What happens during radiation therapy?
Radiation therapy delivers focused high-energy x-rays (photons), gamma rays, or atomic particles. It affects cells that are rapidly dividing—such as cancer cells—much more than those that are not. Most cancers, including lung tumors, are made of cells that divide more rapidly than those in normal lung tissue. This means the tumor may be eliminated without damaging surrounding normal tissues. Radiotherapy acts by attacking the DNA within tumor cells, making it impossible for them to grow and create more cancer cells. Normal body cells may also be damaged, but they are able to repair themselves and function properly once again. The key is to give daily doses of radiation large enough to kill a high percentage of the rapidly dividing cancer cells, while minimizing damage to the more slowly dividing normal tissue cells in the same area.
