Iizuka Takafumi, Matsumoto Kazuma, Hagihara Yoshiaki, Nasada Toshiya, Ikeuchi Youko, Kikuchi Keisuke, Mitsuie Chiemi, Kotoura Noriko, Yamakado Kouichirou, Kobayashi Kaoru, Takaki Haruyuki, Kako Yasukazu
Department of Radiological Technology, Hyogo College of Medicine.
Department of Radiology, Hyogo College of Medicine.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2019;75(7):625-630. doi: 10.6009/jjrt.2019_JSRT_75.7.625.
In April 2011, the International Radiological Protection Committee recommended that "The equivalent dose of the crystalline lens should not exceed 20 mSv/year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv". Based on this recommendation, it is predicted that the equivalent dose limit of our crystalline lens can be lowered in the near future. Therefore, it is important to grasp the current situation of radiation exposure. The purpose of this study is to measure the crystalline lens of surgeons by focusing on the CT-fluoroscopy guided interventional radiology's (IVRs). We also examined whether the exposure dose of the crystalline lens can be correctly evaluated by measuring the unequal exposure dose of the neck, which is usually used for the unequal exposure measurement. Results of the analysis of 200 CT-fluoroscopy guided IVR procedures showed that the unequal exposure dose of the neck was significantly correlated with the exposure dose of the crystalline lens which was measured near the left eye ball (R=0.83). However, the exposure dose of the crystalline was 33% lower than those of the neck. Therefore, although the individual dosimeter worn on the neck can be used as the useful index of the exposure dose of the crystalline lens, the results can be overestimated.
2011年4月，国际放射防护委员会建议“晶状体的当量剂量在规定的5年期间内平均每年不应超过20毫希沃特，且任何单一年份不应超过50毫希沃特”。基于这一建议，预计在不久的将来我们晶状体的当量剂量限值可能会降低。因此，掌握当前的辐射暴露情况很重要。本研究的目的是通过聚焦于CT透视引导下的介入放射学（IVRs）来测量外科医生的晶状体。我们还研究了通过测量通常用于非均匀照射剂量测量的颈部非均匀照射剂量，是否能够正确评估晶状体的照射剂量。对200例CT透视引导下的IVR手术的分析结果表明，颈部的非均匀照射剂量与在左眼球附近测量的晶状体照射剂量显著相关（R = 0.83）。然而，晶状体的照射剂量比颈部的照射剂量低33%。因此，尽管佩戴在颈部的个人剂量计可作为晶状体照射剂量的有用指标，但结果可能会被高估。
