Computed Tomography (CT) scans use ionizing radiation to create detailed images of the inside of the body. This radiation is a form of energy that can damage cells and DNA, which raises concerns about whether CT scan radiation can cause leukemia, a type of blood cancer originating in the bone marrow.
The relationship between CT scan radiation and leukemia is complex and depends on several factors, including the amount of radiation exposure, the frequency of scans, the age of the patient, and individual susceptibility. Ionizing radiation is a known carcinogen, meaning it has the potential to cause cancer by inducing mutations in DNA. Leukemia is particularly sensitive to radiation because it affects blood-forming cells in the bone marrow, which are rapidly dividing and more vulnerable to DNA damage.
Recent large-scale studies have shown that children and adolescents exposed to radiation from medical imaging, especially CT scans of the head and brain, have an increased risk of developing hematologic cancers such as leukemia and lymphoma. For example, children who undergo one or two head CT scans face nearly double the risk of blood cancers, and this risk can increase to more than three times with multiple scans. This dose-dependent relationship means that the more radiation a child receives, the higher the risk of developing leukemia later in life. This heightened risk in children is due to their greater radiosensitivity and longer expected lifespan, which allows more time for radiation-induced mutations to manifest as cancer.
In adults, the risk is generally lower but still present. The cumulative radiation dose from repeated CT scans can contribute to a small increase in cancer risk, including leukemia. However, the absolute risk for an individual adult is typically low, especially when CT scans are medically justified and optimized to use the lowest radiation dose necessary. Advances in CT technology and imaging protocols have reduced radiation exposure per scan, helping to mitigate these risks.
It is important to balance the benefits and risks of CT scans. These scans are invaluable diagnostic tools that can detect life-threatening conditions quickly and accurately. The immediate benefits of accurate diagnosis and treatment often outweigh the potential long-term risk of radiation-induced leukemia. Nonetheless, medical professionals emphasize minimizing unnecessary CT scans, especially in children, and using alternative imaging methods without ionizing radiation, such as ultrasound or MRI, when appropriate.
Repeated exposure to radiation, such as multiple CT scans over time, increases the cumulative dose and thus the risk of leukemia. This is why guidelines recommend careful consideration before ordering CT scans, particularly in young patients or when multiple scans are planned. Protective measures, such as shielding and dose optimization, are also critical to reduce radiation exposure.
In summary, CT scan radiation can increase the risk of leukemia, particularly in children and with repeated exposures. The risk is dose-dependent and influenced by patient age and scan frequency. While the absolute risk for any single scan is low, awareness and cautious use of CT imaging are essential to minimize potential harm while preserving its diagnostic benefits.