Radiation therapy is one of the most important means to treat tumors. About 70%-75% of all tumors should be treated by radiotherapy alone or in combination with other methods. However, the previous clinical experience of radiotherapy proves that because the tumor form is irregular and the output of the machine is uniform, radiation therapy for tumor also causes radiation damage to the normal tissues around the tumor — in most cases, improving the local control rate of the tumor while inevitably causing In most cases, while improving the rate of local control of tumor, it is bound to cause more damage to normal tissues. The three-dimensional intensity-controlled conformal radiotherapy system introduced by the hospital applies advanced computer technology to imaging, and the so-called intensity-controlled means that the machine outputs uneven rays — so that the high dose distribution is consistent with the irregular shape of the main body of the tumor, which realizes the optimization and individualization of the treatment plan and the three-dimensional radiation. Directional radiotherapy. Its greatest advantage is that the dose of radiation is concentrated to the lesion area, which can make the tumor obtain a much higher dose than conventional radiotherapy, and the surrounding normal tissues are protected by significantly reduced irradiation dose. At the same time, the increased dose of each radiotherapy treatment can reduce the number of radiotherapy treatments and shorten the period of patients receiving tumor treatment. “3D Intensity Modulated Conformal Radiotherapy” is mainly used to treat a variety of tumors such as head and neck tumors, brain tumors, lung cancer, prostate cancer, liver cancer and pancreatic cancer.