%0 Dataset
%T Stability analysis of Octavius 4D system
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/4b497eca-fbaa-402f-88eb-08eabed65783
%W NCDC
%R 10.12072/ncdc.imp.db4137.2023
%A Xiao Guoqing
%K Octavius 4D system;volume modulated radiation therapy;detector matrix;γ Pass rate;stability
%X "This paper discusses the stability of Octavius 4D system in three-dimensional dose verification of volumetric intensity modulated radiation therapy (VMAT). The response of semiflex ionization chamber and Octavius 729 detector array to field size, dose linearity, dose rate linearity and field output factor under 6 MV and 10 MV beams are compared and analyzed. Measure and observe the angle deviation between the indicator value of the goniometer and the frame angle during the rotation of Octavius 4D system. 3% / 3 mm standard (10 × 10) The two-dimensional dose distribution of rotation irradiation plan and VMAT plan were compared; The VMAT plan was evaluated with 3% / 3 mm gamma analysis standard. The results show that the preheating dose greater than 6 Gy is necessary for the stability of the detector. The dose response of detector array is linear, and the dose measurement is stable under different nominal dose rates. The error between the angle of accelerator frame and the rotation angle of Octavius 4D phantom is less than 0.4 ° Within. When the analysis standard of 6 MV and 10 MV beam VMAT was 3% / 3 mm, the average passing rate of three-dimensional dose distribution was 96.03% and 95.56%, respectively, which met the standard of clinical dose verification. Octavius 4D phantom combined with Octavius 729 detector array is a set of stability device, which is used to verify the reliability of VMAT plan before treatment“