Methods to estimate fetal dose from fluoroscopically guided prophylactic hypogastric artery balloon occlusion (HABO)

Abstract

Introduction Parturient women diagnosed with abnormal placentation are at high risk of major haemorrhage that may cause maternal death. Despite the risk of a potential damage to adjacent organs and loss of child bearing ability, hysterectomy is the gold standard technique. An alternative effective treatment technique associated with less complications and preservation of fertility is the prophylactic hypogastric artery balloon occlusion (HABO) under fluoroscopic guidance. However, concerns regarding fetal radiation exposure and the associated radiogenic risks cannot be ignored. Purpose To provide methods and data for fetal radiation dose estimation from HABO procedures. Material and methods Mathematical phantoms that simulate a pregnant patient at the 9th month of gestation and Monte-Carlo-N-particle (MCNP) transport code were employed. Projection-specific normalized fetal dose (NFD) data for various beam qualities were produced through simulations of the left and right internal iliac arteries. The effects of X-ray field location relative to the fetus, field size and maternal body size on NFD were investigated. To verify MCNP results, fetal dose measurements were carried out by using a physical anthropomorphic phantom simulating pregnancy at the 3rd trimester and thermoluminescence dosimeters (TLDs). Results NFD was found to markedly depend on tube voltage, filtration, X-ray field location and size. Presented results have taken into account the effect of maternal body size on NFD. NFD derived from TLDs showed a difference of less than 13.5% compared to those estimated by MCNP simulations. Conclusion Methods provided allow for reliable estimation of fetal radiation burden from HABO performed at any institution. Disclosure This study was supported by the Greek Ministry of Education and Religious Affairs, General Secretariat for Research and Technology, Operational Program ’Education and Lifelong Learning’, ARISTIA (Research project: CONCERT).