Objective:To evaluate the performance of RapidArc technique on cervical cancer patients with various filling status of the bladder. Methods: Conventional fixed field intensity modulation radiated therapy (IMRT) is used as the benchmark. In 10 fe-males suffering from cervical cancer, two CT scans were performed for treatment planning:one with an empty bladder and the other with filled bladder. The prescribed dose was 50 Gy. The images of that with an evacuated bladder and that with filled bladder were planned in the dual-arc RapidArc and the 7-field IMRT, respectively. The implementor of the plan was the Varian TrueBeam linear ac-celerator. Dose-volume histogram was used to evaluate the data from each plan. Results:When the bladder was filled, IMRT and Rapi-dArc homogeneity were 1.05 and 1.04 (P>0.05), respectively. When the bladder was emptied, the homogeneity was 1.04 for both plans (P>0.05). With or without bladder filling, the conformity index was 0.71 and 0.73 for IMRT and RapidArc (P>0.05), respectively. The effect of V30 and V40 (volume for receiving doses of 30 and 40 Gy) on the intestine and the bladder was more favorable in a full than in an empty bladder. No significant difference between the two plans was observed. IMRT exhibited improved V30 on the rectum and on the bladder. RapidArc was much better in terms of monitor unit (MU) and deliver time. Conclusion:No significant differences in the homogeneity and conformity index between dual-arc RapidArc and 7-field IMRT were observed. Filled bladder is better than empty bladder in intestine and bladder protection in both RapidArc and IMRT. IMRT is better on V30 of the rectum and the bladder, whereas RapidArc improved MU and deliver time.%目的：比较不同放疗技术及膀胱充盈状态对宫颈癌术后放疗靶区剂量的分布及正常组织受照体积的影响，探讨宫颈癌术后放疗的理想模式。方法：选择10例宫颈癌术后患者，分别进行膀胱充盈状态及排空状态下模拟CT扫描，处方剂量50 Gy，分别制定双弧快速旋转调强计划（RapidArc）及7野调强适形计划（IMRT）。计划的实施均为Varian公司的TrueBeam直线加速器。利用每个计划的剂量一体积直方图（DVH）进行数据分析。结果：膀胱充盈状态下IMRT及RapidArc的靶区均匀性指数分别为1.05及1.04（P>0.05），膀胱排空状态下IMRT及RapidArc的靶区均匀性指数均为1.04（P>0.05）。膀胱充盈状态下，IMRT及Rapi-dArc的靶区适形度指数分别为0.71及0.73（P>0.05）。膀胱排空状态下，IMRT及RapidArc的靶区适形度指数分别为0.71及0.73（P>0.05）。小肠及膀胱接受30 Gy及40 Gy剂量的体积，膀胱充盈状态下优于膀胱排空状态，两种技术间无显著性差异。直肠及膀胱接受30 Gy剂量的体积IMRT优于RapidArc。RapidArc在治疗时间及机器跳数上明显优于IMRT。结论：7f-IMRT及双弧RapidArc在靶区适形度及均匀性方面无显著性差异；无论何种技术，膀胱充盈状态对小肠及膀胱的保护均优于膀胱排空状态；IMRT在直肠及膀胱的保护方面均优于RapidArc，RapidArc在机器跳数及治疗时间上优于IMRT。
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