Radiation therapy, or radiotherapy, uses high-energy rays to damage or kill cancer cells by preventing them from growing and dividing. Unlike chemotherapy, which targets cancer cells systemically, radiation therapy is a localized treatment primarily aimed at eradicating visible tumours, similar to surgery. The primary goals of radiation therapy are to cure or control cancer as well as to alleviate symptoms caused by the disease. It can be used independently or in conjunction with other treatments, such as chemotherapy and surgery, depending on the specific circumstances of each case. There are two main methods of delivering radiation therapy: external and internal. External radiation entails directing high-energy rays directly to the tumor site from a machine located outside the body. On the other hand, internal radiation, also called brachytherapy, involves implanting a small amount of radioactive material in or near the cancerous area.