ICG-based NIR fluorescence imaging can help to detect residual giant cell tumor of bone after intralesional curettage: Results of two-year follow-up.

Aim: Identification of clinical occult tumor residuals is crucial during giant cell tumor (GCT) intralesional curettage. This study investigated the capacity of indocyanine green (ICG) fluorescence imaging to detect tumor residual during intralesional curettage of GCT. Methods: Clinical data of 20 patients with GCT who received ICG near-infrared (NIR) fluorescence-assisted intralesional curettage with a minimal two-year follow-up in our institute were reviewed. Tumors were initially curetted under white light with naked eyes. Then, wounds were scanned to detect fluorescence residuals. Biopsies were conducted on the sites with fluorescence positivity or negativity. The fluorescence intensity (FI) of biopsied samples were determined using standardized process, and samples were sent for pathological examination. Results: All the tumors were successfully stained (100%). One patient (5%) experienced a local recurrence. The overall accuracy of ICG fluorescence in detecting tumor residuals (true positivity and true negativity) was 68%. The false positive rate and false negative rate were 38% and 21%, respectively. Fluorescence-positive samples showed a significantly higher rate of pathological positivity than negative samples ( Conclusion: ICG-based NIR fluorescence imaging can detect residual GCT after intralesional curettage, and can be used as a supplement to extended curettage to reduce recurrence. The FI is positively related to pathological results. However, false signals may occur. Efforts to increase accuracy and confirm its clinical benefits in preventing recurrence are still needed.