Local Dose Coefficients for Radionuclide Contamination in Wounds

When a radiation accident has occurred that leads to radioactive material being imparted to a wound, this is treated as an internal contamination scenario. It is common for the material to transport throughout the body based upon biokinetics of the material in the body. While standard internal dosimetry approaches can be used to estimate committed effective dose from the insult, some material may get fixed for longer periods of time at the wound location, even after medical procedures such as decontamination and debridement have been applied. In this case, the radioactive material becomes a local dose contributor. This research was to generate local dose coefficients for radionuclide-contaminated wounds to supplement committed effective dose coefficients. These dose coefficients can be used to calculate activity limits at the wound site that could lead to a clinically significant dose. This is useful for emergency response to assist in decisions on medical treatment, including decorporation therapy. Wound models were created for injections, lacerations, abrasions, and burns, and the MCNP radiation transport code was used to simulate the dose to tissue considering 38 radionuclides. Biokinetic models accounted for biological removal of the radionuclides from the wound site. It was found that radionuclides that are not retained well at the wound site are likely of little concern locally, but for highly retained radionuclides, estimated local doses may require further investigation by medical and health physics personnel.