In vivo quantification of 18f-fdg uptake in human placenta during early pregnancy.
18F-FDG is the most widely used PET radiopharmaceutical. Nevertheless, no data for 18F-FDG uptake in the human placenta have been reported. We recently reported on embryo dosimetry in a woman who underwent an 18F-FDG PET/CT scan during early pregnancy. In the present work we attempt an in vivo quantification of the 18F-FDG uptake by the placenta. The 27-y-old woman received 320 MBq of 18F-FDG for a follow-up study for Hodgkin's lymphoma and was later discovered to be pregnant (embryo age = 8 wk). Imaging started 1 h after injection. The maximum placental tissue uptake (SUVmax) was 2.5. This value was conservatively attributed to the entire placental volume, i.e., 45 mL, a value representative of the average dimensions of a normal placenta at 8 wk. On the basis of these measurements, placenta 18F-FDG uptake in our patient was 0.19% of the injected activity. A Monte Carlo simulation was used to derive the photon dose to the embryo from the placenta (0.022 x 10(-2) mGy per MBq of injected 18F-FDG) and from the surrounding amniotic fluid (0.017 x 10(-2) mGy MBq(-1)). This increases our previously calculated dose (3.3 x 10(-2) mGy MBq(-1)) by only a small fraction (1.18%), which does not justify modifying the previous estimate given the overall uncertainties.
Zanotti-Fregonara
Paolo
P
DSV/I2BM/SHFJ, Commissariat à l'Energie Atomique, Orsay, France. paolo.zanotti-fregonara@cea.fr
Jan
Sebastien
S
Champion
Christophe
C
Trébossen
Régine
R
Maroy
Renaud
R
Devaux
Jean-Yves
JY
Hindié
Elif
E
D000328:Adult; D003198:Computer Simulation; D004622:Embryo, Mammalian / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008431:Maternal-Fetal Exchange / Q000502:physiology*; D008954:Models, Biological; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18