Towards a patient-specific hepatic arterial modeling for microspheres distribution optimization in SIRT protocol

Abstract

Selective internal radiation therapy (SIRT) using Yttrium-90 loaded glass microspheres injected in the hepatic artery is an emerging, minimally invasive therapy of liver cancer. A personalized intervention can lead to high concentration dose in the tumor, while sparing the surrounding parenchyma. We propose a computational model for patient-specific simulation of entire hepatic arterial tree, based on liver, tumors, and arteries segmentation on patient's tomography. Segmentation of hepatic arteries down to a diameter of 0.5 mm is semi-automatically performed on 3D cone-beam CT angiography. The liver and tumors are extracted from CT-scan at portal phase by an active surface method. Once the images are registered through an automatic multimodal registration, extracted data are used to initialize a numerical model simulating liver vascular network. The model creates successive bifurcations from given principal vessels, observing Poiseuille's and matter conservation laws. Simulations provide a coherent reconstruction of global hepatic arterial tree until vessel diameter of 0.05 mm. Microspheres distribution under simple hypotheses is also quantified, depending on injection site. The patient-specific character of this model may allow a personalized numerical approximation of microspheres final distribution, opening the way to clinical optimization of catheter placement for tumor targeting.

Computational Modeling of the Liver Arterial Blood Flow for Microsphere Therapy: Effect of Boundary Conditions

“…In this study, the blood was assumed to behave like a Newtonian fluid because most of the vasculature included in the computational model had a diameter greater than one millimeter [ 38 ]. This assumption was consistent with previous studies investigating the blood flow in the hepatic arterial tree [ 25 , 39 , 40 ]. However, it is well known that blood is a non-Newtonian fluid when it circulates in smaller arteries.…”

A proof-of-concept study of the in-vivo validation of a computational fluid dynamics model of personalized radioembolization

“…On the other hand, since all these local parameters are referred to as modifications in the 3D space, adoption of a 3D approach in the development of the CFD model, as used in this study, seems unquestionable. Not using a complete 3D approach or Bcs based on perfusions are the main limitations affecting some previous studies investigating the use of computational models to predict microsphere distribution after RE [25][26][27] .…”

Virtual Lobule Models Are the Key for Multiscale Biomechanical and Pharmacological Modeling for the Liver

“…Different mathematical/computational techniques are used for modeling the hepatic blood flow. When subject-specific vascular information are essential, for example, in radiotherapies where drugs are administrated through a catheter at a specific vascular site (Simoncini et al, 2018 ), vascular geometry is included in the blood flow model in one or three dimensional (1D or 3D) partial differential equations (Ho et al, 2013b ; Audebert et al, 2017 ). When the blood flow in vessels is considered as a steady Poiseulle flow, the flow equations can be parameterised per the vascular diameter, and length and effectively solved (Barléon et al, 2018 ).…”