A NATIONAL SURVEY OF TRACEABILITY OF ACTIVITY METERS IN LITHUANIAN HOSPITALS.

The activity of prescribed radiopharmaceuticals, which are administered for diagnostic and therapeutic purposes, strongly depends on the accuracy of the measuring equipment used in nuclear medicine. This study presents the current status of uncertainty measurements of activity meters used in Lithuanian hospitals. During 2016-2021, the Ionizing Radiation Metrology Laboratory of the Center for Physical Sciences and Technology, which is the National Metrology Institute, performed a comparison of activity meters in the nuclear medicine departments of Lithuanian hospitals. Responses of 16 activity meters that were used in the daily hospital practice were compared with the reference standard. In total, around 150 measurements of activity of diagnostic, therapeutic and calibration radionuclides in different sources and geometries were fulfilled. The results of the maximum deviation were determined to be 8.9% for calibration sources, 18.3% for diagnostic radionuclides and 20.1% for radionuclides used for therapeutic purposes.