Enhanced national ability to estimate internal contamination following a radiological or nuclear event

Abstract

Following a radiological or nuclear (RN) event there might be a release of radioactive material, posing a threat to workers, members of the public and the environment. Measurement capability for estimation of internal contamination from relevant radionuclides is of utmost importance, to identify contaminated persons in need of medical care, as well as the non-contaminated. The overall aim was to increase the measurement capability for RN emergency preparedness in Sweden, by investigating the potential in using clinically available gamma cameras. In Paper I, the available gamma camera systems in Sweden were identified, and one of the most common models was calibrated for RN event relevant radionuclides. In Paper II, a simple water container phantom with 137Cs was constructed, and a calibration campaign of gamma cameras in the south and west of Sweden was conducted. The dead time was determined for gamma camera measurements of 137Cs. In Paper III, three gamma cameras, two thyroid uptake measurement systems and one whole-body counter was calibrated for 131I thyroid content, and dead time was determined for 131I thyroid measurements. In Paper IV, a Monte Carlo model of a NaI-based gamma camera was constructed and validated, enabling simulation of calibration factors for additional RN event relevant radionuclides. In conclusion, the national ability to estimate the internal contamination following an RN event, utilizing the readily available gamma camera at nuclear medicine departments, has been increased.