Breast compression thickness and composition affect radiation dose in digital mammography and tomosynthesis

Area of Science:

• Radiology
• Medical Imaging
• Radiation Oncology

Background:

• Digital breast tomosynthesis (DBT) offers improved diagnostic performance over full-field digital mammography (FFDM).
• Concerns exist regarding radiation dose and its variability between DBT and FFDM.
• Understanding dose determinants is crucial for optimizing breast cancer screening protocols.

Purpose of the Study:

• To investigate the influence of breast compression thickness and composition on radiation dose in FFDM and DBT.
• To analyze the variations in the dose ratios between DBT and FFDM under different breast conditions.

Main Methods:

• Retrospective analysis of 288 women with paired FFDM and DBT examinations.
• Extraction of exposure parameters, entrance skin exposure (ESE), and average glandular dose (AGD) from DICOM headers.
• Statistical modeling including correlation, regression, and mixed-effects models to identify dose determinants.

Main Results:

• DBT consistently showed higher ESE and AGD compared to FFDM (P < 0.001).
• Breast compression thickness was the primary determinant of radiation dose, with higher thickness correlating with increased absolute dose but decreased DBT-to-FFDM ratios.
• Breast composition also influenced radiation dose, though to a lesser extent than compression thickness.

Conclusions:

• While DBT increases radiation dose, the relative increase is not uniform and is significantly influenced by breast compression thickness.
• Findings suggest the need for individualized radiation dose assessment based on patient breast characteristics.
• Optimizing imaging parameters can help manage radiation exposure in DBT procedures.