Associations between compression force, breast thickness and radiation dose in mammography: A scoping review

INTRODUCTION: In mammography, compression force is applied to immobilise the breast and separate parenchymal structures for enhanced breast cancer detection. This compression reduces breast thickness and, consequently, radiation exposure. Imaging protocols are often based on the assumption that compression reduces breast thickness and radiation dose while maintaining diagnostic accuracy. However, there are currently no known scoping reviews that have examined the relationship between compression force, compressed breast thickness (CBT) and radiation dose in clinical and phantom studies. This review synthesises existing literature on these associations. METHODS: A scoping review was performed using the PRISMA-ScR framework. English-language articles published between January 2014 and June 2024 were searched on MEDLINE, Embase, Scopus and PubMed. Additional studies were identified through manual searches on Google Scholar and backward citation screening. One reviewer screened titles and abstracts, followed by independent full-text screening by two reviewers. RESULTS: A total of 2192 articles were retrieved; 46 met the inclusion criteria. Thirteen studies examined more than one relationship. The most frequent association was between CBT and radiation dose (n = 41, 89.1%) with most demonstrating a moderate to very strong positive correlation. Findings on the association between compression force and CBT (n = 13) or dose (n = 12) were inconsistent, with no consensus. CONCLUSION: Variability in results is likely due to differences in imaging protocols, equipment and a lack of standardisation in compression techniques. While compression is fundamental to mammographic imaging, its relationship with CBT and radiation dose appears complex and inconsistent. IMPLICATIONS FOR PRACTICE: Compression force alone may not be a reliable or consistent means of dose optimisation. Future research should investigate confounding variables such as breast density, practitioner technique and manufacturer differences to support more individualised imaging approaches.