Placental transfer of radiopharmaceuticals and dosimetry in pregnancy

Health Phys. 1997 Nov;73(5):747-55. doi: 10.1097/00004032-199711000-00002.


The calculation of radiation dose estimates to the fetus is often important in nuclear medicine. To obtain the best estimates of radiation dose to the fetus, the best biological and physical models should be employed. In this paper the most recent data available on the placental crossover of many radiopharmaceuticals are presented. This information was used with standard kinetic models describing the maternal distribution and retention and with the best available physical models to obtain fetal dose estimates for these radiopharmaceuticals at all stages of pregnancy (presented in a separate paper). The literature yielded information on placental crossover of 15 radiopharmaceuticals, from animal or human data. From these data, radiation dose estimates were developed in early pregnancy and at 3, 6, and 9 mo gestation for these radiopharmaceuticals, as well as for many others used in nuclear medicine (the latter considering only maternal organ contributions to fetal dose).

MeSH terms

  • Adult
  • Citrates / pharmacokinetics
  • Embryonic and Fetal Development
  • Erythrocytes / metabolism
  • Female
  • Gallium / pharmacokinetics
  • Gallium Radioisotopes / pharmacokinetics
  • Gestational Age*
  • Humans
  • Iodine Radioisotopes / pharmacokinetics
  • Male
  • Maternal-Fetal Exchange*
  • Models, Biological*
  • Placenta / physiology*
  • Pregnancy
  • Radiopharmaceuticals / pharmacokinetics*
  • Technetium / pharmacokinetics
  • Technetium Compounds / pharmacokinetics
  • Thallium Radioisotopes / pharmacokinetics
  • Xenon Radioisotopes / pharmacokinetics


  • Citrates
  • Gallium Radioisotopes
  • Iodine Radioisotopes
  • Radiopharmaceuticals
  • Technetium Compounds
  • Thallium Radioisotopes
  • Xenon Radioisotopes
  • Technetium
  • Gallium
  • gallium citrate