Equivalent dose

The equivalent dose (HT) is a measure of the radiation dose to tissue where an attempt has been made to allow for the different relative biological effect of different types of ionizing radiation. Equivalent dose is therefore a less fundamental quantity than radiation absorbed dose, but is more biologically significant. Equivalent dose has units of sieverts. Another unit, Röntgen equivalent man (REM), is still in common use in the US, although regulatory and advisory bodies are encouraging transition to Sievert (1 REM = 1/100 Sievert.)

Equivalent dose (HT) is calculated by multiplying the absorbed dose to the organ or tissue (DT) with the radiation weighting factor, wR. This factor is selected for the type and energy of the radiation incident on the body, or in the case of sources within the body, emitted by the source. The value of wR is 1 for x-rays, gamma rays and beta particles, but higher for protons, neutrons, alpha particles etc.


 * $$H_{T,R} = w_R \times D_{T,R} \,$$

Where HT,R = equivalent dose to tissue T from radiation R

DT,R = absorbed dose D (in Gray) to tissue T from radiation R

External link

 * Dose equivalent - glossary of the European Nuclear Society

Äquivalentdosis Dosis equivalente fa:دوز معادل Équivalent de dose Dose equivalente Дозен еквивалент Эквивалентная доза Ekvivalentna doza Ekvivalenttiannos Dawka równoważna