Biodosimetry Assessment Tool (BAT) software-dose prediction algorithms.

PURPOSE: Medical management of suspected radiation casualties requires use of multiparameter biodosimetry because no single biodosimetric measurement is sufficiently robust. This report describes the design and algorithms used in a radiation exposure assessment software application that serves as a diagnostic utility for triage and medical treatment formulation, as well as to convey psychological reassurance, for early-phase assessment of radiation exposures, and for surge response assessment for mass radiological casualties. METHODS: The Armed Forces Radiobiology Research Institute's Biological Dosimetry Research Program developed the integrated multiparameter Biodosimetry Assessment Tool computer program using Microsoft Visual Basic 6 with various second party plug-ins and add-ons. Dose-predicting algorithms were adopted by analyzing data from merged databases of human radiation exposure incidents and normal controls (non-irradiated) volunteers. The results are summarized in user-friendly screens. SUMMARY: BAT algorithms are presented and compared to other previously published dose assessment algorithms based on biological indicators (i.e., onset of vomiting, lymphocyte depletion kinetics). These new algorithms are incorporated into a computer-based program that assists responders and medical providers in recording relevant diagnostic information and assessing significant radiation exposures. It promotes early-phase (<10 d) data collection after a radiation exposure incident and provides data templates for entry of diagnostic information using multiparameter indices. It allows for recording of relevant clinical information and summarizes diagnostic information such as estimated multiparameter doses. Data can be printed and archived in accordance with civilian and military guidelines.

Use of a centrifuge-based automated blood cell counter for radiation dose assessment.

Hematological changes create early-response biomarkers for assessing radiation doses. Existing dose-prediction models are based on serial blood lymphocyte counts after acute whole-body exposure to gamma-radiation. Measurements of lymphocyte-depletion kinetics after possible exposures are useful for triaging patients and managing medical resources. The small-footprint QBC Autoread Plus System provides cost-effective hematological analyses with reproducibility, accuracy, and a broad dynamic range. QBC analysis measures centrifugally packed, whole blood cells in microhematocrit tubes and reports pooled lymphocyte and monocyte counts. Our objective was to modify this procedure to report pure lymphocyte counts for radiation biodosimetry applications. The CD14 antigen is strongly expressed on most human monocytes. Using anti-CD14-coated Dynabeads, we have devised a rapid method for depleting monocytes from whole blood without altering the lymphocyte viability or count. This simple dry procedure provides reliable lymphocyte counts for results that fall within the normal lymphocyte count range (1-4 x 10(9) cells per L) for radiation exposure assessment using lymphocyte-depletion kinetics.

Early-response biological dosimetry--recommended countermeasure enhancements for mass-casualty radiological incidents and terrorism.

The effective medical management of a suspected acute radiation overexposure incident necessitates recording dynamic medical data, measuring appropriate radiation bioassays, and estimating dose from dosimeters and radioactivity assessments in order to provide diagnostic information to the treating physician and a dose assessment for personnel radiation protection records. The accepted generic multiparameter and early-response approach includes measuring radioactivity and monitoring the exposed individual; observing and recording prodromal signs/symptoms and erythema; obtaining complete blood counts with white blood cell differential; sampling blood for the chromosome-aberration cytogenetic bioassay using the "gold standard" dicentric assay (translocation assay for long times after exposure) for dose assessment; bioassay sampling, if appropriate, to determine radioactivity contamination; and using other available dosimetry approaches. In the event of a radiological mass-casualty incident, current national resources need to be enhanced to provide suitable dose assessment and medical triage and diagnoses. This capability should be broadly based and include stockpiling reagents and devices; establishing deployable (i.e., hematology and biodosimetry) laboratories and reference (i.e., cytogenetic biodosimetry, radiation bioassay) laboratories; networking qualified reference radioactivity-counting bioassay laboratories, cytogenetic biodosimetry, and deployable hematology laboratories with the medical responder community and national radiation protection program; and researching efforts to identify novel radiation biomarkers and develop applied biological dosimetry assays monitored with clinical, deployable, and hand-held analytical systems. These research and applied science efforts should ultimately contribute towards approved, regulated biodosimetry devices or diagnostic tests integrated into a national radioprotection program.