Flexible radioluminescence imaging for FDG-guided surgery.

Area of Science:

• Medical Imaging
• Optical Imaging
• Radiochemistry

Background:

• Flexible radioluminescence imaging (Flex-RLI) is an optical technique for detecting tumors using 18F-fluorodeoxyglucose (FDG).
• A flexible gadolinium oxysulfide: terbium (GOS:Tb) scintillator may improve signal-to-background ratio (SBR) compared to flat scintillators.

Purpose of the Study:

• To characterize Flex-RLI performance.
• Compare Flex-RLI against RLI, beta-RLI, and Cerenkov luminescence imaging (CLI).

Main Methods:

• In vitro characterization of photon sensitivity, spatial resolution, and signal linearity.
• In vivo studies in 13 nude mice bearing human head and neck tumors (UMSCC1-Luc).
• Comparison of tumor SBR values using the Wilcoxon signed rank test after 18F-FDG injection.

Main Results:

• Flex-RLI showed improved in vivo SBR (median 1.29) compared to RLI (1.08; p < 0.01), a 26% increase.
• Photon sensitivity: RLI, beta-RLI, and flex-RLI produced significantly more radiance than CLI.
• Spatial resolution (FWHM) was 1.5 mm for flex-RLI, superior to RLI (6.9 mm) and beta-RLI (6.4 mm).

Conclusions:

• Flex-RLI yields high-quality images with SBRs comparable to CLI and beta-RLI.
• Achieves comparable SBRs in a rapid 10-second acquisition.
• Demonstrates potential as an effective optical imaging modality for FDG-avid tumors.