The 124Sb activity standardization by gamma spectrometry for medical applications

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 619; no. 1; pp. 365 - 367
• Main Authors: de Almeida, M.C.M., Iwahara, A., Delgado, J.U., Poledna, R., da Silva, R.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2010
• Subjects: 124Sb; Activity standardization; Gamma spectrometry; Medical applications; Metrology; 124Sb; Metrology; Medical applications; Activity standardization; Gamma spectrometry
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2009.10.176

This work describes a metrological activity determination of
124Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis.
124Sb is also applied in animal organ distribution studies to solve some questions in pharmacology.
124Sb decays by β-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700
keV. Efficiency curves to measure point
124Sb solid sources were obtained from a
166mHo standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of
124Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% (
k=2) were obtained.