Cancer in children due to CT examinations?
Neuruppin/Lyon, 7 December 2022
New study results confirm an increased brain cancer risk in children after radiation exposure from computed tomography examinations. Dr. Michael Hauptmann, Professor of Biostatistics and Registry Research at Brandenburg Medical School Theodor Fontane (MHB) in Neuruppin (Germany), in collaboration with researchers from the International Agency for Research on Cancer (IARC) and other partner institutions, evaluated data of 658,752 children who underwent one or more CT examinations. They observed an association between radiation dose to the brain and subsequent brain cancer risk and estimate that one radiation-induced brain cancer is to be expected within 5 to 15 years after 10,000 children underwent a head CT. The Lancet Oncology published the results yesterday.
Prof. Hauptmann, a statistician, analyzed the data and detected a statistically significant linear dose-response relationship for brain cancer: “CT examinations provide important and potentially life-saving diagnostic information. On the other hand, patients are exposed to far higher doses of radiation compared to x-rays and most other diagnostic imaging procedures. Several earlier studies suggested that CTs in pediatric patients may pose an increased risk of brain tumors. But robust estimates of cancer risks by brain dose have been lacking so far and are urgently needed to advance dose optimization. Results of our study now provide these estimates.
The excess relative risk per 100 milligray radiation dose to the brain was 1.27 (with a 95% confidence interval from 0.51 to 2.69). This means that the brain cancer risk after exposure to 100 milligray, which corresponds to between 2 and 3 head CTs, is 127% higher compared to no head CTs. Despite this strong increase, the absolute risk of developing a brain cancer remains very low for individual patients. However, millions of pediatric head CTs are performed per year in Europe and other parts of the world. So, there is a substantial need for further research to determine the risks for all exposed organs where cancer can occur.”
In the study, individual radiation doses to various organs were reconstructed by means of historical device settings and a large sample of CT images. Cohort members were linked with cancer and vital status registries to identify children who developed cancer or died.
Dr. Ausrele Kesminiene from IARC coordinates the EPI-CT cohort study in Lyon; she says it is not easy to produce evidence of CT-induced cancer risks in children, for several reasons: “There is (a) a lack of randomized data, (b) the low incidence of cancer in pediatric patients requires very large studies, and (c) the medical reason for the performed CTs may have an influence on the estimated risks. Having explored these aspects, the EPI-CT researchers conclude that these difficulties have no major impact on the observed association. Results of the study underline the need to justify every single CT examination and reduce radiation doses as much as possible.”
The EPI-CT study is the largest study conducted to date on cancer risks in pediatric patients after CT, including individual radiation dose evaluations. It is based on data from 276 hospitals in nine European countries.
Here is the link to the article: https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(22)00655-6/fulltext.
Further information and details:
For pdf document of the paper see here.
For editorial see here.
For additional material see here.
Prof. Michael Hauptmann
Medizinische Hochschule Brandenburg Theodor Fontane
Professor für Biometrie und Registerforschung
Leiter Institut für Biometrie und Registerforschung
Phone: +49 3391 39-14580