What does RBE measure in radiobiology?

RBE, or Relative Biological Effectiveness, is a crucial concept in radiobiology that quantifies how effective different types of ionizing radiation are at producing biological effects. Specifically, it compares the biological effect of a specific type of radiation to that of a reference radiation, typically X-rays or gamma rays, at the same energy level.

The purpose of RBE is to account for the differences in the damage caused by various types of radiation due to their differing physical and chemical properties, such as linear energy transfer (LET). High LET radiations, like alpha particles, tend to be more biologically damaging per unit of absorbed dose compared to low LET radiations, like beta particles or X-rays. RBE values can be used to adjust radiation dose calculations in treatment planning for cancer therapy, ensuring that the biological impact of various radiation types is taken into consideration.

This concept allows for a more nuanced understanding of radiation effects on living tissues, leading to safer and more effective use of radiation in medical and research settings.