LungIMPACT

AI-based chest X-ray prioritization in the lung cancer diagnostic pathway: the LungIMPACT randomized controlled trial

Patient / Population Intervention / Exposure Comparison Outcome

In 93,326 chest X-rays requested by UK primary care and analysed in the lung-cancer diagnostic pathway, immediate AI prioritisation of the radiology worklist did not reduce time to CT or to lung-cancer diagnosis compared with AI-assisted reporting without worklist prioritisation.

N
93,326
Design
Multicentre RCT (randomised by day), UK
Endpoint
Time to CT and time to lung-cancer diagnosis (co-primary)
Relevance
2
ResultMedian time to CT 53 vs 53 days (ratio of geometric means 0.97, 95% CI 0.93–1.02; P=0.31); time to lung-cancer diagnosis 44 vs 46 days (0.98, 95% CI 0.83–1.16; P=0.84). Lung cancer diagnosed in 558 (0.6%); AI–radiology discordance in 30.3% of CXRs.
Woznitza N, et al. Nat Med. 2026;32(5):1737-1744. 10.1038/s41591-026-04253-5
Discussion & critique

The largest randomised test of AI worklist prioritisation in imaging, and negative: with AI already running in both arms, pushing flagged chest X-rays up the queue changed neither time to CT nor time to diagnosis, so the authors recommend against prioritisation in this setting. Randomisation was by day rather than by patient, the unit of analysis is the X-ray rather than the person, and the trial isolates the effect of prioritisation only — it cannot say what the AI itself contributed to the pathway.