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Description
The harmonisation of in vivo wound monitoring techniques is essential for improving emergency response and ensuring the comparability of results among laboratories. This work presents the methodology applied and the results obtained by the CIEMAT Whole Body Counter (WBC) Laboratory during its participation in the EURADOS/ARADOS intercalibration and intercomparison exercise on wound monitoring. The study addressed the practical implementation of calibration and measurement procedures and the validation of the methodology through radionuclide identification in wounds at different depths, activity assessment, and depth estimation when unknown.
A Broad Energy Germanium (BEGe) detector installed in a low-background shielded room, together with a dedicated 3D wound phantom, was used for calibration. Efficiency calibration was performed for depths ranging from 0 to 16 mm at a fixed detector-to-phantom distance of 20 mm, obtaining depth-dependent efficiency curves that were subsequently applied to realistic measurement scenarios.
For known contamination depths, radionuclide identification and activity determination were fully consistent with the reference values and complied with the performance criteria established in ISO 28218 and ISO 13528. A blind test simulating a realistic emergency situation with unknown contamination depth was also performed. Depth estimation was achieved using net peak area ratios for low- and medium-energy gamma emitters (²⁴¹Am and ¹³³Ba) and comparison with fitted calibration functions. This approach enabled the selection of the most appropriate efficiency curve, resulting in consistent radionuclide identification and activity assessment. The estimated depth (10 mm) yielded results within the acceptable performance limits.
The exercise confirmed the reliability of the CIEMAT calibration and measurement procedures for wound monitoring and highlighted the added value of international intercomparisons for methodological harmonisation, quality assurance, and capability building. The validated methodology strengthens the laboratory’s preparedness for radiological emergencies and supports the implementation of standardised in vivo dosimetry practices.