SCK CEN, Belgian Nuclear Research Centre, Mol, Belgium.
J Radiol Prot. 2023 Feb 17;43(1). doi: 10.1088/1361-6498/acb780.
The International Commission on Radiation Units and Measurements (ICRU) proposed a new set of operational quantities for radiation protection for external radiation in its Report Committee 26 (). The new proposal aims to improve the coherence between the operational quantities and the definitions of the protection quantities in the recommendations of the International Commission on Radiological Protection set out in 2007 (). It is expected that this change in operational quantities will impact current dosimeter designs. Although for many photon energies, the conversion coefficients from physical field quantities to the new operational quantities will change relatively little, for radiation fields with low energy photon components, such as medical x-ray applications, there will be a significant decrease in the values of the conversion coefficients. This means that the numerical values of the new operational quantities will be much lower for the same radiation field. These values will be closer to the effective dose, but this change can still cause confusion for medical staff. It is important to examine the effect of the new set of dose conversion coefficients on the personal dose in realistic radiation fields. We performed a study to assess the effect of changing the definition of the operational quantity, personal dose equivalent (Hp), in realistic radiation fields in interventional radiology (IR) workplaces. The x-ray tube kilovoltage peak (kVp) in IR ranges between 60 and 120 kV. The medical staff is exposed to the scattered photons which have a wide range of energies depending on the beam configuration and the patient size. The objective of this study is to 'quantitatively' estimate the impact of implementing the new ICRU quantities of Report 95 in IR radiation fields using Monte Carlo simulations. Simulations of 560 different configurations in IR were performed using MCNPX to calculate fluence binned per energy and angle of incidence.HpandHp(10)were then calculated for each configuration using dose conversion coefficients from fluence given by ICRU Reports 95 and 57, respectively. The results show that the mean of the ratio,Hp(10)/Hp, is 1.6 for all simulated scenarios. This reduction will correct the current overestimation of the effective dose and should result in better compliance with the dose limits in IR. However, it may also have negative consequences on the safety culture among the medical staff. Special care will be needed when interpreting these lower doses.
国际辐射单位和测量委员会（ICRU）在其报告委员会 26（）中为外部辐射辐射防护提出了一组新的操作数量。新提案旨在提高操作数量与 2007 年国际辐射防护委员会建议中保护数量定义之间的一致性（）。预计这种操作数量的变化将影响当前剂量计的设计。尽管对于许多光子能量，从物理场数量到新操作数量的转换系数变化相对较小，但对于低光子能量成分的辐射场，例如医疗 X 射线应用，转换系数的值将显着降低。这意味着对于相同的辐射场，新操作数量的数值将低得多。这些值将更接近有效剂量，但这种变化仍会给医务人员带来困惑。检查新剂量转换系数对实际辐射场中个人剂量的影响非常重要。我们进行了一项研究，以评估在介入放射学（IR）工作场所的实际辐射场中改变操作量，个人剂量当量（Hp）的定义对个人剂量的影响。IR 中的 X 射线管千伏峰值（kVp）在 60 至 120 kV 之间。医务人员会接触到散射光子，这些光子的能量范围很广，具体取决于光束配置和患者的大小。本研究的目的是使用蒙特卡罗模拟“定量”估计在 IR 辐射场中实施 ICRU 报告 95 的新数量对的影响。使用 MCNPX 对 560 种不同的 IR 配置进行了模拟，以计算按能量和入射角划分的通量。然后，使用 ICRU 报告 95 和 57 给出的通量剂量转换系数分别为每种配置计算 Hp 和 Hp（10）。结果表明，对于所有模拟场景，平均比 Hp（10）/ Hp 为 1.6。这种减少将纠正有效剂量的当前高估，并应导致更好地遵守 IR 中的剂量限制。但是，它也可能对医务人员的安全文化产生负面影响。在解释这些较低剂量时需要特别注意。
