Method for efficient establishment of technical biodosimetry competence

The current gold standard in biodosimetry, the dicentric assay, requires documented technical competence. Expertise is developed over time by evaluation of thousands of metaphases. Competence is documented through establishment of a dose–response curve, required by any service laboratory performing biodosimetry. Consistent and reliable evaluations must be established for new observers that might contribute to analyses for biological dose assessments. Discrepancies in evaluations jeopardize the reliability of assessments.The Swedish Defence Research Agency (FOI) together with the Norwegian Radiation Protection Authority (NRPA) conducted an inter-calibration exercise for the purpose of establishing comparable scoring criteria for evaluation of aberrations in metaphases. The exercise revealed specific aberrations that were difficult to identify and were consistent sources of uncertainty. Subsequently, a report detailing the FOI's scoring criteria was developed with visual examples and a strategy for establishing technical competence in metaphase scoring in an efficient manner evolved. Key components of the strategy are the review of guidance for biodosimetry, performance of inter-calibration exercises with previously established data sets, review of incongruous evaluations with a well-established observer, follow-up exercises depending on the initial outcome, and inter-comparisons to document agreement.Methods suggested here could be applied in training of new personnel. Documentation of methods in other laboratories could facilitate more consistent scoring criteria among the biodosimetry community, a problem observed in previous international inter-comparisons. Improved consistency among biodosimetry laboratories could facilitate reliably sharing the work load among different members of the biodosimetry community in the event of a mass casualty accident.