Radiation therapy is the use of radiation in the treatment of cancer. By means of X-rays, a cancerous tumor can be slowed, stopped, or even completely destroyed. Radiation therapy can be used to ease suffering from tumors by relieving pressure or stopping any bleeding caused by the tumor. It can also be used to prolong lives by stopping growth of tumors, allowing more time to research for a cure. In very early and or small tumors, radiation radiation therapy can be used in conjunction with surgery, or as an alternative to radical surgical procedures.