Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA.
Circulation. 2010 Dec 7;122(23):2403-10. doi: 10.1161/CIRCULATIONAHA.110.941625. Epub 2010 Nov 22.
Myocardial perfusion scans contribute up to 20% of the estimated annual collective radiation dose to the US population. We estimated potential future cancer risk from these scans by age at exposure and current frequency of use in the United States.
Usage patterns were determined from national survey data, and radionuclide dosage was based on current guidelines. Cancer risk projection models were generated on the basis of the National Research Council Biological Effects of Ionizing Radiation VII report, under the assumption that risk has a linear relationship with radiation exposure even at low doses. The mean projected number of radiation-related incident cancers and 95% uncertainty intervals were estimated with the use of Monte Carlo simulations. Estimated risks for a scan performed at age 50 years ranged from 2 cancers per 10,000 scans (95% uncertainty interval, 1 to 5) for a positron emission tomography ammonia-13 test to 25 cancers per 10,000 scans (95% uncertainty interval, 9 to 58) for a dual-isotope (thallium-201 plus technetium-99m) scan. Risks were 50% lower at age 70 years but were similar for men and women. The combination of cancer risk estimates and data on frequency of use suggests that the 9.1 million myocardial perfusion scans performed annually in the United States could result in 7400 (95% uncertainty interval, 3300 to 13,700) additional future cancers.
The lifetime cancer risk from a single myocardial perfusion scan is small and should be balanced against likely benefit and appropriateness of the test. The estimates depend on a number of assumptions, including life expectancy. They apply directly to asymptomatic individuals with life expectancies similar to those of the general population. For individuals with a symptomatic clinical profile, on whom such scans are typically performed, the risks will be lower because of shorter life expectancy.
心肌灌注扫描对美国人口的估计年度集体辐射剂量的贡献高达 20%。我们根据美国的暴露年龄和当前使用频率来估算这些扫描的潜在未来癌症风险。
使用全国性调查数据确定使用模式，根据当前指南确定放射性核素剂量。在假设风险与辐射暴露呈线性关系的情况下，即使在低剂量下也会产生致癌风险，基于《美国国家研究委员会电离辐射生物效应报告第七版》生成癌症风险预测模型。使用蒙特卡罗模拟估计了与辐射相关的偶发癌症的平均预计数量和 95%置信区间。假设在 50 岁时进行扫描，预计正电子发射断层扫描氨-13 试验的辐射相关癌症发生率为每 10000 次扫描 2 例（95%置信区间为 1 至 5），而双同位素（铊-201 加锝-99m）扫描的发生率为每 10000 次扫描 25 例（95%置信区间为 9 至 58）。70 岁时风险降低 50%，但男性和女性相似。癌症风险估计和使用频率数据的结合表明，美国每年进行的 910 万次心肌灌注扫描可能会导致 7400 例（95%置信区间为 3300 至 13700）的额外未来癌症。
单次心肌灌注扫描的终生癌症风险很小，应权衡测试的可能益处和适宜性。这些估计取决于许多假设，包括预期寿命。它们直接适用于预期寿命与一般人群相似的无症状个体。对于那些通常进行此类扫描的具有症状性临床特征的个体，由于预期寿命较短，风险将更低。
