Administered Activities of Radiopharmaceutical Preparations,Radiation Load and Radiation Risk of Examination Procedures in Nuclear Medicine

Overview

Consistent with the worldwide development of nuclear medicine, in the Czech Republic in 1987 to 1996 partlythe spectrum of used radiopharmaceutical preparations and their ratio changed. In the majority of radiopharmaceuticalpreparations the mean administered activity increased by 20 to 80 % and the range of activities administered indifferent departments diminished somewhat. Adherence to principles of radiation protection of patients is assistedby guidelines of administered activities of radiopharmaceutical preparations laid down in new regulations on radiationprotection valid in the CR from the middle of 1997. The radiation burden associated with the majority of examinationsin nuclear medicine expressed as the effective dose is comparable with the radiation burden of radiodiagnosticexaminations, only after administration of preparations with131I,201Tl,67Ga and111In it is markedly higher. Basedon knowledge of the effective dose it may be concluded that the lifetime extra risk of a fatal tumour due toadministration of radiopharmaceutical preparations is by two to three orders lower than the lifetime risk ofspontaneous development of fatal tumours. A special feature of radiation risk is its hypothetical character - it isfrequently projected into the distant future of human life, contrary to immediate non-radiation risks of some medicalprocedures and risks in the living environment which frequently are higher. Any examination using ionising radiationcan be made only if the expected health benefit for the patient is significantly greater than the radiation risk. Excessivefear of radiation risk should not lead to refusal of justified examinations with possible subsequent serious healthdamage for the patient.

Key words:
radiopharmaceutical preparations, mean administered activity, radiation load, effective dose, radiationrisk, nuclear medicine, radiation protection.