ICRU Report 94, Methods for Initial-Phase Assessment of Individual Doses Following Acute Exposures to Ionizing Radiation


Dosimetry methods for use in dose assessment for individuals following acute exposure to radiation are described. Primary methods include biodosimetry and physical dosimetry techniques, while additional supplementary methods are bioassays, neutron activation, and radiation field mapping. Biodosimetry methods include the established techniques of dicentric chromosome assay, cytokinesis-block micronucleus assay, translocation analysis by fluorescent in-situ hybridization, remature chromosome condensation, and the γ-H2AX assay. Emerging techniques include RNA expression-based, protein-based, and metabolomic-based assays. Physical dosimetry methods include electron paramagnetic resonance and the luminescence-based techniques of thermoluminescence and optically stimulated luminescence. Electron paramagnetic resonance methods are used to assess absorbed dose in biologically derived materials, such as bone, teeth, and keratinous tissue, as well as non-biologically derived materials such as sugars, glasses, and polymeric materials used in fabrics and other personal items.

Thermoluminescence and optically stimulated luminescence techniques are used to assess absorbed dose in the components of personal electronics, along with other items such as plastic cards, fabrics, and clothing. There have also been similar efforts for teeth and dental repair ceramics. Since the above-listed techniques cannot distinguish between exposure to internal and external sources, bioassays may be used to assess exposure from internal contamination, including thyroid counting, chest counting, and excretion analysis methods. When a neutron exposure is expected, neutron activation analysis in blood, hair, or other non-biological items is useful. Radiation field mapping can be a useful method for determining locations where doses to individuals may be expected to be high and may complement radiation transport calculations performed for that purpose. Since immediate medical assessment is concerned with tissue reactions (deterministic effects), the quantity of interest for the above dosimetry methods is absorbed dose (expressed in gray). This Report concludes with a summary of the various methods and a brief discussion of the uses of such information in the aftermath of acute radiation exposure.