Cytogenetic Biomarkers of Radiation Exposure

Biological monitoring of radiation exposure relies heavily on the quantification of chromosome aberrations such as dicentrics and reciprocal translocations in the peripheral blood lymphocytes of exposed and potentially exposed subjects. The differences in the spatial deposition of energy and the quality of damage initially induced between individual low- and high-linear energy transfer (LET) radiation tracks are known to impact dramatically on the type and complexity of chromosome aberration induced. Over the years, researchers have proposed numerous cytogenetic markers and signatures based on these differences with the aim of biologically discriminating exposure to radiation of varying qualities. Complex chromosome aberrations are a broad classification of aberration types that are known to be characteristically induced after low doses of high-LET. The mechanistic basis for complex aberration formation and the potential applicability of these complex aberration products as LET-specific biomarkers are considered.