Dose reconstruction with Compton camera during proton therapy via subset-driven origin ensemble and double evolutionary algorithm

分类： 物理学 >> 核物理学 提交时间： 2023-06-01

Yao, Zhiyang Xiao, Yongshun Zhao, Jizhong

摘要：Compton camera-based prompt gamma (PG) imaging has been proposed for range verification during proton
therapy. However, a deviation between the PG and dose distributions, as well as the difference between the
reconstructed PG and exact values, limit the effectiveness of the approach in accurate range monitoring during
clinical applications. The aim of the study was to realize a PG-based dose reconstruction with a Compton
camera, thereby further improving the prediction accuracy of in-vivo range verification and providing a novel
method for beam monitoring during proton therapy. In this paper, we present an approach based on a subsetdriven origin ensemble with resolution recovery (SD-OE-RR) and a double evolutionary algorithm (DEA) to reconstruct the dose depth profile (DDP) from the gamma events obtained by a Cadmium-Zinc-Telluride
(CZT) Compton camera with limited position and energy resolution. Simulations of proton pencil beams with
clinical particle rate irradiating phantoms made of different materials and the CT-based thoracic phantom were
used to evaluate the feasibility of the proposed method. The results show that for the monoenergetic proton
pencil beam irradiating homogeneous-material box phantom, the accuracy of the reconstructed DDP was within
0.3 mm for range prediction and within 5.2% for dose prediction. In particular, for 1.6-Gy irradiation in the
therapy simulation of thoracic tumors, the range deviation of the reconstructed spread-out Bragg peak was
within 0.8 mm, and the relative dose deviation in the peak area was less than 7% compared to the exact values.
The results demonstrate the potential and feasibility of the proposed method in future Compton-based accurate
dose reconstruction and range verification during proton therapy.

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