Chemotherapy is the use of anticancer drugs to kill cancer cells throughout the body. Even after cancer has been removed from the lung, cancer cells may still be present in nearby tissue or elsewhere in the body. Chemotherapy may be used to control cancer growth or to relieve symptoms. Some anticancer drugs are given in the form of a pill. Radiation therapy, also called radiotherapy, involves the use of high-energy rays to kill cancer cells.
Radiation therapy is directed to a limited area and affects the cancer cells only in that area.
Radiation therapy may be used before surgery to shrink a tumor, or after surgery to destroy any cancer cells that remain in the treated area. Doctors also use radiation therapy, often combined with chemotherapy, as primary treatment instead of surgery. Radiation therapy may also be used to relieve symptoms such as shortness of breath. The chemical rapidly leaves normal cells but remains in cancer cells for a longer time. A laser light aimed at the cancer activates the chemical, which then kills the cancer cells that have absorbed it.