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1.
Appl Radiat Isot ; 109: 402-404, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26717794

RESUMO

Source self-attenuation for solutions of (57)Co of varying density and carrier concentration was measured in nine re-entrant ionization chambers maintained at NIST. The magnitude of the attenuation must be investigated to determine whether a correction is necessary in the determination of the activity of a source that differs in composition from the source used to calibrate the ionization chamber. At our institute, corrections are currently made in the measurement of (144)Ce, (109)Cd, (67)Ga, (195)Au, (166)Ho, (177)Lu, and (153)Sm. This work presents the methods used as recently applied to (57)Co. A range of corrections up to 1% were calculated for dilute to concentrated HCl at routinely used carrier concentrations.

2.
Appl Radiat Isot ; 90: 79-83, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24705009

RESUMO

Calibration factors for commercial ionization chambers (i.e. dose calibrators) were determined for a solution of (123)I; the activity was based on the 1976 NBS standard. A link between the NIST standard and the International Reference System (SIR) was established. The two major U.S. dose calibrator manufacturers recommend oppositely biased calibration factors, giving a spread of 11.3% in measured activities. With modern quantitative imaging techniques capable of ≤10% accuracy, this bias for a SPECT nuclide is highly significant.

3.
Appl Radiat Isot ; 70(9): 2227-31, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22578995

RESUMO

The National Institute of Standards and Technology (NIST) maintains a program for the establishment and dissemination of activity measurement standards in nuclear medicine. These standards are disseminated through Standard Reference Materials (SRMs), Calibration Services, radionuclide calibrator settings, and the NIST Radioactivity Measurement Assurance Program (NRMAP, formerly the NEI/NIST MAP). The MAP for the radiopharmaceutical industry is described here. Consolidated results show that, for over 3600 comparisons, 96% of the participants' results differed from that of NIST by less than 10%, with 98% being less than 20%. Individual radionuclide results are presented from 214 to 439 comparisons, per radionuclide, for (67)Ga, (90)Y, (99m)Tc, (99)Mo, (111)In, (125)I, (131)I, and (201)Tl. The percentage of participants results within 10% of NIST ranges from 88% to 98%.


Assuntos
Indústria Farmacêutica/normas , Programas Governamentais , Garantia da Qualidade dos Cuidados de Saúde/normas , Radiometria/normas , Compostos Radiofarmacêuticos/análise , Compostos Radiofarmacêuticos/normas , Doses de Radiação , Padrões de Referência , Valores de Referência , Estados Unidos
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