1什么是三维适形调强放疗?放疗是用放射线杀灭肿瘤细胞,在恶性肿瘤的治疗中起重要作用。放射线损伤肿瘤细胞的DNA,使肿瘤细胞不能分裂和生长而死亡。放疗对分裂活跃的细胞杀伤力最大。和正常细胞相比,肿瘤细胞对放疗敏感,是因为它们比正常细胞分裂得快,同时它们不能像正常细胞那样对DNA损伤进行有效的修复。有些肿瘤不用手术、单用放疗就可以治愈,如鼻咽癌、喉癌、宫颈癌、淋巴瘤和前列腺 1 What is three-dimensional conformal intensity modulated radiation therapy? Radiation therapy is the use of radiation to kill tumor cells and play an important role in the treatment of malignant tumors. Radiation damage DNA in tumor cells, so that tumor cells can not divide and grow and die. Radiotherapy is most damaging to actively dividing cells. Tumor cells are more radiosensitive to radiotherapy than normal cells because they divide faster than normal cells and at the same time they do not effectively repair DNA damage as normal cells do. Some tumors without surgery alone can be cured with radiotherapy, such as nasopharyngeal carcinoma, laryngeal cancer, cervical cancer, lymphoma and prostate