Radiation therapy is the use of high energy x-rays to treat disease. Radiation therapy can be used alone or in combination with surgery and/or chemotherapy to cure or control cancer. The equipment used to generate these x-rays are called linear accelerators. It is similar to the machine which takes x-ray pictures except that in a linear accelerator, the energy is much more focused and precise. This precise focus enables us to carefully calculate the amount and exact location of the radiation delivered and allows us to limit the dosage to the tissues surrounding the tumor.