Fluorescence image correction with constrained least squares filtering method for 3D dose verification in radiotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2023年第9期
- Page:
- 1083-1090
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Fluorescence image correction with constrained least squares filtering method for 3D dose verification in radiotherapy
- Author(s):
- DU Yonghuan; YANG Yue; DONG Shuncheng; ZHANG Peiyi; WEN Wanxin
- School of Radiation Medicine and Protection, Suzhou Medical College, Soochow University, Suzhou 215123, China
- Keywords:
- Keywords: dose verification constrained least squares filtering point spread function Gamma passing rate
- PACS:
- R318；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2023.09.005
- Abstract:
- Abstract: Objective To correct the fluorescence image of the plastic scintillators under beam irradiation using the constrained least squares filtering method for improving the accuracy of 3D radiation dose verification system based on scintillator fluorescence. Methods The radiation-induced fluorescence map taken from orthogonal 3-view angle was denoised, and the point spread function (PSF) of the imaging system was calculated using Zemax optical simulation software and adjusted by Lorentz function. Then, the constrained least squares filtering method was used for the deconvolution of the orthogonal 3-view projection image after denoising. The 3D dose distribution reconstruction was carried out on the images before and after correction, and the results were compared with the dose distribution calculated in the Pinnacle3 treatment planning system. Results For the square radiation fields of 4 cm×4 cm and 3 cm×3 cm, the average 2D Gamma passing rates (threshold 10%, 3%/3 mm) after correction with the constrained least squares filtering method were increased by 22.95% and 5.76%, respectively, and the root-mean-square errors (RMSE) of the percentage depth dose (PDD) curve on the center axis were reduced by 1.13% and 0.63%, respectively. For the square radiation field of 2 cm×2 cm, the average 2D Gamma pass rate (threshold 20%, 3%/3 mm) after filtering correction was increased by 1.54%, and the RMSE of the PDD curve was reduced by 0.49%. Conclusion The correction of orthogonal 3-view projection image before 3D dose reconstruction can effectively improve the accuracy of 3D radiation dose verification system based on scintillator fluorescence.
Last Update: 2023-09-26