RESUMO
The national traceability chain for (131)I activity measurements performed in nuclear medicine in Cuba is described. At the highest (primary) level, liquid scintillation counting employing the CIEMAT/NIST method is used; at the secondary level, a secondary standard radionuclide calibrator is utilized that allows for a quick and simple transference of the measurement unit to the tertiary level of end-users' instruments. The equivalence of Cuban standards and the assessment of measurement uncertainties at the end-user level are determined through the results of measurement comparisons.
Assuntos
Radioisótopos do Iodo/análise , Radioisótopos do Iodo/normas , Medicina Nuclear/normas , Radiometria/normas , Compostos Radiofarmacêuticos/análise , Compostos Radiofarmacêuticos/normas , Cuba , Padrões de Referência , Valores de ReferênciaRESUMO
This paper describes the results obtained using a simulated test for administration of activity in nuclear medicine between 2002 and 2004. Measurements in the radionuclide calibrator are made during the different stages of the procedure. The test attempts to obtain supplementary information on the quality of the measurement, with the aim of evaluating in a more complete way the accuracy of the administered activity value compared with the prescribed one. The participants' performance has been assessed by means of a statistical analysis of the reported data. Dependences between several attributes of the simulated administration tests results are discussed. Specifically, the proportion of satisfactory results in the 2003-2004 period was found to be higher than in 2002. It reveals an improvement of the activity administration in the Cuban nuclear medicine departments since 2003.
Assuntos
Medicina Nuclear , Calibragem , Meia-Vida , Medicina Nuclear/instrumentação , RadioisótoposRESUMO
A national program of ongoing comparisons for assaying gamma-emitting radiopharmaceuticals for amount of radioactivity using radionuclide calibrators was begun in 2000. Nuclides of the most wide-spread use in Cuban nuclear medicine, 131I, 201Tl and (99m)Tc, as well as two measurement geometries, glass vials and plastic syringes, were employed. In this paper, the participants' performance is assessed by mean of a statistical analysis of the reported data. Performance tables have been obtained and a chi2 statistic is calculated from observed and expected frequencies, with the aim of testing the hypothesis about the independence of some characteristics of the comparison results, at a significance level alpha=0.05. The proportion of satisfactory results in the years 2002-2004 were found to be at the same level, but higher than in 2000. It reveals an improvement of the measurement quality since 2002. The causes of improvement were investigated using the statistical treatment of several data available as supplementary information.
Assuntos
Medicina Nuclear/normas , Garantia da Qualidade dos Cuidados de Saúde , Compostos Radiofarmacêuticos/normas , CalibragemRESUMO
The correct administration to a patient of the prescribed activity of a radiopharmaceutical is an important factor to ensure the confidence in the diagnosis or the therapeutic efficiency, while at the same time keeping the unnecessary human exposure as low as possible. Comparisons of activity measurements for 131I, 201Tl and 99mTc with radionuclide calibrators were organized the first time in Cuba during 2002 with the aim of obtaining information about the quality of administration of radiopharmaceuticals. Ten Cuban nuclear medicine departments and the laboratories involved in the production of these kinds of compounds participated in the comparison runs. The results presented in this paper facilitated the identification of several problems and initiated corrective actions. In addition, they indicate the necessity of establishing Quality Systems in nuclear medicine in Cuba.
Assuntos
Radioisótopos/normas , Compostos Radiofarmacêuticos/normas , Calibragem , Cuba , Embalagem de Medicamentos , Humanos , Serviço Hospitalar de Medicina Nuclear/normas , Garantia da Qualidade dos Cuidados de Saúde , Radioisótopos/análise , Compostos Radiofarmacêuticos/análiseRESUMO
A simplified procedure for the standardization of gamma reference sources, for use in quality assurance of activity measurements during production and application of radiopharmaceuticals in Cuban nuclear medicine laboratories, is described. The method is based on the reliable achievement of consistent measurements by both gamma-spectrometry and ionization chamber techniques, and allows to obtain reference sources with uncertainties lower than 2%. Experimental setup, validation procedure and typical results obtained for 99mTc, 131I, 201Tl and 153Sm are described and discussed. The method will serve also as a secondary reference system for radioactivity measurements in the country.