Smartphone Augmented Reality Outperforms Conventional CT Guidance for Composite Ablation Margins in Phantom Models

Area of Science:

• Medical Imaging
• Surgical Technology
• Interventional Radiology

Background:

• Large liver tumors present challenges for accurate ablation.
• Conventional guidance methods like CT may have limitations in precision and real-time feedback.
• Iterative planning is crucial for effective ablation of large tumors.

Purpose of the Study:

• To develop and evaluate a smartphone augmented reality (AR) system for guiding the ablation of large liver tumors (50 mm).
• To assess the system's effectiveness in treatment planning for composite overlapping ablation zones.
• To compare AR guidance with conventional CT guidance for liver tumor ablation.

Main Methods:

• Developed a smartphone AR application displaying tumor, probe, paths, and ablated volume.
• Used fiducial markers for tracking in phantom studies.
• Four interventional radiologists performed probe insertions using AR and CT guidance.
• Compared ablation percentages and analyzed correlation with experience levels.

Main Results:

• AR guidance resulted in a significantly higher mean percentage of tumor ablated (47% ± 4) compared to CT guidance (36% ± 7).
• Displaying recorded ablation zones during AR guidance further improved the mean composite percentage of tumor ablated (50% ± 2).
• AR guidance showed less correlation with physician experience (r < 0.5) than CT guidance (r > 0.9).

Conclusions:

• Smartphone AR guidance is accurate and effective for large liver tumor ablation.
• The AR system outperforms conventional CT guidance, particularly for interventional radiologists with less experience.
• The AR system promotes more standardized performance across varying experience levels.