乳腺癌术后切线野照射是放射治疗乳腺癌的一项重要技术[1]。用模拟机定位设计乳腺癌切线野直观、准确，但在无模拟机情况下如何定位，如何确定切线野投照角度、投照范围及可能照射肺组织的深度？我们通过实践摸索出脱模画图法设计乳腺癌切线野照射技术的定位方法。方法1．病人 The tangential field irradiation after breast cancer surgery is an important technique for radiation therapy for breast cancer [1]. Using a simulator to locate and design a breast cancer tangent field is intuitive and accurate. However, how do you locate it without a simulator? How do you determine the angle of the tangent field, the scope of projection, and the depth to which the lung tissue may be exposed? We have explored the positioning method of breast tangent field irradiation technology by practicing the demoulding drawing method. method 1. patient