Appl Radiat Isot. 2025 Sep 18;226:112192. doi: 10.1016/j.apradiso.2025.112192. Online ahead of print.
ABSTRACT
Partially shielded systems such as Quick Scan Whole Body Counter (QSWBC) are used to assess internal contamination due to fission and activation products. The present work aims at studying the counting efficiencies (CEs) of the QSWBC taking into account the biodistribution of 131I, 137Cs and 60Co in computational phantoms within the scope of occupational and environmental exposures. For this purpose, the age-specific biokinetic models of the radionuclides were used to compute the fractional retained activities in biokinetically relevant compartments. Monte Carlo simulations were carried out in FLUKA to estimate the CEs for these radionuclides considering both time-dependent biodistribution and homogeneous distribution using ICRP adult and paediatric reference computational phantoms for both male and female. The time-dependent efficiency correction factors (ECFs) were derived to investigate the influence of biodistribution of activity on the CEs. The results highlight that CEs are highest for 131I and most pronounced in the case of organs located in the anterior regions of the body. The ECFs are highest on the first day of intake and then decline, tending towards constant values after ∼10 days of intake. For all the age groups, the ECFs vary between 0.90-2.34, 0.97-1.25 and 0.93-1.56 for 131I, 137Cs and 60Co respectively. The age and gender specific ECFs will be useful in reducing the impact of biodistribution of radionuclides on the whole body counting measurements, thereby enhancing the accuracy of internal dose assessment.
PMID:40983016 | DOI:10.1016/j.apradiso.2025.112192
