Hizukuri Kyoko, Fujibuchi Toshioh, Han Donghee, Arakawa Hiroyuki, Furuta Takuya
Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Division of Medical Quantum Science, Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Radiol Phys Technol. 2025 Mar;18(1):196-208. doi: 10.1007/s12194-024-00873-z. Epub 2024 Dec 29.
One radiation protection measure for medical personnel in X-ray fluoroscopy is using radiation protective plates. A real-time interactive tool visualizing radiation-dose distribution varied with the protective plate position will help greatly to train medical personnel to protect themselves from unnecessary radiation exposure. Monte Carlo simulation can calculate the individual interactions between radiations and objects in the X-ray room, and reproduce the complex dose distribution inside the room. However, Monte Carlo simulation is computationally time-consuming and not suited for real-time feedback. Therefore, we developed a new method to calculate the dose distribution with the presence of protective plates instantly using pre-computed directional vectors, named Directional vector-based Quick evaluation method for Protective plates Effects in X-ray fluoroscopy (DQPEX). DQPEX uses a database of dose distributions and directional vectors precomputed by Monte Carlo code, Particle and Heavy Ion Transport code System (PHITS). Assuming the dose at each position was all contributed from radiations in the direction indicated by the directional vector, the dose reduction by the protective plates at the position was determined whether the backtrace line of the directional vector has a intersect with the protective plate or not. With DQPEX, the whole dose distribution in X-ray room with the presence of a protective plate can be computed about 13 s, which is approximately 1/6000 of the full PHITS simulation. Sufficient accuracy of DQPEX to visualize the effect of a protective plate was confirmed by comparing the obtained dose distribution with those obtained by the full PHITS simulation and measurements.
X射线透视检查中针对医务人员的一项辐射防护措施是使用辐射防护板。一种能实时交互显示随防护板位置变化的辐射剂量分布的工具，将极大地有助于培训医务人员保护自己免受不必要的辐射照射。蒙特卡罗模拟可以计算X射线室内辐射与物体之间的个体相互作用，并再现室内复杂的剂量分布。然而，蒙特卡罗模拟计算耗时，不适合实时反馈。因此，我们开发了一种新方法，利用预先计算的方向向量即时计算存在防护板时的剂量分布，称为基于方向向量的X射线透视防护板效果快速评估方法（DQPEX）。DQPEX使用由蒙特卡罗代码粒子与重离子输运代码系统（PHITS）预先计算的剂量分布和方向向量数据库。假设每个位置的剂量均由方向向量指示方向上的辐射贡献，通过判断方向向量的反向追踪线是否与防护板相交来确定该位置防护板的剂量减少情况。使用DQPEX，存在防护板时X射线室内的整个剂量分布大约可在13秒内计算出来，这大约是完整PHITS模拟时间的1/6000。通过将获得的剂量分布与完整PHITS模拟和测量得到的剂量分布进行比较，证实了DQPEX在可视化防护板效果方面具有足够的准确性。
