DoSReMC: Domain Shift Resilient Mammography Classification using Batch Normalization Adaptation

TL;DR

This paper introduces DoSReMC, a BN adaptation framework that improves cross-domain mammography classification performance by fine-tuning only specific layers, enhancing robustness without full retraining.

Contribution

It proposes a novel BN layer adaptation method combined with adversarial training to address domain shift in mammography classification.

Findings

BN layers are key to domain dependence in CNNs.

Fine-tuning BN and FC layers improves cross-domain accuracy.

Adversarial training further enhances generalization.

Abstract

Numerous deep learning-based solutions have been developed for the automatic recognition of breast cancer using mammography images. However, their performance often declines when applied to data from different domains, primarily due to domain shift - the variation in data distributions between source and target domains. This performance drop limits the safe and equitable deployment of AI in real-world clinical settings. In this study, we present DoSReMC (Domain Shift Resilient Mammography Classification), a batch normalization (BN) adaptation framework designed to enhance cross-domain generalization without retraining the entire model. Using three large-scale full-field digital mammography (FFDM) datasets - including HCTP, a newly introduced, pathologically confirmed in-house dataset - we conduct a systematic cross-domain evaluation with convolutional neural networks (CNNs). Our results demonstrate that BN layers are a primary source of domain dependence: they perform effectively when training and testing occur within the same domain, and they significantly impair model generalization under domain shift. DoSReMC addresses this limitation by fine-tuning only the BN and fully connected (FC) layers, while preserving pretrained convolutional filters. We further integrate this targeted adaptation with an adversarial training scheme, yielding additional improvements in cross-domain generalizability while reducing the computational cost of model training. DoSReMC can be readily incorporated into existing AI pipelines and applied across diverse clinical environments, providing a practical pathway toward more robust and generalizable mammography classification systems.