MED In the literature: contested

Causal cancer risk from diagnostic CT exposure

In plain words

Children scanned by CT show slightly more cancers later, but sicker children get scanned more often, which could explain the association by itself.

Precise statement

Establish whether the excess leukaemia, haematological-cancer and brain-tumour incidence observed in paediatric CT cohorts, reported as excess relative risk of about 1 to 2.5 per 10 rad organ dose, is causal after removing reverse causation from scans prompted by the undiagnosed disease and from cancer-predisposition syndromes, and after correcting organ-dose reconstruction errors. An answer is a causal risk coefficient or a demonstration that the association is confounded.

What would settle it

Cohorts with clinical indication for each scan recorded, adequate lag exclusion and individual organ-dose reconstruction.

Status in the literature

Unverified note

EPI-CT (2023; ERR about 1.3 per 10 rad for brain cancer, about 2.0 per 10 rad for haematological malignancy) and a North American cohort of about 3.7 million children (Smith-Bindman et al., NEJM 2025; ERR about 2.5 per 10 rad for haematologic cancer) report dose-related excesses; residual confounding by indication and by cancer-predisposition syndromes is still debated.