Vascularity Assessment of Parathyroid Glands Using Low-Dose ICG and Probe-Based Fluorescence Detection

Area of Science:

• Endocrine Surgery
• Surgical Innovation
• Medical Imaging

Background:

• Indocyanine green (ICG) angiography is crucial for assessing parathyroid gland perfusion post-thyroidectomy to mitigate hypocalcemia.
• Current methods rely on subjective visual assessment, leading to variability.
• This study aimed to evaluate a quantitative approach using probe-based fluorescence detection.

Purpose of the Study:

• To assess the efficacy of probe-based indocyanine green (ICG) fluorescence detection for quantitative parathyroid gland perfusion assessment.
• To compare quantitative probe measurements with subjective surgeon scoring of ICG angiography.
• To establish a reliable method for predicting parathyroid gland vascularity.

Main Methods:

• Prospective study involving patients undergoing endocrine neck surgery.
• Intraoperative identification of parathyroid glands using near-infrared autofluorescence (NIRAF).
• Administration of low-dose ICG and measurement of fluorescence change using a probe-based system.
• Comparison of probe-measured ICG ratios with surgeon-scored ICG images.

Main Results:

• Analysis of 25 patients revealed moderate agreement in subjective ICG image scoring (κ=0.48-0.58).
• Significant disagreement in scoring occurred for glands with poor blood flow, highlighting the need for quantitative methods.
• A fluorescence increase threshold (≥4.5-fold) identified well-vascularized glands, while ≤1.0-fold indicated devascularized glands.

Conclusions:

• Subjective scoring of ICG angiography for parathyroid glands is inconsistent among surgeons.
• Probe-based fluorescence measurements following low-dose ICG administration provide a quantitative and reliable prediction of parathyroid gland vascularity status.