Abstract：Objective To evaluate the effect of the ArcCHECK setup error on the dosimetric verification pass rate of of
volumetric modulated arc therapy (VMAT) in the treatment of rectal cancer. Methods The VMAT plans of 10 cases with rectal
cancer were collected, and the dose distribution was measured by ArcCHECK array. By simulating ArcCHECK setup errors of
3 mm, 4 mm, and 5 mm in the X, Y, and Z directions at the isocenter location on TPS, the pass rate of each plan was obtained
using 3%/3 mm of absolute dose Gamma as the evaluation index. Results The average pass rate of the original plans was more
than 99%. After introducing ArcCHECK setup errors in three directions, the dose verification pass rate of VMAT for rectal cancer
decreased to a certain extent, and the higher the error, the lower the pass rate. After introducing the errors, the plan's pass rate was
statistically significant compared with the original plan's pass rate (P<0.05). The influence of errors in different directions on the
pass rate was different, and the influence of errors in the Y direction was greater. Conclusion ArcCHECK setup errors have a great
effect on the dose verification pass rate of the VMAT plans for rectal cancer. In clinical radiatherapy for rectal cancer, we need
to strictly control the setup error of Y direction.
王宁，孙海涛，黄国森. ArcCHECK摆位误差对直肠癌VMAT计划剂量验证通过率的影响[J]. 中国医疗设备, 2019, 34(5): 65-67.
WANG Ning, SUN Haitao, HUANG Guosen. Effect of ArcCHECK Setup Errors on the Dosimetric Verification Pass Rate of VMAT Plan in
the Treatment of Rectal Cancer. China Medical Devices, 2019, 34(5): 65-67.
