[Application of radioactive substances in nuclear medicine research: current trends and radiation exposure of study subjects].

AIM

Analysis of the application of radioactive substances in research in the field of nuclear medicine in human beings and of the resulting radiation exposure to study subjects.

METHODS

Assessment of applications for approval submitted in accordance with Paragraph 41 of the Radiation Protection Ordinance, evaluated by the Federal Office for Radiation Protection together with the Federal Institute for Pharmaceuticals and Medical Products, within the period from 1997 to 1999.

RESULTS

The focus of the studies on the diagnostic application of radioactive substances in medicine evaluated has, since 1998, shifted from oncological to neurological and psychological aspects, while, at the same time, the number of PET studies increased constantly. The proportion of healthy study subjects included in the diagnostic studies increased from 7 to 22%. The number of therapeutic applications of radioactive substances has, since 1997, undergone a three-fold increase, and in the process of this, the focus of attention lay within the area of radioimmuno-therapy and endovascular brachytherapy. The effective dose was, among up to 49% of the investigated healthy study subjects higher than 5 mSv, and among up to 6% of these subjects was at levels of over 20 mSv. Up to 22% of the patients received, within the scope of diagnostic studies, an effective dose of between 20 and 50 mSv. An exceeding of the 50 mSv limit occurred among up to 3% of the patients.

CONCLUSIONS

In spite of the increasing numbers of PET applications, conventional nuclear medicine has maintained its importance in the field of medical research. Further developments in the areas of radiochemistry and molecular biology led to an increase in the importance of radio-immuno therapy. The evaluation of new radiopharmaceuticals and the extension of basic biomedical research, resulted in an increase in the proportion of healthy study subjects included in the studies. The radiation exposure among subjects resulting directly from the studies showed, for the period of evaluation, an overall trend towards reduction.