鼻咽癌(nasopharyngeal carcinoma,NPC)为我国常见的恶性肿瘤之一,在世界上多数国家发病率为0～1/10万,但在我国发生率大约10～30/10万,其中又以南方地区为甚。由于其发病部位特殊,手术根治困难,病理类型多为低分化鳞癌,放疗效果好,故放疗为其首选治疗方法。但是,在目前放疗设备 Nasopharyngeal carcinoma (NPC) is one of the common malignant tumors in our country. The incidence in most countries in the world is 0-1 / 100,000 but in our country, the incidence is about 10-30 / 100,000, Very regionally. Because of its special site of disease, radical surgery difficult pathological type mostly poorly differentiated squamous cell carcinoma, radiotherapy effect is good, so the radiotherapy for the treatment of choice. However, the current radiotherapy equipment