CT Radiation Exposure Linked to Blood Cancer in Children and Adolescents

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CT Radiation Exposure Linked to Blood Cancer in Children and Adolescents

CT Radiation Exposure Linked to Blood Cancer in Children and Adolescents

Avoid Overuse of CT Scans! Analysis of 900,000 Data Shows Link Between CT Radiation Exposure and Increased Risk of Blood Cancer in Children and Adolescents.

When it comes to radiation, there’s no such thing as zero risk, even with our most familiar clinical tool: computed tomography (CT).

Researchers led by Elisabeth Cardis from the Barcelona Institute for Global Health (ISGlobal) analyzed data from nearly 900,000 individuals across nine countries.

They discovered a correlation between accumulated radiation doses from CT scans and the risk of malignant blood system tumors, with an excess relative risk (ERR) of 1.96 per 100mGy.

It’s estimated that among 10,000 children undergoing CT scans, 1-2 individuals are expected to develop malignant blood tumors within 12 years due to radiation exposure.

This large multinational cohort study provides compelling evidence regarding the association of low-dose radiation with increased cancer risks. Cardis and her team stress that this isn’t meant to instill new panic but rather to highlight the importance of caution when it comes to the increasingly widespread use of low-dose CT scans. They call for a cautious approach, urging physicians to avoid overusing CT technology and adjust doses as much as possible.

CT Radiation Exposure Linked to Blood Cancer in Children and Adolescents

While moderate (≥100mGy) to high doses (≥1Gy) of ionizing radiation have been identified as established risk factors for leukemia in children and adults, the association between the lower doses of radiation used in CT diagnostic exams (less than 100mGy) and the risk of cancer in children and adolescents has remained controversial.

With the widespread use of CT scans in disease diagnosis and treatment monitoring, it has become the largest single source of medical radiation exposure globally, for both children and adults. There’s an urgent need for a precise assessment of CT scan-related radiation doses and their impact on health, enabling healthcare professionals to make wiser clinical decisions.

The EPI-CT cohort study involved a large-scale multicenter research across nine countries, aiming to evaluate the risk of malignant blood system tumors related to radiation exposure from CT scans in children and adolescents, providing vital supplemental evidence to the existing body of knowledge.

The researchers analyzed data from 876,771 individuals enrolled in the EPI-CT cohort study, all of whom had undergone at least one CT scan between the ages of 10 and 22, totaling 1,331,896 scans at an average of 1.52 scans per person. They assessed the active bone marrow (ABM) radiation doses based on the body parts scanned, participant characteristics, time periods, and CT technical parameters.

Following the initial CT scan, the average follow-up period was 7.8 years, during which 790 cases of malignant blood tumors were diagnosed. At the end of the follow-up, the median cumulative ABM dose for all participants was 10.7mGy, while for all blood cancer patients, it was 13.0mGy.

The analysis revealed an increased relative risk (RRs) for all types of malignant blood tumors when the cumulative ABM dose exceeded 10mGy. Compared to doses below 5mGy, the risk for blood cancer increased by 1.66 times (RR 2.66; 95%CI 1.92-3.70) for doses ≥50mGy.

Overall, for every cumulative 100mGy, the excess relative risk (ERR) for blood cancer was 1.96 (95%CI 1.10-3.12). Specifically, for every 100mGy, the excess relative risk for lymphoma was 2.01 (95%CI 1.02-3.42), and for myeloid tumors, it was 2.02 (95%CI 0.47-4.77).

CT Radiation Exposure Linked to Blood Cancer in Children and Adolescents

Presently, the average ABM dose per CT scan is 8mGy. Researchers found that with an increase in the number of CT scans, there’s a corresponding increase in the relative risk of developing all types of blood tumors. With each additional CT scan, the overall risk of blood cancer increases by 43%.

In the medical field, radiation is a double-edged sword. It can be a powerful tool for clinical treatment and diagnosis, yet it can also be a hidden carcinogenic agent. Once the radiation exposure reaches excessive levels, it can lead to DNA mutations and even trigger cancer. This extensive cohort study underscores the continual need to assess the appropriateness of pediatric CT scans and optimize doses to minimize the associated cancer risks.