RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested.VII Programa Marco de Investigación y Desarrollo (VIIPM) de la Unión Europea. nº 29551

RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested

Quantitation of chromosome damage by imaging flow cytometry

Biodosimetry is a method for measuring the dose of radiation to individuals using biological markers such as chromosome damage. Following mass casualty events, it is important to provide this information rapidly in order to assist with the medical management of potentially exposed casualties. Currently, the gold standard for biodosimetry is the dicentric chromosome assay, which accurately estimates the dose from the number of dicentric chromosomes in lymphocytes. To increase throughput of analysis following a largescale mass casualty event, this assay has been adapted for use on the imaging flow cytometer. This chapter describes the methods for the identification and quantification of mono-and multicentric chromosomes using the imaging flow cytometer

The application of imaging flow cytometry to high-throughput biodosimetry

Biodosimetry methods, including the dicentric chromosome assay, the cytokinesis-block micronucleus assay and the γH2AX marker of DNA damage are used to determine the dose of ionizing radiation. These techniques are particularly useful when physical dosimetry is absent or questioned. While these assays can be very sensitive and specific, the standard methods need to be adapted to increase sample throughput in the case of a large-scale radiological/nuclear event. Recent modifications to the microscope-based assays have resulted in some increased throughput, and a number of biodosimetry networks have been, and continue to be, established and strengthened. As the imaging flow cytometer (IFC) is a technology that can automatically image and analyze processed blood samples for markers of radiation damage, the microscope-based biodosimetry techniques can be modified for the IFC for high-throughput biological dosimetry. Furthermore, the analysis templates can be easily shared between networked biodosimetry laboratories for increased capacity and improved standardization. This review describes recent advances in IFC methodology and their application to biodosimetry

Validation of the cytokinesis-block micronucleus assay using imaging flow cytometry for high throughput radiation biodosimetry

The cytokinesis-block micronucleus assay can be employed in triage radiation biodosimetry to determine the dose of radiation to an exposed individual by quantifying the frequency of micronuclei in binucleated lymphocyte cells. Partially automated analysis of the assay has been applied to traditional microscope-based methods, and most recently, the assay has been adapted to an automated imaging flow cytometry method. This method is able to automatically score a larger number of binucleated cells than are typically scored by microscopy. Whole blood samples were irradiated, divided into 2 mL and 200 mL aliquots, cultured for 48 h and 72 h, and processed to generate calibration curves from 0-4 Gy. To validate the method for use in radiation biodosimetry, nine separate whole blood samples were then irradiated to known doses, blinded, and processed. Results indicate that dose estimations can be determined to within ±0.5 Gy of the delivered dose after only 48 h of culture time with an initial blood volume of 200 mL. By performing the cytokinesis-block micronucleus assay using imaging flow cytometry, a significant reduction in the culture time and volume requirements is possible, which greatly increases the applicability of the assay in high throughput triage radiation biodosimetry

Evolution of the Health Canada astronaut biodosimetry program with a view toward international harmonization

Biodosimetry of astronaut lymphocyte samples, taken prior to- and post-flight, provides an important in vivo measurement of radiation-induced damage incurred during space flight which can be included in the medical records of the astronauts. Health Canada has been developing their astronaut biodosimetry program since 2007 and since then has analyzed data from 7 astronauts.While multiple cytogenetic endpoints may be analyzed for the astronauts, the Fluorescent in situ hybridization (FISH) assay is considered to be key for detecting long-lasting stable damage. It is believed that this long-lasting damage is most likely to lead to an increased risk to the health of the astronauts during long-term flights (lasting 6 months or more).The complexity of damage that results from protracted, non-homogeneous radiation exposure, like that found in the space environment, requires a detailed scoring schematic to capture as much information as possible. To that end, this paper outlines the efforts to harmonize the manner in which Health Canada's FISH data are recorded to better facilitate the comparison of results with other international biodosimetry programs

Evaluation of the annual Canadian biodosimetry network intercomparisons

Purpose: To evaluate the importance of annual intercomparisons for maintaining the capacity and capabilities of a well-established biodosimetry network in conjunction with assessing efficient and effective analysis methods for emergency response. Materials and methods: Annual intercomparisons were conducted between laboratories in the Canadian National Biological Dosimetry Response Plan. Intercomparisons were performed over a six-year period and comprised of the shipment of 10-12 irradiated, blinded blood samples for analysis by each of the participating laboratories. Dose estimates were determined by each laboratory using the dicentric chromosome assay (conventional and QuickScan scoring) and where possible the cytokinesis block micronucleus (CBMN) assay. Dose estimates were returned to the lead laboratory for evaluation and comparison. Results: Individual laboratories performed comparably from year to year with only slight fluctuations in performance. Dose estimates using the dicentric chromosome assay were accurate about 80% of the time and the QuickScan method for scoring the dicentric chromosome assay was proven to reduce the time of analysis without having a significant effect on the dose estimates. Although analysis with the CBMN assay was comparable to QuickScan scoring with respect to speed, the accuracy of the dose estimates was greatly reduced. Conclusions: Annual intercomparisons are necessary to maintain a network of laboratories for emergency response biodosimetry as they evoke confidence in their capabilities