ABSTRACT
The quantity absorbed dose is used in medical physics on the assumption that when its value is the same, irradiation of equal objects results in equal biological effects. In reality, most of the biological effects of radiation depend on the microscopical pattern of energy deposition and the absorbed dose is only the expected value (average) of the energy deposited per unit mass. That the same dose of radiation may result in different effects, when delivered by different types of radiation, is well documented. For instance, at low doses, the relative biological effectiveness (RBE) of neutrons relative to )I-rays to induce a cell to become malignant is on the order of 100, which means that the ratio of absorbed doses of )I-rays and neutrons causing equal effects is about 100 [1-13].
