The Impact of Injection Distance to Bifurcations on Yttrium-90 Distribution in Liver Cancer Radioembolization

Purpose: To model the effect of the injection location on the distribution of yttrium-90 (Y-90) microspheres in the liver during radioembolization using computational simulation and to determine the potential effects of radial movements of the catheter tip. Materials and Methods: Numerical studies were conducted using images from a representative patient with hepatocellular carcinoma. The right hepatic artery (RHA) was segmented from contrast-enhanced cone-beam computed tomography scans. The blood flow was investigated in the trunk of the RHA using numerical simulations for 6 injection position scenarios at 2 sites located at a distance of approximately 5 and 20 mm upstream of the first bifurcation (RHA diameters of approximately 4.6 mm). The Y-90 delivery to downstream vessels was calculated from the simulated hepatic artery hemodynamics. Results: Varying the injection location along the RHA and across the vessel cross-section resulted in different simulated microsphere distributions in the downstream vascular bed. When the catheter tip was 5 mm upstream of the bifurcation, Y-90 distribution in the downstream branches varied by as much as 53% with a 1.5-mm radial movement of the tip. However, the catheter radial movement had a weaker effect on the microsphere distribution when the injection plane was farther from the first bifurcation (20 mm), with a maximum delivery variation of 9% to a downstream branch. Conclusions: An injection location far from bifurcations is recommended to minimize the effect of radial movements of the catheter tip on the microsphere distribution.

Automated summary

This study used computational simulation to investigate the effect of injection location on the distribution of Y-90 microspheres in the liver during radioembolization. The results showed that varying the injection location resulted in different microsphere distributions in the downstream vascular bed, and the radial movement of the catheter tip had a weaker effect on microsphere distribution when the injection plane was farther from the bifurcation.