Radiotherapy is categorized into external and internal radiation. Patients can touch children after external radiation and patients treated with internal radiation cannot touch children during treatment. External radiation is to kill the tumor cells through the rays emitted by the equipment, and after the treatment is finished, the patient will leave the radioactive environment, and the patient will not have radioactive substances on his body, so he can contact the children normally. However, internal radiation therapy involves implanting radioactive particles in the patient’s body. During internal radiation therapy, radioactive particles in the patient’s body may cause harm to people in close proximity, so it is best not to come into contact with children. Patients should consult their doctors and follow their instructions. If internal radiation therapy is determined, contact with special populations such as pregnant women and children should be avoided as much as possible.