Effectiveness of continuously infused DTPA therapy in reducing the radiation dose from inhaled 244Cm2O3 aerosols.

Radionuclide decorporation is the only effective method of reducing radiation dose for persons contaminated accidentally. In this study, dogs that had inhaled a moderately soluble aerosol of 244Cm2O3 were treated with either discrete intravenous injections of the chelating agent diethylenetriaminepentaacetic acid (Zn-DTPA) or with subcutaneous infusion of Zn-DTPA at either 30 or 120 mumol kg-1 d-1. Each treatment regimen was continued for 64 d, whereupon all animals were killed, and collected excreta and tissue samples were analyzed for curium. All DTPA treatment methods were effective. A total of 89% of the initial pulmonary burden (IPB) was removed by DTPA injection, whereas 94% IPB was removed by the low dose of infused DTPA and 97% by the high dose treatment. Thus, low and high infused doses of DTPA prevented the translocation of greater than 99.5% of curium to liver and 97-99% to bone and kidney. The resultant dose reductions to these organs were superior to those achieved by intravenous DTPA injections.