Radiologic-pathologic analysis of increased ethanol localization and ablative extent achieved by ethyl cellulose

Area of Science:

• Hepatobiliary interventions
• Minimally invasive oncology
• Biomaterials science

Background:

• Ethanol ablation is a low-cost liver tumor treatment but lacks precision due to diffusion.
• Ethyl cellulose (EC) incorporation aims to localize ethanol distribution for improved accuracy.
• Non-invasive CT imaging is explored for quantitative assessment of ethanol ablation.

Purpose of the Study:

• Establish a CT-based methodology to quantify EC-ethanol delivery parameters and distribution.
• Determine the relationship between EC-ethanol formulation, distribution volume, and necrotic volume.
• Compare the efficacy of EC-ethanol formulation against pure ethanol in liver ablation.

Main Methods:

• Characterized radiodensity-ethanol concentration relationship using water-ethanol surrogates.
• Optimized EC-ethanol formulation ex vivo.
• Performed in vivo liver ablations comparing 12% EC-ethanol to pure ethanol, monitored by CT.
• Quantified ethanol distribution volume and ablation extent via histology (NADH-diaphorase staining).

Main Results:

• CT imaging confirmed a linear relationship between radiodensity and ethanol concentration.
• 12% EC-ethanol formulation showed an eight-fold greater distribution volume ex vivo compared to pure ethanol.
• In vivo, 12% EC-ethanol achieved a three-fold greater distribution volume and six-fold larger ablation zone than pure ethanol.
• Histology confirmed larger necrotic volumes with EC-ethanol, with similar healing responses at 1-4 weeks post-ablation.

Conclusions:

• CT imaging is suitable for quantifying ethanol distribution volume and concentration in tissues.
• The EC-ethanol formulation significantly enhances distribution volume and necrotic extent compared to pure ethanol.
• EC-ethanol distribution volume closely approximates the resulting necrotic volume, offering improved precision for liver tumor ablation.