Organ dose and lifetime attributable risk of cancer in children undergoing computed tomography scan

Exposure to low doses of radiation from medical imaging continues to increase over time. Amongst various imaging modalities, radiation from Computed Tomography (CT) scans mainly delivers doses to organs within the field of scan, which can increase the risk of cancer. Therefore, in the present study, we aim to derive the organ dose and estimate the Lifetime Attributable Risk (LAR) of cancer incidence for South Indian pediatric participants receiving radiation during whole abdomen, urogram, chest, and brain CT scans.

Pediatric participants (n = 100) who underwent different types of CT scans were recruited. The study participants were categorized into four sub-groups based on their age: 0-2.5, 2.5-7.5, 7.5-12.5, and 12.5-18 years. Organ doses were calculated by entering scan parameters in the VirtualDose™ CT software. Cancer risk models in Biological Effects of Ionizing Radiation VII phase 2 report were used to estimate LAR.

The highest organ doses were observed in the colon, stomach, bladder, and liver from whole abdomen CT; bladder, colon, gonads, stomach, breast (females), and liver from urogram CT; lungs, liver, stomach, and breast (females) from chest CT; and salivary glands and brain from brain CT. Predicted LAR of cancer incidence was highest for the colon (58.55) and bladder (35.76) from whole abdomen CT, colon (67.23), bladder (49.37), and breast (females) (46.25) from urogram CT, breast (females) (76.69) and lungs (73.34) from chest CT, and thyroid (16.43) from brain CT, with gonads and thyroid showing the lowest LAR across most scans except brain CT scan.

The present study provides a clearer comprehension of the organ dose and its contribution in estimating the LAR of cancer incidence from a single CT scan, thereby indicating the importance of radiation safety to avoid unwanted exposure in pediatric participants.