[Radioisotopic diagnostic examination as a factor responsible for the Polish population exposure to ionizing...

For the general population, in vivo radioisotopic radiological examinations are the second, after x-ray diagnostics, artificial source of ionizing radiation used for medical purposes. The 1981 survey was the first review of the radioisotopic examinations in Poland and revealed that 80,000 examinations are performed annually (2 examinations per 1,000 population on average). It was also found that 131 I was the most common isotope used during thyroid examinations very frequently performed at that time. According to the 1996 data published by the National Consultant on Nuclear Medicine, "In Poland there are 36 centers of nuclear medicine within the network of public health care services. Every year about 130,000 radioisotopic examinations are performed." In order to estimate real exposure of the Polish population resulting from radioisotopic diagnostic examinations it is necessary to gather detailed data on the age structure of patients, as well as on the type and activity of radiopharmaceutical be administered. The paper presents the preliminary results of the follow-up study on radioisotopic examinations in Poland carried out by the Department of Radiological Protection, Nofer Institute of Medicine, Łódź. The data have been collected according to the adopted schedule, taking account of the organ (system) examined, the type of administered radiopharmaceutical, the kind and activity of radioactive isotopes used to mark radiopharmaceutics, age and sex of examined patient. By the end of December 2000 the data on radioisotopic examinations performed in 12 centers of nuclear medicine (Warsaw--7; Kielce--2; Gdańsk, Łódź and Zgierz--one center in each city) had been collected. Thus far almost 40,000 radioisotopic examinations have been registered. According to the above mentioned procedure it was possible to collect data on all examinations performed in 1998. In addition, general numbers of examinations performed in the centers visited in 1999 were registered; the 2000 data are now being completed. It was finally established that the thyroid and musculoskeletal examinations constitute about 50% of the total number of examinations, which is in agreement with the data applying to the countries classified as those with the first level of health care. However, while an average effective dose per examination in those countries accounts for about 4 mSv, in the Polish centers the analogues indicator, estimated on the basis of the results collected thus far, is about 9 mSv, of this number, over 7 mSv is contributed by thyroid examinations with the use of iodine (131I). The obtained result is a strong stimulus to supplement and complete the data already gathered and to carry out a thorough analysis of radioisotopic examination in view of patients' exposure. Such an analysis would provide the subject matter arguments for the optimization of radiological protection in nuclear medicine in Poland.