Abstract：Objective To compare the effect of Eclipse planning system calculation grid size on the quality of volume modulated arc
radiotherapy (VMAT) plan for glioma, and to provide a basis for clinical diagnosis and treatment. Methods Atotal of 33 patients
with glioma who received VMAT program in our hospital from September 2021 to June 2022 were retrospectively selected. Under
the same optimization parameters, three VMAT plans (1.25 mm group, 2.50 mm group, 5.00 mm group) were designed using 1.25,
2.50, and 5.00 mm computational grid respectively for all patients. The target area dosimetry parameters [clinical tumor volume
(CTV), planning target volume (PTV)], monitor units, organs at risk dose, and plan optimization time of three VMAT plans were
compared. Results The Dmax and CTV Dmax of trunk in 5.00 mm group were significantly higher than those in 1.25 mm group and
2.50 mm group. The PTV Dmin and CTV Dmin of the 1.25 mm group were significantly higher than those of the 2.50 mm group and
5.00 mm group. There were no significant differences in organs at risk dose and monitor units among the three groups (P>0.05). The
relative deviations of CTV Dmin and PTV Dmin in 1.25 mm group were larger than those in 2.50 mm group and 5.00 mm group, while
the relative deviations of other target dose parameters were smaller. The relative deviation of left lens, left optic nerve and right optic
nerve in 1.25 mm group were greater than that in 2.50 mm group and 5.00 mm group. The relative deviation of monitor units in
1.25 mm group was small compared with 2.50 mm group and 5.00 mm group. The optimal planning time of 1.25 mm group
was significantly shorter than that of 2.50 mm group and 5.00 mm group. Conclusion In glioma radiotherapy, the use of
different computational grids in the Eclipse planning system can cause differences in the VMAT program target area and the dose
of organs at risk. From the comprehensive consideration of plan quality and optimization time, it is recommended to use a 2.50 mm
computing grid for VMAT plan design. But it should be noted that a small grid will lead to an increase in the capacity of small organs
at risk. Therefore, when selecting a small grid for optimization, it is recommended to appropriately increase the limited weight of
organs at risk to reduce the capacity of organs at risk.
王天赋，李星月，马明旭，许海燕，关大维，高峰，宫瑾. Eclipse计划系统计算网格大小对脑胶质瘤
VMAT计划影响分析[J]. 中国医疗设备, 2023, 38(10): 67-72.
WANG Tianfu, LI Xingyue, MA Mingxu, XU Haiyan, GUAN Dawei, GAO Feng, GONG Jin. Analysis of the Impact of Eclipse Planning System Computational Grid Size on VMAT
Planning for Glioma. China Medical Devices, 2023, 38(10): 67-72.
