基于PBU-60体模的介入患者及职业人员辐射剂量学研究

目的 基于仿真人体模型实验及蒙卡模拟,对于一种介入程序中患者入射及出射体表剂量、职业人员辐射剂量、DSA辐射场空间分布进行研究,旨在为患者皮肤损伤推断以及介入工作人员放射防护提供依据。方法 模拟实验中将岛津PBU-60人体模型作为患者,利用热释光剂量计对患者胸腹部入射及出射体表剂量进行测量实验;利用X/γ剂量率仪（型号为：AT1121）对DSA辐射场空间分布进行测量,并利用蒙特卡洛软件MCNP对其进行验证性的计算机模拟;同时对术中工作人员在不同站位、不同防护条件下的辐射剂量学进行实验研究。结果 通过实验测量,表明在某一腹部介入程序PA照射情况下,每5 min介入透视操作将会给患者带来的最大皮肤剂量为18.62 mGy;通过蒙卡模拟及实验测量,表明DSA辐射场空间分布呈现出类似蝴蝶状分布,剂量分布与距离、角度相关;铅防护用品防护效果实验结果表明剂量率与铅当量呈指数衰减规律。结论 开展介入手术中患者皮肤剂量测量,对高剂量患者进行术后随访十分必要。在介入手术中,若条件允许,医生应尽量避开剂量率偏高的站位;如手术需要,必须加强术者位和助手位的辐射防护。在床边铅防护用品和个人防护用品的双重保护下,可显著降低介入人员的受照剂量。

Radiation dosimetric study of patients and professionals in an intervention procedure based on PBU-60 anthropomorphic phantom

Objective Based on the anthropomorphic phantom experiment and Monte Carlo simulation, the patients’ skin dose, professionals’ dose, and spatial distribution of DSA (Digital Subtraction Angiography) radiation field in an intervention procedure, was performed, in order to provide the basis for the inference of patients’ skin injury and professionals’ radiation protection in intervention procedure.Methods In the simulation experiment, a PBU-60 anthropomorphic phantom was used as the patient and the skin dose of patient’s abdomen was measured by TLD (Thermoluminescence Dosimeters). X-ray and gamma radiation dosimeter (AT1121) was applied to measure the spatial distribution of DSA radiation field, which was verified using Monte Carlo software MCNP meanwhile. Furthermore, the radiation dosimetry of operative staffs at different stations and under different protection conditions was studied experimentally.Results The experimental measurements showed that the maximum skin dose of patients every 5-minute fluoroscopy was 18.62 mGy under the irradiation of PA in an abdominal interventional procedure. The results of Monte Carlo simulation and measurement experiments showed that the spatial distribution of DSA radiation fieldis similar to the butterfly distribution, which is related to distance and angle. The experimental results showed that the dose rate decreases exponentially with the increase of lead equivalent.Conclusion It is very significant to carry out skin dose measurementof patients during interventional surgery and follow-up patients with high dose after surgery. In interventional surgery, doctors should try to avoid the station of high dose rate. However, it is necessary to strengthen the radiation protection of the operator and the first assistant. Under the dual protections of bedside lead protective equipment and personal protective equipment, the exposure dose of intervention personnel can be significantly reduced.