【原】术中透视，你的大脑吃了多少辐射？｜JBJS 2020

前言：

      骨科手术通常涉及术中透视，常规个人防护设备包括衣裤、围裙、围领、护目镜等，保护重要器官及腺体。

       那我们的大脑，接受了多少辐射，哪种防护措施最有效呢？

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参考文献：Ramoutar DN, Thakur Y, Batta V, Chung V, Liu D, Guy P. Orthopaedic Surgeon Brain Radiation During Fluoroscopy: A Cadaver Model. J Bone Joint Surg Am. 2020 Nov 18;102(22):e125. doi: 10.2106/JBJS.19.01053. PMID: 33208643.

在2020.10 JBJS期刊上，来自加拿大的学者对常规骨科髓内钉手术术中透视时不同防护措施下的头颅辐射剂量进行了相关研究。

Background

该研究的目的是为了研究在短髓内钉手术过程中外科医生头颅的辐射剂量并推测终身剂量，决定头颅辐射的个人防护有效措施。

（The aims of this study were to quantify exposure of the surgeon’s brain to radiation during short cephalomedullary (SC) nailing, to extrapolate lifetime dose, and to determine the effects of personal protective equipment (PPE)on brain dose. ）

Methods

2具尸体标本被用于本试验：（1）完整的尸体替代患者，左侧置入髓内钉作为辐射的分散媒介；（2）孤立的头颈标本替代手术医生，在大脑不同部位置入辐射剂量计。“患者标本”暴露在前后位和侧位平面。在头颅无遮挡屏蔽和不同的个人防护装置情况下测量辐射剂量。从部分数据中估计外科医生的职业生涯平均为40年（25-65岁）。

（Two cadaveric specimens were used: (1) a whole cadaveric body representing the patient, with a left nail inserted to act as the scatter medium, and (2) an isolated head-and-neck cadaveric specimen representing a surgeon, with radiation dosimeters placed in specific locations in the brain. The “patient” cadaver’s left hip was exposed in posteroanterior and lateral radiographic planes. Measurements were performed without shielding of the head-and-neck specimen and then repeated sequentially with different PPE configurations. An average surgeon career was estimated to be 40 years (ages 25 to 65 years) with the caseload obtained from the department’s billing data. ）

图1：研究中患者、医生与透视机位置模式图

图2：研究示意图

Results

在没有防护措施情况下，每次髓内钉手术平均的大脑辐射剂量为3.35 mGy (95% 置信区间 [CI]: 2.4 to 4.3)，在使用甲状腺围领后显著减小(2.94 mGy [95% CI: 1.91 to 3.91], p = .04)。与单独使用甲状腺围领相比，增加使用护目镜、头帽或联合使用护目镜和头帽，头颅的辐射剂量均无明显差异。推测未使用防护设备且工作超过40年终身辐射为2,146 mGy (95% CI: 1,539 to 2,753)，有效剂量21.5 mSv.

（The mean radiation dose to the surgeon brain without PPE was 3.35 mGy (95% confidence interval [CI]: 2.4 to 4.3) per nail procedure. This was significantly reduced with use of a thyroid collar (2.94 mGy [95% CI: 1.91 to 3.91], p = .04). Compared with use of the thyroid collar in isolation, there was no significant additional reduction in radiation when the collar was used with leaded glasses (2.96 mGy [95% CI: 2.15 to 3.76], p = 0.97), with a lead cap (3.22 mGy [95% CI: 2.31 to 4.13], p = 0.55), or with both (2.31 mGy [95% CI: 1.61 to 3.01], p = 0.15). The extrapolated lifetime dose over 40 working years for SC nailing without PPE was 2,146 mGy (95% CI: 1,539 to 2,753), with an effective dose of 21.5 mSv. ）

表5：侧位透视时大脑不同部位的辐射剂量及大脑平均辐射剂量

图6：正位透视时大脑不同部位的辐射剂量及大脑平均辐射剂量

图7：不同防护措施下每次手术、每年、每个终生工作时间的大脑辐射剂量

Conclusion

在根据我们机构的工作情况和技术，髓内钉对外科医生大脑的终生累积辐射推断值较低，与从伦敦到纽约的单程飞行辐射值相差无几。但值得注意的是，我们仅研究了许多辐射辅助检查中的一种，如果包括其他过程的辐射量，则可能会低估了其一生的总辐射量。 这项研究还表明，甲状腺围领可显着减少该手术的脑部辐射剂量，而其他头/颈个人防护装备（如铅帽）似乎具有很小的附加作用。 这项研究为将来的研究提供了一种方法，可以量化其他常见的骨科手术的大脑辐射剂量。

（The extrapolated cumulative lifetime radiation to a surgeon’s brain from SC nailing based on our institution’s workload and technology is low and comparable with radiation during a one-way flight from London to New York. Of note, we studied only one of many fluoroscopy-aided procedures and likely underestimated total lifetime exposure if exposures from other procedures are included. This study also demonstrates that thyroid collars significantly reduce brain dose for this procedure whereas other head/neck PPE such as lead caps appear to have minimal additional effect. This study provides a methodology for future studies to quantify brain dose for other common orthopaedic procedures. ）

Clinical Relevance 

根据我们的机构数据，这项研究表明，尽管髓内钉的终生脑部辐射剂量很低，但甲状腺围领可以显着降低该剂量。 因此，根据“尽可能合理地降低”放射线照射的原则，放射线安全计划和外科医生应考虑在这种情况下使用甲状腺围领。

（This study, based on our institutional data, demonstrates that although the lifetime brain dose from SC nailing is low, thyroid collars significantly reduce this dose further. As such, in accordance with the “as low as reasonably achievable” radiation exposure principle, radiation safety programs and individual surgeons should consider use of thyroid collars in this setting. ）