^(90)Y玻璃微球用于胰腺癌治疗时的器官剂量计算  

Calculation of organ dose of ^(90)Y TheraSphere in the treatment ofpancreatic cancer

作　　者：王江霞 王薇[1] 汪传高[1] 郭金森[1] 庞洪超[1] WANG Jiangxia;WANG Wei;WANG Chuangao;GUO Jinsen;PANG Hongchao(China Institute for Atomic Energy,Beijing 102413 China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《中国辐射卫生》2024年第3期234-241,共8页Chinese Journal of Radiological Health

摘　　要：目的通过建立个体体素模型,模拟计算胰腺癌治疗中^(90)Y玻璃微球给药后对胰腺及周围敏感器官的吸收剂量,为^(90)Y玻璃微球应用于胰腺癌治疗的临床应用提供技术支撑。方法在Geant4软件中基于患者CT图像构建个体体素模型,计算0.01~1 MeV 12种单能电子比吸收分数(SAF)与ICRP权威数据进行比对验证;利用上述模型及方法计算^(90)Y微球在胰腺中均匀和非均匀分布时各靶器官的吸收剂量。结果基于建立的模型计算的SAF值与经质量校准后的ICRP数据比较误差不超过3.89%;^(90)Y在胰腺内均匀分布时,胰腺吸收剂量为4.69×10^(-7) Gy/Bq,肝、肾脏以及脾的吸收剂量分别为6.15×10^(-12)、6×10^(-12)和1.65×10^(-11) Gy/Bq;^(90)Y在肿瘤内分布时,肿瘤吸收剂量为6.69×10^(-6) Gy/Bq,正常胰腺剂量为5.75×10−8 Gy/Bq;处方剂量120 Gy情况下,肿瘤体积V与给药活度A的拟合关系为二次函数;肿瘤中心集中给药所需活度相对较低。结论建立的基于个体体素模型的MC剂量计算方法,准确预测了^(90)Y玻璃微球治疗胰腺癌时周围敏感器官(肝、肾脏以及脾脏)的吸收剂量,计算结果以及对给药活度影响因素的分析将为^(90)Y玻璃微球用于胰腺癌的临床研究提供数据支持。Objective To calculate the absorbed dose of ^(90)Y TheraSphere in the pancreas and the surrounding sensitive organs after the administration in the treatment of pancreatic cancer through the establishment of an individual voxel model,and to provide technical support for the clinical application of ^(90)Y TheraSphere in the treatment of pancreatic cancer.Methods An individualized voxel model was constructed in Geant4 software based on the CT images of the patient.12 monoenergetic electron specific absorption fractions(SAFs)in the range of 0.01 to 1 MeV were calculated and validated against the ICRP data.The model and method were used to calculate the absorbed doses in the target organs under uniform and nonuniform distribution of ^(90)Y microspheres in the pancreas.Results The relative errors between the SAF values calculated based on the individualized voxel model and the ICRP data after mass calibration were less than 3.89%.When ^(90)Y was uniformly distributed in the pancreas,the absorbed dose in the pancreas was 4.69×10^(-7) Gy/Bq;the absorbed doses in the liver,kidneys,and spleen were 6.15×10^(-12),6×10^(-12),and 1.65×10^(-11) Gy/Bq,respectively.When ^(90)Y was distributed within the tumor,the absorbed dose in the tumor was 6.69×10^(-6) Gy/Bq and the absorbed dose in normal pancreas was 5.72×10−8 Gy/Bq.The fitted relationship between tumor volume V and administered activity A at the prescribed dose of 120 Gy was quadratic,with relatively low activity required for concentrated administration in the center of the tumor.Conclusion The Monte Carlo dose calculation method based on individual voxel model accurately predicted the absorbed doses in the surrounding sensitive organs(liver,kidneys,and spleen)when ^(90)Y TheraSphere was used to treat pancreatic cancer.These results and the analysis of the factors affecting the drug delivery activity will provide data support for the clinical research of ^(90)Y TheraSphere in pancreatic cancer.

关 键 词：^(90)Y玻璃微球 胰腺癌治疗 剂量计算 

分 类 号：X591[环境科学与工程—环境工程]