Induction and persistence of chromosomal aberrations in peripheral blood lymphocytes of pediatric participants exposed to diagnostic CT scans.

The increasing use of computed tomography (CT) in pediatrics raises concerns about low-dose ionizing radiation and its potential to induce DNA damage, as pediatric patients are more radiosensitive and have a longer lifespan than adults. This study evaluated the induction and persistence of chromosomal aberrations (CA) in peripheral blood lymphocytes (PBL) of pediatric participants following a CT scan and examined their association with dose indices and estimated blood dose. Pediatric participants who underwent CT scans (Group 1, n = 48) and healthy pediatric volunteers (Group 2, n = 8) were included. In Group 1, blood samples were collected before and 1-2 h after the scan for CA analysis. In Group 2, blood samples were irradiated in vitro with 20, 60, and 120 mGy using fabricated phantoms to simulate CT exposures. CA were assessed using cytogenetic assays at 48 and 240 h, and stable aberrations were analyzed using multicolour fluorescence in situ hybridization (m-FISH). A significant increase in CA frequency was observed in Group 1 after CT scans compared to pre-scan levels (p < 0.001). Similarly, in vitro irradiation showed a significant dose-dependent increase in CA frequency at 48 h. However, CA frequency declined after 240 h, with no significant difference compared to controls. m-FISH analysis did not detect stable CA in either short- or long-term cultures. No correlation was found between CA frequency and age, size-specific dose estimate, or estimated blood dose, except for the dose-length product. Although CT exposure increases CA frequency, most aberrations are unstable and decline over successive cell divisions, highlighting the importance of evaluating both the induction and persistence of chromosomal damage to better understand potential long-term health consequences.