A study by scientists from nine European countries of nearly a million people confirms a strong and clear association between young people’s exposure to radiation during a CT scan and an increased risk of blood cancer, according to an analysis conducted by the Barcelona Institute for Global Health ( ISGlobal) and is published in the journal “Nature Medicine”.

In the research, coordinated by the International Agency for Research on Cancer, analyzed data from nearly a million people who had at least one CT scan before the age of 22 and found a clear association between total bone marrow radiation doses from CT scans and risk of blood cancer.

The dose of radiation delivered to the bone marrow, where the blood cells are made, was calculated for each person. The researchers were then able to track through national cancer registries those who developed blood cancers over time. The results suggest that a typical CT scan today (with an average dose of about 8 mGy) increases the risk of developing myeloid and lymphoid malignancies by about 16%.

“In absolute risk terms this means that for every 10,000 children who undergo a CT scan, we can expect to see about one to two cases of cancer in the twelve years following the test.”notes the study’s first author, researcher at the Barcelona Institute for Global Health (ISGlobal), Magda Bos de Basea.

Today more than one million children in Europe undergo a CT scan each year. Although radiation doses from CT scans have decreased significantly in recent years, the widespread use of this examination in recent decades has raised concerns in the scientific community. The findings of the study highlight the need to raise awareness among the medical community and continue to implement strict radiation protection measures, especially in younger patients.

The researchers point out that more work is needed to ensure that data on doses and technical parameters are systematically and adequately collected in clinics in real time, to further improve risk assessments in the future.