Radiation therapy is a familiar term to tumor patients. Radiotherapy is radiation therapy, commonly known as “baking electricity” and “shining light”, which is a method of using ionizing radiation to treat tumors. Radiotherapy is one of the main treatment methods for malignant tumors. It is a treatment method to control the growth and spread of cancer cells by irradiating them with various kinds of rays of different energies, in order to inhibit and kill them. Radiotherapy can be used alone or in combination with surgery and chemotherapy as part of a comprehensive treatment to improve the cure rate of cancer, and about 70% of tumor patients will use radiotherapy during their treatment. Many people are afraid when they think of radiotherapy: a red bar painted on their face, no food, no drink, extremely low blood count and broken skin. Some patients even give up the regular anti-tumor treatment because of the fear of radiotherapy, and turn to believe in the “anti-cancer prescriptions” in “advertisements”, which finally delay the disease and lose the best time for tumor treatment. In fact, this is a kind of prejudice against radiotherapy, most of the tumor treatment depends on radiotherapy. In the past, the technology of radiotherapy was relatively backward, and radiotherapy for head and neck tumors was marked with red skin ink, i.e. “red bar” on the face, which was somewhat scary. But nowadays, radiotherapy for head and neck tumors is usually fixed by plastic masks, and low-melting lead is used as the model to set the radiotherapy target area by computer or simulator. Radiation therapy patients rarely see the “red bar” on their faces anymore. The response to radiation therapy is related to the size of the irradiated area, the site of exposure, the dose, the susceptibility of the individual, and whether the individual has received previous radiation therapy or chemotherapy. Radiotherapy generally does not significantly affect the blood picture, and it is rare for someone to experience severe myelosuppression as a result of radiotherapy alone. Most reactions are local to the area of radiotherapy, i.e., radiological changes within the irradiated field. There are many simple ways to mitigate radiotherapy reactions, such as the use of appropriate medications, timely field reduction, educating patients about relevant functional organ exercises, good rest, etc. Through the above treatment, only a few patients have more than third degree radiotherapy reactions. The current radiotherapy technology is changing rapidly, and many new technologies are applied in the clinic. For example, computer-guided stereotactic radiotherapy and intensity-modulated radiotherapy have been widely carried out in our hospital. These new technologies make the treatment more precise, improve the treatment effect of tumor, and also reduce the reaction of radiotherapy. It is believed that with the progress of technology and the widespread application of standardized tumor treatment in the clinic, more and more tumor patients will accept that radiotherapy brings happiness rather than pain.