Biokinetics and dosimetry for 195Au, evaluated in an animal model

The use of the generator produced radionuclide 195mAu, half life 30 s, has become feasible for several different investigations, e.g. cardiac studies. To assess the absorbed dose from the long lived radionuclide 195Au (the daughter of 195mAu, half life 183 days), a biodistribution study of 195Au was performed in animals. Seven rabbits were injected with eluate from a 195mHg-195mAu generator and the retention and the biodistribution of the long lived gold isotope was investigated. The activity was localized mainly in the liver and the kidneys. Transforming the data to man resulted in an absorbed dose from 195Au from 1 elution (approximately 925 MBq 195mAu) of 2.2 mGy to the kidney and 1.3 mGy to the liver and an effective dose equivalent of 0.26 mSv. The total effective dose equivalent from all radionuclides in the eluate (195mAu, 195Au, 195mHg and 195Hg), was estimated to be 0.65 mSv for a single injection (925 MBq 195mAu).