New Fetal Dose Estimates from 18F-FDG Administered During Pregnancy: Standardization of Dose Calculations and Estimations with Voxel-Based Anthropomorphic Phantoms.
Data from the literature show that the fetal absorbed dose from18F-FDG administration to the pregnant mother ranges from 0.5E-2 to 4E-2 mGy/MBq. These figures were, however, obtained using different quantification techniques and with basic geometric anthropomorphic phantoms. The aim of this study was to refine the fetal dose estimates of published as well as new cases using realistic voxel-based phantoms.


METHODS
The18F-FDG doses to the fetus (n = 19; 5-34 wk of pregnancy) were calculated with new voxel-based anthropomorphic phantoms of the pregnant woman. The image-derived fetal time-integrated activity values were combined with those of the mothers' organs from the International Commission on Radiological Protection publication 106 and the dynamic bladder model with a 1-h bladder-voiding interval. The dose to the uterus was used as a proxy for early pregnancy (up to 10 wk). The time-integrated activities were entered into OLINDA/EXM 1.1 to derive the dose with the classic anthropomorphic phantoms of pregnant women, then into OLINDA/EXM 2.0 to assess the dose using new voxel-based phantoms.


RESULTS
The average fetal doses (mGy/MBq) with OLINDA/EXM 2.0 were 2.5E-02 in early pregnancy, 1.3E-02 in the late part of the first trimester, 8.5E-03 in the second trimester, and 5.1E-03 in the third trimester. The differences compared with the doses calculated with OLINDA/EXM 1.1 were +7%, +70%, +35%, and -8%, respectively.


CONCLUSIONS
Except in late pregnancy, the doses estimated with realistic voxelwise anthropomorphic phantoms are higher than the doses derived from old geometric phantoms. The doses remain, however, well below the threshold for any deterministic effects. Thus, pregnancy is not an absolute contraindication of a clinically justified18F-FDG PET scan.
Department of Nuclear Medicine, University Hospital of Bordeaux, Bordeaux, France paolo.zanotti-fregonara@chu-bordeaux.fr.
Paolo
P
Zanotti-Fregonara
Department of Nuclear Medicine, Centre Henri Becquerel, Rouen, France.
Mathieu
M
Chastan
Department of Nuclear Medicine, Centre Henri Becquerel, Rouen, France.
Agathe
A
Edet-Sanson
Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey; and.
Ozgul
O
Ekmekcioglu
Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey; and.
Ezgi Basak
EB
Erdogan
Department of Nuclear Medicine, Centre Henri Becquerel, Rouen, France.
Sebastien
S
Hapdey
Department of Nuclear Medicine, University Hospital of Bordeaux, Bordeaux, France.
Elif
E
Hindie
Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee.
Michael G
MG
Stabin
D065638:Absorption, Radiation / Q000502:physiology*; D005260:Female; D005333:Fetus / Q000378:metabolism* / Q000528:radiation effects; D019788:Fluorodeoxyglucose F18 / Q000032:analysis / Q000493:pharmacokinetics*; D006801:Humans; D019047:Phantoms, Imaging / Q000592:standards*; D049268:Positron-Emission Tomography / Q000295:instrumentation / Q000592:standards; D011247:Pregnancy / Q000378:metabolism*; D011829:Radiation Dosage; D011874:Radiometry / Q000592:standards*; D019275:Radiopharmaceuticals / Q000032:analysis / Q000493:pharmacokinetics
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
18F-FDG; PET; dosimetry; pregnancy; radiation safety; radiobiology/dosimetry