The Support Offered by the Romanian Primary Activity Standard Laboratory to the Nuclear Medicine Field (original) (raw)
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Radionuclide calibrator comparisons and quality improvement in nuclear medicine
Applied Radiation and Isotopes, 2008
The traceability of activity measurements performed during the development phase of the radiopharmaceutical and in its clinical application is essential for establishing the comparability of clinical results reported in the nuclear medicine field. This paper presents and discusses the evaluation over time of the quality of activity measurement results obtained in Cuban nuclear medicine, on the basis of statistical samples taken during the radionuclide calibrator comparison program. An attempt is also made to evaluate the role played by such comparisons in quality measurement improvement in nuclear medicine, on the basis of results obtained in a number of countries and published by several authors over a period of time. Specifically, improvements of the measurement performance over time assessed by such exercises were found dissimilar in magnitudes for different countries. Two phases could be distinguished in the improvement process over time. Firstly, a fast improvement can be obtained resulting from the improvement in measurement accuracy of devices. After that, the achievement of new and sustained improvements goes slowly and requires an application of quality assurance programs where the qualification upgrading of personnel become an essential point.
Physica Medica, 2019
Reliable quantification of radioactivity in nuclear medicine is becoming increasingly important in various therapeutic applications requiring a high accuracy of nuclear medicine measuring equipment, such as radionuclide calibrators. In this study the accuracy of four different radionuclide calibrators was assessed for 99m Tc, 111 In, 68 Ga and 18 F for measurement geometries clinically used. Methods: Syringes and vials were prepared with a reference activity using a stock solution of which the activity concentration was determined using gamma-ray spectroscopy. The accuracy of four different radionuclide calibrator systems, ISOMED 2000, ISOMED 2010, VIK-202 and Capintec CRC-25R, was assessed by comparing the measured activity to the reference activity. Results: Deviations in measured activity from reference values were found up to 12.5%, 32.0%, 29.0% and 12.6% for 99m Tc, 111 In, 68 Ga and 18 F, respectively. For 68 Ga all radionuclide calibrators systematically overestimated the activity by 10-20%. For 111 In, large differences in activity measurements were observed between different source geometries, in particular between syringes and vials. Deviations between radionuclide calibrator systems were found up to 11.8%, 44.4%, 14.4% and 8.7% for 99m Tc, 111 In, 68 Ga and 18 F, respectively. When comparing similar syringe types of different brands filled with identical stock solution volume, deviations up to 1.8%, 5.8%, 10.2% and 3.2% were found for 99m Tc, 111 In, 68 Ga and 18 F. Conclusion: Substantial deviations in measured activity were found for all radionuclides and radionuclide calibrators, which may result in erroneous activity dosing and image quantification. This underlines the importance of thorough validation of radionuclide calibrators for all measurement geometries and radionuclides clinically used.
E3S Web of Conferences
Ensuring the effective use of a dose calibrator used for the practice of nuclear medicine, and the injection of the correct dose to the patient is the subject of a long traceable calibration chain, which serves to establish the relationship between the values of the activity indicated by the dose calibrator and the activity corresponding to ISO 2919 certified sealed sources whose activity is known with an uncertainty of less than 1 %. Our calibration program consists in carrying out various quality control on the CRC 55TR activimeter, namely the daily control which is carried out in the absence of any radioactive source, then the fidelity control carried out by a source of 37Cs and a source of 60Co, then the reproducibility check performed with a 137Cs source, and finally the linearity check performed with a 99mTc source. In our case the results obtained from the specific tests used to verify the proper functioning of the Capintec CRC 55tR activimeter in a nuclear medicine service i...
Teste de proficiência para medições de radioatividade na medicina nuclear
Radiologia Brasileira, 2009
OBJECTIVE: To assess the performance of radionuclide calibrators in 55 Brazilian nuclear medicine services in the measurement of 99 Tc m radiopharmaceutical activity. Proficiency tests were applied to data sets with 63 results originated from the comparison program developed by Laboratório Nacional de Metrologia das Radiações Ionizantes of Instituto de Radioproteção e Dosimetria. MATERIALS AND METHODS: The calibrators' performance was evaluated in compliance with the acceptance criterion of ±10% accuracy required by the Brazilian standards and also the criteria established by the ISO/IEC Guide 43-1, and classified as either "acceptable" or "non-acceptable". The samples of 99 Tc m utilized in the comparison were supplied by some of the participants and calibrated at Laboratório Nacional de Metrologia das Radiações Ionizantes for determining the activity reference value. RESULTS: The present study utilizing 99 Tc m has shown that 82.5% of the calibrators were considered as acceptable according to the Brazilian standards, while by the criteria established by ISO/IEC 43-1, 81.0% were considered as acceptable. On the other hand, radionuclide calibrators with Geiger-Müller detectors presented unsatisfactory performance when compared with calibrators with ionization chambers. CONCLUSION: The performance evaluation based on the ISO/IEC 43-1 criteria, which are applied to analytical laboratories, in spite of being more restrictive, has demonstrated to be quite consistent with the accuracy criterion established by the Brazilian standard.
International Journal of Advanced Research (IJAR), 2019
The aim of this study is to evaluate and compare the performance of two dose calibrators which are used in Nuclear Medicine Center by standard tests accuracy, constancy, linearity and geometry. To check the performance status of the dose calibrators the activity of radiopharmaceuticals must be accurately known before administered to the patients. Two dose calibrators of Institute Nuclear Medicine and Allied Sciences, Dhaka (Capintec, Inc.,Model no. CRC 25R and Veenstra , model no. VDC 404) performances were compared in accordance with varying geometry because most common measurement geometries utilized in clinical practice are glass vials, solid capsules and various types of plastic syringes. Vials and syringes filling volumes can be widely different, according to clinical needs. It was found that the measurement activity readings of one of these two dose calibrator, VDC-404, showed slightly deviating from accurate value because readings might be affected by the frequent change in background count. The results of the quality control (QC) tests revealed that the parameters that were traced for both dose calibrators were within the limits of the international standards, ?5%. Regular QC should cover precision, accuracy, linearity, and geometry of instrument, according to IAEA standards, e.g. (IAEA TECDOC-602 and 1599), that will guarantee to assure the proper practice of nuclear medicine diagnosis. It is also vital to fulfill radiation protection requirements as well as successful therapies and good quality image production in nuclear medicine practices.
Proficiency test for radioactivity measurements in nuclear medicine
Journal of Radioanalytical and Nuclear Chemistry, 2009
Proficiency tests established by ISO/IEC-43 were applied to assess the performance of 69 Brazilian nuclear medicine services in the radiopharmaceuticals activity measurements of 131 I, 99 Tc m , 67 Ga and 201 Tl. The 214 datasets originated from comparison programs promoted by the Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI) in 2006/2007 were also evaluated against acceptance criteria of ±10% limits for accuracy required by Brazilian regulatory authority. The results of performance evaluation were assigned as ''Acceptable'' or ''Not-acceptable'' accordingly and have shown a large dispersion when the statistical criteria assays were applied and also compared with regulatory requirements.
Progress in Organizing National and International Comparisons for Nuclear Medicine Measurements
2009
The paper presents the progress registered by the Radionuclide Metrology Laboratory (RML) from IFIN-HH, in improvement of the quality of radiopharmaceuticals activity measurement, and assurance of the whole traceability chain from international level to the national users. The progress in organization of comparisons for radiopharmaceuticals activity measurement is analyzed. A detailed description of two recent national comparisons, and an international one, regarding 131I solutions, within the frame of the IAEA‘s CRP E2.10.05 “Harmonization of quality practices for nuclear medicine radioactivity measurements” is done, with the analysis of the strong and week points in measurements. The most important outcome of the paper is the analysis of the evolution in quality of comparisons since a previously reported one. At the RML level, the improvements are: demonstration of the international equivalence of primary Romanian activity standard, improvement of the secondary standard, relevance...
Applied Radiation and …, 2010
The activity of radiopharmaceuticals in nuclear medicine is measured before patient injection with radionuclide calibrators. In Switzerland, the general requirements for quality controls are defined in a federal ordinance and a directive of the Federal Office of Metrology (METAS) which require each instrument to be verified. A set of three gamma sources (Co-57, Cs-137 and Co-60) is used to verify the response of radionuclide calibrators in the gamma energy range of their use. A beta source, a mixture of 90 Sr and 90 Y in secular equilibrium, is used as well. Manufacturers are responsible for the calibration factors. The main goal of the study was to monitor the validity of the calibration factors by using two sources: a 90 Sr/ 90 Y source and a 18 F source. The three types of commercial radionuclide calibrators tested do not have a calibration factor for the mixture but only for 90 Y. Activity measurements of a 90 Sr/ 90 Y source with the 90 Y calibration factor are performed in order to correct for the extracontribution of 90 Sr. The value of the correction factor was found to be 1.113 whereas Monte Carlo simulations of the radionuclide calibrators estimate the correction factor to be 1.117. Measurements with 18 F sources in a specific geometry are also performed. Since this radionuclide is widely used in Swiss hospitals equipped with PET and PET-CT, the metrology of the 18 F is very important. The 18 F response normalized to the 137 Cs response shows that the difference with a reference value does not exceed 3% for the three types of radionuclide calibrators.