beams emitted by the quadrupole iron 2013 are diverged in the parallel exit direction, so that the electron beams emitted by the quadrupole iron 2021 are focused and exited in the focused exit direction and parallel exited in the parallel exit direction. , and different electrons in the electron beam emitted by the quadrupole iron 2021 will inject into the target object at different positions and focus on the target target area in the target object, so as to achieve a large-angle flat focus to the target target area, and achieve Radiation dose deposition in the target area.

Among them, in the beam focusing transmission system shown in Fig. 3, the function of the quadrupole iron 2011 in the focused outgoing direction is to make the electron beam diverge from the approximate pencil beam into a divergent beam, and the quadrupole iron 2013 makes the electron beam diverge in the focused outgoing direction Let the electron beam diverge further. When it reaches the quadrupole 2021, after the divergence of the quadrupole 2011 and the quadrupole 2013, the divergence scale and the beam spot size of the electron beam in the focused outgoing direction are already very large. 2021 makes the divergent electron beam focus to the target target area at a large angle; while in the parallel outgoing direction, the quadrupole 2011 and quadrupole 2013 focus the electron beam with the initial divergence angle into a smaller beam spot, and then through the defocusing effect of the quadrupole iron 2021, the near-parallel emission of the electron beam current in the parallel emission direction is realized; the deflection diode iron 2012 is set in the gap between the quadrupole iron 2011 and the quadrupole iron 2013, so that the electron beam The current deflection specifies an angle α (for example, α=90 degrees), so that the transmission direction of the electron beam is folded in space, which is beneficial to realize the folding in space of the beam focus transmission system, and makes the beam focus transmission system more compact.

Exemplarily, based on the beam focusing transmission system shown in FIG. 3, FIG. 4a shows the trajectory of the electron beam current in the focused outgoing direction of the beam focusing transmission system, and FIG. The trajectory of the electron beam current in the direction, as shown in Figure 4a, in the focused outgoing direction, the quadrupole iron 2011 and the quadrupole iron 2013 have a defocusing effect on the electron beam current, and the quadrupole iron 2021 has a focusing effect on the electron beam current. That is to say, the electron beams gradually diverge and exit after passing through the quadrupole 2011 and quadrupole 2013, and focus and exit after passing through the quadrupole 2021; as shown in Figure 4b, in the parallel exit direction, the quadrupole 2011 and The quadrupole 2013 has a focusing effect on the electron beam, and the quadrupole 2021 has a defocusing effect on the electron beam. It should be understood that due to the comprehensive focusing of the quadrupole 2011 and the quadrupole 2013 on the electron beam in the parallel exit direction The effect is strong. The defocusing effect of the quadrupole iron 2021 on the electron beam current only offsets the comprehensive focusing effect of the quadrupole iron 2011 and the quadrupole iron 2013 on the electron beam current, which makes the electron beam emitted by the quadrupole iron 2021 The flow produces the effect of nearly parallel exit in the parallel exit direction, or the divergence angle in the parallel exit direction will not be very large.

Among them, the divergent emission can be understood as the electrons in the electron beam are emitted with a divergent effect, or in other words, the trajectory of the electrons in the divergent emitted electron beam is divergent, for example, the quadrupole iron 2011 and the quadrupole iron 2013 in Figure 4a emit The electron beam current; focused emission can be understood as the electrons in the electron beam are emitted with a focusing effect, or in other words, the trajectory of the electrons in the focused and emitted electron beam is focused, such as the quadrupole iron 2021 in Figure 4a. Electron beam, parallel exit can be understood as the electrons in the electron beam maintain parallel effect and exit, or in other words, the trajectory of electrons in the parallel exit electron beam is parallel to each other.

It should be understood that the beam focusing transmission system shown in FIG. 3 is a possible implementation provided by the embodiments of the present disclosure, and does not represent all the implementations of the embodiments of the present disclosure. In fact, those skilled in the art can according to Actual requirements (such as the hardware structure of radiotherapy equipment, the spatial scale of quadrupole irons and dipole irons, etc.) custom design the number of quadrupole irons in the transmission module 201, design the position and deflection of the deflection diodes in the transmission module 201 The specified angle deflected by the dipole iron is not limited in this embodiment of the present application.

For example, if the transmission module 201 is designed to include a quadrupole iron, the deflection diode can be located behind the quadrupole iron, and if the transmission module 202 is designed to include two quadrupole irons, the deflection diode can be located behind the two quadrupole irons. It can also be located after or before the two quadrupole irons. If the design transmission module 201 contains three quadrupole irons, the deflection diode can be located behind the first two quadrupole irons, or it can be located in the front quadrupole iron After that, it can also be located behind three quadrupole irons; that is, when the transmission module includes at least two quadrupole irons, the deflection diode in the transmission module can be located in any pair of adjacent two pole irons in the transmission module. between four quadrupole irons, or after at least two quadrupole irons in the transmission module, or before at least two quadrupole irons in the transmission module.

It should be understood that the deflection angle that the deflection diode can deflect can include any angle from 30 degrees to 150 degrees, specifically, for example, it can include custom angles such as 90 degrees, 80 degrees, 95 degrees, etc., depending on the beam current The overall hardware structure of the focusing system, but no matter what the deflection angle of the deflection diode is, the focusing module 202 should be located in the transmission direction of the electron beam emitted by the transmission module 201 . The transmission direction of the electron beam can be understood as the overall trajectory of the electron beam in the system. For example, the transmission direction of the electron beam shown in FIG. The previous transport direction becomes portrait.

It can be known that the electron beam is usually transmitted in the beam transmission pipeline, the beam transmission pipeline can be a vacuum-sealed pipeline, for example, and the transmission module 201 and the focusing module 202 can be arranged outside the beam transmission pipeline of the electron beam, that is, , the quadrupole iron in the transmission module 201, the deflection diode iron and the quadrupole iron in the focusing module 202 are all arranged outside the beam transmission pipeline of the electron beam, because the deflection diode can deflect the transmission direction of the electron beam Specify the angle, so the beam transmission pipe has the same rotation angle as the specified angle at the deflection diode, for example, in Fig. The lines may represent beam delivery ducts that have the same rotation angle as the specified angle of 90° at the deflection diode 2012 . It should be understood that, the embodiment of the present disclosure does not limit the arrangement manner of the transmission module 201 and the focusing module 202 outside the beam transmission pipeline.

Wherein, the quadrupole iron in the transmission module 201, the deflection dipole iron and the quadrupole iron in the focusing module 202 can all be electromagnets, so the quadrupole iron, the deflection dipole iron and the The current size of the quadrupole irons in the focusing module 202 is used to control the magnitude of the magnetic induction intensity of each quadrupole iron and deflection dipole irons; and, the quadrupole irons, deflection dipole irons and focusing The current direction of the quadrupole irons in the module 202 is used to control the polarity (or magnetic field direction) of each quadrupole iron and the magnetic field direction of the deflection dipole irons respectively, thereby realizing the quadrupole irons and the deflection dipole irons in the transmission module 201 of the system. The iron and the quadrupole iron in the focusing module 202 need to play their respective functional roles.

In practical applications, under the condition that the electron energy of the electron beam current is fixed, the magnetic induction intensity of the quadrupole iron and the deflection dipole iron in the transmission module 201 can be fixed, and by adjusting the magnetic induction intensity of the quadrupole iron in the focusing module 202 size, to realize that the electron beam emitted by the beam focusing transmission system can be focused to the target target area at any depth. It is also possible to focus the beam by adjusting the magnetic induction intensity of the quadrupole iron in the transmission module 201, the deflection diode iron, and the quadrupole iron in the focusing module 202 when the electron energy of the electron beam current is not fixed. The electron beam emitted by the transmission system can be focused to the target area at any depth.

Wherein, the magnetic induction intensity that the quadrupole iron in the focusing module 202 should have can be determined according to the focal depth corresponding to the target target area, and according to the magnetic induction intensity that the quadrupole iron in the focusing module 202 should have, adjust the flow through the quadrupole in the focusing module 202. The magnitude of the current of the iron, so that the electron beam emitted by the focusing module 202 can be focused to the target target area; or, the transmission can also be determined according to the focal depth corresponding to the target target area and the initial beam current parameters of the electron beam to be focused. The quadrupole iron in the module 201, the deflection dipole iron and the quadrupole iron in the focusing module 202 should have the magnetic induction respectively, and according to the quadrupole iron in the transmission module 201, the deflection dipole iron and the quadrupole iron in the focusing module 202 should respectively With the magnetic induction intensity, adjust the current flowing through the quadrupole iron in the transmission module 201, the deflection diode iron and the quadrupole iron in the focusing module 202, so that the electron beam emitted by the focusing module 202 can be focused to the target area.

Among them, the initial beam parameters can be understood as the beam parameters of the electron beam generated by the ultra-high-energy electron source (such as a laser plasma accelerator or a high-gradient electron linear accelerator), or the electron beam parameters before entering the beam focusing transmission system. Beam parameters, the initial beam parameters may include at least one of the following: electron energy, divergence angle, and beam spot size. Depth of focus can be understood as the distance between the quadrupole iron in the focusing module 202 and the target area, or the distance between the launch port of the laser plasma accelerator and the target area, or the distance between the surface layer of the target object and the target area. distance between areas, etc. In practical applications, the focal depth and initial beam current parameters may be input into the system as known parameters, and the embodiment of the present disclosure does not limit the manner of obtaining the focal depth and initial beam current parameters.

It should be understood that the magnetic induction intensity required by the same beam parameter at different depths of focus is different, and the magnetic induction intensity required by different beam parameters at the same depth of focus is also different. Therefore, those skilled in the art can theoretically Combining the analysis with the Monte Carlo simulation verification, the magnetic induction intensity of each electromagnet (including the quadrupole iron in the transmission module 201, the deflection dipole iron and the quadrupole iron in the focusing module 202) under different beam parameters and different focus depths should be obtained , that is, the corresponding relationship between different beam current parameters and different focal depths and the magnetic induction intensity of each electromagnet is obtained. The corresponding relationship can be a linear relationship or a nonlinear relationship, so that based on the corresponding relationship, the above-mentioned The magnetic induction intensity of any electromagnet in the beam focusing transmission system; or, the corresponding relationship can also be converted into a MAP chart, and in practical applications, query at any focal depth and any initial beam parameter by means of table lookup Below, the magnetic induction intensity that any electromagnet in the above-mentioned beam focusing transmission system should have. The embodiment of the present disclosure does not limit the manner of determining the above correspondence.

According to the implementation case of the present disclosure, the electron beam current is diverged and emitted in the focused emission direction through the quadrupole iron in the transmission module, and the electron beam current is focused and emitted in the parallel emission direction, and the quadrupole iron in the focusing module is used to focus In the exit direction, the divergent electron beams emitted by the transmission module are changed into strong focused exits, and in the parallel exit direction, the focused electron beams emitted by the transmission module are changed into parallel exits, which can make the electron beams emitted by the focusing module flat at a large angle The formula is strongly focused to the target area of the target object (such as the lesion area inside the patient's body), and because different electrons in the electron beam emitted by the focusing module will shoot into the target object at different positions and focus on the target area in the target object area, which can reduce the dose deposition of the electron beam at the entrance/exit of the target object, and realize the peak dose deposition of the electron beam in the target area, thereby greatly reducing the radiation dose to other normal tissues in the target object and improving the effect of electron radiotherapy At the same time, the deflection diode is used to deflect the electron beam at a specified angle, and the entire beam focusing transmission system can be folded spatially, making the entire beam focusing transmission system more compact and more suitable for miniaturized radiotherapy equipment.

As mentioned above, the quadrupole iron and the deflection dipole iron in the transmission module 201 can adopt a fixed magnetic induction intensity, and by adjusting the magnetic induction intensity of the quadrupole iron in the focusing module 202, the electron beam emitted by the above-mentioned beam focusing transmission system can be made Can focus to the target target area of arbitrary focus depth, optionally, the beam focus transmission system also includes a control module 203, the control module 203 can be electrically connected to the quadrupole iron 2021 in the focus module 202;

The control module 203 is used to control the quadrupole iron 2021 in the focusing module 202 to generate a magnetic induction intensity matching the target target area according to the focal depth corresponding to the target target area, so that the electron beam emitted by the focusing module 202 is focused on the target target area .

It should be understood that magnetic fields with different magnetic induction intensities have different effects on electron beams with different energies. Therefore, the beam focusing transmission system in which the control module 203 is electrically connected to the quadrupole iron 2021 in the focusing module 202 can be applied to electron beams In the focused transmission scenario where the initial beam parameters of the stream are fixed, the effect of the quadrupole iron and the deflection diode in the transmission module 201 on the electron beam with the same initial beam parameters is the same, so it can be achieved only by adjusting the focus The magnetic induction intensity of the quadrupole iron in the module 202 is used to control the focus of the electron beam to the target area of any focus depth.

Wherein, since the control module 203 is electrically connected to the quadrupole iron 2021 in the focusing module 202, the control module 203 can supply power to the quadrupole iron 2021 in the focusing module 202. Specifically, the control module 203 can control the The magnitude of the current of the quadrupole iron 2021 in the focusing module 202 is used to control the magnetic induction intensity generated by the quadrupole iron 2021 in the focusing module 202 to match the target area. It should be understood that the embodiments of the present disclosure do not impose limitations on the hardware structure, hardware type, etc. of the control module 203, as long as the functions it should have can be realized.

As mentioned above, the depth of focus can be understood as the distance between the quadrupole iron in the focusing module 202 and the target target area, or it can also be the emission port and the target of an ultra-high-energy electron source (such as a laser plasma accelerator or a high-gradient electron linear accelerator). The distance between the target areas may also be the distance between the surface layer of the target object and the target target area, etc., which is not limited by the embodiments of the present disclosure. In practical applications, the depth of focus can be input into the system as a known parameter, and the embodiment of the present disclosure does not limit the acquisition method of the depth of focus. For example, the above-mentioned control module 203 can communicate with an external computing device to obtain the target Depth of focus of the target area; of course, the control module 203 may also directly acquire the depth of focus manually input by the user, which is not limited in this embodiment of the present disclosure.

Based on this, the above-mentioned control module 203 controls the quadrupole iron 2021 in the focusing module 202 to generate a magnetic induction intensity matching the target target area according to the focal depth corresponding to the target target area, so that the electron beam emitted by the focusing module 202 is focused and transmitted to the target. The target area includes: determining the target magnetic induction intensity that the quadrupole iron 2021 should have according to the focal depth corresponding to the target target area and the corresponding relationship between the preset different focal depths and the magnetic induction intensity of the quadrupole iron 2021; 2021 should have the target magnetic induction intensity, and control the magnitude of the current flowing through the quadrupole iron 2021, so that the electron beam emitted by the focusing module 202 can be focused to the target area. In this way, under the condition that the initial beam parameters of the electron beam are fixed, the peak dose of the electron beam at the target target area at any focus depth can be realized.

As mentioned above, the magnetic induction intensity required at different focus depths is different. In order to focus the electron beam to the target area at any focus depth, the focus at different focus depths can be obtained through theoretical analysis combined with Monte Carlo simulation verification. The magnetic induction intensity that the quadrupole iron 2021 in the module 202 should have, that is, the corresponding relationship between different focus depths and the magnetic induction intensity of the quadrupole iron 2021 can be quickly determined based on the corresponding relationship. The iron 2021 should have the target magnetic induction intensity, that is, determine the magnetic induction intensity matching the target target area. The embodiment of the present disclosure does not limit the manner of determining the above correspondence.

According to the embodiment of the present disclosure, the control module 203 can efficiently control the quadrupole iron in the focusing module 202 in the system to generate a magnetic induction intensity that matches the target target area, so that the system can efficiently focus and transmit the electron beam to any focal depth The target area under the target can achieve the peak dose deposition of the electron beam at any focal depth.

Considering that in actual situations, there may also be a need to focus and transmit electron beams with different initial beam parameters to the target target area, that is, the initial beam parameters of the electron beams injected into the beam focus delivery system may be different Therefore, the quadrupole iron 2011 and 2013 in the transmission module 201, the deflection dipole iron 2012 and the quadrupole iron 2021 in the focusing module 202 can all be electromagnets with adjustable magnetic induction, so as to adjust the magnetic induction of each electromagnet Intensity, to realize the focused transmission of electron beams with different initial beam current parameters to the target target area under any focus depth. Optionally, as shown in FIG. 5, the control module 203 can be electrically connected to the quadrupoles in the transmission module 201 respectively Irons 2011 and 2013, deflection diode iron 2012 and quadrupole iron 2021 in focusing module 202.

The control module 203 is used to control the quadrupole irons 2011 and 2013 in the transmission module 201, the deflection diode iron 2012 and the focusing module 202 according to the focal depth corresponding to the target target area and the initial beam current parameters of the electron beam to be focused. The quadrupole irons 2021 respectively generate the magnetic induction intensity matching the target target area, so that the electron beam emitted by the focusing module 202 can be focused to the target target area; wherein, the initial beam current parameters include at least one of the following: electron energy, divergence angle, beam spot size.

Among them, by controlling the deflection dipole iron to generate a magnetic induction intensity that matches the target area, the energy selection of electrons with different energies in the incoming electron beam can be realized; by controlling the quadrupole iron in the transmission module and the quadrupole iron in the focusing module The pole irons respectively generate magnetic induction intensity matching the target area, and realize the control of the incident position and incident angle of different electrons in the electron beam emitted by the focusing module when they are injected into the target object, as well as the focal depth after entering the target object.

It should be understood that the energies of electrons in the same electron beam are usually different, and electrons with different energies will have different deflection radii under the same magnetic induction. The electrons of different energies in the incoming electron beam are selected, so that the electrons in the electron beam entering the focusing module 202 are high-energy electrons that meet the requirements of radiotherapy.

In practical applications, the correspondence between the magnetic induction intensity of each quadrupole iron in the transmission module and the focusing module under different initial beam current parameters and the incident position, incident angle and focus depth can be determined through theoretical analysis combined with simulation experiments. Based on the corresponding relationship, the quadrupole iron in the transmission module and the quadrupole iron in the focusing module are controlled to generate the electron beam corresponding to the target target area according to the focal depth corresponding to the target target area and the initial beam current parameters of the electron beam to be focused. Matching magnetic induction intensity, so as to realize the control of the incident position and incident angle of different electrons in the electron beam emitted by the focusing module when entering the target object, as well as the focus depth after entering the target object.

Wherein, since the control module 203 is electrically connected to the quadrupole irons 2011 and 2013 in the transmission module 201, the deflection diode 2012 and the quadrupole iron 2021 in the focusing module 202, the control module 203 can respectively send signals to the quadrupole irons in the transmission module 201. Irons 2011 and 2013, deflection diode iron 2012, and quadrupole iron 2021 in the focusing module 202 provide power. Specifically, the control module 203 can control the quadrupole iron 2011 and 2013, deflection diode iron 2012 and the current magnitude of the quadrupole iron 2021 in the focusing module 202 to control the quadrupole iron 2011 and 2013 in the transmission module 201, the deflection diode 2012 and the quadrupole iron 2021 in the focusing module 202 to generate and match the target area respectively. of magnetic induction.

In practical applications, the above-mentioned control module 203 can communicate with an external computing device to obtain the focus depth of the target target area and the initial beam current parameters of the electron beam; of course, the control module 203 can also directly obtain the user's manual input The depth of focus and the initial beam parameters are not limited by this embodiment of the present disclosure.

Based on this, the above-mentioned control module 203 controls the quadrupole irons 2011 and 2013, the deflection diode iron 2012 and the focusing module 202 in the transmission module 201 according to the focal depth corresponding to the target target area and the initial beam current parameters of the electron beam to be focused The quadrupole iron 2021 in each generates the magnetic induction intensity matched with the target target area, so that the electron beam current emitted by the focusing module 202 can be focused to the target target area, which may include: according to the focal depth corresponding to the target target area, the initial electron beam current Correspondence between the beam current parameters and different preset beam current parameters and different focus depths and the magnetic induction intensity of each electromagnet (including the quadrupole iron in the transmission module 201, the deflection dipole iron and the quadrupole iron in the focusing module 202) , to determine the target magnetic induction intensity that each of the above-mentioned electromagnets should have respectively; according to the target magnetic induction intensity that each of the above-mentioned electromagnets should have respectively, control the magnitude of the current flowing through each of the above-mentioned electromagnets, so that the electron beams emitted by the focusing module 202 are focused on target area. In this manner, the peak dose deposition of the electron beam at the target target area at any focal depth can be achieved without the initial beam parameters of the electron beam being fixed.

As mentioned above, different initial beam parameters require different magnetic induction at different focus depths. In order to focus the electron beams with different initial beam parameters to the target area at any focus depth, theoretical analysis can be combined with Monte Carlo simulation verification, obtained the corresponding relationship between different beam parameters and different focal depths and the magnetic induction intensity of each electromagnet, and then based on the corresponding relationship, can quickly determine the above-mentioned The target magnetic induction intensity that each electromagnet should have, that is, the magnetic induction intensity that each electromagnet matches with the target target area is determined. The embodiment of the present disclosure does not limit the manner of determining the above correspondence.

According to the embodiment of the present disclosure, the quadrupole iron in the transmission module 201, the deflection dipole iron, and the quadrupole iron in the focusing module 202 can be efficiently controlled by the control module 203 to generate the magnetic induction intensity matching the target area, so that the system It can efficiently focus and transmit the electron beam with any initial beam current parameter to the target target area at any focal depth, and realize the peak dose deposition of the electron beam with any initial beam current parameter at any focal depth.

Experiments obtained by injecting a 200 MeV electron beam (such as a single-energy electron beam with a beam spot size of 100 microns and a divergence angle of 4 mrad) generated by an ultra-high-energy electron source (such as a laser plasma accelerator or a high-gradient electron linear accelerator) into a water body As a result, advantageous effects obtained by using the electron beam focusing system of the above-described embodiments of the present disclosure are introduced.

Fig. 6a, Fig. 6b and Fig. 6c show the sliced dose distribution diagrams of the electron beam deposited in the water body obtained by using the beam focusing transmission system of the embodiment of the present disclosure. Specifically, Fig. 6a shows that the focused outgoing direction is along the scanning plane ( Figure 6b shows the two-dimensional slice dose distribution along the scanning plane slice in the parallel exit direction, and Figure 6c shows the axial slice dose distribution along the x-axis As well as the integrated dose distribution along the x-axis, as shown in Figure 6a, Figure 6b and Figure 6c, the dose deposited by the electron beam reaches its peak at a depth of about 10cm in the water body, and the entrance dose/exit dose on the axis is compared with the peak value The dose is lower. That is to say, the beam focusing transmission system of the embodiment of the present disclosure realizes the flat focusing of the electron beam at a certain depth inside the water body, wherein the design of each quadrupole iron and deflection diode iron in the system conforms to the parameters achievable in engineering scope.

According to the beam focusing transmission system of the above-mentioned embodiments of the present disclosure, it is possible to utilize the opposite characteristics of the focusing and defocusing properties of the two directions of the quadrupole iron, and realize a flat focusing beam focusing transmission system, which uses multiple quadrupoles The pole iron array realizes a large-angle flat strong focus to the lesion area inside the human body, and achieves the purpose of radiation dose deposition at a deeper focal depth; 90-degree deflection in the direction, thereby reducing the spatial scale of the beam focus transmission system, and greatly improving the compatibility of the ultra-high-energy electron radiotherapy system.

According to the beam focus transmission system of the embodiment of the present disclosure, the conversion of the ultra-high energy electron beam from the pencil beam to the flat strongly focused ultra-high energy electron beam can be realized, so as to realize the deposition of the peak dose in the target area of the human body, and can By adjusting the magnetic induction intensity of the quadrupole iron in the focusing module, the focus position of the electron beam is adjusted (while maintaining the electron beam in the parallel exit direction is still approximately parallel), so as to adjust the position of the dose deposition to obtain better radiation. Therapeutic effect; and, using the property that the deflecting dipole iron can deflect the charged beam, the beam focusing transmission system for transmitting the ultra-high energy electron beam is folded, so that the entire beam focusing transmission system and the beam focusing transmission system are applied The spatial scale of radiotherapy equipment is greatly reduced, so as to adapt to miniaturized radiotherapy equipment.

Based on the beam focusing transmission system in the above-mentioned embodiments of the present disclosure, the embodiments of the present disclosure also provide a radiotherapy device, which includes: an ultra-high-energy electron source for generating electron beams; and, the beam of the above-mentioned embodiments of the present disclosure Stream focused delivery system. Wherein, the ultra-high-energy electron source may include an accelerator such as a plasma accelerator or a high-gradient electron linear accelerator, which is not limited in this embodiment of the present disclosure.

In a possible implementation manner, the beam focusing transmission system described above may be arranged in a mechanical arm of a radiotherapy device, and the mechanical arm may rotate around a target object. Wherein, the length of the mechanical arm depends on the overall structure of the beam focus transmission system. For example, if the beam focus transmission system shown in FIG. 3 is used, the length of the mechanical arm can be shortened to 1.2m. In this way, radiation therapy can be performed on the lesion area at any position and depth within the target object, which increases the range of affine therapy, and at the same time the length of the robotic arm is also greatly reduced, thereby making the radiation therapy equipment more miniaturized.

It should be understood that the target object can lie on the treatment bed, and the mechanical arm can rotate around the treatment bed, so as to realize the rotation around the target object, so as to perform radiotherapy on any lesion area in the target object. The focused beam transmission system of the embodiments of the present disclosure can be applied to various radiotherapy equipment, especially the radiotherapy equipment using ultra-high-energy electron beams. The embodiments of the present disclosure do not limit the hardware structure and equipment type of the radiotherapy equipment.

According to the radiotherapy equipment in the embodiments of the present disclosure, the above-mentioned beam focusing transmission system can be used to realize the peak dose of the ultra-high-energy electron beam in the lesion area, greatly reduce the radiation dose of the electron beam to other normal tissues in the target object, and improve the electron density. Improve the effect of radiotherapy, reduce the time-consuming of electronic radiotherapy, and at the same time reduce the spatial scale of radiotherapy equipment, make the radiotherapy equipment more compact and miniaturized, and improve the application prospects of radiotherapy equipment.

Having described various embodiments of the present disclosure above, the foregoing description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and alterations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principle of each embodiment, practical application or technical improvement in the market, or to enable other ordinary skilled in the art to understand each embodiment disclosed herein.

Claims (9)

1. A beam focusing transmission system applied to ultra-high-energy electron beams, characterized in that it comprises: a transmission module and a focusing module, wherein the electron beam to be focused enters the transmission module and the focusing module in sequence; The transmission module includes at least one quadrupole iron and deflection diode iron; each quadrupole iron in the transmission module is used to diverge the incoming electron beam in the focused outgoing direction and to diverge the incoming electron beam in the parallel outgoing direction. Focusing the electron beam current, so that the electron beam current emitted by the transmission module is an electron beam current that diverges in the focused outgoing direction and focuses in the parallel outgoing direction; wherein, the focused outgoing direction perpendicular to the magnetic field direction of the deflecting dipole iron, and the parallel outgoing direction is parallel to the magnetic field direction of the deflecting dipole iron; The deflection diode in the transmission module is used to deflect the incoming electron beam at a specified angle in the parallel outgoing direction, so as to change the transmission direction of the incoming electron beam, and the electron beam emitted by the transmission module The transmission direction is different from the transmission direction of the electron beam before entering the transmission module; The focusing module includes a quadrupole iron, and the quadrupole iron in the focusing module is used to focus the electron beam emitted by the transmission module in the focusing outgoing direction and to focus the electron beam in the parallel outgoing direction. The electron beams emitted by the transmission module are diverged, so that the electron beams emitted by the focusing module are focused and emitted in the focused emission direction and nearly parallel in the parallel emission direction, and the focused Different electrons in the electron beam stream emitted by the module are used to inject into the target object at different positions and focus to the target target area within the target object. 2. The system according to claim 1, further comprising a control module, the control module is electrically connected to the quadrupole iron in the transmission module, the deflection dipole iron and the focusing quadrupole in the module; The control module is configured to control the quadrupole iron, the deflection diode iron and the The quadrupole irons in the focusing module respectively generate magnetic induction intensity matching the target target area, so that the electron beam emitted by the focusing module is focused on the target target area; wherein, the initial beam current parameters include At least one of the following: electron energy, divergence angle, and beam spot size. 3. The system according to claim 2, characterized in that, by controlling the deflection dipole iron to generate a magnetic induction intensity that matches the target target area, the energy selection of electrons with different energies in the incoming electron beam is realized ; By controlling the quadrupole iron in the transmission module and the quadrupole iron in the focusing module to generate the magnetic induction intensity matching the target target area respectively, it is possible to control the different electrons in the electron beam emitted by the focusing module The incident position and incident angle when shooting into the target object, and the depth of focus after entering said target object. 4. The system according to any one of claims 1 to 3, wherein the specified angle includes any angle from 30 degrees to 150 degrees. 5. The system according to any one of claims 1 to 3, characterized in that, when the transmission module includes at least two quadrupoles, the deflection diodes in the transmission module are located at the Between any pair of adjacent two quadrupole irons in the transmission module, or before at least two quadrupole irons in the transmission module, or behind at least two quadrupole irons in the transmission module. 6. The system according to any one of claims 1 to 3, wherein the transmission module and the focusing module are arranged outside the beam transmission pipeline of the electron beam, wherein the beam transmission The pipeline has the same rotation angle as the specified angle at the deflection diode. 7. The system according to any one of claims 1 to 3, wherein the electron beam current comprises a high-energy electron beam current of 50 MeV to 250 MeV generated by an ultra-high energy electron source. 8. A radiotherapy device, characterized in that it comprises: An ultra-high-energy electron source, used to generate an electron beam; and, the beam focusing transmission system according to any one of claims 1 to 7. 9 . The device according to claim 8 , wherein the focused beam delivery system is arranged in a mechanical arm of the radiotherapy equipment, and the mechanical arm can rotate around the target object.