Evaluation and comparison of human absorbed dose of (90)Y-DOTA-Cetuximab in various age groups based on distribution data in rats

The organ radiation-absorbed doses have been evaluated for humans in six age groups and both genders based on animal data. After intravenous administration of (90)Y-DOTA-Cetuximab to five groups of rats, they were sacrificed at exact time intervals (2, 24, 48, 72, and 96 h) and the percentage of injected dose per gram of each organ was calculated by direct counting from rat data. By using the formulation that Medical Internal Radiation Dose suggests, radiation-absorbed doses for all organs were calculated and extrapolated from rat to human. The total body absorbed dose for all groups was >22 mGy due to pure β-emission of the applied radiopharmaceutical. The effective dose resulting from an intravenously injected activity of 100 MBq is 56.7 mSv for a 60-kg female adult and 60.3 mSv for a 73-kg male adult. The results demonstrated the usefulness of this method for estimation of β-absorbed dose in humans.