Dicentric Chromosome Assay (DCA) and Cytokinesis-Block Micronucleus (CBMN) Assay in the Field of Biological Dosimetry.

Biological dosimetry is an essential tool for estimating radiation doses received from individuals when the physical dosimetry is not available or inadequate. Early knowledge about the absorbed dose levels in radiation accidents is of paramount importance for selecting the unaffected subjects from those individuals requiring medical evaluation and intervention. A lesson learned from many radiological incidents is the importance to identify the "worried well."Several assays are useful for biological dosimetry approaches, since no one single assay is sufficiently robust for all potential radiation scenarios including early-phase acute exposures, partial-body exposures, and biosampling years after exposure or in case of suspected mixed exposures (radiological and chemicals).The most commonly used biodosimetry methods are based on the evaluation of the radiation-specific dicentric chromosomes (Dic) and micronuclei (MN) in exposed individuals' peripheral blood lymphocytes (PBL).The present chapter does not claim to make an exhaustive and complete picture on the complex world of biodosimetry, to which a large number of specific guidelines for performing laboratory services by the International Organization for Standardization (ISO) are dedicated, but it aims to support the reader in understanding the application of two cytogenetic methods in the individual ionizing radiation dose assessment, suggesting some appropriate scientific sources to consult for each case.