上半世纪(20世纪中前叶),良性疾病的放射治疗很常见。后来由于对放射治疗能诱发恶性肿瘤等不良作用的了解,其应用曾一度锐减。近年来,西方国家对其关注又日益增多,并出现了一些新的适应证,如治疗血管黄斑变性、预防内支架后再狭窄等。有必要从临床研究、剂量计算及危险度等方面 In the first half of the 20th century (mid-20th century), radiotherapy of benign diseases was common. Later, due to the radiation therapy can induce malignant tumors and other adverse effects of understanding, its use has dropped sharply. In recent years, Western countries are paying more and more attention to it, and some new indications have emerged, such as treatment of vascular macular degeneration and prevention of restenosis after stent implantation. It is necessary from the clinical research, dose calculation and risk and so on