Exposure to Tomographic Scans and Cancer Risks
Menée à Taïwan à partir de données 2000-2013 de l'Assurance maladie portant sur des patients atteints d'une leucémie (13 040 cas), d'un cancer de la thyroïde (22 853 cas) ou d'un lymphome non hodgkinien (20 157 cas) et sur des témoins (âge : plus de 25 ans ; durée médiane de suivi : 9 à 10 ans), cette étude analyse l'association entre une exposition aux rayonnements ionisants liés à la tomodensitométrie et le risque de développer ces maladies, en fonction du sexe et de catégories d'âges
Worldwide use of computed tomographic (CT) scans has increased. However, the ionizing radiation from CT scans may increase the risk of cancer. This study examined the association between medical radiation from CT scans and the risk of thyroid cancer, lymphoma, and non-Hodgkin lymphoma (NHL) in adults.We conducted a nested case-control study in a cohort constructed from a population-based universal health insurance dataset in Taiwan in 2000-2013. In total, 22,853 thyroid cancer, 13,040 leukemia, and 20,157 NHL cases with their matched controls were included. Median follow-up times were 9.29∼9.90 years for the three case-control groups. Medical radiation from CT scans were identified through physician order codes in medical insurance data from the index date to 3 years prior to a cancer diagnosis. Conditional logistic regression modeling was used for the overall and subsets of the population defined by sex and age groups to estimate the odds ratio (OR) and 95% confidence interval (CI) of the cancer risk associated with medical radiation.Exposure to medical radiation from CT scans was associated with elevated risk of thyroid cancer [odds ratio (OR) = 2.55, 95% confidence interval (CI): 2.36∼2.75] and leukemia (OR = 1.55, 95% CI: 1.42∼1.68). The elevated risk in thyroid cancer and leukemia in association with medical CT was stronger in females than males. No significant association between the risk of cancer and CT scans was observed in overall patients with NHL (OR = 1.05, 95% CI: 0.98∼1.12); however, increased risks were found in patients ≤45 years of age. Clear dose-response relationship was observed in patients ≤45 years of age for all three cancers.CT scans may be associated with an increased risk of thyroid cancer and leukemia and those diagnosed with NHL at a younger age.