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Updated: Dec 11, 2025
Image-guided Convection-enhanced Delivery into Agarose Gel Models of the Brain
Published on: May 14, 2014
Controlled Catheter Movement Affects Dye Dispersal Volume in Agarose Gel Brain Phantoms
Jason N Mehta1, Gabrielle R McRoberts2, Christopher G Rylander1
1Walker Department of Mechanical Engineering, The University of Texas at Austin, 204 E. Dean Keeton Street, Stop C2200, Austin, TX 78712-1591, USA.
Abstract:
The standard of care for treatment of glioblastoma results in a mean survival of only 12 to 15 months. Convection-enhanced delivery (CED) is an investigational therapy to treat glioblastoma that utilizes locoregional drug delivery via a small-caliber catheter placed into the brain parenchyma. Clinical trials have failed to reach their endpoints due to an inability of standard catheters to fully saturate the entire brain tumor and its margins. In this study, we examine the effects of controlled catheter movement on dye dispersal volume in agarose gel brain tissue phantoms. Four different catheter movement control protocols (stationary, continuous retraction, continuous insertion, and intermittent insertion) were applied for a single-port stepped catheter capable of intrainfusion movement. Infusions of indigo carmine dye into agarose gel brain tissue phantoms were conducted during the controlled catheter movement. The dispersal volume (Vd), forward dispersal volume (Vdf), infusion radius, backflow distance, and forward flow distance were quantified for each catheter movement protocol using optical images recorded throughout the experiment. Vd and Vdf for the retraction and intermittent insertion groups were significantly higher than the stationary group. The stationary group had a small but significantly larger infusion radius than either the retracting or the intermittent insertion groups. The stationary group had a greater backflow distance and lower forward flow distance than either the retraction or the intermittent insertion groups. Continuous retraction of catheters during CED treatments can result in larger Vd than traditional stationary catheters, which may be useful for improving the outcomes of CED treatment of glioblastoma. However, catheter design will be crucial in preventing backflow of infusate up the needle tract, which could significantly alter both the Vd and shape of the infusion.
Insights
Controlled catheter movement during convection-enhanced delivery (CED) can improve drug dispersal for glioblastoma treatment. Continuous retraction of the catheter significantly increased dye dispersal volume in brain phantom models.
Area of Science:
- Neurosurgery
- Biomedical Engineering
- Oncology
Background:
- Glioblastoma treatment has a poor prognosis, with standard care offering limited survival benefits.
- Convection-enhanced delivery (CED) is an investigational locoregional therapy for glioblastoma, delivering drugs directly into brain tissue.
- Current CED clinical trials face challenges due to inadequate tumor coverage with standard stationary catheters.
Purpose of the Study:
- To investigate the impact of controlled catheter movement on drug dispersal volume in glioblastoma treatment.
- To compare the efficacy of different catheter movement protocols (stationary, continuous retraction, continuous insertion, intermittent insertion) on infusion parameters.
Main Methods:
- Utilized a single-port stepped catheter with intrainfusion movement capabilities in agarose gel brain tissue phantoms.
- Applied four distinct catheter movement protocols: stationary, continuous retraction, continuous insertion, and intermittent insertion.
- Infused indigo carmine dye and quantified dispersal volume (Vd), forward dispersal volume (Vdf), infusion radius, backflow, and forward flow using optical imaging.
Main Results:
- Retraction and intermittent insertion protocols resulted in significantly larger dispersal volumes (Vd and Vdf) compared to the stationary protocol.
- The stationary catheter group exhibited a larger infusion radius but also greater backflow and reduced forward flow.
- Continuous catheter retraction during CED demonstrated potential for enhanced drug distribution over traditional stationary methods.
Conclusions:
- Continuous catheter retraction during CED may improve glioblastoma treatment outcomes by increasing drug dispersal volume.
- Catheter design is critical for preventing infusate backflow along the needle tract, which can negatively impact dispersal.
- Optimizing catheter movement strategies holds promise for enhancing the effectiveness of convection-enhanced delivery for brain tumors.
