Measurement- and simulation-based evaluation and optimization of fetal radiation exposure for fluoroscopy-guided interventions demonstrated for a splenic artery aneurysm.

Abstract

IntroductionA splenic artery aneurysm (SAA) during pregnancy poses a potentially life-threatening risk to patients and is challenging to treat. One treatment option is fluoroscopy-guided embolization, which is often met with apprehensiveness due to potential prenatal radiation exposure. Therefore, knowledge of the expected uterus dose and effective radiation protection measures is critical for an informed decision on the course of the treatment.MethodsFetal radiation exposure is evaluated for a fluoroscopy-guided coil-embolization of a SAA, and key factors determining the uterus dose are identified by exploring different simulation scenarios. A Monte-Carlo-based software (PCXMC) is used to simulate the expected uterus dose from a clinical case and simulation results are validated through thermoluminescent dosimeter (TLD) measurements with a phantom.ResultsThe simulations revealed fetal dose levels, at which no adverse deterministic effects or significant increase in likelihood of childhood cancer are expected. However, the dose can increase significantly if x-ray fields are uncollimated, a small distance between the inferior field edge and the uterus, or if the uterus lies in the primary beam during femoral access. Uncertainty in the uterus position is a non-negligible source of variability. The simulation findings were confirmed by TLD measurements.ConclusionA fluoroscopy-guided SAA embolization on a pregnant woman was conducted with minimal fetal exposure. Simulation of the x-ray fields allows reliable retrospective estimation of the fetal dose and prospective consultations with the medical team on radiation protection measures or whether techniques without ionizing radiation should be considered.