Radiation therapy is a cancer treatment that involves using high-energy particles or waves to destroy cancer cells. It is also known as radiotherapy or radiation oncology. Other synonyms for radiation therapy could be radiation treatment, radiation medicine, radiation healing, irradiation therapy, or irradiation treatment. These terms all refer to the same treatment modality, but they may be used in different contexts or by different healthcare professionals. Radiation therapy can be given from an external machine (external beam radiation) or from radioactive sources implanted within the body (brachytherapy). It is an effective and common treatment option for many types of cancer, and is often used in combination with other treatments like chemotherapy and surgery.