3.7. Radiation dosimetry comparison between ante-mortem and post-mortem animal tissue: Is post- mortem radiation dosimetry an adequate proxy for measurements in the living?

Objectives Radiation dose from diagnostic imaging procedures is a growing public health concern. Implanting dosimeters is a more accurate way to assess organ dose, relative to commonly used mathematical estimations. However, there are problems with performing accurate dosimetry using live subjects, including patient motion and patient safety considerations, which limit the radiation dose and placement of implanted dosimeters. Therefore, our objective is to assess whether radiation doses measured in post-mortem (PM) subjects are equivalent to doses measured in live subjects. Material and methods 4 MOSFET radiation dosimeters were placed enterically in each subject (2 sedated Rhesus Macaques) to measure the radiation dose at 4 levels (carina, lung, heart, and liver) during CT scanning. The CT scanning protocol was repeated three times for each condition, ante- mortem (AM) and 2 h after euthanasia, to obtain the average AM and PM dose to each organ. Results A two sample z -test was performed to evaluate the observed AM/PM differences. No significant difference was observed in 8/9 measurements between the AM and PM radiation doses. Only one individual measurement (liver of the first subject) showed a significant difference (7% lower on PM measurement), possibly attributable to repositioning of dosimeters. Conclusions We conclude that realistic radiation dosimetry can be performed PM as a valid alternative to dosimetry of live patients, which poses several problems. This study is an example of translational forensic research, with the potential for immediate and direct benefits to clinical medicine.