Impact of injection velocity on microsphere distribution in transarterial radioembolization, an in vitro analysis
T.J. Snoeijink (RadboudUMC – Department of Medical Imaging, TNW-M3i), J.L. van der Hoek (TNW-M3i), A. van den Brekel (RadboudUMC – Department of Medical Imaging), J.F.W. Nijsen (RadboudUMC – Department of Medical Imaging), E. Groot Jebbink (TNW-M3i)
Abstract
Introduction: Transarterial radioembolization (TARE) is an established treatment method for patients with liver malignancies, concerning the injection of radioactive microspheres into the liver artery supplying the tumour. Distribution depends on blood flow and vessel morphology and will differ per procedure, medical practitioner and patient. The aim of the current study was to investigate the influence of injection profile on the microsphere distributions.
Methods: A symmetrical hepatic artery phantom was developed which bifurcates three times into eight outlets. A physiological representative blood flow waveform was imposed using a programmable piston pump. Microsphere injections were performed with non-irradiated holmium loaded microspheres using two different injection devices (Quirem administration box and rotational syringe device) and different injection profiles (pulsatile and continuous, 24-10-5 ml/min). Blue dyed injection solution and microspheres were collected at each outlet and measured using a spectrophotometer and by weighing, respectively.
Results: A very strong correlation between dyed injection solution and microsphere distribution was observed. At 24 ml/min, the continuous injection spread throughout the entire lumen after the first bifurcation in the phantom, while the pulsatile profile remained more targeted. Reducing injection speed resulted in more targeted injection jets.
Conclusion: In TARE it is assumed that microspheres will follow the blood flow, which is favourable for non-targeted injections. However, this work showed that altering the injection profile could lead to more targeted injections, which might be used in clinic for more specific tumour targeting. Future research should focus on current administration methods and their influence on in vivo TARE microsphere distribution.