In recent years, with the advancement of medical technology and the popularization of health science knowledge, people’s understanding of cancer has gradually become clearer. Cancer as a preventable, treatable and common chronic disease is also gradually recognized by the general public. People are generally aware of the scientific knowledge that “radiation” may cause cancer, but they still ask, “Is there radiation for radiation therapy patients?” “Is there any contraindication for me to live and eat with radiotherapy patients?” The following author will lead you to understand the relationship between radiation therapy and radiation. Let’s say goodbye to the “old days” of “talking about radiotherapy”. 1.What is radiotherapy? Radiotherapy is the abbreviation of radiation therapy, which is a kind of treatment that kills tumor tissues through the action of radiation (such as X-rays, γ-rays, etc.), using the different biological sensitivity of normal tissues and tumor tissues to radiation, including external and internal irradiation. 2.What is external irradiation? What is meant by internal irradiation? Simply speaking, external irradiation refers to the radiation emitted from the machine outside the human body at a certain distance to irradiate the tumor, external irradiation is one of the more applied methods of radiotherapy at present. Internal irradiation is called proximity irradiation, which refers to the radiation source placed inside the tumor (such as particle implantation) or placed into the tumor’s adjacent tube cavity (trachea, esophagus, vagina, etc.) for radiotherapy, and currently internal irradiation is often applied as a supplementary dose to external irradiation. 3.Does radiation therapy patients carry their own three-point radiation? If radiotherapy patients receive external radiation radiotherapy, they are the radiation object, not the radiation source, so the external radiation radiotherapy patients cannot constitute radiation. For internal radiation patients, if the radiation source is placed into the tumor’s adjacent lumen (trachea, esophagus, vagina, etc.) for radiation therapy, and the source is removed after the internal radiation therapy is completed, it cannot constitute radiation (this is the majority of cases of internal radiation). In contrast, if a radioactive substance (such as iodine 125 or iodine 131) is permanently implanted into the patient’s body, the radioactive source constitutes radiation if it decays slowly over time in the patient’s body and the radioactive source moves with the patient. Simply speaking, except for internal irradiation where the radiation source is permanently implanted inside the patient’s tumor, the rest of external and internal irradiation patients are not exposed to radiation. 4.3 elements of radiation protection Distance The farther away from the radiation source, the less harm, we live in the environment of radiation all the time, because the sun is the largest source of radiation on earth, just because it is too far away, we can not feel its harm. There is also nature, as well as our bodies themselves are sources of radiation, usually we can contact the energy is too small, so there is no harm to the human body. Time There is a huge difference between one second less and one second more exposure to a radioactive source. Shielding Radioactive sources have a wide range of uses, and very specialized shielding is used during production, storage, transportation, use, and decommissioning. If there are children and pregnant women in the family, radiation protection in terms of distance, time and shielding is required if the patient is receiving internal irradiation with the source permanently implanted inside the patient’s tumor (which is currently only a very small percentage of radiotherapy patients). In summary, except for radiotherapy patients who are permanently implanted with radioactive materials (such as Iodine 125 or Iodine 131), radiotherapy patients in the usual sense do not “carry three parts of radiation”, so you can “spend time” with radiotherapy patients around you without worries and concerns. “You can spend time with your radiation therapy patients without any worries or concerns.