Influence of heterogeneous alpha irradiation of Chinese hamster liver on the induction of cancer. II

To investigate the influence of heterogeneity of alpha-radiation dose on the induction of liver cancer, Chinese hamsters were injected intravenously with colloidal thorium dioxide particles (Thorotrast) and are being maintained for life span observations. The biological effects seen as a result of a Thorotrast injections are being compared with results obtained in other hamsters that were injected intravenously with 239Pu-citrate. As of 9-30-86, 80% of the animals receiving the highest dose of Thorotrast, 200 pCi (7.4 Bq) per gram body mass), 25% of the group receiving 40 pCi Thorotrast (1.5 Bq) per gram, and 22% of the group receiving 8 pCi Thorotrast (0.3 Bq) per gram had died. This compared with a 24% mortality for the animals injected with 200 pCi 239Pu-citrate (7.4 Bq) per gram and 16 to 18% in control animals. It is premature to draw any inferences relative to the effect of α-radiation dose pattern on the induction of liver cancer in these animals. 1 table