Department of Trauma and Orthopaedics, University Hospitals Coventry and Warwickshire, Coventry, United Kingdom.
Department of Radiology, Faculty of Medicine (Y.T.), and Division of Orthopaedic Trauma, Department of Orthopaedics (P.G.), University of British Columbia, Vancouver, British Columbia, Canada.
J Bone Joint Surg Am. 2020 Nov 18;102(22):e125. doi: 10.2106/JBJS.19.01053.
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.
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.
The mean radiation dose to the surgeon brain without PPE was 3.35 µGy (95% confidence interval [CI]: 2.4 to 4.3) per nail procedure. This was significantly reduced with use of a thyroid collar (2.94 µGy [95% CI: 1.91 to 3.91], p = 0.04). 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 µGy [95% CI: 2.15 to 3.76], p = 0.97), with a lead cap (3.22 µGy [95% CI: 2.31 to 4.13], p = 0.55), or with both (2.31 µGy [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 µGy (95% CI: 1,539 to 2,753), with an effective dose of 21.5 µSv.
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.
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.
本研究旨在量化在短股骨（SC）钉固定术期间外科医生大脑暴露于辐射的程度，推断终生剂量，并确定个人防护设备（PPE）对大脑剂量的影响。
使用了两个尸体标本：（1）一个完整的尸体代表患者，插入左侧钉子作为散射介质；（2）一个单独的头颈部尸体标本代表外科医生，在大脑的特定位置放置辐射剂量计。“患者”尸体的左髋在前后位和侧位放射影像平面中暴露。在未屏蔽头颈部标本的情况下进行测量，然后依次重复使用不同的 PPE 配置进行测量。根据科室计费数据估算了平均 40 年（25 岁至 65 岁）的外科医生职业生涯。
不使用 PPE 时，外科医生大脑的平均辐射剂量为每次钉手术 3.35µGy（95%置信区间 [CI]：2.4 至 4.3）。使用甲状腺领时，这一剂量显著降低（2.94µGy [95%CI：1.91 至 3.91]，p = 0.04）。与单独使用甲状腺领相比，当领与铅眼镜（2.96µGy [95%CI：2.15 至 3.76]，p = 0.97）、铅帽（3.22µGy [95%CI：2.31 至 4.13]，p = 0.55）或两者同时使用（2.31µGy [95%CI：1.61 至 3.01]，p = 0.15）时，辐射剂量没有明显降低。不使用 PPE 情况下，40 年 SC 钉手术期间的终生剂量推算值为 2,146µGy（95%CI：1,539 至 2,753），有效剂量为 21.5µSv。
根据我们机构的工作量和技术，从 SC 钉固定术推算出的外科医生大脑的累积终生辐射量较低，与从伦敦到纽约的单程飞行期间的辐射量相当。值得注意的是，我们仅研究了众多透视辅助手术中的一种，而且如果包括其他手术的总终生暴露量，可能会低估总终生暴露量。本研究还表明，甲状腺领显著降低了该手术的脑剂量，而其他头部/颈部 PPE 如铅帽似乎没有明显的额外效果。本研究为未来其他常见骨科手术中大脑剂量的量化提供了一种方法。
本研究基于我们机构的数据，表明尽管 SC 钉固定术的终生脑剂量较低，但甲状腺领可进一步显著降低脑剂量。因此，根据“尽可能低”的辐射暴露原则，辐射安全计划和个别外科医生应考虑在这种情况下使用甲状腺领。
