鼻咽癌临床较常见,因其部位深在,周围有骨和软组织包绕、放疗宜选择穿透力大,皮肤量低、骨吸收小的高中能射线为好。我科均用~(60)钴治疗机,外照射一般以双耳前野为主,眶下野或品字野为辅助野,因为肿瘤容易转移至上颈及后上颈淋巴结。我们多采用前颈切线野进行放疗,野的上界达下颌骨下缘,下界平锁骨头下缘,照射此野时要求:仰卧,肩垫枕或角度板,头后仰,两肩水平对称,使下颌骨体下缘延长线通过乳突尖,垂直于治疗床面。野的正中挡野3cm,以保护喉、气管、食管颈段,减少对脑干,脊髓的损伤,照射耳前野时,摆位要求:张口含木塞,侧卧,冠状面与床面垂直,矢状面与床面平行。垂直照射或仰卧,机头转90度水平照射。因前 Nasopharyngeal carcinoma is more common clinically, because its parts are deep, surrounded by bone and soft tissue wrap around, radiotherapy should choose to penetrate large, low-skin, low bone absorption of high school energy rays as well. In our department, ~(60)cobalt treatment machines are used. The external radiation is generally based on the prefrontal field, and the armpit field or product field is the auxiliary field because the tumor is easily transferred to the upper cervical and upper cervical lymph nodes. We often use the front neck tangential field for radiotherapy. The upper boundary of the wild reaches the lower edge of the mandible, and the lower border flats the lower edge of the clavicle. When the field is exposed, it requires: supine, shoulder pillow or angle plate, head backwards, horizontal symmetrical shoulders. The extension of the lower edge of the mandible is made through the mastoid tip and perpendicular to the treatment bed. 3cm in the middle of the field to protect the neck of the larynx, trachea, and esophagus, to reduce damage to the brain stem and spinal cord, and to illuminate the front of the ear. Position requirements: open mouth with cork, lateral, coronal plane perpendicular to the bed, The sagittal plane is parallel to the bed surface. Vertical irradiation or supine, the head turned 90 degrees horizontal irradiation. Before