Absorbed 18F-FDG Dose to the Fetus During Early Pregnancy

Journal of Nuclear Medicine

Paolo Zanotti-Fregonara¹  Serge Cammilleri¹  Sébastien Jan¹  Régine Trébossen¹  Olivier Mundler¹  Elif Hindié¹  David Taieb¹ 

关键词: fetal dosimetry;    ¹⁸F-FDG PET/CT;    Monte Carlo simulation;   

DOI  :  10.2967/jnumed.109.071878

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

We describe a rare case of a woman who underwent 18F-FDG PET/CT during early pregnancy (fetus age, 10 wk). The fetal absorbed dose was calculated by taking into account the 18F-FDG fetal self-dose, photon dose coming from the maternal tissues, and CT dose received by both mother and fetus. Methods: The patient (weight, 71 kg) had received 296 MBq of 18F-FDG. Imaging started at 1 h, with unenhanced CT acquisition, followed by PET acquisition. From the standardized uptake value measured in fetal tissues, we calculated the total number of disintegrations per unit of injected activity. Monte Carlo analysis was then used to derive the fetal 18F-FDG self-dose, including positrons and self-absorbed photons. Photon dose from maternal tissues and CT dose were added to obtain the final dose. Results: The maximum standardized uptake value in fetal tissues was 4.5. Monte Carlo simulation showed that the fetal self-dose was 3.0 × 10−2 mGy/MBq (2.7 × 10−2 mGy/MBq from positrons and 0.3 × 10−2 mGy/MBq from photons). The estimated photon dose to the fetus from maternal tissues was 1.04 × 10−2 mGy/MBq. Accordingly, the specific 18F-FDG dose to the fetus was about 4.0 × 10−2 mGy/MBq (11.8 mGy in this patient). The CT scan added a further 10 mGy. Conclusion: The dose to the fetus during early pregnancy can be as high as 4.0 × 10−2 mGy/MBq of 18F-FDG. Current dosimetric standards in early pregnancy may need to be revised.

【 授权许可】

Unknown