Radiology:CT的致癌风险被夸大
2013-01-07 Radiology dxy zyj0630
美国科学家提醒临床医生注意,不要在患者进行计算机断层扫描(CT)成像监视时过分强调辐射诱导的癌症风险。来自波士顿马萨诸塞州总医院的研究团队对睾丸癌患者运用马尔科夫模型,证明辐射诱导癌症发生的延迟时间,意味着CT监视给患者带来的早期诊断癌症复发的潜在益处超过了给患者生活带来的风险。 研究者解释道,如果医生不考虑时间差别直接比较这些风险,那么这些风险可能是相似的。但是,如果让患者在相等的风险
美国科学家提醒临床医生注意,不要在患者进行计算机断层扫描(CT)成像监视时过分强调辐射诱导的癌症风险。来自波士顿马萨诸塞州总医院的研究团队对睾丸癌患者运用马尔科夫模型,证明辐射诱导癌症发生的延迟时间,意味着CT监视给患者带来的早期诊断癌症复发的潜在益处超过了给患者生活带来的风险。
研究者解释道,如果医生不考虑时间差别直接比较这些风险,那么这些风险可能是相似的。但是,如果让患者在相等的风险下选择现在死亡还是几年后死亡,可以理解大部分患者都将选择后者,这些所谓“相等”的风险其实是不相等的。
他们以33岁精原细胞瘤I期患者睾丸切除术后十年间进行CT监视为例,来自睾丸癌的生命死亡率风险仅略高于辐射诱导癌症相关风险,分别为598和505例每十万人。但是,归因于睾丸癌的预期减寿是归因于辐射诱导癌症预期减寿的3倍,分别为83天和24天。研究人员解释说,时间悖论的存在意味着归因于睾丸癌和归因于辐射诱导癌症的预期寿命缩短时间差异对年轻男性患者来说比生命死亡率风险差异更重要。
因此,对于33岁非精原生殖细胞肿瘤(NSGCT)男性患者(他们的睾丸癌特异性死亡率更高,比精原细胞癌患者需要的CT监视却更少),归因于睾丸癌的死亡率风险相对高于归因于辐射诱导癌症的风险,分别为2243和262例每十万人。来自睾丸癌和辐射诱导癌症的期望减寿也有很大差异,分别为311天和12天。研究者为非精原生殖细胞肿瘤患者增加胸部CT扫描后,其归因于辐射诱导癌症的生命死亡率风险上升为每十万人454例,预期减寿22天。
主要作者Pari Pandharipande在一份新闻稿中评价这项研究,通常在人群水平讨论的辐射诱导癌症风险,概念化和应用于患者个人水平的成像决定方面具有一定挑战性。我们作为医生可以受益于专门的教育方面努力来提高决策能力和更好地表达对患者的风险。
Purpose: 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.
Materials and Methods: 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.
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.
Conclusion: Lifetime radiation risk estimates, when used for decision making, may overemphasize radiation-induced cancer risks relative to short-term health risks.
作者:Radiology
版权声明:
本网站所有注明“来源:梅斯医学”或“来源:MedSci原创”的文字、图片和音视频资料,版权均属于梅斯医学所有。非经授权,任何媒体、网站或个人不得转载,授权转载时须注明“来源:梅斯医学”。其它来源的文章系转载文章,本网所有转载文章系出于传递更多信息之目的,转载内容不代表本站立场。不希望被转载的媒体或个人可与我们联系,我们将立即进行删除处理。
在此留言
#致癌风险#
68
#癌风险#
62
#致癌#
73