Abstract：Objective To compare the protection of the organs at risk between two arc and dual arc plans for patients during
radiotherapy for cervical cancer by using dual arc function of Raystation treatment planning system. Methods A total of 20 patients
with cervical cancer who received radiotherapy in the Department of Oncology, Liuzhou Worker’s Hospital from December 2020
to May 2021 were selected as the research subjects. The two arc plan and dual arc plan were designed to compare the target dose
distribution, conformity index (CI), homogeneity index (HI), subfield shape and exposure dose of organs at risk. Results Both
treatment plans met the requirements of clinical treatments. The planning target volume (PTV ) D50% of dual arc plan was higher
than those of two arc plan, while the V50.4,Body(the volume of normal tissue was covered when the prescription dose was 50.4 Gy)
was lower than of two arc plan, the difference was statistically significant (P<0.05). The CI of dual arc plan was better than that of
two arc plan, and the total number of monitor units (MU) increased compared with two arc plans, the difference was statistically
significant (P<0.05). There was no statistically difference in PTV D2%, D98% and HI between the two plans (P>0.05). As to organs
at risk, the Dmean, V30 and V40 of rectum, bladder and small intestine in dual arc plan were all lower than those of two arc plan, the femoral
head V30 and V40 of dual arc plan were lower than those of two arc plan, the difference was statistically significant (P<0.05). The shapes
of A1 and A2 segments in two arc plan were similar. The opening of A1 segments of dual arc plans was biased to the X1 side, while the
opening of A2 segments was biased to X2 side, A1 and A2 were complementary to each other. Conclusion For the volumetric intensity
modulated arc therapy plan design of cervical cancer, both the dual arc plan and the two arc plan can achieve better target coverage, and
the dual arc plan has better conformality, and the use of dual arc function can further reduce the radiation dose of most organs at risk,so
the dual arc function can be given priority in the clinical design of volumetric intensity modulated arc therapy plan for cervical cancer
冯永富，龙雨松，谭军文，贺先桃，李钢，王占宇. 对偶弧功能在宫颈癌VMAT计划中的应用[J]. 中国医疗设备, 2023, 38(2): 47-51.
FENG Yongfu, LONG Yusong, TAN Junwen, HE Xiantao, LI Gang, WANG Zhanyu. Application of Dual Arc Function in VMAT Plan for Cervical Cancer. China Medical Devices, 2023, 38(2): 47-51.
