Fetal dose assessment in diagnostic and interventional radiology: a systematic review and European survey on methods,...

An increasing number of pregnant patients undergo radiological examinations or procedures each year, raising concerns about fetal radiation exposure. Several methods for fetal dose (FD) estimation are available. Within the EU-funded SONORA project, this study aims to identify, evaluate, and synthesize existing FD estimation methods used in diagnostic and interventional radiology (DIR). The objective is to compare evidence from the literature with real-world clinical practices across Europe, identifying discrepancies and areas requiring harmonization.

A systematic review of PubMed and Embase databases (2000-2025) was conducted following PRISMA guidelines, including 75 original studies. In parallel, a survey was distributed across European countries to investigate current FD estimation practices, tools, reported dose ranges, and optimization strategies. Fifty-two valid responses, mainly from Medical Physicists, were analyzed.

Literature and survey data identified three main FD estimation approaches: Monte Carlo simulations, physical phantom measurements, and software tools, the latter being most used in clinical practice. Reported FD values varied by imaging modality: 10-60 mGy for abdominal or pelvic CT, <1 mGy for chest CT and conventional radiography, and a wide range (0.01->100 mGy) for interventional procedures. While strong agreement was observed on technical optimization strategies-such as collimation, tube current modulation, and reduction of CT acquisition phases-substantial variability persists in the choice of software tools.

Despite the growing use of ionizing radiation during pregnancy, FD estimation methods remain heterogeneous. Harmonization of international guidelines and development of standardized tools incorporating maternal biometric data are urgently needed to improve risk assessment and ensure safer management of pregnant patients.