Radiation medicine refers to a branch of medical science that deals with the use of radiation therapy in treating various diseases, particularly cancer. It involves using high-energy particles or electromagnetic waves such as X-rays, gamma rays, electron beams, and protons to target and destroy cancer cells while minimizing damage to healthy tissue. Radiation medicine also includes the use of radioactive substances called radiopharmaceuticals for diagnostic purposes, such as imaging or treating specific organs or systems in the body. The goal of radiation medicine is to provide a non-invasive and effective treatment option for patients with cancer while ensuring their quality of life during and after therapy.