鼻咽癌调强放疗计划设计中自动勾画剂量限制结构的初步应用

Application of automatic generation of dose limited structures in intensity modulated radiation therapy planning for nasopharyngeal carcinoma

目的 鼻咽癌（NPC）调强适形放射治疗（IMRT）（简称调强放疗）计划设计中,需勾画一定数量剂量限制结构（DLSs）,传统的常规方法只能逐一单个处理,极大浪费了物理师的有效工作时间.本研究利用MIM（V6.5）软件编译工作流,根据NPC计划优化需求,自动生成DLSs,观察、对比其与常规方法在不同分期NPC计划DLSs勾画上的时间差异,探讨其临床推广的应用价值.方法 对10例不同TNM分期的NPC患者,按统一要求由3名物理师采用Eclipse放射治疗计划系统（TPS,V11.0）提供的勾画工具逐一处理方法与MIM软件设计编译的工作流批处理方法,分别生成DLSs,观察工作流自动处理结果并对比完成时间.结果 工作流可一键自动生成包括计划靶区（PTVs）外、PTVs内、危及器官（OARs）及辅助等4类最多28个DLSs,所花费时间较逐一处理方法最多可节省92.8％,平均节省90.5％,其差异具有统计学意义（t=32.14～61.59,P＜0.05）.结论 在NPC的IMRT计划设计中,利用MIM平台编译的工作流,可批处理自动生成DLSs,可有效减少勾画时间,提高了物理师的工作效率.

Objective The contour of dose limited structures （DLSs） are needed for intensity modulated radiation therapy （IMRT） design for nasopharyngeal carcinoma （NPC）,while using conventional method will cost lots of time of medical physicist.In this study,workflow was compiled and DLSs were automatically generated based on MIM software （V6.5） for IMRT planning optimization of NPC,in order to compare the time difference of workflow method with that of conventional method.Methods According to the unified requirements of IMRT planning optimization,the DLSs of 10 NPC cases with different tumor node metastasis （TNM） stages were contoured by three medical physicists using two methods.One was delineating with contour tools of Eclipse （V11.0） treatment planning system （TPS） for each procession one by one,and the other was contouring with MIM software to design and compile workflow for batch procession.The effect of workflow automatic processing was observed and the time-consumption was compared between the two methods.Results The workflow method could automatically generate 4 types of 28 DLSs including out-planning target volumes （PTVs）,in-PTVs,organs at risk （OARs） and other subsidiary structures.The contour time-consumption of the workflow method was much lower than that of conventional method,with an average of 90.5% and up to 92.8% of time could be saved （t=32.14～61.59,P〈0.05）.Conclusions The workflow compiled with MIM platform can automatically generate batch DLSs,and effectively reduce the time of contour,thus improving work efficiency of medical physicist in IMRT planning for NPC.