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Objective@#To standardize the operation and data processing in radiological health institutions in China, in order to promote the assessment of γ-spectrometry, improve the measurement and analysis capabilities of each laboratory, and accordingly improve accuracy of environment sample measuring.@*Methods@#By collecting the values of 232Th, 40K and 137Cs contents in soil samples from 2015 to 2017, the assessment results of γ-spectrometry laboratores were summarized and analyzed.@*Results@#The technical institutions from 25 provinces were involved in the assessment until 2017, including disease control and prevention centers, entry-exit inspection and quarantine agencies, research institutes, universities and companies. The number of participants was increased from 40 to 48, and the qualified rate exceeded 90%, and the excellent rate was no less than 11% each year. The percentage of relative deviation less than 10% between the measuring result of 232Th, 40K and 137Cs contents and the reference value was larger than 80% in 2017. The accuracy became better. However, the number of institutions with U and Z score less than 1 was increased from 11 to 25, suggesting that the precision of measuring result has also been greatly improved.@*Conclusions@#Radiological health institutions in China have good measurement and analysis capabilities with regard to γ-spectrometry, which can meet the needs of environmental sample measurement and in-food radionuclide risk monitoring in an emergency of nuclear and radiation. But a few institutions′ measuring results were largely different from the reference values, as a consequence, it is important to strengthen their ability of measurement and analysis.
RESUMO
Objective To standardize the operation and data processing in radiological health institutions in China, in order to promote the assessment of γ-spectrometry, improve the measurement and analysis capabilities of each laboratory, and accordingly improve accuracy of environment sample measuring. Methods By collecting the values of 232 Th, 40 K and 137 Cs contents in soil samples from 2015 to 2017, the assessment results of γ-spectrometry laboratores were summarized and analyzed. Results The technical institutions from 25 provinces were involved in the assessment until 2017, including disease control and prevention centers, entry-exit inspection and quarantine agencies, research institutes, universities and companies. The number of participants was increased from 40 to 48, and the qualified rate exceeded 90％, and the excellent rate was no less than 11％ each year. The percentage of relative deviation less than 10％ between the measuring result of 232 Th, 40 K and 137 Cs contents and the reference value was larger than 80％ in 2017. The accuracy became better. However, the number of institutions with U and Z score less than 1 was increased from 11 to 25, suggesting that the precision of measuring result has also been greatly improved. Conclusions Radiological health institutions in China have good measurement and analysis capabilities with regard to γ-spectrometry, which can meet the needs of environmental sample measurement and in-food radionuclide risk monitoring in an emergency of nuclear and radiation. But a few institutions′ measuring results were largely different from the reference values, as a consequence, it is important to strengthen their ability of measurement and analysis.
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Glucose meters often have similar performance when compared by error grid analysis.This is one reason that other statistics such as mean absolute relative deviation (MARD) are used to further differentiate performance.The problem with MARD is that too much information is lost.But additional information is available within the A zone of an error grid by using the Taguchi loss function.Applying the Taguchi loss function gives each glucose meter difference from reference a value ranging from 0 (no error) to 1 (error reaches the A zone limit).Values are averaged over all data which provides an indication of risk of an incorrect medical decision.This allows one to differentiate glucose meter performance for the common case where meters have a high percentage of values in the A zone and no values beyond the B zone.Examples are provided using simulated data.
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Objective To evaluate the radionuclide measurability and analyzability of the γ-spectrometry laboratories in radiological technology institutions countrywide,ensure the quality of radionuclide γ-spectrometry and outlook the evaluation work in γ-spectrometry.Methods The 2016 annual evaluation of radionuclide γ-spectrometry was carried,and the accuracy and precision of 232Th,40K and 137Cs,activity concentration in soil samples were summarized and analyzed in γ-spectrometry laboratories of radiological technology institutions countrywide.Results Of received 45 revaluation receipts,43 were effective and the other two were ineffective due to the suspension of the evaluation.The relative deviation of the activity concentration values of 232Th,40K and 137Cs given by most of the institutions were within the range of ± 20％,only with two measurements beyond 20％.The evaluation results from the 43 participants were qualified with the overall qualified rate of 100％,of which five were excellent accounting for 11.6％ of all.Conclusions All of the elevation results submitted were accurate,showing better measurability.However,some submittals deviated from the references to some degree.Henceforth,it is necessary to strengthen experimental operation and data processing according to the defend procedures and improve the accuracy and precision of measurement results.
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Objective To explore the elementary properties of LiF (Mg,Cu,and P) thermoluminescent dosimeter (TLD) in dosimetry for tumor radiotherapy,and to provide a reliable basis for thermoluminescent dosimetry in clinical radiotherapy.Methods 60Coγ-ray and 6 MV X-ray were used for evaluation of the dispersion,repeatability,and dose response of LiF TLD.To meet the requirement of clinical radiotherapy,the effects of energy,dose (50-600 cGy),radiation dose rate (50-600 MU/min),and the angle of incidence for accelerator gantry (0°-± 90°) on TLD were determined and the respective correction factors were calculated.Results The errors of repeatability and dispersion of TLD were less than ±3％.There was a linear relationship between readout and irradiation dose within a certain range of irradiation dose.The minimal relative deviation of 0.3％ was obtained when 6 MV X-ray was used with a dose rate of 300 MU/min and an angle of incidence of 0°.Conclusions LiF TLD shows excellent repeatability,low dispersion,high stability,and strong linear correlation.It meets the international criteria and can be used for dose measurement in tumor radiotherapy.
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Objective To evaluate accuracy and consistency of the coagulation convention that involves PT, INR, FIB, APTT on two coagulation analysators(ACL-9000 and ACL-200, Beckman-Coulter Corporation, US). Methods The repeatability test was used to assess the precision, the accuracy and consistency of the coagulation convention on two coagulation analysators were evaluated by comparison and analysis. Results The repeatability of related test results based on ACL-9000 coagulation analysator was better that CV value less than 5%, but the repeatability of abnormal specimens FIB based on ACL-200 was poor that CV value of 6.6%. Through comparing ACL-9000 analyzer, the test results of ACL- 200 coagulation analysator has good correlation with it, correlation coefficient ?﹥0.975. Conclusion In the condition of the excellent precision and stability, we can also find system errors existed in the analyzer on time by verificating. Through being adjusted and calibrated, the examination department can deliver the results of accuracy consistency.