relative biologic effectiveness

Relative biologic effectiveness (RBE) is a concept used in physics to compare the biological damage caused by different types of ionizing radiation. It quantifies how effectively a particular type of radiation can cause injury compared to a reference radiation, typically X-rays or gamma rays.12

Different types of radiation, such as alpha particles or neutrons, can cause more damage at the same absorbed dose than X-rays or gamma rays. This is because their ionizations are clustered more closely together, leading to greater molecular damage at critical sites within cells. For instance, alpha particle radiation is considered about 20 times more effective as a carcinogen than the same dose of gamma rays. The concept of RBE is crucial for radiation protection, helping to normalize doses and assess risks associated with various radiation sources.132