[Risk assessment in diagnostic radiation dosimetry]

Regulation of radiological protection in diagnostic radiology is based primarily on theoretical assumptions and hypotheses rather than on quantitative data regarding harmful effects. Bionegative effects of low doses have not been demonstrated in individuals or by epidemiological data. Nonetheless, in every case involving radiodiagnostic or nuclear medicine procedures, a benefit-versus-risk analysis is necessary. Therefore, knowledge of both radiobiological aspects and all the above assumptions, hypotheses and simplifications are necessary in order to optimize radiological protection in diagnostic radiology.