Factors Associated With CT Scan Repetition in Pediatrics and Its Relationship With Cancer Risk: A Systematic Review and Meta-Analysis

Background Rising use of pediatric CT scans has heightened concerns about radiation exposure compared to non-ionizing imaging modalities. This systematic review investigated factors contributing to repeat CT scans in children and assessed their association with cancer risk. Main body Main body: A comprehensive search of Web of Science, Scopus, and PubMed identified 30 eligible studies, with five studies involving over seven million participants included in the meta-analysis. CT exposure was associated with a significantly increased overall cancer risk (RR = 1.49, 95% CI: 1.44-1.54). Risk of brain tumors was significantly elevated (RR = 1.55, 95% CI: 1.22-1.97), whereas evidence for leukemia was less conclusive (RR = 1.23, 95% CI: 0.72-2.12). A dose-response relationship was observed, with patients receiving two or more CT scans showing substantially higher cancer risk (RR = 2.51, 95% CI: 1.74-3.61) compared with a non-significant risk for those receiving only one scan (RR = 1.07, 95% CI: 0.73-1.56). Conclusion These results highlight the need for practical pediatric CT guidelines. CT scans should be performed only when clinically justified, using optimized low-dose protocols and non-ionizing imaging alternatives when appropriate. Future research should develop evidence-based recommendations that balance diagnostic benefits with the long-term risks of radiation exposure, ensuring safe and effective imaging practice for children.