A radiation dose to one part of the body does not have the same potential health effect as a dose to another part. The EDE is used to put different types of radiation doses on an equivalent basis in terms of their potential for causing damage.
An equivalent dose to the whole body, calculated by multiplying the dose to a particular organ (or collection of organs) by a factor that allows a rough representation of equivalent whole body dose and hence the risk of radiogenic cancer.
A quantity used to estimate the biological effect of ionizing radiation. It is the sum over all body tissues of the product of absorbed dose, the quality factor (to account for the different penetrating ability of the various radiations), and the tissue weighting factor (to account for the different radiosensitivity of the various tissues of the body).