基于DMLC技术的不同布野方式治疗复杂食管癌的剂量学研究

Dosimetric differences of different methods of fields distribution in complex esophageal cancer based on DMLC therapy

为研究复杂食道癌放疗动态多叶光栅(dynamic multi-leave collimator,DMLC)技术中9野方式的可行性,我们选取13例复杂食道癌患者,使用DMLC在相同的优化条件下分别使用7野和9野进行优化。确保两种方式95%的计划靶区(planning target volume,PTV)体积都达到处方剂量,比较两种布野方式危及器官受量、计划靶区的适形度指数(conformity index,CI)、均匀性指数(heterogeneity index,HI)、计划体积最大剂量(maximum dose,Dmax)以及机器跳数(monitor unit,MU)和控制点数(control point,CP)的差异。9野DMLC计划危及器官受量降低,差异有统计学意义;HI和CI改善,Dmax降低,但差异均无统计学意义;CP,MU增加,差异有统计学意义。因此,9野方式较7野方式具有更好的剂量学优势,可以减少正常组织的高剂量照射区域。

In order to study the feasibility of 9-field plan in treating patients with complex esophageal cancer based on dynamic multi-leave collimators(DMLC)technology,we selected 13 patients with complex esophageal cancer and optimized 7-field and 9-field plans respectively under the same optimization conditions with DMLC technology.By ensuring that 95%of planning target volume(PTV)volume of the two ways can both reach the prescription dose,we compared the differences between the two ways in terms of organs at risk,conformality index(CI),heterogeneous index(HI),maximum dose(Dmax)of the planned volume,monitor unit(MU)and control point(CP).We found that in the 9-field plan,the dose of organs at risk decreased,the difference was statistically significant;the improvement of HI and CI was not statistically significant;the reduction of Dmax was not statistically significant;the increase of CP and MU was statistically significant.Therefore,9-field DMLC plan has better dosimetric advantages compared with7-field plan and it can reduce the high-dose radiation area of normal tissue.