Massachusetts General Hospital Institute for Technology Assessment, Department of Radiology, 101 Merrimac St, 10th Floor, Boston, MA 02114, USA.
Radiology. 2013 Mar;266(3):896-904. doi: 10.1148/radiol.12121015. Epub 2012 Dec 18.
To demonstrate a limitation of lifetime radiation-induced cancer risk metrics in the setting of testicular cancer surveillance-in particular, their failure to capture the delayed timing of radiation-induced cancers over the course of a patient's lifetime.
Institutional review board approval was obtained for the use of computed tomographic (CT) dosimetry data in this study. Informed consent was waived. This study was HIPAA compliant. A Markov model was developed to project outcomes in patients with testicular cancer who were undergoing CT surveillance in the decade after orchiectomy. To quantify effects of early versus delayed risks, life expectancy losses and lifetime mortality risks due to testicular cancer were compared with life expectancy losses and lifetime mortality risks due to radiation-induced cancers from CT. Projections of life expectancy loss, unlike lifetime risk estimates, account for the timing of risks over the course of a lifetime, which enabled evaluation of the described limitation of lifetime risk estimates. Markov chain Monte Carlo methods were used to estimate the uncertainty of the results.
As an example of evidence yielded, 33-year-old men with stage I seminoma who were undergoing CT surveillance were projected to incur a slightly higher lifetime mortality risk from testicular cancer (598 per 100 000; 95% uncertainty interval [UI]: 302, 894) than from radiation-induced cancers (505 per 100 000; 95% UI: 280, 730). However, life expectancy loss attributable to testicular cancer (83 days; 95% UI: 42, 124) was more than three times greater than life expectancy loss attributable to radiation-induced cancers (24 days; 95% UI: 13, 35). Trends were consistent across modeled scenarios.
Lifetime radiation risk estimates, when used for decision making, may overemphasize radiation-induced cancer risks relative to short-term health risks.
展示终生辐射致癌风险指标在睾丸癌监测中的局限性，特别是它们无法捕捉到患者一生中辐射致癌的延迟时间。
本研究获得了机构审查委员会对使用计算机断层扫描（CT）剂量学数据的批准。豁免了知情同意。本研究符合 HIPAA 要求。开发了一个马尔可夫模型，以预测接受睾丸癌切除术 10 年后进行 CT 监测的患者的结果。为了量化早期和晚期风险的影响，将因睾丸癌导致的预期寿命损失和终生死亡率风险与因 CT 辐射导致的癌症的预期寿命损失和终生死亡率风险进行了比较。与终生风险估计不同，预期寿命损失的预测考虑了一生中风险的时间，这使得可以评估终生风险估计的局限性。使用马尔可夫链蒙特卡罗方法来估计结果的不确定性。
作为证据的一个例子，33 岁患有 I 期精原细胞瘤的男性正在接受 CT 监测，预计终生死于睾丸癌的风险略高于因辐射引起的癌症（598 例/100000；95%不确定性区间[UI]：302 例，894 例）（505 例/100000；95% UI：280 例，730 例）。然而，归因于睾丸癌的预期寿命损失（83 天；95% UI：42 天，124 天）是归因于辐射引起的癌症的预期寿命损失（24 天；95% UI：13 天，35 天）的三倍多。在建模场景中，趋势是一致的。
在决策时使用终生辐射风险估计可能会过度强调辐射致癌风险相对于短期健康风险。
