Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, CA 95616.
Department of Radiology, University of California Davis, 4860 Y Street, Suite 3100, Sacramento, CA 95817.
J Biomech Eng. 2021 Jan 1;143(1). doi: 10.1115/1.4047656.
Yttrium-90 (90Y) radioembolization is a minimally invasive procedure increasingly used for advanced liver cancer treatment. In this method, radioactive microspheres are injected into the hepatic arterial bloodstream to target, irradiate, and kill cancer cells. Accurate and precise treatment planning can lead to more efficient and safer treatment by delivering a higher radiation dose to the tumor while minimizing the exposure of the surrounding liver parenchyma. Treatment planning primarily relies on the estimated radiation dose delivered to tissue. However, current methods used to estimate the dose are based on simplified assumptions that make the dosimetry results unreliable. In this work, we present a computational model to predict the radiation dose from the 90Y activity in different liver segments to provide a more realistic and personalized dosimetry. Computational fluid dynamics (CFD) simulations were performed in a 3D hepatic arterial tree model segmented from cone-beam CT angiographic data obtained from a patient with hepatocellular carcinoma (HCC). The microsphere trajectories were predicted from the velocity field. 90Y dose distribution was then calculated from the volumetric distribution of the microspheres. Two injection locations were considered for the microsphere administration, a lobar and a selective injection. Results showed that 22% and 82% of the microspheres were delivered to the tumor, after each injection, respectively, and the combination of both injections ultimately delivered 49% of the total administered 90Y microspheres to the tumor. Results also illustrated the nonhomogeneous distribution of microspheres between liver segments, indicating the importance of developing patient-specific dosimetry methods for effective radioembolization treatment.
钇-90（90Y）放射性栓塞是一种越来越多地用于治疗晚期肝癌的微创方法。在这种方法中，放射性微球被注入肝动脉血流中，以靶向、辐照和杀死癌细胞。准确和精确的治疗计划可以通过向肿瘤输送更高的辐射剂量，同时最大限度地减少周围肝实质的暴露，从而实现更有效和更安全的治疗。治疗计划主要依赖于组织接受的估计辐射剂量。然而，目前用于估计剂量的方法基于简化的假设，这些假设使得剂量计算结果不可靠。在这项工作中，我们提出了一种计算模型，以预测不同肝段中 90Y 活性的辐射剂量，从而提供更真实和个性化的剂量计算。在从肝细胞癌（HCC）患者获得的锥形束 CT 血管造影数据分割的 3D 肝动脉树模型中进行了计算流体动力学（CFD）模拟。从速度场预测微球轨迹。然后从微球的体积分布计算 90Y 剂量分布。考虑了两种微球给药位置，即叶状和选择性注射。结果表明，每次注射后，分别有 22%和 82%的微球输送到肿瘤，两种注射的组合最终将 49%的总给药 90Y 微球输送到肿瘤。结果还说明了微球在肝段之间的不均匀分布，表明为有效的放射性栓塞治疗开发患者特异性剂量计算方法的重要性。
