Assessment of clinical potential of X-ray dark-field imaging for breast cancer

Aim:

Mammography aims at the detection of early breast cancer and can identify calcifications of up to 50 – 100 µm. However, there is evidence that also microcalcifications of less than 50 µm are associated with breast cancer. These small calcifications are frequently not detected in mammography, whereas this is possible with dark-field imaging. The aim of this study was to prove whether the additional use of dark-field imaging can increase the detection rate of breast cancer.

Material and methods:

Images of breast specimens were acquired with Talbot-Lau X-ray phase-contrast and dark-field imaging (XPCI). With the use of three X-ray gratings with periods in the order of 5 – 10 micrometers three different images were acquired in sequence: the conventional attenuation image, the differential phase image and the dark-field image. In this study, dark-field imaging was compared with conventional mammography. We investigated the detection capability of microcalcifications and malignant or premalignant lesions in both imaging techniques. This imaging system is a research device and is not commercially available.

Results:

81 breast specimens were investigated using the Talbot-Lau X-ray imaging and mammography. In total, 199 significant structures were pathologically processed consisting of 135 benign and 64 malignant lesions. The addition of dark-field imaging identified 14 further histological confirmed carcinoma lesions which were visible but not declared suspicious in digital mammography alone. Another 4 malignant lesions were exclusively detected with dark-field imaging but were invisible in mammography.

Conclusion:

The addition of X-ray dark-field imaging to digital mammography increases the detection rate of breast cancer associated with micrometer-sized calcifications.