Towards personalized compression in mammography: a comparison study between pressure- and force-standardization.

Objective: To compare a conventional 14 decanewton (daN) force-standardized compression protocol with a personalized 10kilopascal (kPa) pressure-standardized protocol.

Methods: A new add-on contact area detector, which enables pressure-standardized compression, is validated in a double-blinded intra-individual comparison study. Breast screening participants (433) received one craniocaudal (CC) and one mediolateral oblique (MLO) compression for both breasts. Three of these compressions were force-standardized, and one, blinded and randomly assigned, was pressure-standardized. Participants scored their pain experience on an 11-point numerical rating scale (NRS). Three experienced breast-screening radiologists, blinded for compression protocol, indicated which images required retakes.

Results: An unanticipated under-compression issue that occurred at forces below 5daN was effectively solved with minimal extra radiographer training during the study. For pressure-standardized compressions obtained at 5daN or more, the compressed breasts thickness increased on average 4.2% (MLO)-6.3% (CC), average pain scores were reduced by 10% (MLO)-17% (CC) and the proportion of women experiencing severe pain (NRS≥7) was reduced by 27% (MLO)-32% (CC), compared with force-standardized compressions (all p-values <0.05). Average glandular dose (AGD) and proportions of retakes were similar for both protocols.

Conclusion: Pressure-standardized compressions resulted in AGD values and a retake proportion similar to force-standardized compressions, while pain was significantly reduced.