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目的:比较近距离放疗分次间靶区和正常组织在形变配准(DIR)和简单累加剂量体积直方图(DVH)情况下，累积剂量的剂量学差异，分析在宫颈癌三维近距离放疗计划中，形变配准技术应用于靶区和正常组织剂量评估的可行性。方法:回顾性选取13例宫颈癌近距离放疗病例，每个病例均进行了4次CT定位的近距离放疗。对每个病例的4次CT进行形变配准后，计算并统计靶区n D90和膀胱、直肠、小肠、结肠n D2 cmn 3、n D1 cmn 3、n D0.1 cmn 3的形变累积剂量，与简单累加DVH得到的累积剂量进行对比，分析剂量差异与相似系数(DSC)的相关性。以此剂量差异(即形变配准造成的正常组织剩余剂量)作为限量，在最新一次的CT上重新做计划，分析此差异给靶区剂量提升带来的收益。n 结果:经形变配准后，膀胱n D2 cmn 3、n D1 cmn 3的累积剂量分别比简单累加DVH低(2.47±1.92)、(2.82±2.73)Gy(n t＝-3.65、-2.93, n P0.05)。利用形变配准可一定程度上提升靶区剂量，中位数为150 cGy。但形变配准精度有待提高。n 结论:在宫颈癌三维近距离放疗分次间，仍建议采用简单剂量累加方法评估靶区和危及器官累积剂量。“,”Objective:To study the differences in the cumulative dose between deformable image registration (DIR) and simple dose-volume histogram (DVH) summation in the fractionated brachytherapy of cervical cancer, and to analyze the feasibility of the application of DIR in the dosimetry assessment of targets and organs-at-risk (OARs) in the brachytherapy.Methods:A retrospective analysis was conducted for 13 cases with primary cervical cancer treated with four fractions of interstitial brachytherapy guided by CT images. The four CT images of each cases were registered using an intensity-based DIR. Then, the cumulative doses (the n D2 cmn 3, n D1 cmn 3, and n D0.1 cmn 3 of the bladder, rectum, intestine, and colon and the n D90for targets) after DIR were calculated and compared to those obtained using simple DVH summation. Afterward, the correlation between the dose difference and dice similarity coefficient (DSC) was analyzed. With the dose difference (the remaining dose of OARs caused by the DIR) as limits, a new plan was made for the latest CT to calculate the dose increase to targets.n Results:Compared to simple DVH summation, DIR allowed the cumulative doses of the n D2 cmn 3 and n D1 cmn 3 of bladder to be decreased by (2.47±1.92) and (2.82±2.73) Gy, respectively on average (n t=-3.65, -2.93, n P 0.05). The DIR increased the dose to targets, with a median value of 150 cGy. However, the accuracy of the DIR should be improved.n Conclusions:In clinical practice of multiple fractions of brachytherapy for cervical cancer, it′s still recommended to adopt the simple dose summation method to assess the doses to targets and OARs.