鼻咽癌是我国常见的恶性肿瘤 ,发生部位隐蔽 ,手术难以进行 ,而肿瘤病理类型中 90 %以上是低分化癌和未分化癌 ,对放射线较敏感 ,且鼻咽、颅底和颈淋巴结又易被包括在照射野内 ,因此 ,放射治疗为首选方法。 193 1年～ 195 8年间 ,经放疗的鼻咽癌患者平均 5年生存率为 15 % ,此 Nasopharyngeal carcinoma is a common malignant tumor in our country. The site of the tumor is hidden and the operation is difficult. However, more than 90% of the tumor types are poorly differentiated and undifferentiated carcinoma, which are sensitive to radiation. Nasopharyngeal, skull base and cervical lymph nodes Easy to be included in the radiation field, therefore, radiation therapy is the preferred method. 193 1 year ~ 195 8 years, the average 5-year survival rate of patients with nasopharyngeal carcinoma after radiotherapy was 15%, this