Numerical dosimetric reconstruction of a radiological accident in South America in April 2009.

A severe irradiation accident involving a victim occurred in April 2009 in South America. The victim has found a (192)Ir source fallen from a gammagraphy device and has put it in the left pocket of his pants. Very quickly, an erythema and a blister appeared on the left leg of the victim involving hospitalisation. Following the request of the IAEA assistance, the Ionizing Radiation Dosimetry Laboratory of IRSN was asked to perform a numerical dosimetric reconstruction. A personalised voxel phantom of the victim has been constructed thanks to the Simulation of External Source Accident with Medical images tool developed by the laboratory, and a calculation of the dose with the MCNPX computer code allowed to determine the boundary of the necrotic dose at 25 Gy. On the basis of these calculations, the physicians have performed exeresis of the necrotic region on the left leg on 4 May 2009. Associated with mesenchymal stem cell injection, the leg of the victim was healthy on December 2009.