View source for Relative biological effectiveness

[[File:Glossary Icon-2.png|100px|frameless|right|link=ICRP Glossary]]
The ratio of a dose of a low-LET reference radiation (usually of <sup>137</sup>Cs or <sup>60</sup>Co γ rays or kilovoltage x-ray quality) to a dose of the test radiation considered that gives the identical level of a biological effect. For a given radiation quality, RBE values vary with the dose, dose fractionation, dose rate, and species, strains and biological endpoint considered. 

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== Previous glossary entries ==

=== from [[ICRP Publication 136]], 2017 ===

A theoretical concept that expresses the property of the given radiation type to aﬀect living biological tissue. RBE is deﬁned as the ratio of absorbed dose of a low-linear-energy-transfer reference radiation to absorbed dose of the radiation considered that gives an identical biological eﬀect. RBE values vary with absorbed dose, dose rate and biological endpoint considered.

=== from [[ICRP Publication 131]], 2015 ===

The ratio of a dose of a low-LET reference radiation (usually of <sup>60</sup>Co γ rays or kilovoltage x-ray quality) to a dose of the test radiation considered that gives an identical biological effect. RBE values vary with the dose, dose fractionation, dose rate, and biological endpoint considered.

=== from [[ICRP Publication 127]], 2014 ===

The ratio of a dose of a low-LET reference radiation to a dose of the radiation considered that has an identical biological eﬀect. RBE values vary with the dose, dose rate and biological endpoint considered.

=== from [[ICRP Publication 123]], 2013 ===

The ratio of absorbed dose of a low-LET reference radiation to absorbed dose of the radiation considered that gives an identical biological effect. RBE values vary with absorbed dose, absorbed dose rate, and the biological endpoint considered. In radiological protection, the RBE at low and very low doses (RBEM) is of particular interest.

=== from [[ICRP Publication 118]], 2012 ===

The ratio of a dose of a low-linear energy transfer reference radiation to a dose of the radiation considered that gives an identical biological effect. Values vary with the dose, dose rate, and biological endpoint considered.

=== from [[ICRP Publication 103]], 2007 ===

The ratio of a dose of a low-LET reference radiation to a dose of the radiation considered that gives an identical biological effect. RBE values vary with the dose, dose rate, and biological endpoint considered. In radiological protection, the RBE for stochastic effects at low doses (RBEM) is of particular interest.