Extending the Hybrid Surgical Guidance Concept With Freehand Fluorescence Tomography

Area of Science:

• Medical Imaging
• Surgical Navigation
• Hybrid Imaging Modalities

Background:

• Image-guided surgery increasingly utilizes hybrid guidance technologies.
• Integrating radioactive and fluorescence guidance offers complementary benefits.
• Freehand SPECT (fhSPECT) and freehand fluorescence (fhFluo) are emerging techniques.

Purpose of the Study:

• To explore the complementary value of a novel freehand fluorescence (fhFluo) imaging approach with freehand SPECT (fhSPECT) in a hybrid setup.
• To evaluate the performance of fhFluo and fhSPECT in terms of image resolution and signal penetration.
• To assess the combined potential of these freehand technologies for surgical navigation in cancer specimens.

Main Methods:

• Developed a hybrid opto-nuclear detection probe with near-infrared optical tracking for position and orientation registration.
• Utilized dedicated look-up table models for 3D reconstruction.
• Investigated fhSPECT and fhFluo in phantom and excised tissue settings, and on prostate cancer patient specimens.

Main Results:

• The hybrid setup generated 3D nuclear and fluorescence tomography scans.
• fhFluo achieved superior imaging resolution (1 mm) compared to fhSPECT (6 mm).
• Fluorescence imaging was limited to 0.5 cm depth, while nuclear imaging penetrated <2 cm; both enabled accurate navigation.

Conclusions:

• Freehand fluorescence imaging (fhFluo) provides complementary value to freehand SPECT (fhSPECT) when using both radioactive and fluorescent tracers.
• The combined freehand technologies create a unique hybrid imaging and navigation modality for image-guided surgery.
• This hybrid approach enhances localization and navigation accuracy in surgical procedures.