Simulating convection-enhanced delivery in the putamen using probabilistic tractography

The treatment of brain diseases is complicated by the presence of the blood-brain barrier. This barrier limits the crossing of therapeutic molecules from the blood vessels into the brain. Today, direct intracerebral infusion applying convection-enhanced delivery (CED) is proposed to circumvent this problem and enhance the area of distribution of infusate beyond the parameters of diffusion. Several factors affect the efficacy, predictability and replicability of CED, such as the catheter model, infusion rate and site of infusion. We set out to investigate if probabilistic tractography can be used to model the infusion flow and predict the intracerebral movement of molecules. In this study we describe a modeling and analysis framework based upon probabilistic tractography. This framework was used to compare probabilistic tractography modeling and actual CED infusion measurements in the putamen of non-human primates, as this gray matter structure is proposed as a target for CED treatment of Parkinson´s disease.