International Conference on Radiation Applications, Granada, Spain, June 10-12, 2024
Dr. George Tabatadze recently attended the International Conference on Radiation Applications (RAP.24) in Granada, Spain, where he presented his latest research, “From mapping to quantification: digital autoradiography of 226Ra in human skeleton.” The conference, held in the beautiful city of Granada, was a tremendous success, featuring insightful discussions and engaging presentations. Dr. Tabatadze’s presentation was received with great enthusiasm by his peers. His research, conducted under the United States Transuranium and Uranium Registries (USTUR), focused on expanding the capabilities of the ionizing radiation quantum imaging detector (iQID) to quantify the activity concentrations of 226Ra in bone samples. By mapping the micro-distribution of alpha-emitting radionuclides in human tissues, this study aims to improve the understanding of actinide biokinetics and tissue dosimetry. Dr. Tabatadze’s work, particularly on radium dial painters, highlights the effectiveness of iQID imaging in studying micro-scale heterogeneous radionuclide distributions and accurately estimating activity concentrations, further advancing the field of radiation research.
From mapping to quantification digital autoradiograpy of 226Ra in human skeleton
George Tabatadze (USTUR)
The United States Transuranium and Uranium Registries (USTUR) studies actinide biokinetics and tissue dosimetry by following up occupationally exposed individuals. Currently, the USTUR employs the ionizing radiation quantum imaging detector (iQID) to map the micro-distribution of alpha-emitting radionuclides in human tissues. This research aims to expand upon the capabilities of the iQID, primarily focusing on quantifying the activity concentrations of 226Ra in bone samples. In this study, two plastic-embedded bone sections were selected from the middle shaft of a left femur and the left side of the thoracic vertebra of a radium dial painter (RDP). These samples were obtained from the National Human Radiobiology Tissue Repository (NHRTR), an integral component of the Registries. The NHRTR preserves an extensive collection of tissue materials from a variety of radium worker studies, including histological bone slides and tissue blocks from RDPs. In this study, the 226Ra micro-distribution was mapped in bones of a female who had worked as a dial painter for 6 years, had an estimated 226Ra uptake of 58.9 MBq, and passed away at age 24. Regions of interest for both cortical bone and trabecular bone were segmented. A computational model was developed to simulate the geometric efficiencies unique to the geometry of each sample, enabling the estimation of volumes and sample masses. This simulation utilized alpha particle transport models based on the particle interactions within the images of individual bone samples. The activity concentrations derived using iQID measurement were compared to results from the radiochemical analysis of these samples. The iQID imaging technique proves not only effective in studying micro-scale heterogeneous radionuclide distributions but also in accurately estimating activity concentrations of alpha-emitting radionuclides. [USTUR-0671-24A]