[Fundamental facts on dosimetry in the assessment of radioexposure and risk of such exposure in children (author's transl)].

Various methods for determining exposure to radiation are critically reviewed on the basis of 358 x-ray examinations of children (218 cardiac catheters with angiocardiography, 39 gastrointestinal examinations, 101 urological examinations). It is shown that the surface dose is an insufficient parameter for the actual exposure of the child to radiation. Estimates of the radiation risk based thereon are misleading. Even the determination of the area dose product and the integral dose alone will not allow any valid comparison of the exposure in different age groups. The important factor for an accurate determination of the somatic radiation risk is the ratio of integral dose to the body mass (mean body dose), since this is the only factor which is independent of body variables, i.e. only this figure will yield the relation of radiation risks in different age groups. Independent of the examination methods, a higher radiation risk must be assumed in infants than in older children or adults. These relationships are demonstrated on the basis of the author's own measurements and calculations.