Play 0:00 Radiation therapy uses high-energy rays or waves to destroy cancer cells, using a device that targets the affected area and delivers the radiation directly to the cancer cells. Radiation may be used when the skin cancer is in a difficult location to remove, for elderly patients, for those who are in poor health, or if the cancer is invasive to nerves or surrounding tissues. Radiation may also be used if the cancer returns after surgery. In higher doses, radiation destroys cells or keeps them from multiplying. Most normal cells recover from radiation therapy, unlike the cancer cells. To protect normal cells, the radiation dosage is limited and treatment is spread out over time.