Which mnemonic is used for Equivalent Dose?

• A. CBAM
• B. SRED
• C. GRAD
• D. Rex

Answer: (B)

Equivalent dose is the quantity that translates the biological effect of different radiation types into a common unit, the sievert, by weighting the absorbed dose with a radiation weighting factor. The mnemonic SRED helps remember this: Sievert Radiation Equivalent Dose. It highlights that you’re thinking in sieverts and that the dose depends on the radiation type through the weighting factor. For example, 1 Gy of absorbed dose from gamma radiation (weighting factor about 1) and the same 1 Gy from alpha radiation (weighting factor about 20) would yield very different equivalent doses, since H_T = D_T × w_R and the result is expressed in sieverts. This is why SRED is used as a memory aid for Equivalent Dose.