Medical exposure to ionizing radiations at diagnosis aim of the French population: situation at the end of 2002 in order to implement a surveillance system

The principal result of this study, in the perspective of the implementation of an epidemiological follow-up of radiological practices, is to show that the scanner and the interventional radiology, that regroup about 8% and 1.5% of the examinations number, represent respectively about 35% and 19% of the dose to the population. These examinations are in regular progression these last years. A such evaluation allows to better adapt the efforts of the epidemiological surveillance of radiological practices. Our evaluation of the situation in France in 2002 allows a comparison with the previous data registered in France but also international comparisons. The comparison of French data during the twenty last years is based, firstly, on the comparison of the number of examinations. on this period, we observe a reduction of abdomen examinations with injection of contrast product without substitution at the profit of abdomen scanner but likely at the profit of non irradiating examinations such MRI or echography. Conversely, other indications of the scanner have been developed (head and thorax). The resultant of changes in the radiological practice in term of exposure to X radiation of the population is more difficult to analyse. In addition of the number of examinations, the radiological technique has reduced the exposure. More, the coefficient of weighting used for the calculation of efficient dose have been changed in 1990 with the passage of the ICRP 26 to the ICRP 60 recommendation. The international comparisons are also a problem of method: different approaches to compare acts, values of average efficient doses by examination are referred to doses established in Great britain when the real average efficient doses by examination vary from a country to another. An European project called 'Dose Datamed' is underway to homogenize the methods of collection. The strategies of examinations uses can be different in each country. The cumulative exposure of patients should also be taken into consideration. (N.C.)