Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Unit 97, Houston, TX 77030, USA.
AJR Am J Roentgenol. 2013 Jul;201(1):W81-7. doi: 10.2214/AJR.12.9226.
The cancer risks associated with patient exposure to radiation from medical imaging have become a major topic of debate. The higher doses necessary for technologies such as CT and the increasing utilization of these technologies further increase medical radiation exposure to the population. Furthermore, the use of CT for population-based cancer screening continues to be explored for common malignancies such as lung cancer and colorectal cancer. Given the known carcinogenic effects of ionizing radiation, this warrants evaluation of the balance between the benefit of early cancer detection and the risk of screening-induced malignancy.
This report provides a brief review of the process of radiation carcino-genesis and the literature evaluating the risk of malignancy from CT, with a focus on the risks and benefits of CT for cancer screening. The available data suggest a small but real risk of radiation-induced malignancy from CT that could become significant at the population level with widespread use of CT-based screening. However, a growing body of literature suggests that the benefits of CT screening for lung cancer in high-risk patients and CT colonography for colorectal cancer may significantly outweigh the radiation risk. Future studies evaluating the benefits of CT screening should continue to consider potential radiation risks.
与患者接受医学影像学辐射相关的癌症风险已成为一个主要的争论点。CT 等技术所需的更高剂量以及这些技术的日益普及进一步增加了人群的医疗辐射暴露。此外，CT 也被用于肺癌和结直肠癌等常见恶性肿瘤的人群筛查。鉴于电离辐射的已知致癌作用，这就需要评估早期癌症检测的益处与筛查诱导恶性肿瘤的风险之间的平衡。
本报告简要回顾了辐射致癌的过程以及评估 CT 致癌风险的文献，重点关注 CT 用于癌症筛查的风险和益处。现有数据表明，CT 可能会导致很小但确实存在的辐射致癌风险，而随着 CT 筛查的广泛应用，这种风险在人群层面可能会变得显著。然而，越来越多的文献表明，CT 筛查对高危患者的肺癌和 CT 结肠成像对结直肠癌的益处可能显著超过辐射风险。未来评估 CT 筛查益处的研究应继续考虑潜在的辐射风险。
