Convection-enhanced delivery with controlled catheter movement: A parametric finite element analysis.

Convection-enhanced delivery (CED) is an investigational method for delivering therapeutics directly to the brain for the treatment of glioblastoma. However, it has not become a common clinical therapy due to an inability of CED treatments to deliver therapeutics in a large enough tissue volume to fully saturate the target region. We have recently shown that the combination of controlled catheter movement and constant pressure infusions can be used to significantly increase volume dispersed (V(d) ) in an agarose gel brain tissue phantom. In the present study, we develop a computational model to predict V(d) achieved by various retraction rates with both constant pressure and constant flow rate infusions. An increase in V(d) is achieved with any movement rate, but increase in V(d) between successive movement rates drops off at rates above 0.3-0.35 mm/min. Finally, we found that infusions with retraction result in a more even distribution in concentration level compared to the stationary catheter, suggesting a potential increased ability for moving catheters to have a therapeutic impact regardless of the required therapeutic concentration level.