中文摘要：

目的 评估一种利用Eclipse治疗计划系统的基部剂量计划进行补偿（base dose plan compensation,BDPC）的调强放疗（IMRT）计划优化方法应用于上段食管癌的可行性.方法 选择19例上段食管癌患者,设计初始IMRT计划,并分别用BDPC法和热点冷点控制（hot and cold spotcontrol,HCSC）法进一步优化.比较两种计划的靶区覆盖、适形指数（CI）、均匀指数（HI）、危及器官保护、计划设计时间、机器跳数（MU）以及投照时间.结果 BDPC计划高危靶区PTV64的D2％低于HCSC计划（Z=-3.823,P＜0.05）,CI和HI明显优于HCSC计划（Z=-3.662、-3.745,P＜0.05）,而D98％差异无统计学意义（P＞0.05）.BDPC计划低危靶区PTV54的CI高于HCSC计划（Z＝-3.340,P＜0.05）,D95％和D98％低于HCSC计划（Z=-3.582、-2.616,P＜0.05）.BDPC计划脊髓和肺的剂量均略低于HCSC计划（Z=-3.625～-3.369,P＜0.05）.BDPC与HCSC计划设计时间分别为（26.05±0.88）和（33.73 ±3.24）min（Z=-3.823,P＜0.05）,MU分别为1 019±167和1 003±159（Z=-2.616,P＜0.05）,投照时间分别为（3.52±0.29）和（3.50±0.28）min（Z＝-2.548,P＜0.05）.结论 BDPC优化方法在上段食管癌应用能明显提高靶区剂量的均匀性和适形性,减少危及器官剂量,并且操作简便,能提高计划设计效率.

英文摘要：

Objective To evaluate the dosimetric characteristics of base dose plan compensation （BDPC） optimization method applied on the intensity-modulated radiotherapy （IMRT） for upper esophageal carcinoma,based on the Eclipse treatment planning system.Methods Nineteen patients were included.For each case initial IMRT plan was generated and further optimized respectively by the two following methods：the BDPC method and hot and cold spot control （HCSC） method.Then the BDPC and HCSC plans were compared concerning planning-target-volume （PTV） coverage,conformity index （CI）,and homogeneity index （HI）,as well as organ-at-risk （OAR） sparing,planning time,monitor unit （MU） and delivery time.Results Compared with the HCSC plans,the BDPC plans provided superior CI and HI （Z =-3.662,-3.745,P 〈 0.05）,as well as lower D2% （near-maximum dose） （Z =-3.823,P 〈 0.05） and comparable D98% （near-minimum dose） （P 〉 0.05） for PTV64 （high-risk PTV）,and provided superiorCI （Z=-3.340,P〈0.05）,lower D95% and D98% （Z=-3.582,-2.616,P〈0.05） for PTV54 （low-risk PTV）.The BDPC plans also provided slightly lower doses to the spinal cord and lung compared with the HCSC plans （Z =-3.625--3.369,P 〈 0.05）.Moreover,the planning time [（26.05 ±0.88） min] for BDPC plans was less than that of the HCSC plans [（33.73 ± 3.24） min] （Z =-3.823,P 〈0.05）.The MU of the BDPC plans （1 019 ± 167） was higher than that of the HCSC plans （1 003 ±159） （Z=-2.616,P〈0.05）,while the delivery time [（3.52 ±0.29） min] was more than that of the HCSC plans [（3.50±0.28） min] （Z=-2.548,P〈0.05）.Conclusions The BDPC optimization method can significantly improve target dose homogeneity and conformity with effective reduction of the dose to OARs for upper esophageal carcinoma.Moreover,it is simple and can improve the treatment planning efficiency.