Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan.
Department of Nuclear Medicine, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan.
Technol Health Care. 2020;28(S1):151-160. doi: 10.3233/THC-209015.
Single-photon emission computed tomography (SPECT) as well as dual energy X-ray absorptiometry (DXA) scanners were designed in July 2018 at the Nuclear Medicine Department (NM), of the Taiwan Medical University Hospital. These scanners emit substantial X-rays from the target, which are tungsten, iron. Therefore, patients undergoing SPECT and DXA diagnosis, in addition to medical personnel, are exposed to undesirable photon leakage.
Following administration of radiopharmaceuticals, patients become radioactive sources; thus, it is necessary to evaluate a possible increase in the environmental gamma exposure rates in the NM as a result of the operation of the new scanners. A three month evaluation of environmental radiation in the NM was performed using the accurate and sensitive TLD-100H approach, which gives an error rate less than 10%.
Detected exposure radiation rates in the NM ranged from 0.12 ± 0.02 to 1.00 ± 0.15 mSv per month, indicating that the imaging room had significantly different radiation rates. The results were compared with previous results, and no significant contribution to the enhancement of environmental gamma radiation was detected, which remained far below the occupational dose recommended by ICRP 60. The minimum detectable dose (MDD) for environmental radiation is also discussed herein to demonstrate the reliability of TLD-100H.
Recommendations were sent to the authorities of AEC-ROC to implement actions that could reduce doses at these high-dose locations to meet the ALARA principle.
单光子发射计算机断层扫描（SPECT）和双能 X 射线吸收仪（DXA）扫描仪于 2018 年 7 月在台湾医科大学附属医院核医学科（NM）设计。这些扫描仪从目标（钨、铁）发出大量 X 射线。因此，接受 SPECT 和 DXA 诊断的患者，除了医务人员之外，还会受到不必要的光子泄漏的照射。
放射性药物给药后，患者成为放射源；因此，有必要评估新扫描仪运行对 NM 环境γ辐射暴露率可能增加的情况。使用准确且灵敏的 TLD-100H 方法对 NM 环境辐射进行了为期三个月的评估，误差率小于 10%。
NM 中的照射辐射率检测范围为 0.12±0.02 至 1.00±0.15 mSv/月，表明成像室的辐射率有明显差异。将结果与以前的结果进行比较，未发现对环境γ辐射增强有显著贡献，仍远低于 ICRP 60 推荐的职业剂量。还讨论了环境辐射的最小可检测剂量（MDD），以证明 TLD-100H 的可靠性。
向台湾原子能委员会当局提出建议，采取行动以降低这些高剂量区域的剂量，以符合 ALARA 原则。
