Medicina Nuclear e Radioterapia

Computational Fluid Dynamics Modeling of 90Y Microspheres in Human Hepatic Tumors

Abstract

Christopher A. Basciano, Clement Kleinstreuer and Andrew S. Kennedy

The number of patients afflicted with liver tumors continues to rise being a major concern of international healthcare. Yttrium-90 microsphere radioembolization can be an effective and safe treatment of unresectable primary and secondary liver tumors, and has the potential to be a forefront treatment option for tumor-afflicted patients. Computational fluid-particle dynamics is a powerful research tool that can be used to understand the underlying physics of Yttrium-90 microsphere transport and deposition, leading to improved clinical strategies and ultimately to a better treatment of tumor-afflicted patients. Two representative, patient-inspired three-dimensional geometries of the hepatic arterial system with assumed connections to liver tumors have been considered. Experimentallyvalidated computational fluid-particle dynamics modeling results have shown the significant influence of vessel morphology, downstream resistance to flow, catheter radial and axial location associated with microsphere injection time interval, and injection velocity on microsphere transport through the hepatic arterial system. Moreover, the computational investigations have identified the ability to preferentially deliver microspheres to a specific arterial vessel outlet, presumably connected to a tumor, by selecting appropriate temporal and spatial parameters of the microsphere injection. As the computational findings are extended to additional experiments as well as nextgeneration smart micro-catheters, clinicians can implement a refined set of treatment strategies that utilize the aforementioned physical phenomena. Computational fluid-particle dynamics models have thus provided valuable physical insight as well as suggestions for the improvement of current Yttrium-90 microsphere radioembolization treatment. Additional computational investigations are needed to create more encompassing conclusions from a large collection of patient-specific analyses plus the design, prototyping, and testing of a new smart micro-catheter and high-resolution imaging devices that give radiation and interventional oncologists new degrees of control and precision when administering Yttrium-90 microsphere radioembolization.