Radiation therapy is to x-ray and gamma ray radiation, electron irradiation in cancer tissues, kill cancer cells, and safe dose not to exceed normal tissue. Radiotherapy works to kill cancer cells through the ionization process and achieve its purpose. Some cells immediately after radiation, because of the direct effect, but most cancer deaths is because radiation causes chromosomal DNA and a lot of damage, so cannot mitosis and cancer cells. Due to the biological effects of radiation, the maximum amount of anti cancer, destroying cancer, make it smaller. Due to sufficient exposure to radiation dose is only to be part of effective treatment, therefore, is the same and surgical therapy for partial treatment. Recently, in order to affect as little as possible to the surrounding normal tissue, a way to focus light from multiple directions; this radical radiation for therapy, palliative radiation and surgery and radiation therapy.
Radioactive factors that cause hair loss include radiation, radioactive isotope and radiation of electromagnetic waves. Radiation damage in four degrees, can cause hair loss.