Proton helium ion treatment device and positioning method thereof

Abstract

The invention provides a proton helium ion treatment device. The proton helium ion treatment device comprises an injector, an accelerator, a rotating rack, a treatment head, a beam distribution system and a six-dimensional treatment bed which are sequentially arranged in the conveying direction of a beam. The injector comprises a hydrogen ion source and a helium ion source which can be switched; the treatment head and beam distribution system comprises an integrated scanning magnet, a position ionization chamber, a dose ionization chamber, a ridge-shaped filter and a range shifter which are installed on a treatment head support and sequentially arranged in the beam conveying direction, and the integrated scanning magnet is used for beam deflection in the transverse X direction and the transverse Y direction at the same time. A cone beam CT system is further fixedly installed on the rotating rack, and precise positioning and positioning correction of a patient are achieved in combination with the six-dimensional mechanical arm treatment bed. The proton helium ion treatment device can meet the requirement for high precision of patient positioning in ion treatment, ion treatment with optional proton helium ions can be achieved, and the treatment system is more compact through the design of the integrated scanning magnet.

Description

Technical Field

[0001] The present invention belongs to the field of particle radiotherapy, and specifically relates to a proton helium ion therapy device and a positioning method thereof, which are used for high-precision tumor positioning and for implementing more effective and safer radiotherapy for patients. Background Art

[0002] Particle therapy is one of the most advanced cancer treatments in the world. Compared to traditional photon radiotherapy, particle irradiation produces a maximum dose peak at the end of the beam's range, known as the Bragg peak effect. By precisely controlling the particle beam energy and spot position, the dose can be concentrated primarily within the tumor target, while minimizing the dose to surrounding normal tissue. Particle therapy offers advantages such as short treatment cycles, precise targeting, high cure rates, and minimal side effects. Ion radiotherapy systems typically employ two main irradiation techniques: scattered irradiation and scanning irradiation. The irradiation technique employed in this invention is scanning irradiation. Helium ions, with a mass between that of protons and carbon ions, offer the advantage of proton therapy without tailing at the end of its range, while also possessing a higher LET, thus killing cancer cells. From 1975 to 1993, the Lawrence Berkeley National Laboratory in the United States conducted research on cancer treatment using broad-beam helium ions, treating a total of 2,054 patients. In August 2020, the Heidelberg Ion Beam Therapy Center in Germany treated its first patient with helium ion therapy and subsequently initiated clinical trials to evaluate the efficacy and safety of helium ion therapy.

[0003] Ion therapy has the characteristics of concentrated dose and strong lethality, so accurate positioning of the patient before treatment is crucial.

[0004] Before ion therapy, the patient is usually initially positioned using a six-dimensional robotic arm treatment bed and a laser light positioning system, and precise positioning and verification are performed through positioning technologies such as surface image guidance, orthogonal DR imaging, cone beam CT (CBCT) and slide CT.

[0005] Therefore, a new proton helium ion therapy device and its positioning method are needed to solve the range error caused by this conversion. Summary of the Invention

[0006] The object of the present invention is to provide a proton helium ion therapy device and a positioning method thereof, so as to meet the high-precision positioning requirements in ion therapy, and the device is compact.

[0007] To achieve the above-mentioned objectives, the present invention provides a proton helium ion therapy device, comprising an injector, an accelerator, a rotating gantry, a treatment head, a beam matching system, and a six-dimensional treatment bed, which are sequentially arranged along the beam transport direction. A cone beam CT system is also fixedly mounted on the rotating gantry.

[0008] Among them, the injector includes a switchable hydrogen ion source and a helium ion source; the treatment head and beam delivery system include an integrated scanning magnet, a position ionization chamber, a dose ionization chamber, a ridge filter, and a range shifter that are installed on the treatment head bracket and arranged in sequence along the beam transport direction. The integrated scanning magnet is also used for beam deflection in the transverse XY directions.

[0009] The integrated scanning magnet is provided with a vacuum chamber and a vacuum window, and is connected to a scanning power supply to drive the magnetic field of the scanning magnet through the scanning power supply.

[0010] The position ionization chamber is a multi-wire ionization chamber; the dose ionization chamber includes a main dose ionization chamber and a secondary dose ionization chamber, and the secondary dose ionization chamber provides redundant measurement of the irradiation dose; the ridge filter is used to expand the Bragg peak width of the beam.

[0011] The range shifter is connected to the treatment head bracket through a treatment head telescopic mechanism to enable the distance between the scanning magnet and the range shifter to be adjustable.

[0012] The cone beam CT system is switchable between a cone beam CT imaging mode and an orthogonal DR imaging mode; the cone beam CT system includes two sets of CT imaging components that are orthogonal to each other. Each set of CT imaging components includes an X-ray tube fixedly installed on a rotating gantry and a flat panel detector fixedly installed on one side of the treatment head.

[0013] Each X-ray tube is sequentially connected to a high voltage generator, a synchronization controller, and a computer. The two synchronization controllers are simultaneously connected to an exposure control box, and a collimator and a butterfly grid are installed at the front end of the X-ray exit of the X-ray tube; the central axis of the X-ray of the X-ray tube is vertically centered relative to the detection surface of the flat panel detector and passes through the isocenter of the rotating gantry.

[0014] The six-degree-of-freedom treatment couch includes a control cabinet, a six-axis robotic arm electrically connected to the control cabinet, and a treatment couch board connected to the end of the six-axis robotic arm. The material of the treatment couch board is carbon fiber.

[0015] On the other hand, the present invention provides a positioning method for a proton helium ion treatment device, which is characterized by including:

[0016] S0: Provide the proton helium ion treatment device described above;

[0017] S1: Perform initial positioning on the imaging object according to the crosshairs on the surface of the imaging object to make the imaging object in an initial position; according to the positioning deviation of the initial position relative to the isocenter, preliminarily move the imaging object to the isocenter through the six-degree-of-freedom treatment couch;

[0018] S2: Move the rotating gantry to the initial angle of the CT imaging mode;

[0019] S3: Perform corresponding CT imaging according to the specified CT imaging mode; the CT imaging mode includes the cone beam CT mode and the orthogonal DR mode;

[0020] S4: Reconstruct and register according to the CT imaging results to obtain the setup deviation;

[0021] S5: Perform setup correction using the treatment couch according to the setup deviation.

[0022] S6: Perform CT imaging again to verify the result of the setup deviation. If the setup deviation meets the clinical requirements, the setup is completed; otherwise, return to step S2 until the setup deviation meets the clinical requirements.

[0023] In the said step S3, the CT imaging mode includes the cone beam CT mode and the orthogonal DR mode; when the specified CT imaging mode is the cone beam CT mode, use one set of CT imaging components of the cone beam CT system to collect multi-frame sequence images of 360 degrees; when the specified CT imaging mode is the orthogonal DR mode, use two sets of mutually orthogonal CT imaging components of the cone beam CT system to perform orthogonal DR imaging of 45 degrees or 315 degrees.

[0024] When the included angle between the long axis direction of the treatment couch and the rotation axis of the gantry is less than the angle threshold, the cone beam CT mode is adopted; otherwise, the orthogonal DR mode is adopted.

[0025] The present invention adopts the cone beam CT positioning technology based on the gantry. In the positioning process, multi-angle cone beam CT imaging can be performed through the 360-degree rotation of the gantry. The cone beam CT positioning has the advantages of three-dimensional imaging, good soft tissue imaging quality, high positioning accuracy, etc. The cone beam CT based on the gantry can perform imaging and positioning in the treatment position, reducing the additional deviation brought by the non-treatment position positioning technology, simplifying the treatment process, so that the positioning accuracy of proton and helium ion therapy is more accurate and effective; and adopts an integrated scanning magnet scheme, thus effectively shortening the source axis distance, making the treatment head more compact, which is more conducive to the installation of the cone beam CT system. The cone beam CT system is used to realize the accurate setup and setup correction of the patient in combination with the six-degree-of-freedom robotic treatment couch.

[0026] In addition, the present invention can select to use orthogonal DR or cone beam CT for positioning according to the clinical situation; among them, high-precision positioning of the tumor target area is performed through the cone beam CT. The cone beam CT has higher positioning accuracy and can generate clearer three-dimensional images at the same time, which is convenient for oncology doctors to judge the positioning results through the images; the orthogonal DR has the advantages of fast positioning speed and low requirements for the angle of the treatment couch, making up for the positioning scenarios where cone beam CT imaging cannot be performed due to the offset of the treatment couch position.

[0027] The present invention selects protons and helium ions for radiotherapy according to clinical needs, and can perform multi-angle intensity modulation treatment through a 360-degree rotating gantry, solving the problems of setup errors in particle therapy and the immunity of hypoxic tumors to proton therapy, and can meet the needs of different cancer treatment centers and patients for particle therapy with better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram of a proton-helium ion therapy system based on cone beam CT imaging according to the present invention.

[0029] Figure 2 is a structural diagram of a treatment head and beam delivery system of a proton-helium ion therapy system according to the present invention.

[0030] Figure 3 is a schematic structural diagram of an integrated scanning magnet.

[0031] Figure 4 is a structural block diagram of an electrical part of a cone beam CT system of a proton-helium ion therapy system according to the present invention.

[0032] Figure 5 is a structural diagram of a six-degree-of-freedom treatment couch of a proton-helium ion therapy system according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following will give and describe in detail the preferred embodiments of the present invention with reference to the accompanying drawings.

[0034] As Figure 1 and Figure 2 shown, a proton-helium ion therapy device and its setup method according to the present invention include an injector, an accelerator, a rotating gantry 10, a treatment head and beam delivery system 30, and a six-degree-of-freedom treatment couch 40 arranged in sequence along the transport direction of the beam. A cone beam CT system 20 is also fixedly installed on the rotating gantry 10. Based on the original proton-helium ion therapy device, the present invention adds a set of cone beam CT systems based on the existing rotating gantry only inside the rotating gantry, and can realize the cone beam CT positioning function. Thus, through the integrated design of the rotating mechanism of the cone beam CT and the rotating gantry for treatment, the cone beam CT scanning and treatment for protons and helium ions are realized.

[0035] Among them, the rotating gantry 10 is a compact 360-degree rotating gantry, which can provide high-precision rotation conditions for proton-helium ion intensity modulation treatment. The structure of the compact 360-degree rotating gantry is basically the same as that of the existing rotating gantry, but the weight is reduced through mechanical optimization, so as to provide high-precision continuous rotation conditions of up to 6° / s for cone beam CT imaging. During the setup stage, the rotating gantry 10 can cooperate with the cone beam CT system to perform cone beam CT imaging or orthogonal DR imaging, and is used to adjust the treatment head to irradiate at different treatment angles during the treatment stage.

[0036] The treatment head and beam delivery system 30 includes a vacuum flange 37, an integrated scanning magnet 31, a position ionization chamber 32, a dose ionization chamber 33, a ridge filter 34, and a range shifter 35 that are mounted on the treatment head bracket and arranged in sequence along the beam transport direction. The range shifter 35 is connected to the treatment head bracket through a treatment head telescopic mechanism to enable the distance from the scanning magnet to the range shifter 35 to be adjustable, reducing the influence of beam spot diffusion. In this embodiment, the range shifter 35 is made of a plexiglass plate with a thickness of 2 cm or 4 cm.

[0037] The integrated scanning magnet 31 is simultaneously used for beam deflection in the transverse XY directions, significantly shortening the source axis distance, thereby enabling point scanning or continuous scanning irradiation.

[0038] For the specific structure of the integrated scanning magnet 31, reference can be made to the patent document with the application publication number 119925833, specifically as Figure 3 shown, where the integrated scanning magnet 31 includes a scanning magnet skeleton 313 and coil windings 314 in two XY directions. The material of the scanning magnet skeleton 313 is an engineering plastic that is resistant to high temperatures and corrosion.

[0039] Based on the traditional discrete scanning magnet, the present invention adopts an integrated scanning magnet solution, changing from two discrete secondary magnets in two XY directions to two integrally designed coil windings, significantly shortening the length of the scanning magnet in the beam direction, making the treatment head more compact, thus being more conducive to the installation of the cone beam CT system and the improvement of imaging quality, and also reducing the building space of the treatment room; and by applying specified currents to the coil windings 314 in two XY directions to generate a magnetic field, the beam is deflected to irradiate the target position.

[0040] The integrated scanning magnet 31 is also provided with a vacuum box 311 and a vacuum window 312 on its axis and is connected to a scanning power supply (not shown in the figure) to drive the formation of the magnetic field required for the scanning magnet through the scanning power supply. In the present invention, the integrated scanning magnet 31 requires two scanning power supplies, one for controlling the deflection degree in the X direction and the other for controlling the deflection degree in the Y direction. Both the X and Y directions are perpendicular to the beam transport direction and perpendicular to each other.

[0041] The injector includes a switchable hydrogen ion source and helium ion source. Specifically, the control system can be used to switch the required ion source to generate the target ion. Thus, proton or helium ion therapy can be selected according to the patient's indication, or mixed ion therapy (sequential irradiation is set by the treatment plan) can be performed. Among them, most solid tumors can use proton therapy, and tumor types with radioresistance use helium ion therapy.

[0042] The position ionization chamber 32 is used for real-time measurement of the beam position, and it is preferably a multi-wire ionization chamber. The irradiation technique adopted in the present invention is a fast-scan irradiation technique. The signal-to-noise ratio of the position ionization chamber is poor at a high sampling rate, and it is difficult to use a traditional strip ionization chamber for position measurement. Therefore, the multi-wire proportional ionization chamber technique is adopted, and the primary signal is amplified by avalanche to perform the measurement, so as to obtain a position measurement signal with a high signal-to-noise ratio. The position measurement signal is subjected to Gaussian fitting to obtain the beam spot position and size, so as to achieve high-signal-to-noise ratio position measurement.

[0043] The dose ionization chamber 33 is used for dose control and dose monitoring, and it preferably includes a main dose ionization chamber and a secondary dose ionization chamber. The position ionization chamber 32 monitors the position of ions in real time. The main dose ionization chamber of the dose ionization chamber 33 accurately measures the irradiation dose, and the secondary dose ionization chamber provides redundant measurement of the irradiation dose. Thus, the secondary dose ionization chamber uses the redundant measurement results for dose monitoring, and immediately interlocks to stop irradiation when there is an unexpected deviation from the measurement result of the main dose ionization chamber.

[0044] The ridge filter 34 is used to expand the Bragg peak width of the beam.

[0045] As Figure 1 and Figure 4 shown, the cone beam CT system 20 is switchable between a cone beam CT imaging mode and an orthogonal DR imaging mode. The cone beam CT system 20 includes two sets of CT imaging components that are orthogonal to each other. Each set of CT imaging components includes an X-ray tube 21 fixedly installed on the rotating gantry 10 and a flat panel detector 22 fixedly installed on one side of the treatment head. The flat panel detectors 22 of the two sets of CT imaging components are installed on both sides of the treatment head and the beam delivery system 30 through a mechanical structure. Thus, the cone beam CT system 20 can perform cone beam CT imaging in cooperation with the rotation of the rotating gantry 10.

[0046] Each X-ray tube 21 is sequentially connected to a high-voltage generator 23, a synchronization controller 24, and a computer 25. The two synchronization controllers 24 are simultaneously connected to an exposure control box 26, and a beam limiter and a butterfly grid are installed at the front end of the ray exit of the X-ray tube 21; the ray central axis of the X-ray tube 21 is perpendicular and centered with respect to the detection surface of the flat panel detector 22 and passes through the isocenter of the rotating gantry 10. Each flat panel detector 22 is connected to the computer 25 through an image acquisition workstation 27. An image-guided positioning software system is installed on the computer 25.

[0047] The X-ray tube 21 is used to generate X-rays; the high-voltage generator is used to control and drive the X-ray tube to generate X-rays; the collimator is used to limit the size of the X-ray field; the butterfly grid is used to filter out low-energy X-rays to reduce their impact on image quality; the synchronization controller performs high-real-time synchronization control on the X-ray generation by the X-ray tube exposure, the image acquisition by the flat-panel detector, and the gantry angle acquisition, so as to ensure the image quality (that is, while the X-ray tube is exposing, the flat-panel detector acquires images, and this time is from dozens to hundreds of milliseconds; the gantry angle at the middle moment of the exposure time is obtained; the exposure time can be set by the user according to experience in the software interface, and the values such as the exposure time are related to the image quality, and the software will also give default empirical values); the exposure control box is used for the control of moving parts and the start or termination of X-ray exposure; the image-guided positioning software system is used for the workflow control of the cone-beam CT system 20, image display, and the execution of the reconstruction and registration algorithm. In the present invention, this image-guided positioning software system can perform three-dimensional imaging and reconstruction registration on the patient at the treatment position to calculate the positioning deviation. After correcting the positioning deviation by using the treatment couch, the positioning can be confirmed again through the imaging results of cone-beam CT or orthogonal DR.

[0048] The flat-panel detector 22 is used to detect X-rays to generate projection images.

[0049] The six-degree-of-freedom treatment couch 40 is used to accurately position the imaging object (such as a patient) and perform positioning correction according to the positioning deviation of the cone-beam CT system, so as to achieve precise positioning of the imaging object.

[0050] In this embodiment, as Figure 5 shown, the six-degree-of-freedom treatment couch 40 includes a control cabinet 41, a six-axis robotic arm 42 electrically connected to the control cabinet, and a treatment couch plate 43 connected to the end of the six-axis robotic arm 42. The material of the treatment couch plate 43 is carbon fiber.

[0051] Based on the proton and helium ion treatment device described above, a positioning method for the proton and helium ion treatment device is realized, including the following steps:

[0052] Step S0: Provide the proton and helium ion treatment device described above;

[0053] Step S1: Perform initial positioning on the imaging object according to the crosshairs on the surface of the imaging object, so that the imaging object is in the initial position; according to the positioning deviation of the initial position relative to the isocenter, the imaging object is preliminarily moved to the isocenter through the six-degree-of-freedom treatment couch.

[0054] Step S2: Move the rotating gantry to the initial angle of the CT imaging mode, so that the components of the cone-beam CT system (such as the flat-panel detector, collimator, disc filter, etc.) move to the correct initial position of the CT imaging mode along with the rotating gantry.

[0055] The cone beam CT system 20 includes two sets of mutually orthogonal CT imaging components. Each set of CT imaging components includes an X-ray tube 21 fixedly mounted on the rotating gantry 10 and a flat panel detector 22 fixedly mounted on one side of the treatment head. The flat panel detectors 22 of the two sets of CT imaging components are mounted on both sides of the treatment head and the beam collimation system 30 through a mechanical structure. Thus, the cone beam CT system 20 can perform cone beam CT imaging in cooperation with the rotation of the rotating gantry 10.

[0056] As Figure 1 and Figure 4 shown, each X-ray tube 21 is sequentially connected to a high-voltage generator 23, a synchronization controller 24, and a computer 25. The two synchronization controllers 24 are simultaneously connected to an exposure control box 26. And a beam limiter and a butterfly grid are installed at the front end of the X-ray exit of the X-ray tube 21. The central axis of the X-ray of the X-ray tube 21 is vertically centered relative to the detection surface of the flat panel detector 22 and passes through the isocenter of the rotating gantry 10. The flat panel detector is mounted on one side of the treatment head and the beam collimation system 30 through a mechanical structure. Thus, the flat panel detector 22 is used to detect X-rays to generate a projection image, the X-ray tube 21 is used to generate X-rays, the high-voltage generator 23 is used to control and drive the X-ray tube to generate X-rays, the beam limiter is used to limit the X-ray field size, and the butterfly grid is used to filter out low-energy X-rays to reduce their impact on the image quality.

[0057] Step S3: Perform corresponding CT imaging according to the specified CT imaging mode.

[0058] Among them, the CT imaging modes include the cone beam CT mode and the orthogonal DR mode. When the specified CT imaging mode is the cone beam CT mode, one set of CT imaging components of the cone beam CT system 20 is used to collect multi-frame sequential images of 360 degrees. When the specified CT imaging mode is the orthogonal DR mode, two sets of mutually orthogonal CT imaging components of the cone beam CT system 20 are used to perform orthogonal DR imaging at 45 degrees or 315 degrees.

[0059] In step S3, orthogonal DR or cone beam CT can be selected for positioning according to the clinical situation. Among them, the cone beam CT is used for high-precision positioning of the tumor target area. The cone beam CT has higher positioning accuracy and can generate relatively clear three-dimensional images, which is convenient for oncology doctors to judge the positioning result through the image. The orthogonal DR has the advantages of fast positioning speed and low requirements for the angle of the treatment couch, making up for the positioning scenario where cone beam CT imaging cannot be performed due to the offset of the treatment couch position. In this embodiment, when the long axis direction of the treatment couch is parallel to the rotation axis of the rotating gantry (i.e., the included angle is less than the angle threshold), the cone beam CT mode is adopted. Otherwise, the long axis direction of the treatment couch is not parallel to the rotation axis of the rotating gantry, exceeding the angle threshold, and at this time, the orthogonal DR mode is adopted. The angle threshold can be, for example, 3 degrees.

[0060] Step S4: Reconstruct and register according to the CT imaging results to obtain the setup deviation.

[0061] Both reconstruction and registration are implemented using existing mature software. In this embodiment, 3D reconstruction of the cone-beam CT imaging results is performed through the general FDK reconstruction algorithm, and the setup deviation is calculated through the general 3D registration algorithm based on mutual information.

[0062] Among them, the setup deviation includes the setup deviations of the treatment couch in six dimensions: the X-axis, Y-axis, Z-axis, Rx-axis, Ry-axis, and Rz-axis. By moving the values of the setup deviation, the patient can be accurately positioned at the isocenter of treatment.

[0063] Step S5: Perform setup correction using the treatment couch according to the setup deviation.

[0064] Step S6: Perform CT imaging again to verify the result of the setup deviation. If the setup deviation meets the clinical requirements, the setup is completed; otherwise, return to Step S2 until the setup deviation meets the clinical requirements.

[0065] Among them, the clinical requirements refer to the deviations in six dimensions: the X-axis, Y-axis, Z-axis, Rx-axis, Ry-axis, and Rz-axis being less than 1 mm and 1 degree.

[0066] Step S7: Switch the injector to a proton source or a helium ion source according to the treatment plan.

[0067] Step S8: Perform sequential scanning irradiations of multiple energy layers at the treatment angle specified by the treatment plan until all energy layer scans at this treatment angle are completed.

[0068] During the scanning irradiation of the energy layer, rotate the gantry 10 to the treatment angle specified by the treatment plan, and move the range shifter 35 to the position required by the treatment plan through the treatment head telescoping mechanism 36 to reduce the influence of beam spot diffusion. Among them, the range shifter 35 is connected to the treatment head bracket through the treatment head telescoping mechanism 35 to achieve adjustable distance between the scanning magnet and the range shifter 35 and reduce the influence of beam spot diffusion.

[0069] In addition, switch to the next energy layer for irradiation by adjusting the accelerator energy.

[0070] Step S9: Rotate to the next specified treatment angle according to the treatment plan, and return to Step S8 until all-angle scanning irradiations are completed. At this time, the scanning irradiation of this imaging object is completed.

[0071] The present invention adopts the cone beam CT positioning technology based on a rotating gantry. In the positioning process, multi-angle cone beam CT imaging can be performed through a 360-degree rotating gantry. Cone beam CT positioning has the advantages of three-dimensional imaging, good soft tissue imaging quality, and high positioning accuracy. The cone beam CT based on a rotating gantry can perform imaging and positioning at the treatment position, reducing the additional deviation brought by the non-treatment position positioning technology and simplifying the treatment process, thus making the positioning accuracy of proton and helium ion therapy more accurate and effective. In addition, an integrated scanning magnet scheme is adopted, effectively shortening the source axis distance and making the treatment head more compact, which is more conducive to the installation of the cone beam CT system.

[0072] In addition, the present invention can select to use orthogonal DR or cone beam CT for positioning according to the clinical situation. Among them, high-precision positioning of the tumor target area is performed through cone beam CT. Cone beam CT has higher positioning accuracy and can generate relatively clear three-dimensional images, facilitating tumor doctors to judge the positioning result through the image. Orthogonal DR has the advantages of fast positioning speed and low requirements for the angle of the treatment couch, making up for the positioning scenario where cone beam CT imaging cannot be performed due to the offset of the treatment couch position.

[0073] The present invention selects protons and helium ions for radiotherapy according to clinical needs and can perform multi-angle intensity-modulated radiotherapy through a 360-degree rotating gantry, solving the problems of setup errors in particle therapy and the immunity of hypoxic tumors to proton therapy, and meeting the needs of different cancer treatment centers and patients for particle therapy with better performance.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various changes can be made to the above embodiments of the present invention. That is, all simple, equivalent changes and modifications made according to the claims and the content of the specification of the present invention application fall within the scope of the claims of the present invention patent. The content not described in detail in the present invention is all conventional technical content.

Claims

1. A proton-helium ion treatment device, characterized in that, It includes an injector, an accelerator, a rotating gantry, a treatment head, a beam collimation system and a six-dimensional treatment couch arranged in sequence along the transport direction of the beam. A cone beam CT system is also fixedly installed on the rotating gantry. Among them, the injector includes a switchable hydrogen ion source and a helium ion source; the treatment head and the beam collimation system include an integrated scanning magnet, a position ionization chamber, a dose ionization chamber, a ridge filter, and a range shifter arranged in sequence along the transport direction of the beam on a treatment head bracket. The integrated scanning magnet is also used for beam deflection in the transverse XY directions.

2. The proton-helium ion therapy device according to claim 1, characterized in that, The integrated scanning magnet is provided with a vacuum chamber and a vacuum window and is connected to a scanning power supply to drive the magnetic field of the scanning magnet through the scanning power supply.

3. The proton helium ion therapy device according to claim 1, characterized in that, The position ionization chamber is a multi-wire ionization chamber; the dose ionization chamber includes a main dose ionization chamber and a secondary dose ionization chamber, and the secondary dose ionization chamber provides redundant measurement of the irradiation dose; the ridge filter is used to expand the Bragg peak width of the beam.

4. The proton-helium ion therapy device according to claim 1, wherein The range shifter is connected to the treatment head bracket through a treatment head telescopic mechanism to enable the distance between the scanning magnet and the range shifter to be adjustable.

5. The proton-helium ion therapy device according to claim 1, wherein The cone beam CT system is switchable between a cone beam CT imaging mode and an orthogonal DR imaging mode. The cone beam CT system includes two groups of mutually orthogonal CT imaging components. Each group of CT imaging components includes an X-ray tube fixedly installed on the rotating gantry and a flat panel detector fixedly installed on one side of the treatment head.

6. The proton-helium ion therapy device according to claim 5, characterized in that, Each X-ray tube is sequentially connected to a high-voltage generator, a synchronization controller and a computer. The two synchronization controllers are simultaneously connected to an exposure control box. A beam limiter and a butterfly grid are installed at the front end of the ray outlet of the X-ray tube. The ray central axis of the X-ray tube is vertically centered relative to the detection surface of the flat panel detector and passes through the isocenter of the rotating gantry.

7. The proton-helium ion therapy device according to claim 1, characterized in that, The six-dimensional treatment couch includes a control cabinet, a six-axis robotic arm electrically connected to the control cabinet, and a treatment couch board connected to the end of the six-axis robotic arm. The material of the treatment couch board is carbon fiber.

8. A method for positioning a proton-helium ion therapy device, characterized in that, It includes: Step S0: Provide the proton and helium ion treatment device according to any one of claims 1-7. Step S1: Perform an initial positioning of the imaging object according to the crosshairs on the surface of the imaging object to make the imaging object in an initial position; according to the positioning deviation of the initial position relative to the isocenter, preliminarily move the imaging object to the isocenter through the six-dimensional treatment couch. Step S2: Move the rotating gantry to the initial angle of the CT imaging mode. Step S3: Perform corresponding CT imaging according to the specified CT imaging mode; the CT imaging mode includes a cone beam CT mode and an orthogonal DR mode. Step S4: Perform reconstruction and registration according to the CT imaging results to obtain the positioning deviation. Step S5: Perform positioning correction using the treatment couch according to the positioning deviation. Step S6: Perform CT imaging again to verify the result of the positioning deviation. If the positioning deviation meets the clinical requirements, the positioning ends; otherwise, return to step S2 until the positioning deviation meets the clinical requirements.

9. The method for positioning a proton-helium ion therapy device according to claim 8, characterized in that, In the step S3, the CT imaging modes include a cone beam CT mode and an orthogonal DR mode; when the specified CT imaging mode is the cone beam CT mode, a group of CT imaging components of the cone beam CT system is used to collect multi-frame sequence images of 360 degrees; when the specified CT imaging mode is the orthogonal DR mode, two groups of mutually orthogonal CT imaging components of the cone beam CT system are used to perform orthogonal DR imaging at 45 degrees or 315 degrees.

10. The method for positioning a proton-helium ion therapy device according to claim 9, wherein When the included angle between the long axis direction of the treatment couch and the rotation axis of the rotating gantry is less than the included angle threshold, the cone beam CT mode is adopted; otherwise, the orthogonal DR mode is adopted.

Images