The harm of radiotherapy is not very great, and it is still within the controllable range. Radiotherapy is a more commonly used means of cancer treatment in clinical practice, although it will cause certain damage to the body, but overall it is still controllable, and the harm is not very serious if the relevant dose control and protection work are done well, and the specific needs to be determined by the individual treatment plan and physical condition. Radiotherapy will mainly cause local and systemic adverse reactions, such as skin redness, swelling, rash, mucosal edema and regurgitation, bone marrow suppression, etc., generally after the end of radiotherapy, the situation can be naturally relieved to improve, and some serious patients need to use targeted drugs for treatment, such as ascending white needles, ondansetron and so on.