A proton beam flow intensity modulation method and system

Abstract

The invention discloses a proton beam flow intensity modulation method and system. In a proton therapy device based on a cyclotron, an energy selection module makes the transmission efficiency of the proton beam with different energies very different, but a treatment end requires the proton beam to maintain a stable flow intensity range. The method of the invention firstly obtains the beam loss and the transmission efficiency of the proton beam with different energies in an energy reduction process after the energy modulation of the proton beam, and obtains a flow intensity ratio from low energy to high energy. According to the clinical requirements of the proton beam flow intensity dynamic ratio, after different energy points which have been subjected to energy modulation undergo expansion and collimation, the flow intensity modulation within a design proportional region is completed and the flow ratio can be controlled within a certain value. The method and the system of the invention are based on the Monte Carlo calculation method and the beam optics. The design method is reliable, and the realization scheme has a small space requirement, which is important for maintaining the beam stability in the proton therapy process.

Description

technical field [0001] The invention belongs to the technical field of proton therapy device development, and more specifically relates to a proton beam current intensity modulation method and system. Background technique [0002] Proton therapy is the current precision radiation therapy method for cancer. Based on the unique Bragg peak dose distribution characteristics of the proton beam, the Bragg peak dose control at different depths can be achieved by adjusting the proton beam energy, thereby achieving precise emission therapy. Cyclotrons are widely used in proton therapy, and the proton beams produced by them have the advantage of being continuous and stable. However, since the energy of the beam drawn by the cyclotron is fixed, it is necessary to modulate the energy through the energy reducer on the transport line, so as to treat tumors of different depths. [0003] The energy degrader usually uses a material with high density and low atomic number (such as carbon), ...

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Problems solved by technology

[0005] In view of the above defects or improvement needs of the prior art, the purpose of the present invention is to provide a proton beam current intensity modulation method and system, thereby solving the technical problem of poor current intensity modulation stability in existing proton therapy devices

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