A fast energy modulation system for proton therapy and a proton therapy device

Abstract

The application discloses a kind of fast energy regulation system and proton radiotherapy device for proton radiotherapy, belong to medical equipment technical field, including first quaternary iron, energy switching device and momentum cooling device sequentially arranged on energy beam transmission line, energy switching device includes sequentially connected first impact magnet, second quaternary iron, second impact magnet, energy switching energy reducer, third impact magnet and fourth impact magnet, first impact magnet is connected with first quaternary iron, fourth impact magnet is connected with momentum cooling device, energy switching energy reducer is one-piece wedge structure, it includes low-energy beam energy reduction zone, ideal beam energy reduction zone and high-energy beam energy reduction zone.It is simple in structure, energy switching time is short, transmission efficiency is high, and it can safely and efficiently transmit energy divergence less than 15%, energy is 70-230MeV proton, and transmission efficiency can reach 5%.

Description

Technical Field

[0001] This invention belongs to the field of medical equipment technology, specifically relating to a rapid energy regulation system and a proton radiotherapy device for proton radiotherapy. Background Technology

[0002] Cancer is one of the most difficult serious diseases for humanity to address today. In developed countries, it has become the leading cause of death. How to prevent and treat cancer is one of the most pressing issues for the global medical community and relevant government departments. Data from my country's National Cancer Prevention and Control Office shows that approximately 1.4 million people die from cancer each year, accounting for 20% of all deaths, and this number is still increasing at a rate of 1.3% annually. In the 21st century, a century of knowledge innovation, a series of new technologies, methods, and equipment are impacting all aspects of social life. How to use these new technologies, methods, and equipment to treat malignant tumors has become one of the most important research directions in cancer treatment.

[0003] Proton therapy is one of the most advanced radiotherapy technologies internationally, requiring only 8 minutes per session and no hospitalization. More than 90 institutions in 16 countries worldwide have begun using proton therapy equipment, primarily concentrated in a few developed countries such as the United States, Japan, and Germany. Compared to traditional X-ray radiotherapy, proton therapy not only precisely targets and destroys tumors in a stereotactic manner but also significantly reduces the radiation dose to normal tissues, decreasing the incidence of secondary cancers and maximizing patient survival and quality of life.

[0004] Proton therapy has become a prominent high-tech treatment for tumors. To implement proton therapy, corresponding equipment is required. A proton therapy system mainly consists of the following components: accelerator, energy selection system, beam flow system, rotating gantry, treatment head, treatment bed, and treatment planning system. Currently, commercially available proton therapy systems primarily use two types of accelerators: synchrotrons and cyclotrons. Synchrotrons can extract protons of different energies according to treatment needs, eliminating the need for an energy selection system. Over the past decade, the number of cyclotron-based proton therapy systems has grown exponentially, making them the most common type of proton accelerator, accounting for two-thirds of all installed systems. Because cyclotrons produce a fixed-energy beam (235-250 MeV), to achieve the clinically required energy (70-230 MeV), an energy selection system (ESS) consisting of a degrader of varying thickness is needed. (See reference...) Figure 3As shown, this is mainly achieved through a wedge-shaped graphite body. The thickness of the graphite is changed by separating and bringing the wedge-shaped graphite body closer together. After the beam passes through graphite of different thicknesses for energy reduction, its energy decreases, but the beam spot size, beam divergence angle, emittance, and energy dispersion increase. Multiple Coulomb scattering and range divergence in the energy reducer increase the beam's lateral emittance (phase space area) and momentum / energy dispersion, exceeding the acceptable range of the subsequent beam transmission system. This results in beam transmission efficiency being energy-dependent; the lower the energy, the lower the transmission efficiency. For most proton therapy systems, the transmission efficiency through the ESS in the low-energy region (70–100 MeV) is very low, typically less than 0.1%. This loss leads to increased treatment and irradiation time, especially when combined with motion relief techniques (beam delivery approximately 15–30 minutes), reducing patient comfort. Simultaneously, the inserted wedge-shaped energy reducer has a relatively slow energy switching time (e.g., the energy switching time of the IBA proton therapy system exceeds 1 second), poor stability, and requires regular checks of motion accuracy.

[0005] Using an insertable de-energizer to obtain the clinically required proton beam significantly increases the layer-switching time in tumor treatment, resulting in low efficiency. Furthermore, employing momentum-selective slits to control the energy divergence of the de-energized beam leads to a rapid decline in the beam transmission efficiency of the energy-selective system. Despite numerous improvements aimed at shortening proton therapy irradiation time, the fastest energy switching time currently achieved by the Paul Scherrer Institute (PSI) proton therapy system in Switzerland is approximately 50-80 ms. Limited by mechanical constraints, further breakthroughs in energy switching time are difficult to achieve. Summary of the Invention

[0006] The purpose of this invention is to provide a rapid energy regulation system for proton radiotherapy, which has a simple structure, is easy to use, and can effectively improve the above-mentioned problems.

[0007] The embodiments of the present invention are implemented as follows:

[0008] This invention provides a rapid energy regulation system for proton radiotherapy, used in conjunction with a proton accelerator. The proton accelerator outputs a fixed energy beam. The energy regulation system includes a first quadrupole iron, an energy switching device, and a momentum cooling device sequentially arranged on the energy beam transmission line. The energy switching device includes a first impact magnet, a second quadrupole iron, a second impact magnet, an energy switching de-energizer, a third impact magnet, and a fourth impact magnet connected sequentially. The first impact magnet is connected to the first quadrupole iron, and the fourth impact magnet is connected to the momentum cooling device. The energy switching de-energizer is an integrated wedge-shaped structure, including a low-energy beam de-energizing region, an ideal beam de-energizing region, and a high-energy beam de-energizing region. The thickness of the low-energy beam de-energizing region is 94mm-150mm, the thickness of the ideal beam de-energizing region is 86mm-94mm, and the thickness of the high-energy beam de-energizing region is 30mm-94mm. The magnetic field regulation response time of the first, second, third, and fourth impact magnets is 10µs-100µs.

[0009] Furthermore, the first and second impact magnets are used to translate different energy beams to different energy reduction zones of the energy switching de-energizer, and the third and fourth impact magnets are used to translate the de-energized energy beams to the reference center orbit. The translation distance of the energy beam trajectory by the first, second, third, and fourth impact magnets is -16mm to 16mm, the deflection angle range of each impact magnet is -20mrad to 20mrad, and the corresponding magnetic field strength is -2265Gs to 2265Gs.

[0010] Furthermore, the momentum cooling device includes a third and fourth stage iron, a second stage iron, a fourth and fourth stage iron, and a momentum cooling energy degrader connected in sequence. The third and fourth stage irons are connected to the fourth impact magnet. The second stage iron is used to adjust the trajectory of the beam with energy divergence. The low-energy beam is deflected to the inside of the second stage iron, the ideal beam is deflected to the reference center track, and the high-energy beam is deflected to the outside of the second stage iron. The fourth and fourth stage iron is used to defocus and focus the trajectory-adjusted beam, so that each energy beam is incident on the momentum cooling energy degrader in a manner parallel to the center track.

[0011] Furthermore, the momentum cooling energy depletion device has a right-angled triangular structure, which includes a low-energy beam cooling energy depletion region, an ideal beam cooling energy depletion region, and a high-energy beam cooling energy depletion region. The thickness of the high-energy beam cooling energy depletion region is greater than the thickness of the ideal beam cooling energy depletion region, and the thickness of the ideal beam cooling energy depletion region is greater than the thickness of the low-energy beam cooling energy depletion region.

[0012] Furthermore, the inclined surface of the momentum cooling energy depletion device is the energy beam inlet surface, and the right-angled surface on the opposite side is the energy beam outlet surface, with the energy beam outlet surface perpendicular to the transmission trajectory of the energy beam.

[0013] Furthermore, the number of the first four-stage iron is at least two and they are connected in series, the number of the third four-stage iron is at least two and they are connected in series, and the number of the fourth four-stage iron is at least two and they are connected in series.

[0014] Furthermore, the energy switching de-energizer is made of boron carbide, and the momentum cooling de-energizer is made of polyethylene.

[0015] Furthermore, the magnetic field adjustment response time of the first impact magnet, the second impact magnet, the third impact magnet, and the fourth impact magnet is 50µs.

[0016] Embodiments of the present invention also provide a proton radiotherapy device, including a proton accelerator, a beam transmission system, a treatment head, and the aforementioned rapid energy regulation system. One end of the rapid energy regulation system is connected to the proton accelerator, and the other end is connected to the beam transmission system, which is connected to the treatment head.

[0017] The beneficial effects of this invention are as follows:

[0018] The rapid energy modulation system for proton radiotherapy provided by the embodiments of the present invention has a simple structure, short energy switching time, and high transmission efficiency. It can safely and efficiently transmit protons with an energy dispersion of less than 15% and an energy of 70-230 MeV, with a transmission efficiency of up to 5%.

[0019] The proton radiotherapy device provided by the embodiments of the present invention has high energy beam utilization and short treatment time, which greatly improves the comfort of patients and has good potential for widespread application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the rapid energy regulation system for proton radiotherapy provided in Embodiment 1 of the present invention;

[0022] Figure 2 This is a schematic diagram of the energy beam trajectory of the energy switching device of the present invention;

[0023] Figure 3 This is a schematic diagram illustrating the thickness adjustment of the graphite body structure in the prior art.

[0024] Figure 4 This is a schematic diagram of the proton radiotherapy device provided in Embodiment 2 of the present invention;

[0025] In the diagram: 10-First and fourth-level iron; 20-Energy switching device; 21-First impact magnet; 22-Second and fourth-level iron; 23-Second impact magnet; 24-Energy switching de-energizer; 25-Third impact magnet; 26-Fourth impact magnet; 30-Momentum cooling device; 31-Third and fourth-level iron; 32-Second-level iron; 33-Fourth and fourth-level iron; 34-Momentum cooling de-energizer; 40-Proton accelerator; 50-Beam transmission system; 60-Treatment head. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this invention, it should be noted that the terms "inner," "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] Example 1

[0033] refer to Figure 1 As shown, Embodiment 1 of the present invention provides a rapid energy regulation system for proton radiotherapy, which is connected to a proton accelerator 40 and used in conjunction with the proton accelerator 40, which is capable of outputting a fixed energy beam.

[0034] The energy regulation system includes a first four-stage iron 10, an energy switching device 20, and a momentum cooling device 30, which are sequentially arranged on the energy beam transmission line.

[0035] The number of first and fourth stage iron 10 is two and set in series. Of course, the number of first and fourth stage iron 10 can also be three or more set in series.

[0036] The energy switching device 20 includes a first impact magnet 21, a second quadrupole iron 22, a second impact magnet 23, an energy switching de-energizer 24, a third impact magnet 25, and a fourth impact magnet 26 connected in sequence. The first impact magnet 21 is connected to the first quadrupole iron 10, and the fourth impact magnet 26 is connected to the momentum cooling device 30.

[0037] The first and second fourth-level iron 10 and the second fourth-level iron 22 are used together to focus the energy beam.

[0038] The energy switching de-energizer 24 is an integrated wedge-shaped structure, comprising a low-energy beam de-energizing region, an ideal beam de-energizing region, and a high-energy beam de-energizing region. The thickness of the low-energy beam de-energizing region is greater than that of the ideal beam de-energizing region, and the thickness of the ideal beam de-energizing region is greater than that of the high-energy beam de-energizing region. In this embodiment, the thickness of the low-energy beam de-energizing region is 94mm-150mm, the thickness of the ideal beam de-energizing region is 86mm-94mm, and the thickness of the high-energy beam de-energizing region is 30mm-86mm.

[0039] It should be noted that in this embodiment, a beam trajectory that does not need to be translated is an ideal beam, a beam trajectory that needs to be translated upwards is a high-energy beam, and a beam trajectory that needs to be translated downwards is a low-energy beam.

[0040] refer to Figure 2 As shown, the first impact magnet 21 and the second impact magnet 23 are used to translate different energy beams to different energy reduction zones of the energy switching de-energizer 24. The third impact magnet 25 and the fourth impact magnet 26 are used to translate the de-energized energy beams to the reference center orbit. The translation distance of the energy beam trajectory by the first impact magnet 21, the second impact magnet 23, the third impact magnet 25 and the fourth impact magnet 26 is -16mm to 16mm, the deflection angle range of each impact magnet is -20mrad to 20mrad, and the corresponding magnetic field strength is -2265Gs to 2265Gs.

[0041] The magnetic field adjustment response time of the first impact magnet 21, the second impact magnet 23, the third impact magnet 25, and the fourth impact magnet 26 is 10-100 μs. In this embodiment, the magnetic field adjustment response time of each impact magnet is 50 μs, which greatly shortens the energy switching time.

[0042] The energy beam experiences varying degrees of energy reduction after passing through different reduction regions of the energy switching de-energizer 24. For example, a proton beam with an energy of 250 MeV extracted from the proton accelerator 40 experiences an energy reduction to 230 MeV when passing through a 30 mm thick section of the energy switching de-energizer 24, to 164 MeV when passing through a 90 mm thick section, and to 86 MeV when passing through a 150 mm thick section.

[0043] The momentum cooling device 30 includes a third and fourth stage iron 31, a second stage iron 32, a fourth and fourth stage iron 33, and a momentum cooling energy deflector 34 connected in sequence. The third and fourth stage iron 31 is connected to the fourth impact magnet 26. The second stage iron 32 is used to adjust the trajectory of the beam with energy divergence. The low-energy beam is deflected to the inside of the second stage iron 32, the ideal beam is deflected to the reference center track, and the high-energy beam is deflected to the outside of the second stage iron 32. In this embodiment, the deflection angle of the second stage iron 32 is between 10° and 20°. The fourth and fourth stage iron 33 is used to defocus and focus the trajectory-adjusted beam, so that each energy beam is incident on the momentum cooling energy deflector 34 in a manner parallel to the center track.

[0044] The third and fourth level iron 31 units are two in series, and of course, the third and fourth level iron 31 units can also be three or more in series. The fourth level iron 33 units are two in series, and of course, the fourth level iron 33 units can also be three or more in series.

[0045] The momentum cooling energy depletion device 34 has a right-angled triangular structure, which includes a low-energy beam cooling energy depletion region, an ideal beam cooling energy depletion region, and a high-energy beam cooling energy depletion region. The thickness of the low-energy beam cooling energy depletion region is greater than the thickness of the ideal beam cooling energy depletion region, and the thickness of the ideal beam cooling energy depletion region is greater than the thickness of the high-energy beam cooling energy depletion region.

[0046] The high-energy beam passes through a large thickness, while the low-energy beam passes through a small thickness. This significantly reduces the energy divergence of the proton beam, which has a large momentum divergence. Compared with the traditional method of using selective slits to reduce the momentum divergence of the proton beam, there is no large loss of high-energy or low-energy particles in the selective slit, thus greatly improving the transmission efficiency.

[0047] The inclined surface of the momentum cooling de-energizer 34 is the energy beam inlet surface, and the right-angled surface on the opposite side is the energy beam outlet surface. The energy beam outlet surface is perpendicular to the transmission trajectory of the energy beam, which ensures that the proton beams exit at the same position.

[0048] The momentum cooling device 30 in this embodiment can safely and efficiently transmit protons with an energy divergence of less than 15% and an energy of 70-230 MeV, with a transmission efficiency of up to 5%.

[0049] Multiple sets of momentum cooling devices 30 can also be set, and multiple sets of momentum cooling devices 30 are connected in series.

[0050] The energy switching de-energizer 24 uses a density of 2.52 g / cm³. 3 It is made of boron carbide, a material that is easy to process, low in cost, and has good stability. The momentum cooler 34 uses boron carbide with a density of 0.94 g / cm³. 3 It is made of polyethylene.

[0051] In this embodiment, the components are connected by a vacuum tube, and the proton beam is transmitted inside the vacuum tube.

[0052] Example 2

[0053] refer to Figure 4 As shown, Embodiment 2 of the present invention provides a proton radiotherapy device, including a proton accelerator 40, a beam transmission system 50, a treatment head 60, and a rapid energy regulation system.

[0054] It should be noted that the rapid energy regulation system in this embodiment can be the rapid energy regulation system in Embodiment 1. Its structure, working principle and technical effects are the same as those in Embodiment 1, and will not be repeated here.

[0055] In this embodiment, the proton accelerator 40 can be a cyclotron accelerator.

[0056] The first and fourth stage iron 10 of the rapid energy regulation system is connected to the proton accelerator 40, the momentum cooling de-energizer 34 of the rapid energy regulation system is connected to the beam transmission system 50, and the beam transmission system 50 is connected to the treatment head 60. In this way, the energy beam output from the proton accelerator 40 is regulated by the rapid energy regulation system to meet the required specifications, and then transmitted to the treatment head 60 via the beam transmission system 50 to treat the affected area.

[0057] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A rapid energy modulation system for proton radiotherapy, used in conjunction with a proton accelerator, the proton accelerator being capable of outputting a fixed energy beam, characterized in that: The energy regulation system includes a first quadrupole iron, an energy switching device, and a momentum cooling device sequentially arranged on the energy beam transmission line. The energy switching device includes a first impact magnet, a second quadrupole iron, a second impact magnet, an energy switching de-energizer, a third impact magnet, and a fourth impact magnet connected in sequence. The first impact magnet is connected to the first quadrupole iron, and the fourth impact magnet is connected to the momentum cooling device. The energy switching de-energizer is an integrated wedge-shaped structure, which includes a low-energy beam de-energizing region, an ideal beam de-energizing region, and a high-energy beam de-energizing region. The thickness of the low-energy beam de-energizing region is 94-154 mm, the thickness of the ideal beam de-energizing region is 86-94 mm, and the thickness of the high-energy beam de-energizing region is 30-86 mm. The magnetic field regulation response time of the first impact magnet, the second impact magnet, the third impact magnet, and the fourth impact magnet is 10-100 μs. The momentum cooling device includes a third and fourth stage iron, a second stage iron, a fourth and fourth stage iron, and a momentum cooling energy depletion device connected in sequence. The third and fourth stage irons are connected to the fourth impact magnet. The second stage iron is used to adjust the trajectory of the beam with energy divergence. The low-energy beam is deflected to the inside of the second stage iron, the ideal beam is deflected to the reference center track, and the high-energy beam is deflected to the outside of the second stage iron. The fourth and fourth stage iron is used to defocus and focus the trajectory-adjusted beam, so that each energy beam is incident on the momentum cooling energy depletion device in a manner parallel to the center track. The momentum cooling energy depletion device has a right-angled triangular structure, which includes a low-energy beam cooling energy depletion region, an ideal beam cooling energy depletion region, and a high-energy beam cooling energy depletion region. The thickness of the low-energy beam cooling energy depletion region is greater than the thickness of the ideal beam cooling energy depletion region, and the thickness of the ideal beam cooling energy depletion region is greater than the thickness of the high-energy beam cooling energy depletion region.

2. The rapid energy regulation system for proton radiotherapy according to claim 1, characterized in that: The first and second impact magnets are used to translate different energy beams to different energy reduction zones of the energy switching de-energizer. The third and fourth impact magnets are used to translate the de-energized energy beams to the reference center orbit. The translation distance of the energy beam trajectory by the first, second, third, and fourth impact magnets is -16mm to 16mm, the deflection angle range of each impact magnet is -20mrad to 20mrad, and the corresponding magnetic field strength is -2265Gs to 2265G.

3. The rapid energy regulation system for proton radiotherapy according to claim 1, characterized in that: The inclined surface of the momentum cooling energy depletion device is the energy beam inlet surface, and the right-angled surface on the opposite side is the energy beam outlet surface. The energy beam outlet surface is perpendicular to the transmission center trajectory of the energy beam.

4. The rapid energy regulation system for proton radiotherapy according to claim 1, characterized in that: The first four-stage iron has at least two units and is connected in series, the third four-stage iron has at least two units and is connected in series, and the fourth four-stage iron has at least two units and is connected in series.

5. The rapid energy regulation system for proton radiotherapy according to claim 1, characterized in that: The energy switching de-energizer is made of boron carbide, and the momentum cooling de-energizer is made of polyethylene.

6. The rapid energy regulation system for proton radiotherapy according to claim 1, characterized in that: The magnetic field adjustment response time of the first impact magnet, the second impact magnet, the third impact magnet, and the fourth impact magnet is 50 μs.

7. A proton radiotherapy device, characterized in that: The device includes a proton accelerator, a beam delivery system, a treatment head, and a rapid energy modulation system as described in any one of claims 1-5, wherein one end of the rapid energy modulation system is connected to the proton accelerator, the other end is connected to the beam delivery system, and the beam delivery system is connected to the treatment head.

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