TY - JOUR T1 - Fetal Dose from PET and CT in Pregnant Patients JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 312 LP - 319 DO - 10.2967/jnumed.122.263959 VL - 64 IS - 2 AU - Christiane Sarah Burton AU - Kirk Frey AU - Frederic Fahey AU - Mark S. Kaminski AU - Richard K.J. Brown AU - Judith M. Pohlen AU - Barry L. Shulkin Y1 - 2023/02/01 UR - http://jnm.snmjournals.org/content/64/2/312.abstract N2 - When pregnancy is discovered during or after a diagnostic examination, the physician or the patient may request an estimate of the radiation dose received by the fetus as per guidelines and standard operating procedures. This study provided the imaging community with dose estimates to the fetus from PET/CT with protocols that are adapted to University of Michigan low-dose protocols for patients known to be pregnant. Methods: There were 9 patients analyzed with data for the first, second, and third trimesters, the availability of which is quite rare. These images were used to calculate the size-specific dose estimate (SSDE) from the CT scan portion and the SUV and 18F-FDG uptake dose from the PET scan portion using the MIRD formulation. The fetal dose estimates were tested for correlation with each of the following independent measures: gestational age, fetal volume, average water-equivalent diameter of the patient along the length of the fetus, SSDE, SUV, and percentage of dose from 18F-FDG. Stepwise multiple linear regression analysis was performed to assess the partial correlation of each variable. To our knowledge, this was the first study to determine fetal doses from CT and PET images. Results: Fetal self-doses from 18F for the first, second, and third trimesters were 2.18 mGy (single data point), 0.74–1.82 mGy, and 0.017–0.0017 mGy, respectively. The combined SSDE and fetal self-dose ranged from 1.2 to 8.2 mGy. These types of images from pregnant patients are rare. Conclusion: Our data indicate that the fetal radiation exposure from 18F-FDG PET and CT performed, when medically necessary, on pregnant women with cancer is low. All efforts should be made to minimize fetal radiation exposure by modifying the protocol. ER -