Long-term changes in breast density reporting after implementation of BI-RADS 5^th edition guidelines

Area of Science:

• Radiology and Medical Imaging
• Oncology
• Public Health

Background:

• The Breast Imaging Reporting and Data System (BI-RADS) provides standardized criteria for mammographic interpretation.
• Changes in BI-RADS 5th Edition aimed to refine breast density assessment, focusing on tissue masking and removing percentage-based criteria.
• Understanding the impact of these changes on clinical practice is crucial for patient management.

Purpose of the Study:

• To evaluate long-term changes in mammographic density reporting following the implementation of BI-RADS 5th Edition guidelines.
• To assess radiologist reporting patterns for breast density at a single institution.
• To determine if revised BI-RADS criteria alter the proportion of mammograms classified as dense.

Main Methods:

• A retrospective analysis of 132,326 mammograms from a single institution.
• Data collected from 4 years prior to and 4 years after the BI-RADS 5th Edition update.
• Chi-square tests were used to compare density distributions before and after the guideline changes.

Main Results:

• A statistically significant, albeit small, increase in mammograms classified as dense was observed after the BI-RADS 5th Edition implementation (39.1% vs. 38.4%).
• The observed difference in density classification had a negligible practical magnitude (Phi = 0.01).
• The study confirmed a modest but sustained shift towards classifying mammograms as dense.

Conclusions:

• The adoption of BI-RADS 5th Edition density assessment guidelines resulted in a slight but consistent increase in dense breast classifications.
• Despite the small effect size, changes in density categorization can influence patient management and decisions regarding supplemental screening.
• This study highlights the implications of evolving breast density reporting standards in the context of mandatory breast density notification policies.