Radiation is currently being used in the treatment of keloid, thus enabling the epidemiological characteristics of patients, analysis of treatment response, modeling the influence of risk factors on patients´ risk of developing long term complications such as a cancer, as well as the detailed analysis of the dose delivered, equipment used and radiation planning. This study intends to gather data about the long term efficacy and safety of radiation therapy and rate of developing secondary cancers in patients who have received radiation therapy for treatment of their keloid.