Time sequence based proton or heavy ion radiotherapy dose real-time monitoring method

Abstract

The invention discloses a time sequence based proton or heavy ion radiotherapy dose real-time monitoring method, and belongs to the field of nuclear medical images. The method is based on a proton or heavy ion radiotherapy system and a prompt gamma photon imaging system, a projection sequence of prompt gamma photons generated in the spot scanning process of each rumor target region according to time sequence information of detected prompt gamma photons, rebuilding prompt gamma photon space distribution of the spot scanning process of each tumor target region according to prior information of the prompt gamma photons, and thus dose deposition space distribution of protons or heavy ions in the spot scanning process of the corresponding tumor target region is calculated, so that real-time dose monitoring for the proton or heavy ion radiotherapy process is realized. The dose monitoring method disclosed by the invention effectively utilizes the prior information of prompt gamma photon space distribution, the design of the prompt gamma photon imaging system can be simplified, influences of prompt gamma photon counting statistical noises can be reduced, and the accuracy of proton or heavy ion dose monitoring is improved.

Description

Technical field [0001] The invention belongs to the field of nuclear medicine imaging, and in particular relates to a real-time monitoring method of proton or heavy ion radiotherapy dose based on time series. Background technique [0002] Radiotherapy is one of the effective methods of current cancer treatment. Its purpose is to deliver the prescribed dose of radiation to the tumor target area while minimizing the dose deposition of surrounding normal tissues. Compared with photon radiotherapy methods such as X-rays or gamma rays, the advantage of proton or heavy ion radiotherapy is that its dose deposition spatial distribution has a maximum position, that is, the Bragg peak position. Utilizing the characteristics of the maximum dose deposition at the position of the Bragg peak of protons or heavy ions can effectively increase the dose deposition in the tumor target area and significantly reduce the dose deposition in the surrounding normal tissues. [0003] The point-by-point sc...

AI Technical Summary

Problems solved by technology

[0005] In order to realize the acquisition of the spatial distribution of prompt gamma photons, traditional gamma photon imaging methods usually need to collect the projections of prompt gamma photons on the gamma photon detector at a certain angular sampling interval; in order to ensure the acquired prompt gamma For the accuracy of photon spatial distribution, the traditional gamma photon imaging method needs to consider the completeness of the spatial sampling angle, that is, the sampling angle coverage must reach more than 180°, and the gamma photon detector head often needs to be rotated to achieve the coverage of the sampling angle range, so the existing gamma photon imaging system design is more complex

On the other hand, the traditional gamma photon imaging method does not record the time information of the detected prompt gamma photons, but combines the gamma photon projections collected in different time series to reconstruct the spatial distribution of prompt gamma photons , so the reconstructed prompt gamma photon spatial distribution is susceptible to the statistical noise of prompt gamma photon counting, resulting in limited monitoring accuracy of the spatial distribution of proton or heavy ion dose deposition

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