Patient exposure and radiation risk in Bulgarian diagnostic nuclear medicine. I. Survey of diagnostic nuclear medicine procedures in Bulgaria in 1980.

For the estimation of population exposure and radiation risk due to diagnostic nuclear medicine in Bulgaria a nationwide survey for 1980 was made of the number and type of radiopharmaceutical applications, administered activity and age and sex distribution of the examined patients. The total number of diagnostic applications was 116418 (40,5% males and 59,5% females), i.e. 13.1 applications per 1000 inhabitants. The total administered activity of all 44 radiopharmaceuticals used in vivo was about 2.1 TBq (or 56 Ci). The age and sex distribution of the examined patients was similar to that in other countries: only 17.4% of all patients were within the reproductive age, 52.7% were over 45 years old. In comparison with the situation in other developed countries it is noted that the number of diagnostic applications of 131I-iodide was relatively high in the year of the survey performed.