Chodick Gabriel, Ronckers Cécile M, Shalev Varda, Ron Elaine
Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, MD 20892-7238, USA.
Isr Med Assoc J. 2007 Aug;9(8):584-7.
The use of computed tomography in Israel has been growing rapidly during recent decades. The major drawback of this important technology is the exposure to ionizing radiation, especially among children who have increased organ radiosensitivity and a long lifetime to potentially develop radiation-related cancer.
To estimate the number of excess lifetime cancer deaths related to annual CT scans performed in children in Israel.
We used CT scan utilization data from 1999 to 2003 obtained from the second largest health management organization in the country to project age and gender-specific CT scan use nationwide. Based on published organ doses for common CT examinations and radiation-related cancer mortality risk estimates from studies in survivors of the atomic bomb, we estimated the excess lifetime risks for cancer mortality attributed to use of CT in children and adolescents (up to 18 years old) in Israel.
We estimated that 17,686 pediatric scans were conducted annually in Israel during 1999-2003. We project that 9.5 lifetime deaths would be associated with 1 year of pediatric CT scanning. This number represents an excess of 0.29% over the total number of patients who are eventually estimated to die from cancer in their lifetime.
Pediatric CT scans in Israel may result in a small but not negligible increased lifetime risk for cancer mortality. Because of the uncertainty regarding radiation effects at low doses, our estimates of CT-related cancer mortality should be considered with caution. Nevertheless, physicians, CT technologists, and health authorities should work together to minimize the radiation dose for children to as low as reasonably achievable and encourage responsible use of this essential diagnostic tool.
近几十年来，计算机断层扫描（CT）在以色列的使用量迅速增长。这项重要技术的主要缺点是会使患者暴露于电离辐射中，尤其是儿童，他们的器官对辐射更敏感，且有更长的寿命可能会患上与辐射相关的癌症。
估算以色列儿童每年进行CT扫描所导致的终生癌症死亡超额数。
我们利用1999年至2003年从该国第二大健康管理组织获取的CT扫描使用数据，来推算全国范围内按年龄和性别划分的CT扫描使用情况。基于已公布的常见CT检查的器官剂量以及原子弹幸存者研究中的辐射相关癌症死亡率风险估计值，我们估算了以色列儿童和青少年（18岁及以下）使用CT导致的终生癌症死亡超额风险。
我们估计，1999 - 2003年期间，以色列每年进行17686次儿科CT扫描。我们预计，1年的儿科CT扫描会导致9.5例终生死亡。这个数字占最终估计终生死于癌症的患者总数的0.29%，属于超额死亡数。
以色列的儿科CT扫描可能会导致终生癌症死亡风险有小幅增加，但并非可以忽略不计。由于低剂量辐射影响存在不确定性，我们对CT相关癌症死亡率的估计应谨慎看待。尽管如此，医生、CT技术人员和卫生当局应共同努力，将儿童的辐射剂量降至合理可达到的最低水平，并鼓励合理使用这一重要的诊断工具。
