Designing and testing a fetal protection system for radiotherapy in pregnant patients

Radiotherapy is an effective treatment for cancer, but it should be avoided during pregnancy due to the potential harm to the fetus, which may include malformations, intellectual disability, impaired growth of the head (microcephaly), reduced IQ, and an increased risk of cancer, depending on the gestational age. However, some situations cannot wait until the postpartum period, requiring treatment during pregnancy. The use of mobile shields constructed specially for these specific cases has been reported as a reliable and efficacious way to reduce the fetal doses. In this work, a mobile shield was constructed to be used during the cancer treatment of a pregnant woman's thigh. The shield was built using Monte Carlo simulations and the patient was represented by a voxelized phantom of a 29-year-old pregnant woman. The results show a 26 %-69.5 % reduction on fetal absorbed doses and no extra radiation scattering to the patient, meaning that the mobile shield is safe and efficient.