Abstract：Objective To compare the impact on volumetric intensity modulated arc therapy (VMAT) plans for postoperative cervical
cancer with different jaw settings. Methods 14 cases of cervical cancer postoperative VMAT plans were selected, and three settings
were made for the jaw in Eclipse15.5 planning system: One side of the jaw was fixed, and the other side was set to 2 cm, 3 cm, and 4 cm,
respectively. Other optimization conditions such as radiation field and OAR dose constraints remained the same. Three plans were
obtained by re-optimizing the flux and calculated dose: Plan1 (2 cm), Plan2 (3 cm), Plan3 (4 cm). Comparison of target volume and
organ at risk dosimetry parameters and machine hop count among the three plans by using ANOVA models. Results The dosimetry
parameters significantly different were as follows: there were significant differences in Dmean and D50% of the target volume, Dmax of the
rectum at risk, Dmax and V40 of the left femoral head among the three plans (P<0.05). In addition, machine jump number in Plan1 was
higher than that compared with other plans (P<0.05), and the other parameters were not statistically significant (P>0.05).
Conclusion All the treatment plans with three types of jaw settings can meet the clinical requirement. However, Plan2 and Plan3
with larger lead have less machine jump number, which can improve the treatment efficiency and machine execution rate, but the
protection of organs at risk is slightly weaker than Plan1 with smaller lead.
张向学，张谦，孙春堂，尹如铁，李清丽，曾靖，陈亚正. 铅门设置对宫颈癌术后VMAT计划的剂量学影响[J]. 中国医疗设备, 2022, 37(10): 33-36.
ZHANG Xiangxue, ZHANG Qian, SUN Chuntang, YIN Rutie, LI Qingli, ZENG Jing, CHEN Yazheng. Effect of Jaw Settings on the Dosimetry of VMAT Plan After Cervical Cancer Surgery. China Medical Devices, 2022, 37(10): 33-36.
