Kuttner Hannes, Benninger Emanuel, Fretz Valentin, Meier Christoph
Division for Orthopaedics and Traumatology, Cantonal Hospital Winterthur, Brauerestrasse 15, CH-8401, Winterthur, Switzerland.
Division for Radiology and Nuclear Medicine, Cantonal Hospital Winterthur, Brauerstarsse 15, CH-8401, Winterthur, Switzerland.
Eur J Orthop Surg Traumatol. 2022 Oct;32(7):1399-1405. doi: 10.1007/s00590-021-03111-z. Epub 2021 Sep 22.
Minimally invasive fluoroscopy-guided screw fixation is an established technique to stabilize fractures of the posterior pelvic ring in orthopaedic surgery. However, safe placement of the screws may be associated with prolonged intervention time and extensive fluoroscopy is a concern. In the current literature, the dose area product (DAP) and fluoroscopy time are often used to describe radiation exposure of the patient. It was the aim of the study to compare DAP to organ doses and the effective dose for four standard views commonly used in pelvic surgery.
An anthropomorphic cross-sectional dosimetry phantom, representing the body of a male human (173 cm/73 kg), was equipped with metal-oxide-semiconductor field-effect transistors (MOSFET) in different organ locations to measure radiation exposure. Anteroposterior (APV), lateral (LV), outlet (OLV) and inlet (ILV) of the phantom were obtained with a mobile C-arm, and effective dose and organ doses were calculated. DAP was measured in the built-in ionisation chamber beyond the collimator of the C-arm. The measurements were repeated with a fat layer to simulate an obese patient.
Overall, the highest organ dose was measured in the stomach for ILV (0.918 mSv/min). Effective dose for ILV showed the highest values by far (1.85 mSv/min) and the lowest for LV (0.46 mSv/min). The DAP pattern was completely different to the effective dose with similar values for LV and ILV (12.2 and 12.3 µGy·m/s). Adding a fat layer had no major effect on the measurements.
The exposure to radiation varies considerably between different orthopaedic standard views of the pelvis. About the fourfold amount of the effective dose was measured for ILV compared to LV. DAP and irradiation time do not respect either the body region in the field of radiation or the radiosensitivity of the affected organs. Thus, they do not allow a reliable interpretation of the radiation burden the patient is exposed to.
在骨科手术中，微创荧光透视引导下的螺钉固定是一种用于稳定骨盆后环骨折的成熟技术。然而，螺钉的安全置入可能会导致手术时间延长，且大量的荧光透视是一个问题。在当前文献中，剂量面积乘积（DAP）和荧光透视时间常被用于描述患者的辐射暴露情况。本研究的目的是比较骨盆手术中常用的四种标准视图下的DAP与器官剂量及有效剂量。
使用一个代表男性人体（身高173厘米/体重73千克）的拟人化横断面剂量学体模，在不同器官位置配备金属氧化物半导体场效应晶体管（MOSFET）以测量辐射暴露。使用移动C形臂获取体模的前后位（APV）、侧位（LV）、出口位（OLV）和入口位（ILV），并计算有效剂量和器官剂量。DAP通过C形臂准直器后方的内置电离室进行测量。在体模上加一层脂肪以模拟肥胖患者，重复进行测量。
总体而言，ILV视图下胃部的器官剂量最高（0.918毫希沃特/分钟）。ILV视图的有效剂量迄今为止显示为最高值（1.85毫希沃特/分钟），而LV视图的有效剂量最低（0.46毫希沃特/分钟）。DAP模式与有效剂量完全不同，LV和ILV的DAP值相似（12.2和12.3微戈瑞·米/秒）。添加脂肪层对测量结果没有重大影响。
骨盆不同骨科标准视图下的辐射暴露差异很大。与LV相比，ILV的有效剂量约为其四倍。DAP和照射时间既不考虑辐射区域内的身体部位，也不考虑受影响器官的放射敏感性。因此，它们无法可靠地解释患者所承受的辐射负担。
