Proficiency tests in the determination of activity of radionuclides in radiopharmaceutical products measured by nuclear medicine services in 8 years of comparison programmes in Brazil.

Proficiency tests were applied to assess the performance of 74 nuclear medicine services in activity measurements of (131)I, (123)I, (99)Tc(m), (67)Ga and (201)Tl. These tests produced 913 data sets from comparison programmes promoted by the National Laboratory for Ionizing Radiation Metrology (LNMRI) from 1999 to 2006. The data were evaluated against acceptance criteria for accuracy and precision and assigned as Acceptable or Not acceptable accordingly. In addition, three other statistical parameters were used as complementary information for performance evaluation which related to normative requirements and to radionuclide calibrators. The results have shown a necessity to improve quality control procedures and unsatisfactory performances of radionuclide calibrators, which incorporate Geiger-Müller detectors.

Implementation of a national metrology network of radionuclides used in nuclear medicine.

The Nuclear Medicine Services (NMS) in Brazil routinely use dose calibrators to measure the activity of solutions containing radiopharmaceuticals. These solutions are administered to patients with the intention to diagnose or treat illnesses. However, for optimal results, the activity of these radiopharmaceuticals must be determined as accurately as possible. The National Laboratory for Ionizing Radiation Metrology (LNMRI) led, since 1998, a comparison program for activity measurements of radiopharmaceuticals administered to patients in the NMS with the purpose promoting quality control. This program has been carried out successfully in Rio de Janeiro, but there is a need to implement it around the country. This can be resolved through the implementation of a network of regional laboratories at various locations throughout the national territory. Currently, such a network is active at a second site, located in Brasília, covering the needs of the Center-West Region, and at a third site, located in Porto Alegre, in the South Region. This work presents the results of comparisons for the radiopharmaceuticals nuclides 131I and 99Tcm and proves that the implementation of a radionuclide metrology network is feasible and viable.