目的 实现鼻咽癌放疗计划中剂量限制结构的自动勾画。方法 使用Python语言编程，对医学影像通信标准（Digital Imaging and Communications in Medicine，DICOM）放射治疗（Radiation Therapy，RT）文件进行解析和数据处理，然后 根据放疗计划中靶区和危及器官的相对位置关系和临床处方剂量要求设计剂量限制结构的勾画模块，并生成DICOM RT Structure Set结构集文件。结果 自动勾画生成的结构集文件能成功导入Eclipse放疗计划系统（Radiation Therapy Treatment Planning System，TPS），轮廓结构颜色、名称、形状和3D重建均能正确显示，结构外扩和结构布尔操作精度与Eclipse TPS 系统功能模块常规手动勾画精度无明显差异，自动勾画时间（44.94±1.56）s明显小于常规勾画时间（1475.65±92.16）s （t=-43.788，P<0.05）。结论 本文方法能不依赖TPS完成鼻咽癌剂量限制结构自动勾画，且能完成其他主流TPS自动脚本 无法实现的自定义形状剂量限制结构的勾画，可有效避免物理师在设计计划时的重复劳动，提高工作效率。

Objective To achieve the automatic delineation of dose limited structure of radiotherapy plan for nasopharyngeal carcinoma. Methods The Python programming language was used to parse and process the data of the digital imaging and communications in medicine (DICOM) radiation therapy (RT) files, and then the module for outlining the dose limited structure was designed based on the relative position relationship between the target area and the endangered organs in the radiotherapy plan and the clinical prescription dose requirements, and the DICOM RT Structure Set file was generated. Results The structure set file generated by automatic sketching can be successfully imported into the Eclipse radiation therapy treatment planning system (TPS). The contour structure color, name, shape and 3D reconstruction can all be displayed without any errors. There was no obvious difference between the structure expansion and the structure Boolean operation accuracy and the Eclipse TPS system function module manual sketching accuracy, while the time for automatic outlining (44.94±1.56) s was significantly less than the conventional outlining time (1475.65±92.16) s (t=-43.788, P<0.05). Conclusion The methods in the paper can complete the automatic delineation of the dose limited structure of nasopharyngeal carcinoma without relying on TPS, as well as completing the delineation of dose limited structure of custom shapes that cannot be achieved by other mainstream TPS automatic scripts, which can effectively avoid the repetitive work of physicists in designing plans and improve the work efficiency.