CFD simulation of non-Newtonian blood flow with radioisotope tracking for targeted cancer therapy*

Targeted radioisotope therapy (TRT) for cancer treatment has been the subject of many research studies in recent years. In this project we are developing a multi-scale modeling approach to study both the transport of radioisotopes from injection site to tumor and the consequent tumor dose. This approach constitutes (1) human body geometries (including internal organs and vasculature systems) from high resolution digital whole-body eXtended CArdio-Thoracic (XCAT) phantoms, (2) a physiologically-based pharmacokinetic (PBPK) model to track the amount and clearance of radioisotope within the human body, (3) a CFD model to obtain the spatio-temporal distribution of the isotope within the vasculature of the organ of interest, and (4) a radiation transport model to assess the resulting dose to the cancerous tumor.

               The present talk will focus on the CFD model which takes as an input the PBPK model’s output: time dependent radioisotope concentration. A non-Newtonian blood flow CFD model within the open-source CFD software, OpenFOAM, is used to simulate blood flow characteristics within liver vasculature systems. Validation and verification of the model for laminar and turbulent flow regimes against a relevant test case (blood flow within a syringe, showing results with 1% of experimental data) will be presented. This model is augmented with a passive scalar equation to track the radioisotope concentration within the vasculature system. Results of the spatio-temporal distribution of the radioisotope concentration will be shown and transferring of the data to a radiation transport simulation code, Geant4, discussed. This enables high-fidelity simulation of the radiation dose to the tumor cells. The impact of accounting for the spatio-temporal distribution of radioisotope using 3D CFD blood flow models on the dose will be assessed.