Embryo/Fetal Radiation Doses in Pregnant Women Undergoing SPECT/CT Scans

What is it about?

This study aimed to calculate embryo/fetal doses in pregnant women who received 99m Tc-labeled radiopharmaceuticals for SPECT/CT scans. Using the OLINDA/EXM program and modified CT dose index, doses were estimated for 74 pregnant women from Turkey. The highest embryo/fetal dose was observed in 99m Tc-MIBI myocardial perfusion scintigraphy (MPS) at 15.63 mGy, while the lowest was in 99m Tc-DMSA renal scintigraphy at 1.06 mGy. The study emphasizes the necessity of questioning pregnancy before scintigraphy to avoid radiation risks. It also highlights that diagnostic nuclear medicine examinations generally result in fetal doses below the threshold for pregnancy termination but can still pose deterministic and stochastic risks, including potential carcinogenesis. Adequate maternal hydration and frequent urination are recommended to reduce fetal exposure to radionuclides.

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Photo by Andrew Seaman on Unsplash

Photo by Andrew Seaman on Unsplash

Why is it important?

This research is crucial as it quantifies the radiation exposure to embryos/fetuses from various 99m Tc-labeled radiopharmaceuticals used in SPECT/CT scans, providing vital information for minimizing risks to pregnant women and their unborn children. Understanding these doses is essential to ensure the safety of diagnostic nuclear medicine procedures and to develop guidelines to mitigate potential adverse effects on fetal development. Key Takeaways: 1. Highest and Lowest Doses: The highest embryo/fetal dose was observed in 99m Tc-MIBI myocardial perfusion scintigraphy (MPS) at 15.63 mGy with CT contribution, whereas the lowest dose was recorded in 99m Tc-DMSA static renal scintigraphy at 1.06 mGy. 2. Impact of CT Scans: The addition of CT scans to nuclear medicine modalities significantly increases the embryo/fetal doses, highlighting the need for careful consideration of combined imaging techniques during pregnancy. 3. Risk Mitigation Strategies: Adequate maternal hydration and frequent urination are recommended to reduce fetal exposure to radionuclides, and questioning pregnancy status before scintigraphy is obligatory to prevent unnecessary radiation exposure.