Long-term biologic effects in dogs treated with lung lavage after inhalation of 144Ce in fused aluminosilicate particles

Beagle dogs that inhaled radioactive particles were treated with lung lavage and a chelating agent (CaDTPA) to determine if pulmonary radiation injury could be decreased. The dogs were exposed by inhalation to an aerosol of 144Ce in fused aluminosilicate particles. From 23% to 57% of the 144Ce was removed by the lavages. Twenty-one of 24 untreated dogs exposed to 144Ce died of radiation pneumonitis in less than 750 days; two of 11 treated dogs died with radiation pneumonitis; seven treated dogs died with lung tumors from 750 to 1800 days after exposure. During that same time, two treated dogs died of neoplasis outside of the lungs. It was concluded that lung lavage removed inhaled 144Ce and resulted in the dogs living twice as long as the untreated dogs and changed the cause of death from pneumonitis to pulmonary neoplasia