RESUMEN
(124)I is a radionuclide used in the diagnosis of tumors. The National Health Agency requires identification and activity measurement of impurities. Using gamma spectrometry with an efficiency calibrated high-purity germanium detector, impurities (125)I and (126)I in an (1)(24)I production sample were identified. Activity ratios of (125)I and (126)I to (124)I were approximately 0.5% and 98%, respectively.
Asunto(s)
Contaminación de Medicamentos/prevención & control , Radioisótopos de Yodo/análisis , Radioisótopos de Yodo/normas , Radiometría/métodos , Radiometría/normas , Espectrometría gamma/normas , Brasil , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría gamma/métodosRESUMEN
Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.
Asunto(s)
Radioisótopos de Flúor/análisis , Radioisótopos de Flúor/normas , Sector Público/normas , Radiometría/métodos , Radiometría/normas , Brasil , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
In order to obtain information on the accuracy of activity measurements in Brazilian hospitals, several intercomparison exercises have been organized since 1998. The first exercise consisted of two intercomparison runs of 131I and 99mTc and had the participation of 21 hospitals localized in Rio de Janeiro city and surroundings. The second, with 131I (47 hospitals) and 123I (12 hospitals), had the participation of hospitals localized in the whole country. The results were analyzed under the statistical point of view and conformity to the norms of Regulatory Authority. These results have shown that such exercises are necessary to improve the quality of the measurements and to identify those instruments that are producing incorrect values.