Sakamoto Hajime, Moritake Takashi, Sun Lue, Kobayashi Ikuo, Kawauchi Satoru, Abe Toshi, Tsukamoto Atsuko, Morimoto Yuh, Daida Hiroyuki, Matsumaru Yuji
Department of Radiological Technology, Faculty of Health Science, Juntendo University, Tokyo, Japan.
Department of National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Chiba, Japan.
J Neuroendovasc Ther. 2022;16(7):354-360. doi: 10.5797/jnet.oa.2021-0090. Epub 2021 Dec 7.
To meet the new standard of the annual dose limit for the eye lens recommended by the International Commission on Radiation Protection, radiation doses of neuroendovascular procedures in Japanese institutions were investigated.
Radiation doses to operators involved in 304 neuroendovascular procedures at 30 Japanese institutions were prospectively surveyed. The institutions recruited at an annual meeting of the Japanese Society for Neuroendovascular Therapy participated voluntarily. A maximum of 10 wireless dosimeters were attached to the radiation protection (RP) goggles, the ceiling-mounted RP shielding screen, and the operators' forehead and neck over the protective clothing. Doses recorded inside the goggles were defined as eye lens doses for operators who wore RP goggles, while doses to the forehead were defined as eye lens doses for those who did not. The shielding effect rates of the protection devices were calculated, and statistical analysis was performed for the comparison of radiation doses.
From 296 analyzed cases, mean eye lens radiation doses per procedure were 0.088 mGy for the left eye and 0.041 mGy for the right eye. For the left eye, that dose without RP equipment was 0.176 mGy and that with RP goggles plus an RP shielding screen was 0.034 mGy. Four parameters, including left eye dose, air kerma at the patient entrance reference point, fluoroscopic time, and the total number of frames, were assessed for five types of neurovascular procedures. Of them, transarterial embolization for dural arteriovenous fistula was associated with the highest eye lens dose at 0.138 mGy. The shielding effect rates of protection goggles were 60% for the left and 55% for the right RP goggle. The mean doses to the inner and outer surfaces of the RP shielding screen were 0.831 mGy and 0.040 mGy, respectively, amounting to a shielding effect rate of 95%.
To meet the new standard, both RP goggles and RP shielding screens are strongly recommended to be used effectively. Without proper use of radiological protection devices, the number of neuroendovascular procedures that one operator performs per year will be limited under the new guideline.
为达到国际辐射防护委员会推荐的眼晶状体年度剂量限值新标准，对日本各机构神经血管内介入手术的辐射剂量进行调查。
前瞻性地调查了日本30家机构中304例神经血管内介入手术中术者所接受的辐射剂量。这些机构是在日本神经血管内治疗学会年会上招募的，均为自愿参与。在防护服外，最多在辐射防护（RP）护目镜、天花板安装的RP屏蔽屏以及术者的前额和颈部附着10个无线剂量计。佩戴RP护目镜的术者，护目镜内记录的剂量被定义为眼晶状体剂量；未佩戴护目镜的术者，前额的剂量被定义为眼晶状体剂量。计算防护装置的屏蔽效率，并对辐射剂量进行统计学分析以作比较。
在296例分析病例中，每例手术的平均眼晶状体辐射剂量，左眼为0.088 mGy，右眼为0.041 mGy。对于左眼，无RP设备时剂量为0.176 mGy，使用RP护目镜加RP屏蔽屏时剂量为0.034 mGy。对五种神经血管介入手术评估了包括左眼剂量、患者入口参考点处的空气比释动能、透视时间和总帧数在内的四个参数。其中，硬脑膜动静脉瘘的经动脉栓塞术眼晶状体剂量最高，为0.138 mGy。RP护目镜的屏蔽效率，左RP护目镜为60%，右RP护目镜为55%。RP屏蔽屏内、外表面的平均剂量分别为0.831 mGy和0.040 mGy，屏蔽效率达95%。
为达到新标准，强烈建议有效使用RP护目镜和RP屏蔽屏。若不恰当使用放射防护装置，按照新指南，一名术者每年可进行的神经血管内介入手术数量将受到限制。
