Accurate activity measurement of Lu-177 by the liquid scintillation 4πβ-γ coincidence counting technique.

Autor: Simpson BR; National Metrology Institute of South Africa, 15 Lower Hope Road, Rosebank, 7700 Cape Town, South Africa. bsimpson@nmisa.org, van Staden MJ, Lubbe J, van Wyngaardt WM
Jazyk: angličtina
Zdroj: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine [Appl Radiat Isot] 2012 Sep; Vol. 70 (9), pp. 2209-14. Date of Electronic Publication: 2012 Mar 03.
DOI: 10.1016/j.apradiso.2012.02.102
Abstrakt: This paper reports on absolute measurements made at the NMISA by the 4π[LS]β-γ coincidence extrapolation technique, which formed part of a key comparison of activity measurements of the radionuclide lutetium-177, a beta-gamma emitter. A detection efficiency analysis based on the decay scheme indicated that the coincidence extrapolation method is feasible for extracting the source disintegration rate of (177)Lu. A simulation was undertaken utilizing the efficiency equations to give an indication of the expected variation of the source count rate with efficiency for different gamma-ray windows. Both the simulation and experiment indicated that the window giving the highest counting efficiency was centered about the 208.4 keV photopeak, with the data showing linear variation in the upper efficiency range. The extracted activity concentration of the (177)Lu solution proved to be highly accurate, being higher than the proposed comparison reference value by 0.15%, well within one standard uncertainty (σ=0.26%) as specified by the NMISA.
(Copyright © 2012 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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