Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
Department of Radiology, UC Davis Medical Center, Sacramento, CA, 95817, USA.
Ann Biomed Eng. 2020 May;48(5):1499-1510. doi: 10.1007/s10439-020-02469-1. Epub 2020 Jan 31.
Yttrium-90 (Y-90) transarterial radioembolization uses radioactive microspheres injected into the hepatic artery to irradiate liver tumors internally. One of the major challenges is the lack of reliable dosimetry methods for dose prediction and dose verification. We present a patient-specific dosimetry approach for personalized treatment planning based on computational fluid dynamics (CFD) simulations of the microsphere transport combined with Y-90 physics modeling called CFDose. The ultimate goal is the development of a software to optimize the amount of activity and injection point for optimal tumor targeting. We present the proof-of-concept of a CFD dosimetry tool based on a patient's angiogram performed in standard-of-care planning. The hepatic arterial tree of the patient was segmented from the cone-beam CT (CBCT) to predict the microsphere transport using multiscale CFD modeling. To calculate the dose distribution, the predicted microsphere distribution was convolved with a Y-90 dose point kernel. Vessels as small as 0.45 mm were segmented, the microsphere distribution between the liver segments using flow analysis was predicted, the volumetric microsphere and resulting dose distribution in the liver volume were computed. The patient was imaged with positron emission tomography (PET) 2 h after radioembolization to evaluate the Y-90 distribution. The dose distribution was found to be consistent with the Y-90 PET images. These results demonstrate the feasibility of developing a complete framework for personalized Y-90 microsphere simulation and dosimetry using patient-specific input parameters.
钇-90（Y-90）经动脉放射性栓塞术使用放射性微球注入肝动脉内部照射肝脏肿瘤。其中一个主要挑战是缺乏可靠的剂量测定方法来进行剂量预测和剂量验证。我们提出了一种基于微球运输的计算流体动力学（CFD）模拟与 Y-90 物理建模相结合的患者特异性剂量测定方法，称为 CFDose，用于基于个体的治疗计划。最终目标是开发一种软件来优化活动物质量和注射点，以实现最佳肿瘤靶向。我们提出了一种基于患者在标准护理计划中进行的血管造影的 CFD 剂量测定工具的概念验证。从锥形束 CT（CBCT）中分割出患者的肝动脉树，使用多尺度 CFD 建模来预测微球的运输。为了计算剂量分布，将预测的微球分布与 Y-90 剂量点核卷积。分割出小至 0.45mm 的血管，使用流动分析预测肝段之间的微球分布，计算肝体积内的体积微球和由此产生的剂量分布。在放射性栓塞后 2 小时对患者进行正电子发射断层扫描（PET）成像，以评估 Y-90 分布。发现剂量分布与 Y-90 PET 图像一致。这些结果证明了使用患者特异性输入参数开发完整的个性化 Y-90 微球模拟和剂量测定框架的可行性。
