Novel beam conveying method

Abstract

The invention relates to the field of beam conveying control, in particular to a novel beam conveying method. The method comprises the steps of extracting coordinates of an irradiation point, controlling a first magnet power supply current value based on the coordinates, obtaining the position of the irradiation point and judging whether the irradiation point deviates from the coordinates, and if yes, calculating a new magnetic field value and controlling a second magnet power supply current value; in addition, the scanning magnet power supply current value can be controlled based on the irradiation point coordinates and the deviation value, a TPS plan file is obtained to extract the coordinates, the irradiation point prediction position is calculated according to a preset formula and the coordinates and compared with the actual position, and the proton average energy of the beam is 235 MeV. According to the invention, beam conveying can be controlled more accurately, and the accuracy of beam conveying to an irradiation point is improved.

Description

Technical Field

[0001] The present application relates to the field of beam delivery control, and in particular to a novel beam delivery method. Background Art

[0002] In the field of beam delivery technology, with the continuous advancement of science and technology, beams are playing an increasingly important role in many areas, including medicine and scientific research. In the medical field, particle beams are used in tumor treatment, precisely focusing energy on the tumor target. Compared with traditional radiotherapy methods, they have better therapeutic effects and fewer side effects, greatly improving patients' quality of life and cure rates. In scientific research, beams are used in materials research, nuclear physics experiments, and other fields, helping scientists explore the mysteries of the microscopic world and promoting the development of related disciplines.

[0003] In previous beam delivery processes, the direction and position of the beam were typically controlled by adjusting the magnetic field of the scanning magnet. The accelerator changes the magnetic field of the scanning magnet by controlling the power supply current, thereby directing the beam along a predetermined trajectory. Ionization chambers are also used to monitor the beam's position. However, these conventional methods have limitations. In practice, the magnetic field of the scanning magnet is affected by factors such as hysteresis, resulting in deviations from the intended magnetic field. This deviation can prevent the beam from accurately landing at the intended location, thus affecting the accuracy of the entire beam delivery process. Summary of the Invention

[0004] In order to improve the accuracy of beam delivery, this application provides a new beam delivery method This application provides a novel beam delivery method using the following technical solutions: A novel beam delivery method, comprising: Extract the coordinates of the irradiation point, Based on the irradiation point coordinates, the current value of the first magnet power supply is controlled. Get the irradiation point position, Determine whether the irradiation point position deviates from the irradiation point coordinates, When the irradiation point position deviates from the irradiation point coordinates, calculate the new magnetic field value. Based on the new magnetic field value, the current value of the second magnet power supply is controlled.

[0005] By adopting the above technical solution, the current value of the first magnet power supply can be controlled according to the extracted irradiation point coordinates, so that the beam is transmitted toward the target irradiation point; the position of the irradiation point is obtained and it is determined whether it deviates from the coordinates. If it deviates, the new magnetic field value is calculated and the current value of the second magnet power supply is controlled, thereby realizing the correction of the beam position, avoiding uneven irradiation dose in the target area due to misalignment of the beam position, and reducing the possibility of underdose in the target area, tumor recurrence, and excessive radiation damage to critical organs around the target area.

[0006] Preferably, it also includes: Based on the irradiation point coordinates and the deviation value, the current value of the scanning magnet power supply is controlled; The deviation value is calculated based on the irradiation point coordinates and the irradiation point position. The scanning magnet power supply includes a first magnet power supply.

[0007] By adopting the above technical solution, a deviation value is first calculated based on the irradiation point coordinates and the irradiation point position, and then the current value of the scanning magnet power supply (including the first magnet power supply) is controlled in combination with the irradiation point coordinates and the deviation value. This can further improve the control accuracy of the beam and achieve more precise adjustment of the beam position, thereby effectively avoiding beam position irradiation misalignment, reducing the occurrence of hot spots and cold spots in the irradiated target area, making the irradiation dose in the target area more uniform, reducing the possibility of tumor recurrence due to insufficient dose in the target area, and reducing the risk of critical organs around the target area receiving excessive doses.

[0008] Preferably, the scanning magnet power supply further includes a second magnet power supply.

[0009] By adopting the above technical solution, when controlling the current value of the scanning magnet power supply based on the irradiation point coordinates and the deviation value, the second magnet power supply can be used to participate in the control. Combined with the original solution of controlling the current value of the first magnet power supply according to the irradiation point coordinates, judging whether the irradiation point position deviates from the coordinates, and calculating the new magnetic field value to control the current value of the second magnet power supply, the beam can be adjusted more flexibly and accurately, the beam position can be corrected better, and the accuracy of beam delivery to the target irradiation point position can be improved. This avoids uneven irradiation dose in the target area due to beam position misalignment, reduces the possibility of underdose and tumor recurrence in the target area, and reduces the risk of critical organs around the target area being damaged by excessive irradiation.

[0010] Preferably, the irradiation point position also includes a second irradiation point position, The deviation value is obtained by calculation based on the coordinates of the illumination point and the second position of the illumination point.

[0011] By adopting the above technical solution and using the second position of the irradiation point to participate in the deviation value calculation, the deviation value can be further calculated accurately, the beam position can be corrected more effectively, the beam position irradiation misalignment can be reduced, and obvious hot spots and cold spots in the target area can be avoided. The irradiation dose in the target area is ensured to be uniform, and the possibility of late tumor recurrence due to insufficient dose in the target area is reduced. At the same time, the probability of critical organs around the target area being damaged by doses exceeding the limit is reduced.

[0012] Preferably, it also includes: Get TPS plan documents, Extract irradiation point coordinates based on TPS plan file.

[0013] By adopting the above technical solution, the irradiation point coordinates can be accurately extracted based on the TPS plan file, providing an accurate target position reference for the control and adjustment during the subsequent beam delivery process, which helps to more accurately control the beam irradiation and improve the accuracy and effectiveness of the beam delivery method.

[0014] Preferably, the irradiation point position includes a first irradiation point position; The step of determining whether the irradiation point position deviates from the irradiation point coordinates includes: Calculate the predicted position of the irradiation point based on the preset formula and the coordinates of the irradiation point. Compare the first position of the irradiation point with the predicted position of the irradiation point.

[0015] By adopting the above technical solution, by calculating the predicted position of the irradiation point based on the preset formula and the irradiation point coordinates and comparing it with the first position of the irradiation point, it is possible to accurately determine whether the irradiation point position deviates from the irradiation point coordinates. When it deviates, the new magnetic field value is calculated and the current value of the second magnet power supply is controlled, thereby more accurately realizing beam delivery, ensuring the accuracy of the beam irradiation position, reducing the problem of uneven irradiation dose in the target area due to beam position irradiation misalignment, and reducing the possibility of tumor recurrence and damage to critical organs around the target area.

[0016] Preferably, the average proton energy of the beam is 235 MeV.

[0017] By adopting the above technical solution, the beam can have a specific energy level. Combined with operations such as extracting the irradiation point coordinates, controlling the magnet power supply current value, obtaining and judging the irradiation point position, and calculating the new magnetic field value, the beam can be transported more accurately. In addition, it can cooperate with subsequent possible beam position correction and depth expansion operations to meet specific beam delivery requirements.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. By extracting the irradiation point coordinates and controlling the current value of the first magnet power supply, combined with monitoring and determining the position of the beam irradiation point, the problem of beam position deviation caused by the hysteresis effect of the scanning magnet magnetic field can be solved, thereby improving the beam delivery accuracy; 2. When the irradiation point deviates from the coordinates, the new magnetic field value is calculated and the current value of the second magnet power supply is controlled, which can timely correct the beam position, avoid uneven irradiation dose in the target area due to inaccurate beam position, and reduce the possibility of tumor recurrence and damage to surrounding critical organs; 3. Setting the average proton energy of the beam to 235 MeV can achieve beam expansion in the depth direction, meeting the irradiation requirements of different target depths and lengths. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1This is a schematic diagram of the beam delivery device, used to illustrate the deflection of the beam in the X direction.

[0020] Figure 2 This is a schematic diagram of the beam delivery device, used to show the deflection of the beam in the Y direction.

[0021] Figure 3 Schematic diagram of the positional relationship of the beams at the first ionization chamber IC1 and the second ionization chamber IC2.

[0022] Figure 4 This is a schematic diagram of the effect of magnetic field fluctuations on the beam transport path.

[0023] Figure 5 This is a schematic diagram of the beam delivery method when the correction is applied to the next irradiation point.

[0024] Figure 6 This is a schematic diagram of the beam delivery method when the correction is applied to the current irradiation point.

[0025] Figure 7 is a diagram of relative dose-depth. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to the accompanying drawings.

[0027] For point-scanning irradiation systems, beam spot position is a crucial performance parameter. Misalignment of the beam spot can lead to distinct hot and cold spots within the target area, resulting in uneven irradiation doses. This can lead to insufficient doses within the target area, increasing the likelihood of tumor recurrence later in life. Furthermore, it can cause critical organs around the target area to receive doses exceeding their limits, potentially damaging them.

[0028] Reference Figure 1 and Figure 2 , an embodiment of the present application discloses a beam delivery device, comprising a first magnet, a first ionization chamber IC1, a second magnet, and a second ionization chamber IC2 arranged in sequence.

[0029] The first magnets include a scanning magnet SU1 and a scanning magnet SV1, and the second magnets include a scanning magnet SU2 and a scanning magnet SV2.

[0030] Scanning magnets SU1 and SU2 are used to deflect the beam in the X direction. Scanning magnets SV1 and SV2 are used to deflect the beam in the Y direction. The X and Y directions are perpendicular to each other.

[0031] The first ionization chamber IC1 and the second ionization chamber IC2 are used to verify whether the beams are parallel.

[0032] Reference Figure 3Taking the X-direction beam as an example, since the position of the particle beam at the isocenter plane is fixed (the specific X and Y directions of the particle beam that needs to be irradiated at the isocenter plane can be known according to the TPS plan output), the beam has a fixed position on the IC1 and IC2 ionization chambers after passing through the two scanning magnets in the U direction.

[0033] When the magnetic field of any scanning magnet deviates from the actual value due to the hysteresis effect, the particles passing through the scanning magnet will not hit the preset position.

[0034] Reference Figure 4 Schematic diagram of the beam path through the magnets with and without magnetic field fluctuations, when the two X-direction scanning magnets SU1 and SU2 each have a 0.1 T magnetic field fluctuation. The solid line represents the case without magnetic field fluctuations, and the dashed line represents the case with magnetic field fluctuations.

[0035] Reference Figure 5 , the embodiment of the present application also discloses a novel beam delivery method for correcting the beam position.

[0036] Beam delivery methods include: Obtain TPS plan documents; Extract irradiation point coordinates based on TPS plan file; Based on the irradiation point coordinates, the current value of the first magnet power supply is controlled.

[0037] The TPS plan file can be input by the staff. The TPS plan file is generated by the treatment planning system and contains key parameters such as the three-dimensional dose distribution of the tumor target area, beam energy, scanning path, and irradiation time.

[0038] In the case where the correction is applied to the next irradiation point, the beam delivery method also includes: Get the irradiation point position; Based on the irradiation point coordinates and the offset value, the current value of the scanning magnet power supply is controlled.

[0039] The irradiation point position includes a first irradiation point position and a second irradiation point position; the first irradiation point position is acquired through the first ionization chamber IC1, and the second irradiation point position is acquired through the second ionization chamber IC2.

[0040] The deviation value is calculated based on the irradiation point coordinates and the irradiation point position.

[0041] In one embodiment: a deviation value is calculated based on the irradiation point coordinates and the second position of the irradiation point; the scanning magnet power supply includes a first magnet power supply and a second magnet power supply; the first magnet power supply is used to power the first magnet, and the second magnet power supply is used to power the second magnet.

[0042] Preferably: calculating the predicted position of the irradiation point according to the preset formula and the coordinates of the irradiation point; Calculating a deviation value based on the predicted position of the irradiation point and the first position of the irradiation point; The scanning magnet power supply includes a first magnet power supply, the first magnet power supply is used to supply power to the first magnet; Preset type can be referred to Figure 3 .

[0043] Reference Figure 6 , when the correction is applied to the current irradiation point, the beam delivery method further includes: Determine whether the irradiation point position deviates from the irradiation point coordinates, When the irradiation point position deviates from the irradiation point coordinates, calculate the new magnetic field value. Based on the new magnetic field value, the current value of the second magnet power supply is controlled.

[0044] The step of determining whether the irradiation point position deviates from the irradiation point coordinates includes: Calculate the predicted position of the irradiation point based on the preset formula and the coordinates of the irradiation point; Compare the first position of the irradiation point with the predicted position of the irradiation point.

[0045] The average proton energy of the beam is 235 MeV. The particle beam of the current energy passes through the range shifters of different thicknesses calculated in advance. The number of particles required to pass through the range shifters of different thicknesses is calculated according to the target depth and target length of the TPS plan. The final effect of depth superposition is as follows: Figure 7 shown.

[0046] The implementation principle of a novel beam delivery method in an embodiment of the present application is as follows: first, a TPS plan file is obtained to extract the irradiation point coordinates. Based on the coordinates, the current value of the first magnet power supply is controlled to preliminarily control the beam current. The irradiation point position is then obtained and compared with the coordinates. If there is any deviation, a new magnetic field value is calculated to control the current value of the second magnet power supply to correct the beam current. This method achieves the effect of timely adjusting the beam position according to actual conditions, reducing beam position inaccuracies caused by magnetic field deviations, and improving beam delivery accuracy. This is because through a series of steps, beam position information is continuously obtained and compared, and adjustments are made whenever deviations are detected, allowing the beam to more accurately reach the predetermined position.

[0047] This beam delivery method uses a series of steps, starting with obtaining a TPS plan file, to gradually control and adjust the beam. Utilizing various devices and modules, it continuously acquires relevant beam information, performs comparisons, and performs calculations. Once beam position deviation is detected, the magnetic field is promptly adjusted, ultimately achieving accurate beam delivery to the intended location. By introducing an offset value to control the current of the scanning magnet power supplies (including the first and second magnet power supplies), beam control is achieved more precisely. By calculating the predicted irradiation point position and comparing it with the actual detected first irradiation point position, beam position deviation can be more accurately determined. Compared to existing technologies, this method effectively reduces the impact of magnetic field deviation on beam delivery, significantly improving beam delivery accuracy and possessing significant application value in fields such as medicine and scientific research.

[0048] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A novel beam delivery method, characterized in that: include: Extract the coordinates of the irradiation point, Based on the irradiation point coordinates, the current value of the first magnet power supply is controlled. Get the irradiation point position, Determine whether the irradiation point position deviates from the irradiation point coordinates, When the irradiation point position deviates from the irradiation point coordinates, calculate the new magnetic field value. Based on the new magnetic field value, the current value of the second magnet power supply is controlled.

2. A novel beam delivery method according to claim 1, characterized in that: Also includes: Based on the irradiation point coordinates and the deviation value, the current value of the scanning magnet power supply is controlled; The deviation value is calculated based on the irradiation point coordinates and the irradiation point position. The scanning magnet power supply includes a first magnet power supply.

3. A novel beam delivery method according to claim 2, characterized in that: The scanning magnet power supply also includes a second magnet power supply.

4. A novel beam delivery method according to claim 2, characterized in that: The irradiation point position also includes a second irradiation point position, The deviation value is obtained by calculation based on the coordinates of the illumination point and the second position of the illumination point.

5. A novel beam delivery method according to claim 1, characterized in that: Also includes: Get TPS plan documents, Extract irradiation point coordinates based on TPS plan file.

6. A novel beam delivery method according to claim 1, characterized in that: The irradiation point position includes a first irradiation point position; The step of determining whether the irradiation point position deviates from the irradiation point coordinates includes: Calculate the predicted position of the irradiation point based on the preset formula and the coordinates of the irradiation point. Compare the first position of the irradiation point with the predicted position of the irradiation point.

7. A novel beam delivery method according to claim 1, characterized in that: The average proton energy of the beam is 235 MeV.

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