Medical-AI trial: catching breast cancer opportunistically on chest CT with AI — compared with mammography and MRI (NCT07557654)

Breast-cancer screening usually means mammography, but uptake and eligibility have limits. Meanwhile many people undergo chest CT for lung conditions, health checks, or other symptoms, and the breast is captured in those images. If AI could pick up signs of breast cancer opportunistically from such CTs done for other reasons, it might catch people who slipped through the screening net, without added radiation or visits. This is the idea of opportunistic screening.

This study evaluates opportunistic breast-cancer screening from chest CT, as an observational study.

Per the registry summary, it evaluates the feasibility and effectiveness of using non-contrast chest CT for breast-cancer screening and compares its diagnostic performance with conventional mammography and/or breast MRI. The primary outcome is the screening performance of chest CT for detecting breast cancer, including comparison with mammography and/or MRI. The size is large at 5,000, and it is recruiting.

Opportunistic screening uses the dormant information of images already taken, with AI, to widen screening at no added cost or radiation, an appealing idea for cost-effectiveness and equity. Because CT captures the breast in three dimensions, it may carry information different from mammography.

But non-contrast CT was not designed for breast screening, and its performance and the impact of false positives and negatives need careful validation. This study evaluates feasibility and performance against mammography/MRI; it does not establish replacement of standard screening or effectiveness.