Range of Normalized Glandular Dose for Mammography Using Patient-Specific Glandular Fractions.

Area of Science:

• Medical Physics
• Radiological Dosimetry
• Breast Imaging

Background:

• Mammography is key for breast cancer early detection but uses ionizing radiation.
• Accurate normalized glandular dose (DgN) estimation is vital for risk assessment.
• Current models use population data, but patient-specific glandular distribution is unknown from projections.

Purpose of the Study:

• To develop a framework for estimating a patient-specific range of DgN from projection-derived glandular fraction (GF) maps.
• To assess the impact of glandular tissue depth variation on DgN.
• To evaluate dose estimation accuracy using different placement strategies.

Main Methods:

• Utilized simulated breast data with glandular tissue distributed using Siddon ray-tracing.
• Performed Monte Carlo simulations to calculate DgN normalized to entrance air kerma.
• Calculated dose ratios using randomized TG-282 glandular distributions for CC and MLO views.

Main Results:

• DgN varied up to threefold due to glandular tissue depth, despite identical GF maps.
• Central glandular placement overestimated DgN by <5% (MLO) and <15% (CC) on average.
• Centroid-based placement underestimated DgN by up to 25%.

Conclusions:

• Patient-specific DgN bounds can be estimated from limited mammographic data.
• Central glandular placement offers a conservative dose estimate.
• Understanding glandular distribution improves mammography radiation dose assessment.