SIR 2024
Interventional Oncology
Mohamed Aldallal, BS
Medical Student
Indiana University School of Medicine
Financial relationships: Full list of relationships is listed on the CME information page.
Min Jun Ko, PhD
Postdoctoral Researcher
Northwestern University/Department of Radiology
Disclosure information not submitted.
Sanghee Lee, PhD (she/her/hers)
Postdoctoral researcher
Northwestern University
Financial relationships: Full list of relationships is listed on the CME information page.
Dong-Hyun Kim, PhD (he/him/his)
Associate Professor
Northwestern University/Department of Radiology
Financial relationships: Full list of relationships is listed on the CME information page.
To evaluate the key parameters associated with percutaneous intratumoral therapeutic injection and assess the feasibility of percutaneous intra-tumoral injection as a locoregional cancer therapy method.
Materials and Methods:
Tissue phantoms were created using 1.0% agarose gel solutions, to replicate the properties of liver tissue, and injections were performed with variations in needle sizes, infusion rates, sample volumes, and sample concentrations to assess their impact on the infusion process. After optimization of needle size and volume of samples, three sets of injections were conducted using FDA-approved Doxorubicin to test infusion rates (n = 30, 0.50 µL/min (n = 10), 0.75 µL/min (n = 10), and 1.00 µL/min (n = 10)) and concentrations of Doxorubicin (n = 30, 15 mg/mL (n = 10), 17.5 mg/mL (n = 10), and 20 mg/mL (n = 10)). Each injection was evaluated for leakage from the site of injection and the presence of the drug within the needle track. Furthermore, the morphology of the infused Doxorubicin depots in each group was investigated using high-definition digital images. Subsequently, time-dependent diffusion of the drug was analyzed using a diffusion model to gain insights into the retention of Doxorubicin at the site of interest.
Results:
Optimal conditions for injecting into tissue phantoms composed of 1% agarose (estimated pore size of 0.4 µm) were achieved using infusion rates of 0.50 µL/min and Doxorubicin concentrations of 20 mg/mL. When higher infusion rates were employed, the increased pressure led to reduced Doxorubicin retention within the depot. Consequently, a larger portion of the drug was detected in the needle track and at the injection site. While the drug concentration had a limited impact on the overall infusion process, higher concentrations did result in greater initial distributions of the drug within the depot. However, it is important to note that the small molecular size of Doxorubicin relative to the pore size of the tissue phantom resulted in rapid diffusion of the drug out of the initial depot. This diffusion occurred within 48 hours of the initial injection. Nonetheless, higher drug concentrations did exhibit enhanced retention within the depot, indicating a potential strategy for prolonging the drug's presence at the target site.
Conclusion:
Increasing concentrations of chemotherapeutic agents present a promising avenue to enhance drug retention within the tumor region for intra-tumoral injection. Further development of therapeutic carriers could help overcome the high interstitial pressures of the tumor microenvironment while maximizing retention.