Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, maybe a therapy using radiation, generally as a part of cancer treatment to regulate or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy could also be curative during a number of sorts of cancer if they're localized to at least one area of the body. It may even be used as a part of adjuvant therapy, to stop tumor recurrence after surgery to get rid of a primary malignant neoplasm (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is named radiation oncology. Radiation therapy is usually applied to the cancerous tumor due to its ability to regulate cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue resulting in cellular death.