Which dose quantity is defined as the absorbed dose modified by radiation weighting factors and is expressed in rem or sieverts?

• A. Equivalent dose
• B. Effective dose
• C. Absorbed dose
• D. Radiant dose

Answer: (A)

Equivalent dose is the quantity that adjusts the absorbed dose by the radiation weighting factor to reflect how different types of radiation affect biological tissue. It’s calculated by multiplying the absorbed dose (in Gy) by the radiation weighting factor (wR) and is expressed in sieverts (Sv) or rem. The weighting factor accounts for the varying biological impact of different radiations; for diagnostic X-rays, photons have wR = 1, so the equivalent dose aligns with the absorbed dose numerically but still serves to represent potential harm. This distinguishes it from absorbed dose (energy deposited per mass, in Gy) and from effective dose (which also factors in tissue sensitivities). Radiant dose isn’t a standard dosimetric term used here.