乳腺癌的放疗技术比较复杂，照射野间如何避免重叠或遗漏，是乳腺癌放疗技术的关键之一。我院参照国内外乳腺癌的放疗方法，采用半野或四分之一野照射技术，较好地解决了此问题。本文介绍乳腺癌切线野放疗的半野照射技术。１方法１.１模拟定位 体位要求：仰卧，身体平直，手臂 The technique of radiotherapy for breast cancer is relatively complex. How to avoid overlap or omission in the field of radiation is one of the keys to breast cancer radiotherapy. In our hospital, we refer to radiotherapy methods for breast cancer at home and abroad, using half-field or quarter-field irradiation techniques to better solve this problem. This article describes the technique of half-field irradiation for breast cancer tangential field radiotherapy. 1 Method 1.1 Simulated positioning Position requirements: supine, straight body, arm