Research
Increased risk of blood cancer in young people after CT scan
Neuruppin, 9 November 2023
A multinational study involving almost one million people confirmed a correlation between radiation exposure during computer tomography scans in young people and an increased risk of blood cancer. This is the most significant conclusion from the latest data evaluation of the EPI CT study with participation of the Institute of Biostatistics and Registry Research at the Brandenburg Medical School Theodor Fontane (MHB). Findings published in the journal Nature Medicine underline the importance of continued strict radiation protection measures specifically for young people.
According to Prof. Dr. Michael Hauptmann (photo) from the MHB Institute of Biostatistics and Registry Research who played a major role in the collection and statistical evaluation of data, study results document a clear relation between radiation dose on bone marrow in CT scans and the risk of developing cancer of the blood and lymphatic system (myeloid and lymphoid melanoma). A 100 milligray (mGy) dose increases the risk of this type of cancer threefold. Findings suggest that the current practice of scans (with an average bone marrow dose of approximately 8 mGy) raises the cancer risk by about 16%. First author Magda Bosch de Basea, researcher with ISGlobal at the time of the study, speaks of an absolute risk of about 1 to 2 cancer cases in 10,000 children after CT scans over a period of two to twelve years after the examination. Earlier this year, Prof. Hauptmann published results of the EPI-CT study on brain tumor risks which also found evidence of an increased risk due to radiation.
The benefits of computer tomography for diagnosis and treatment (including diagnostic efficacy, treatment planning and surveillance) remain undisputed. But the extensive application of this medical procedure over the past decades gave rise to growing misgivings among the medical and scientific community, since CT scans use ionizing radiation. Prof. Dr. Elisabeth Cardis, epidemiologist with the Barcelona Institute for Global Health (ISGlobal) and lead author of the study, says radiation exposure from CT scans is considered minor (less than 100 mGy) but is still higher compared to other diagnostic procedures. Earlier studies already suggested increased cancer risks in children after CT but had several methodical flaws.
Experts in epidemiology, statistics, medicine and dosimetry from nine European countries (Belgium, Denmark, France, Germany, Netherlands, Norway, Spain, Sweden and UK) decided to overcome these shortcomings and conducted a multinational study co-financed by the European Commission and coordinated by the IARC (International Agency for Research on Cancer) - the EPI-CT Study. "This comprehensive multinational study was a challenge: data from radiology records had to be collated from 276 hospitals and linked with population-based registries in nine countries, while preserving data confidentiality, so Prof. Hauptmann.
The study involved approximately one million people who had had at least one CT scan prior to their 22nd year of age. The radiation dose on bone marrow where blood cells are produced was estimated for each individual. EPI-CT researchers combined this information with national cancer registries and thus identified persons who developed blood cancer in the years subsequent to the CT scan. These individuals were monitored over 7.8 years on average, and persons with CT scans in the 1980s were observed over 20 years.
The authors insist on the need for further research to ensure that hospitals record radiation exposure and technical parameters systematically and properly in real time for better risk assessment in future.
Today, more than one million children in Europe undergo CT scans per year. Although radiation doses in CT scans were considerably reduced in recent years, the findings from this study underline the need to raise awareness among doctors and maintain strict radiation protection specifically for the youngest patients. According to Prof. Hauptmann, the procedure must be properly justified and optimized, and alternatives must be considered, to ensure the lowest possible dose of radiation for a good image quality for diagnostics.
Reference
Bosch de Basea M, Thierry-Chef I, Harbron R et al. Risk of haematological malignancies
from CT radiation exposure in children, adolescents and young adults. Nat Med.
You find the publication here and for Download.
Contact for scientific information:
Prof. Michael Hauptmann
Medizinische Hochschule Brandenburg Theodor Fontane
Professor für Biometrie und Registerforschung
Leiter Institut für Biometrie und Registerforschung
E-Mail: michael.hauptmann@mhb-fontane.de
Phone: +49 03391 39-14580
