Method, device and system for monitoring and verifying a mixed ion beam for particle therapy

Abstract

The present disclosure provides a monitoring method and a verification method of a particle therapy mixed ion beam, and corresponding devices. The verification method comprises: adding monitoring particles to therapy particles at a predetermined proportion, the monitoring particles having the same charge-to-mass ratio as the therapy particles, and the range of the monitoring particles being greater than that of the therapy particles under the same medium and energy; reconstructing a three-dimensional image of the therapy particles in the phantom based on the residual range and dose distribution of the monitoring particles after passing through the phantom; and verifying whether the therapy plan meets the expectation based on the three-dimensional image. The monitoring method comprises: adding monitoring particles to therapy particles at a predetermined proportion; detecting the residual range and dose distribution of the monitoring particles after passing through a target object in real time; reconstructing a three-dimensional image of the therapy particles in the target object based on the residual range and dose distribution of the monitoring particles; comparing the three-dimensional image with a pre-planned three-dimensional image of the therapy plan, and adjusting the dose and irradiation position of the therapy particles and the monitoring particles based on the comparison result.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of radiotherapy, and in particular to a method and device for monitoring and verifying a mixed ion beam for particle therapy. BACKGROUND

[0002] Compared with conventional photon beam therapy, the advantage of carbon ion beam therapy is that it has deep localization of high dose deposition. The LET dose curve increases from low incidence to a maximum value-Bragg peak, and the deposition decreases sharply beyond this dose. The steep dose gradient at the end makes the ion beam therapy highly sensitive to the uncertainty of the range. In order to improve the accuracy of treatment, individual treatment plans need to be developed by doctors and physicists to determine the irradiation range and dose. Dose delivery is a very complex process, and if there is an error in positioning or a mistake in a certain link, the dose cannot be delivered to the patient's lesion position as planned. To ensure safety, the doctor reviews and verifies the radiotherapy plan after it is developed, and the treatment plan can be executed only after the review and verification are passed.

[0003] However, during treatment, a series of factors that cause changes in the patient's anatomical structure, such as human positioning errors, changes in patient weight or body shape, changes in position due to respiratory rhythm, and tissue swelling, will cause uncertainty in positioning, resulting in healthy tissues near the tumor being affected by radiation, and thus limiting the maximum dose actually applied to the tumor. Existing technologies such as respiratory gating (RG), three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and image-guided radiation therapy (IGRT) are all designed to better concentrate the dose on the tumor target and better protect the adjacent important organs, but these technologies only ensure that the beam cross-section is irradiated on the tumor, and cannot guarantee that the Bragg peak in the beam direction falls on the tumor. The existing plan verification method is performed on a mannequin and a three-dimensional water tank, and this verification method detects the Bragg spread position and dose in the ideal plan, which has low stability in the case of a changing patient. Even with a safety margin, fractionated irradiation can cause a significant decrease in the planned dose or an excessive dose to healthy tissues. Therefore, in order to fully exploit the potential of ion beam radiotherapy, the monitoring method needs to be improved. SUMMARY

[0004] In view of the above problems, the present disclosure provides a real-time monitoring method and device for a mixed ion beam for particle therapy, to solve the problem of excessive dose to healthy tissues before and after the tumor in the irradiation direction caused by changes in Bragg position due to changes in body weight, tissue shape, density, etc. during treatment of the patient by a heavy ion beam.

[0005] The first aspect of the present disclosure provides a method for verifying a mixed ion beam for particle therapy, comprising: adding a predetermined proportion of monitoring particles to treatment particles according to a treatment plan, the monitoring particles having the same charge-to-mass ratio as the treatment particles, and having a range greater than the treatment particles in the same medium and at the same energy; detecting the residual range and dose distribution of the monitoring particles after passing through the phantom; reconstructing a three-dimensional image of the treatment particles in the phantom based on the residual range and dose distribution of the monitoring particles; and verifying whether the treatment plan meets expectations based on the three-dimensional image.

[0006] According to an embodiment of the present disclosure, the reconstructing a three-dimensional image of the treatment particles in the phantom based on the residual range and dose distribution of the monitoring particles comprises: obtaining position information of the monitoring particles based on the residual range of the monitoring particles, and deducing position information of the treatment particles based on the position information of the monitoring particles; obtaining a dose distribution of the treatment particles in the phantom based on the dose distribution of the monitoring particles and the predetermined proportion; and reconstructing the three-dimensional image based on the position information of the treatment particles and the dose distribution of the treatment particles in the phantom.

[0007] According to an embodiment of the present disclosure, the method further comprises: calculating the integrated relative stopping power and thickness of the phantom based on the three-dimensional image, and verifying the equivalent water depth of each tissue of the phantom based on the three-dimensional image.

[0008] According to an embodiment of the present disclosure, the method further comprises: setting a low-energy line that bends by 90° on the emission path of the treatment particles and the monitoring particles, and screening and mixing the treatment particles and the monitoring particles based on the low-energy line; monitoring the flow of the treatment particles and the monitoring particles, and adjusting the proportion of the treatment particles and the monitoring particles based on the treatment plan.

[0009] The second aspect of the present disclosure provides a method for monitoring a mixed ion beam for particle therapy, comprising: controlling the addition of a predetermined proportion of monitoring particles to treatment particles based on a treatment plan, the monitoring particles having the same charge-to-mass ratio as the treatment particles, and having a range greater than the treatment particles in the same medium and at the same energy; controlling the irradiation of a target object by the treatment particles and the monitoring particles, and detecting the residual range and dose distribution of the monitoring particles after passing through the target object in real time; reconstructing a three-dimensional image of the treatment particles in the target object based on the residual range and dose distribution of the monitoring particles; comparing the three-dimensional image with a pre-planned three-dimensional image of the treatment plan, and adjusting the dose and irradiation orientation of the treatment particles and the monitoring particles based on the comparison result.

[0010] According to an embodiment of the present disclosure, before the method is performed, the method further comprises: using the monitoring particles to irradiate a target object for a complete treatment plan, detecting the monitoring particles passing through the target object, and constructing a three-dimensional reference map based on the detection result; before each treatment is performed, using the monitoring particles to respectively irradiate the target object in a horizontal direction and a vertical direction, detecting the monitoring particles passing through the target object in each irradiation, and constructing an actual three-dimensional map based on the detection result; comparing the three-dimensional reference map and the actual three-dimensional map, and adjusting the positioning of the target object to be correct before the treatment is performed.

[0011] According to an embodiment of the present disclosure, the reconstructing the three-dimensional image of the treatment particles in the target object based on the residual range and the dose distribution of the monitoring particles comprises: obtaining position information of the monitoring particles based on the residual range of the monitoring particles, and deducing position information of the treatment particles based on the position information of the monitoring particles; obtaining a dose distribution of the treatment particles in the target object based on the dose of the monitoring particles at each position and the predetermined proportion; and reconstructing the three-dimensional image based on the position information of the treatment particles and the dose distribution of the treatment particles in the target object.

[0012] According to an embodiment of the present disclosure, the comparing the three-dimensional image with a pre-planned three-dimensional image of the treatment plan, and regulating the dose and the irradiation direction of the treatment particles and the monitoring particles based on the comparison result comprises: when the comparison result of the three-dimensional image and the pre-planned three-dimensional image does not meet the expectation, adjusting a low-energy line arranged on an emission path of the treatment particles and the monitoring particles, changing an emission direction of the treatment particles, and stopping irradiating the target object.

[0013] A third aspect of the present disclosure provides a verification device of a particle therapy mixed ion beam, comprising: a verification particle adding module configured to add monitoring particles with a predetermined proportion to treatment particles according to a treatment plan, the monitoring particles having the same charge-to-mass ratio as the treatment particles, and the monitoring particles having a greater range than the treatment particles in the same medium and at the same energy; a verification detection module configured to detect a residual range and a dose distribution of the monitoring particles after passing through a phantom; a verification reconstruction module configured to reconstruct a three-dimensional image of the treatment particles in the phantom based on the residual range and the dose distribution of the monitoring particles; and a verification analysis module configured to verify whether the treatment plan meets the expectation based on the three-dimensional image.

[0014] The fourth aspect of the present disclosure provides a monitoring device for a particle therapy mixed ion beam, comprising: a monitoring particle adding module configured to control adding a predetermined proportion of monitoring particles into therapy particles based on a therapy plan, the monitoring particles having the same charge-to-mass ratio as the therapy particles, and the range of the monitoring particles being greater than that of the therapy particles under the same medium and energy; a monitoring detection module configured to control the therapy particles and the monitoring particles to irradiate a target object, and to detect the residual range and dose distribution of the monitoring particles in real time after passing through the target object; a monitoring reconstruction module configured to reconstruct a three-dimensional image of the therapy particles in the target object based on the residual range and dose distribution of the monitoring particles; and a monitoring analysis module configured to compare the three-dimensional image with a pre-planned three-dimensional image of the therapy plan, and to regulate the dose and irradiation position of the therapy particles and the monitoring particles based on the comparison result.

[0015] The above-mentioned at least one technical solution adopted in the embodiments of the present disclosure can achieve the following beneficial effects:

[0016] The verification method and the monitoring method for the particle therapy mixed ion beam provided by the embodiments of the present disclosure can achieve monitoring during patient treatment, monitoring the dose and position of each position during treatment, save a large amount of manpower, financial resources and time, and also achieve accurate positioning of the dose during patient treatment, and can shut down and apply the beam at any time according to the feedback, so as to ensure that the healthy tissue is not over-dosed and the treatment plan dose is sufficient, and greatly improve the accuracy of patient positioning; by detecting the residual range of the helium ions, the comprehensive relative stopping power and thickness of the patient can be determined, and these data are very important for physicists and physicians, and a more accurate treatment plan can be designed. The verification method and the monitoring method shorten the time of the patient in the treatment room during particle therapy and proton heavy ion radiotherapy, and improve the use efficiency of the particle therapy and proton heavy ion radiotherapy equipment. BRIEF DESCRIPTION OF DRAWINGS

[0017] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which:

[0018] Figure 1 A radiotherapy flowchart provided by the embodiments of the present disclosure is schematically shown;

[0019] Figure 2 A mixed beam working diagram provided by the embodiments of the present disclosure is schematically shown;

[0020] Figure 3 A verification method for a particle therapy mixed ion beam provided by the embodiments of the present disclosure is schematically shown;

[0021] Figure 4A schematic diagram of a monitoring method of a mixed ion beam for particle therapy is shown;

[0022] Figure 5 A schematic diagram of a mixed ion beam treatment process is shown;

[0023] Figure 6 A structural block diagram of a verification device of a mixed ion beam for particle therapy is shown;

[0024] Figure 7 A structural block diagram of a verification device of a mixed ion beam for particle therapy is shown. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood, however, that the description which follows is merely exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description of the embodiments of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it would be apparent to one skilled in the art that the present disclosure can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring the concepts of the present disclosure.

[0026] The terms used herein are merely used to describe specific embodiments and are not intended to limit the present disclosure. The terms "include", "comprise" and the like used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0027] All terms used herein, including technical and scientific terms, have the same meanings as those generally understood by a person skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal manner.

[0028] Some of the blocks and / or flowcharts in the drawings represent computer program instructions or programs. It should be understood that these computer program instructions can be implemented by a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus. When the instructions are executed by the processor, the instructions can create means for implementing the functions / operations specified in the block and / or flowchart.

[0029] Accordingly, the technology of the present disclosure can be realized in the form of hardware and / or software (including firmware, microcode, etc.). In addition, the technology of the present disclosure can take the form of a computer program product on a computer-readable medium having instructions stored thereon that can be used by or in connection with an instruction execution system. In the context of the present disclosure, a computer-readable medium can be any medium that can contain, store, communicate, propagate, or transport instructions. For example, the computer-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, apparatus, or propagation medium. Specific examples of a computer-readable medium include a magnetic storage device, such as a magnetic tape or hard disk (HDD); an optical storage device, such as a compact disc (CD-ROM); a memory, such as a random access memory (RAM) or flash memory; and / or a wired / wireless communication link.

[0030] Figure 1 A radiotherapy flowchart is schematically shown.

[0031] As Figure 1 shown, in order to improve the accuracy of treatment, physicians will discuss the treatment plan for each patient collectively, according to the clinical response of the patient, the onset condition, the physical condition, the imaging data, etc., to outline the target area, determine where the critical organs are, where the tumor is more likely to metastasize, which tissues and structures must be protected and focused on, and which tissues are inevitably or possibly damaged due to the tumor. Then, the individual treatment plan is formulated by the doctor, who will mark the irradiation range and dose according to the treatment needs, ensure that the tumor is not missed, and then hand it over to the physicist to design the irradiation plan.

[0032] The physicist will design the radiotherapy plan according to the determined radiation range and required dose, i.e., the incidence angle and intensity of the rays, etc. At this stage, the physicist and the doctor will repeatedly discuss, compare, and check the CT, magnetic resonance, endoscopic examination, and clinical examination to maximize the protection of normal organs and meet the tumor irradiation dose requirements.

[0033] After the radiotherapy plan is formulated, the doctor will review and verify it. The verification is performed under simulated treatment conditions, and the human body model (or water tank) is irradiated to verify the irradiation plan by positioning the location, measuring the dose, and taking verification films. The irradiation plan verification includes position verification and dose verification, wherein the position verification refers to whether the position of the patient lying on the treatment bed during treatment is consistent with the position designed in the treatment plan. CBCT (cone beam CT) is used to obtain three-dimensional images for DR projection to check the position error. The dose verification is performed under simulated radiotherapy plan, and only needs to place the measurement tool at a certain position or depth of the phantom or water tank to measure whether the dose of the plane is consistent with the dose in the plan.

[0034] Only after the treatment plan has been reviewed and approved can it be sent to the accelerator controller for execution.

[0035] Due to uncertainties such as patient weight gain or loss, tissue swelling, muscle contraction, respiration, and heart rate during actual treatment, it is necessary to improve the verification methods for treatment plans and monitor the position and dose of particle emission in real time during treatment to ensure that the Bragg peak in the beam direction falls on the tumor and reduce the impact on healthy tissue.

[0036] Magnetic stiffness is a measure of the momentum of a moving particle. The greater the magnetic stiffness, the less easily it is "bent" under the same magnetic field. Particles with the same charge-to-mass ratio can be accelerated in the same accelerator, and each nucleon receives the same energy. However, even if different particles have the same energy, their effective range in water will differ. 4 He 2+ and 12 C 6+ The rest mass-to-charge ratios are 4.00236 / 2 a.mu and 12 / 6 a.mu (relative difference ≈ 0.065%), they have the same magnetic stiffness, and under the same medium and energy, 4 He 2+ The range is approximately 12 C 6+ This is three times the range of the main beam. This allows for the use of the range difference to perform treatment with the main beam while simultaneously using the mixed beam for imaging verification, a verification principle similar to proton CT.

[0037] Based on the above theory, this disclosure provides a verification and monitoring method for a mixed ion beam used in particle therapy. During carbon ion therapy, a certain proportion of helium ions with the same charge-to-mass ratio can be added to the carbon ions during acceleration in an accelerator, allowing them to accelerate together. The resulting mixed ion beam is then delivered to the patient. This mixed ion beam achieves a dual purpose: treatment and monitoring.

[0038] Figure 2 The illustration shows a schematic diagram of a hybrid beam operation provided by an embodiment of the present disclosure.

[0039] like Figure 2 As shown, a certain proportion of helium ions with the same charge-to-mass ratio are added to carbon ions. The carbon ions act like a Bragg to kill cancer cells, while the helium ions penetrate the patient's body and are captured by a detector. By analyzing the data captured by the detector, information about the carbon ions used in the treatment can be deduced, such as inferring the location of the carbon ions based on the residual range of helium.

[0040] The following will combine Figures 3-5The verification method and the monitoring method of the mixed ion beam for particle therapy are provided.

[0041] Figure 3 A schematic diagram of the verification method of the mixed ion beam for particle therapy is shown.

[0042] As Figure 3 shown, the verification method of the mixed ion beam for particle therapy comprises S310-S340.

[0043] S310, adding monitoring particles with a predetermined proportion into treatment particles according to a treatment plan, the monitoring particles and the treatment particles have the same charge-to-mass ratio, and the range of the monitoring particles is greater than that of the treatment particles in the same medium and energy.

[0044] In the embodiment, the mixed particles with the same charge-to-mass ratio can implement the verification method, such as H 2+ particles and 12 C 6+ particles, such as 4 He 2+ particles and 12 C 6+ particles, such as 6 Li 3+ particles and 12 C 6+ particles, wherein the carbon ions are used for treatment as the main beam, and the other particles are used for monitoring as the secondary beam. The following embodiments of the disclosure will be exemplified by using 4 He 2+ particles and 12 C 6+ particles.

[0045] S320, detecting the residual range and the dose distribution of the monitoring particles after passing through the phantom.

[0046] The carbon ions act on the cancer cells for killing the cancer cells, and the helium ions penetrate the patient's body and are captured by the detector. By analyzing the data captured by the detector, the information of the carbon ions used in the treatment can be deduced, such as the position of the carbon ions according to the residual range of the helium.

[0047] S330, reconstructing a three-dimensional image of the treatment particles in the phantom based on the residual range and the dose distribution of the monitoring particles.

[0048] Specifically, S330 comprises S331-S333.

[0049] S331, obtaining the position information of the monitoring particles based on the residual range of the monitoring particles, and deducing the position information of the treatment particles based on the position information of the monitoring particles.

[0050] S332, obtaining the dose distribution of the treatment particles in the phantom based on the dose distribution of the monitoring particles and the predetermined ratio.

[0051] S333, reconstructing a three-dimensional image based on the position information of the treatment particles and the dose distribution of the treatment particles in the phantom.

[0052] S340, verifying whether the treatment plan meets the expectation based on the three-dimensional image.

[0053] According to the verification method of the mixed ion beam provided by the present disclosure, in the treatment plan verification stage, the Bragg peak position detection device is placed behind the human phantom or the water tank, and only one complete treatment plan irradiation is needed to detect the residual range of all position helium ions in the simulation treatment; then the computer reversely deduces the position of the carbon ion. In addition, the helium ratio of the carbon ion is determined, and then the dose distribution of the carbon ion can be deduced according to the dose of each position helium ion, and the dose reconstruction in the treatment is completed, so that the position and dose verification are simultaneously performed. Moreover, all the obtained data are recombined and calculated in the computer, and then the three-dimensional image of the internal dose of the phantom or the water tank is obtained. Based on the three-dimensional image, the doctor and the physicist adjust the treatment plan until the irradiation position and dose of the ion beam meet the expectation.

[0054] In actual application, due to the different internal structures of the irradiation target object, for example, the bone density of each person is different, which causes the equivalent water depth to be different. When making the treatment plan, the physicist calculates the equivalent water depth from the skin to the tumor cell according to the image captured by the CT, which is used to determine the energy to be used. The existing technology cannot verify the equivalent water depth of the target object, and the energy used at each position cannot be accurately matched through data deduction.

[0055] In the present embodiment, in the verification stage of the treatment plan, based on the three-dimensional image, the equivalent water depth of each tissue in the heavy ion phantom (the phantom can be a human model) can be verified, which serves as an important reference for the physicist to adjust the heavy ion energy for irradiating the predetermined region. In the present embodiment, in order to ensure that the irradiation depth of the ion beam in the human body is the same as the plan, after the treatment plan is initially established, the patient can be irradiated with a complete treatment plan of helium ion beam, the transmitted helium ions are detected, and the three-dimensional image is obtained through the computer. The physicist and the doctor can determine the comprehensive relative stopping power and thickness of the patient, and then compare and analyze these data, the verified three-dimensional image and the treatment plan, and modify the treatment plan again. In this way, not only the treatment accuracy is improved, but also a large amount of manpower, financial resources and time are saved.

[0056] 4 He 2+ and 12 C 6+The same magnetic rigidity cannot be separated by deflection, and the design of the ion source needs to take this into account. In the present embodiment, two ion sources are involved, which are respectively into helium and carbon to obtain treatment particles 12 C 6+ and monitoring particles 4 He 2+ A low-energy line bent by 90° is arranged on the emission path of the treatment particles and the monitoring particles, and the treatment particles and the monitoring particles are screened and mixed based on the low-energy line.

[0057] Further, in the present embodiment, a monitoring module can be designed to monitor the flow of the treatment particles and the monitoring particles. In the verification process and the monitoring process of the particle treatment mixed ion beam, the flow of the treatment particles and the monitoring particles is monitored by the monitoring module based on the requirements of the treatment plan, and the proportion of the treatment particles and the monitoring particles is adjusted by adjusting the low-energy line and the accelerator, so that the implementation of the treatment plan is more accurate.

[0058] After the treatment plan is verified, the treatment plan can be implemented. Due to a series of changes such as the weight of the patient, the body fat rate, the swelling of the tissue, and the filling of the intestinal tract during the treatment, the position of the heavy ion peak will change. In order to solve such problems, before the treatment plan is implemented, the adjustment plan S401-S403 can be performed first.

[0059] S401, the target object is irradiated with the monitoring particles according to the complete treatment plan, the monitoring particles passing through the target object are detected, and a three-dimensional reference map is constructed based on the detection results.

[0060] S402, before each implementation of the treatment, the target object is irradiated with the monitoring particles in the horizontal direction and the vertical direction respectively, the monitoring particles passing through the target object in each irradiation are detected, and an actual three-dimensional map is constructed based on the detection results.

[0061] S403, the three-dimensional reference map and the actual three-dimensional map are compared, and the target object is adjusted to be correctly positioned before the treatment is implemented.

[0062] According to the above method, the three-dimensional reference map and the actual three-dimensional map, and CT are compared by the physicist and the physician, not only the correctness of the patient positioning can be confirmed, but also whether the tumor changes and whether the Bragg peak moves can be checked, so that the treatment plan can be temporarily adjusted according to a series of changes of the patient, and the treatment plan is more accurate.

[0063] Figure 4 A schematic diagram of a monitoring method of a particle treatment mixed ion beam provided by an embodiment of the present disclosure is schematically shown.

[0064] As Figure 4 shown, the monitoring method of the particle treatment mixed ion beam provided by an embodiment of the present disclosure includes S410-S440.

[0065] S410, adding a predetermined proportion of monitoring particles into the therapeutic particles based on the treatment plan, the monitoring particles having the same charge-to-mass ratio as the therapeutic particles, and the monitoring particles having a greater range than the therapeutic particles in the same medium and energy.

[0066] S420, controlling the therapeutic particles and the monitoring particles to irradiate the target object, and detecting the residual range and the dose distribution of the monitoring particles after passing through the target object in real time.

[0067] S430, reconstructing a three-dimensional image of the therapeutic particles in the target object based on the residual range and the dose distribution of the monitoring particles.

[0068] S430 includes S431-S433.

[0069] S431, obtaining position information of the monitoring particles based on the residual range of the monitoring particles, and inversely deducing position information of the therapeutic particles based on the position information of the monitoring particles.

[0070] S432, obtaining a dose distribution of the therapeutic particles in the target object based on the dose of each position monitoring particle and the predetermined proportion.

[0071] S433, reconstructing the three-dimensional image based on the position information of the therapeutic particles and the dose distribution of the therapeutic particles in the target object.

[0072] S440, comparing the three-dimensional image with a pre-planned three-dimensional image of the treatment plan, and adjusting the dose and irradiation position of the therapeutic particles and the monitoring particles based on the comparison result.

[0073] In the embodiment, the pre-planned three-dimensional image is sent to the accelerator controller before treatment; the helium ion beam is continuously irradiated during treatment, and the detector behind the patient transmits real-time monitoring data to the computer, which verifies the calculated carbon ion data and the data of the pre-planned three-dimensional image; when the comparison result of the three-dimensional image and the pre-planned three-dimensional image does not meet the expectation, the low-energy line arranged on the emission path of the therapeutic particles and the monitoring particles is adjusted, the emission direction of the therapeutic particles is changed, the irradiation of the target object is stopped, and it is ensured that the healthy tissue is not over-dosed and the lesion is sufficiently dosed.

[0074] Figure 5 A mixed ion beam treatment flowchart is schematically shown.

[0075] As Figure 5As shown, based on the particle therapy mixed ion beam verification method and monitoring method provided by the embodiments of the present disclosure, the physician outlines the target region according to the clinical response, the onset condition, the body state, the image examination data and the like of the patient, formulates an individual treatment plan, the doctor will mark the irradiation range and the dose according to the treatment needs, and ensure that there is no omission of the tumor, and then hand over to the physicist to design the irradiation plan. The physicist designs the radiotherapy plan according to the determined radiation range and the required dose, that is, the incidence angle and intensity of the rays and the like. To ensure that nothing goes wrong, after the radiotherapy plan is out, the doctor will perform auditing and verification.

[0076] In the verification stage, the residual range and dose distribution of the monitoring particle after passing through the phantom are detected, and the actual dose three-dimensional image of the treatment particle in the phantom is reconstructed based on the residual range and dose distribution of the monitoring particle by the computer, and compared with the designed three-dimensional image to determine whether the treatment plan meets the expectation. When the position or dose of the treatment particle deviates, the physicist modifies the irradiation plan in the treatment plan, and after re-auditing by the doctor and verification by the phantom, the irradiation is performed. The process is repeated until the position or dose of the treatment particle meets the expectation of the doctor.

[0077] In the treatment plan execution stage, the residual range and dose distribution of the monitoring particle after passing through the target object of treatment are detected, and the three-dimensional image of the treatment particle in the target object is reconstructed by the computer; the three-dimensional image is compared with the pre-planned three-dimensional image of the treatment plan, and the comparison result is fed back to the accelerator to control the dose and irradiation position of the treatment particle and the monitoring particle, so as to ensure the irradiation accuracy.

[0078] It should be noted that the detector must be able to measure the helium residual range in the presence of secondary carbon fragments, which inevitably hit the detector and produce unwanted signals. Therefore, the proportion of He ions to be introduced must be large enough, but also small enough to prevent the total dose from exceeding the standard. In 2018, Graeff et al. have demonstrated the potential of using a mixed helium / carbon beam as a range probe for carbon ion therapy, investigating patients treated with 4D treatment planning for lung cancer. Assuming that the proportion of helium in the carbon ion beam is fixed in the plan, they show that the RBE dose produced by 10% of helium ions in the mixed beam accounts for less than 0.5% of the target dose. This is due to the physical dose difference between helium ions and carbon ions in the plateau region and the Bragg peak, as well as the difference in RBE. In addition, compared with the secondary fragment dose deposition of carbon ions, the helium ions also have a smaller deposition end dose far from the tumor.

[0079] Mazzucconi et al. performed Monte Carlo simulations in which they added 10% of He particles to the Bragg peak carbon ion beam, first explored the possibility of using a mixed beam for treatment monitoring by experiment, and proved that the helium ion signal through the human body can be detected by the scintillation detector although it is affected by carbon secondary fragments. The experiment proves that the verification method and monitoring method of the mixed ion beam of particle therapy provided by the embodiments of the disclosure can be implemented in practical application.

[0080] The verification method and monitoring method of the mixed ion beam of particle therapy provided by the embodiments of the disclosure add a predetermined proportion of monitoring particles to the treatment particles, which can realize monitoring during patient treatment, monitor the dose and position of each position during treatment, save a large amount of manpower, financial resources and time, and also realize accurate positioning of the dose during patient treatment, and according to the feedback, the beam current can be turned off and applied at any time, so as to ensure that the healthy tissue does not exceed the amount, the treatment plan dose is sufficient, and the accuracy of patient positioning is greatly improved; by detecting the residual range of helium ions, the comprehensive relative stopping power and thickness of the patient can be determined, which is very important for physicists and physicians, and a more accurate treatment plan can be designed. The verification method and monitoring method shorten the time of the patient in the treatment room during particle therapy and proton heavy ion radiotherapy, and improve the use efficiency of the particle therapy and proton heavy ion radiotherapy equipment.

[0081] Figure 6 The structure block diagram of a verification device of a mixed ion beam of particle therapy provided by the embodiments of the disclosure is schematically shown.

[0082] As Figure 6 shown, the verification device of the mixed ion beam of particle therapy provided by the embodiments of the disclosure includes a verification particle adding module 610, a verification detection module 620, a verification reconstruction module 630 and a verification analysis module 640.

[0083] The verification particle adding module 610 is configured to add a predetermined proportion of monitoring particles to the treatment particles according to a treatment plan, the charge-to-mass ratio of the monitoring particles is the same as that of the treatment particles, and the range of the monitoring particles is greater than that of the treatment particles in the same medium and energy.

[0084] The verification detection module 620 is configured to detect the residual range and dose distribution of the monitoring particles after passing through the phantom.

[0085] The verification reconstruction module 630 is configured to reconstruct a three-dimensional image of the treatment particles in the phantom based on the residual range and dose distribution of the monitoring particles.

[0086] The verification analysis module 640 is configured to verify whether the treatment plan meets the expectation based on the three-dimensional image.

[0087] The particle therapy mixed ion beam verification device provided by the embodiment of the present disclosure has the same technical features as the particle therapy mixed ion beam verification method provided by the present disclosure, and thus can achieve the same technical effects, which will not be repeated here.

[0088] Figure 7 The structure block diagram of the particle therapy mixed ion beam verification device provided by the embodiment of the present disclosure is schematically shown.

[0089] As shown in Figure 7 The monitoring device for particle therapy mixed ion beam provided by the embodiment of the present disclosure comprises a monitoring particle adding module 710, a monitoring detection module 720, a monitoring reconstruction module 730 and a monitoring analysis module 740.

[0090] The monitoring particle adding module 710 is configured to control the addition of a predetermined proportion of monitoring particles to the therapy particles based on the treatment plan, the monitoring particles and the therapy particles have the same charge-to-mass ratio, and the range of the monitoring particles is greater than that of the therapy particles under the same medium and energy;

[0091] The monitoring detection module 720 is configured to control the therapy particles and the monitoring particles to irradiate a target object, and detect the residual range and the dose distribution of the monitoring particles after passing through the target object in real time;

[0092] The monitoring reconstruction module 730 is configured to reconstruct a three-dimensional image of the therapy particles in the target object based on the residual range and the dose distribution of the monitoring particles;

[0093] The monitoring analysis module 740 is configured to compare the three-dimensional image with a pre-planned three-dimensional image of the treatment plan, and adjust the dose and the irradiation position of the therapy particles and the monitoring particles based on the comparison result.

[0094] The monitoring device for particle therapy mixed ion beam provided by the embodiment of the present disclosure has the same technical features as the particle therapy mixed ion beam verification method provided by the present disclosure, and thus can achieve the same technical effects, which will not be repeated here.

[0095] It can be understood that the verification particle adding module 610, the verification detection module 620, the verification reconstruction module 630, the verification analysis module 640, the monitoring particle adding module 710, the monitoring detection module 720, the monitoring reconstruction module 730, and the monitoring analysis module 740 can be combined in one module, or any one of them can be split into multiple modules. Alternatively, at least part of the function of one or more of these modules can be combined with at least part of the function of other modules and implemented in one module. According to an embodiment of the present application, at least one of the verification particle adding module 610, the verification detection module 620, the verification reconstruction module 630, the verification analysis module 640, the monitoring particle adding module 710, the monitoring detection module 720, the monitoring reconstruction module 730, and the monitoring analysis module 740 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on chip, a system on substrate, a system on package, an application specific integrated circuit (ASIC), or any other reasonable way of integrating or packaging circuits, etc. hardware or firmware, or a suitable combination of software, hardware, and firmware. Alternatively, at least one of the verification particle adding module 610, the verification detection module 620, the verification reconstruction module 630, the verification analysis module 640, the monitoring particle adding module 710, the monitoring detection module 720, the monitoring reconstruction module 730, and the monitoring analysis module 740 can be at least partially implemented as a computer program module that can perform the function of the corresponding module when the program is run by a computer.

[0096] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present disclosure can be combined or / and combined, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, the features described in various embodiments and / or claims of the present disclosure can be combined and / or combined in various combinations without departing from the spirit and teachings of the present disclosure. All these combinations and / or combinations fall within the scope of the present disclosure.

[0097] Although the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it should be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments, but should be determined by the appended claims alone, and by the equivalents thereof.

Claims

1. A method for verifying a hybrid ion beam for particle therapy, characterized in that, include: According to the treatment plan, a predetermined proportion of monitoring particles are added to the treatment particles. The monitoring particles have the same charge-to-mass ratio as the treatment particles, and under the same medium and energy, the range of the monitoring particles is greater than that of the treatment particles. The monitoring particles can penetrate the phantom. The remaining range and dose distribution of the monitored particles after they pass through the phantom are detected; Based on the remaining range and dose distribution of the monitored particles, a three-dimensional image of the therapeutic particles within the phantom is reconstructed; The treatment plan is verified based on the three-dimensional images to determine whether it meets expectations.

2. The verification method according to claim 1, characterized in that, The process of reconstructing a three-dimensional image of the therapeutic particles within the phantom based on the remaining range and dose distribution of the monitored particles includes: The position information of the monitoring particle is obtained based on the remaining range of the monitoring particle, and the position information of the therapeutic particle is inferred from the position information of the monitoring particle. Based on the dose distribution of the monitored particles and the predetermined ratio, the dose distribution of the therapeutic particles in the phantom is obtained; The three-dimensional image is reconstructed based on the positional information of the therapeutic particles and the dose distribution of the therapeutic particles within the phantom.

3. The verification method according to claim 1, characterized in that, The method further includes: The overall relative stopping power and thickness of the phantom are calculated based on the three-dimensional image, and the equivalent water depth of each tissue of the phantom is verified based on the three-dimensional image.

4. The verification method according to claim 1, characterized in that, The method further includes: A low-energy line with a 90° bend is set on the emission path of the therapeutic particles and the monitoring particles, and the therapeutic particles and the monitoring particles are screened and mixed based on the low-energy line; The flow rates of the therapeutic particles and the monitoring particles are monitored, and the ratio of the therapeutic particles to the monitoring particles is adjusted based on the treatment plan.

5. A verification device for particle therapy using a hybrid ion beam, characterized in that, include: The verification particle addition module is used to add a predetermined proportion of monitoring particles to the treatment particles according to the treatment plan. The monitoring particles have the same charge-to-mass ratio as the treatment particles, and under the same medium and energy, the range of the monitoring particles is greater than that of the treatment particles. The monitoring particles can penetrate the phantom. The verification and detection module is used to detect the remaining range and dose distribution of the monitored particles after they pass through the phantom. The verification and reconstruction module is used to reconstruct a three-dimensional image of the therapeutic particles within the phantom based on the remaining range and dose distribution of the monitored particles. The verification analysis module is used to verify whether the treatment plan meets expectations based on the three-dimensional image.

6. A monitoring device for a mixed ion beam used in particle therapy, characterized in that, include: The monitoring particle addition module is used to add a predetermined proportion of monitoring particles to the treatment particles based on the treatment plan. The monitoring particles have the same charge-to-mass ratio as the treatment particles, and under the same medium and energy, the range of the monitoring particles is greater than that of the treatment particles. The monitoring particles can penetrate the target object. The monitoring and detection module is used to control the irradiation of the target object by the therapeutic particles and the monitoring particles, and to detect the remaining range and dose distribution of the monitoring particles after they pass through the target object in real time. A monitoring and reconstruction module is used to reconstruct a three-dimensional image of the therapeutic particles in the target object based on the remaining range and dose distribution of the monitored particles; The monitoring and analysis module is used to compare the three-dimensional image with the pre-planned three-dimensional image of the treatment plan, and adjust the dose and irradiation orientation of the treatment particles and the monitoring particles based on the comparison results.

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