The Analysis of CT Value Stability in Cone-beam CT Images of Varian Image Guidance System
Objective To analyze the stability of CT values of cone-beam CT images,by continuously monitoring the CT values of cone beam CT images in the Varian Trilogy linear accelerator image guidance system.Methods From September 2021 to August 2022,through the Catphan604 module containing nine plug-ins of different densities,images were obtained monthly using kV-cone-beam computed tomography(kV-CBCT)of Trilogy linear accelerator with four commonly used clinical scanning protocols(standard dose head SDH,high quality head HQH,pelvic Pelvis,and low density chest LDT).With the analysis of 48 kV-CBCT image sequences obtained,CT values were obtained using RadiAnt software.The average CT values of 9 different density plugins in the Catphan604 phantom with 4 protocols were recorded and analyzed according to the standard values.Results The cone beam CT images of the Varian Trilogy linear accelerator image guidance system had good stability in CT values,and there were no statistically significant differences in the average CT values(P=0.204,0.170,0.113,0.140).The overlap between CT values and electron density curves was relatively high.Conclusion The cone beam CT images of the Varian Trilogy linear accelerator image guidance system have stable CT values,which can be considered for dose calculation in tumor adaptive radiotherapy in the later stage.
万方数据
维普
