Radiopharmacokinetics and radiation dose from 99mTc-HM-PAO (preliminary report)

Whole body retention measurements were performed in volunteers after i.v. injection of 99mTc-HM-PAO (Ceretec). The organ accumulation was measured in mice and data were transferred to standard man according to ICRP. Absorbed dose calculations were made with these data by using the concept of absorbed fractions (MIRD method). In man, the whole body retention and the retention in the brain could be calculated by direct measurement, absorbed doses to the other organs could only be derived from animal data. The absorbed dose to the brain derived from human data (10.3 microGy/MBq) is greater by a factor of 2 than that derived from animal data. The highest absorbed dose was received by the thyroid (24.4 microGy/MBq), the absorbed dose to the ovaries, testes and whole body ranged from 2.8 to 4.2 microGy/MBq.