A comparison of two digital mammography systems: are there any differences?

Area of Science:

• Radiology and Imaging
• Oncology
• Public Health

Background:

• Digital mammography is crucial for breast cancer screening.
• Comparing new technologies against established services is essential for optimizing screening programs.
• Understanding differences in lesion detection and radiation dose is vital for patient outcomes.

Purpose of the Study:

• To compare the performance of Sectra and Hologic digital mammography systems within the Welsh breast-screening service.
• To assess differences in the number, type, size, and grade of detected tumors.
• To evaluate the radiation dose delivered by each system.

Main Methods:

• Retrospective analysis of 50,000 screening episodes (2012).
• Double-blind reading by two independent readers.
• Detailed comparison of tumor characteristics (type, size, grade, invasive/non-invasive) and statistical analysis of performance differences.

Main Results:

• No significant difference in invasive cancer or subtype detection between Sectra and Hologic.
• Sectra detected significantly fewer non-invasive lesions (ductal carcinoma in situ [DCIS]) compared to Hologic (1.44 vs. 3.24 per 1000).
• Sectra delivered a significantly lower mean glandular dose (0.7 mGy) than Hologic (1.6 mGy).

Conclusions:

• While invasive cancer detection is comparable, Sectra shows a significant difference in non-invasive lesion detection versus Hologic.
• The higher detection of non-invasive lesions by Hologic may lead to over-diagnosis and associated patient morbidity.
• Sectra offers a lower radiation dose, which is beneficial for population screening, but long-term clinical significance requires further investigation.