Dose assessment intercomparisons within the RENEB network using G₀-lymphocyte prematurely condensed chromosomes (PCC assay)

Abstract

Purpose: Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G 0 -lymphocyte PCC for harmonization, standardization and optimization of the PCC assay. Materials and methods: Comparative analysis among different partners for dose assessment included shipment of PCC-slides and captured images to construct dose-response curves for up to 6 Gy c-rays. Accident simulation exercises were performed to assess the suitability of the PCC assay by detecting speed of analysis and minimum number of cells required for categorization of potentially exposed individuals. Results: Calibration data based on Giemsa-stained fragments in excess of 46 PCC were obtained by different partners using galleries of PCC images for each dose-point. Mean values derived from all scores yielded a linear dose-response with approximately 4 excess-fragments/cell/Gy. To unify scoring criteria, exercises were carried out using coded PCC-slides and/or coded irradiated blood samples. Analysis of samples received 24 h post-exposure was successfully performed using Giemsa staining (1 excess-fragment/cell/Gy) or centromere/telomere FISH-staining for dicentrics. Conclusions: Dose assessments by RENEB partners using appropriate calibration curves were mostly in good agreement. The PCC assay is quick and reliable for whole-or partial-body triage biodosimetry by scoring excess-fragments or dicentrics in G 0 -lymphocytes. Particularly, analysis of Giemsa-stained excess PCC-fragments is simple, inexpensive and its automation could increase throughput and scoring objectivity of the PCC assay. ARTICLE HISTORY

Investigation of the influence of calibration practices on cytogenetic laboratory performance for dose estimation

“…A similar study was performed with the results of the second PCC ILC based on the results presented in Terzoudi et al (2016). For this ILC, two samples per dose were distributed to the participants (samples respectively labelled Re5a, Re5b, Re6a and Re6b).…”

“…For the second ILC, all samples were irradiated in air at the same facility with dosimetric references expressed in terms of air kerma, whereas some participants reported results in terms of absorbed dose in water. This fact is not taken into account in the analysis provided in papers submitted in this issue Oestreicher et al 2016;Terzoudi et al 2016). …”

“…The results of this ILC are presented and discussed. Based on these data, some of the results of latest biological dosimetry ILC presented in this issue were discussed and re-evaluated Terzoudi et al 2016). The usefulness of recommendations of the QA&QM RENEB manual regarding dosimetry and irradiation practises is evaluated.…”

The harmonization process to set up and maintain an operational biological and physical retrospective dosimetry network: QA QM applied to the RENEB network

“…Training courses were mainly dedicated to DCA, FISH, MN, cH2AX and PCC assays. After completion of the practical training, a second inter-comparison was performed also on irradiated samples Oestreicher et al 2016;Terzoudi et al 2016). The results showed the benefits of training sessions.…”

“…The first intercomparison focused on biological assays (DCA; FISH; MN and PCC) has shown that the majority of RENEB partners reached the criteria for biological dosimetry indicator scoring and dose estimation: the calculated 95% confidence interval, associated to the estimated dose, should contain the physical dose delivered to the sample Oestreicher et al 2016). However, deviations from the statistically approved intervals for the dicentric (DCA), translocation detection by Fluorescence in situ Hybridization (FISH), micronucleus (MN) and Premature Condensed Chromosome (PCC) (Terzoudi et al 2016) assays were observed for a few laboratories, indicating the requirement for training for these partners. Training courses were mainly dedicated to DCA, FISH, MN, cH2AX and PCC assays.…”