Shah Kaushal H, Slovis Benjamin H, Runde Dan, Godbout Brandon, Newman David H, Lee Jarone
Department of Emergency Medicine, Mount Sinai Medical Center, New York, NY, USA.
Emerg Radiol. 2013 Dec;20(6):485-91. doi: 10.1007/s10140-013-1142-8. Epub 2013 Jul 14.
The risk of cancer from computed tomography (CT) scan radiation is a rising concern in the medical field. Our objectives were to determine how many patients received more than ten CT scans in an academic emergency department (ED) over the course of 7 years and to quantify their radiation exposure and lifetime attributable risk of cancer. An electronic chart review was performed at our urban academic institution with an annual census of 110,000 patients. All patients who underwent a CT scan performed during ED management between the dates of January 2001 and December 2007 were identified. Specific predetermined data elements (e.g., subject demographics, type of CT scan) were extracted by two researchers blinded to hypothesis, using a preformatted data form. After identifying patients with more than ten CTs performed during the study period, radiation exposure was calculated based on accepted and reported radiation doses for the respective anatomic CTs, and lifetime attributable cancer risk was calculated based on the seventh report of the Biological Effects of Ionizing Radiation (BEIR VII) projections. Over the 7-year study period, 24,393 patients received 34,671 CT scans. The vast majority of patients (17,909) received a single CT. Twenty-six (0.1 %) patients received more than ten CTs totaling 374 scans with an average radiation exposure of 83.4 mSv. The maximum lifetime attributable risk for any individual in this cohort was 1.7 % above the baseline cancer risk. Among those undergoing CT imaging in our ED, high-exposure patients (greater than ten scans) constituted a significant minority, while more than one in four patients underwent more than one CT scan during the study period. While the presumed overall risk of radiation-induced cancer continues to be low, it is important for the emergency physician to use clinical knowledge as well as concern for the patient when utilizing radiographic imaging. Increasing attributable cancer risk may have important public health implications in the future, regardless of the low individual risk.
计算机断层扫描（CT）辐射致癌风险在医学领域日益受到关注。我们的目标是确定在一所学术性急诊科中，7年内有多少患者接受了超过十次CT扫描，并量化他们的辐射暴露量以及癌症的终生归因风险。我们在一所年接诊量为110,000例患者的城市学术机构进行了电子病历回顾。确定了2001年1月至2007年12月期间在急诊科管理过程中接受CT扫描的所有患者。由两名对假设不知情的研究人员使用预先格式化的数据表提取特定的预定数据元素（如受试者人口统计学特征、CT扫描类型）。在确定研究期间接受超过十次CT扫描的患者后，根据各解剖部位CT公认的和报告的辐射剂量计算辐射暴露量，并根据《电离辐射生物效应》（BEIR VII）第七次报告的预测计算终生归因癌症风险。在7年的研究期间，24,393例患者接受了34,671次CT扫描。绝大多数患者（17,909例）接受了单次CT扫描。26例（0.1%）患者接受了超过十次CT扫描，共计374次，平均辐射暴露量为83.4毫希沃特。该队列中任何个体的最大终生归因风险比基线癌症风险高1.7%。在我们急诊科接受CT成像的患者中，高暴露患者（超过十次扫描）占少数，而超过四分之一的患者在研究期间接受了不止一次CT扫描。虽然辐射诱发癌症的总体风险仍然较低，但急诊科医生在使用放射影像学检查时，运用临床知识并关注患者是很重要的。无论个体风险多低，但不断增加的归因癌症风险可能在未来对公共卫生产生重要影响。
