(P 63) EVALUATING SURGICAL MARGINS IN SARCOMA RESECTION WITH INDOCYANINE GREEN FLUORESCENCE IMAGING

Objective: Extremity sarcomas are primarily managed surgically, and achieving negative resection margins remains critical for reducing local recurrence and potentially improving survival. While intraoperative indocyanine green (ICG) fluorescence imaging has shown promise in other cancers, its role in sarcoma margin assessment remains underexplored. This study aimed to evaluate ICG’s efficacy as an intraoperative margin assessment tool in sarcoma surgery.

Methods: This was a prospective, non-randomized clinical trial for patients with confirmed or suspected extremity sarcomas. Patients received 2.0 mg/kg ICG intravenously three hours preoperatively. The tumor bed was imaged intraoperatively using a SPY-PHI camera, and signal-to-background ratio was calculated using the formula (SBR = tumor bed fluorescence / average background fluorescence). ICG-positive margins were defined as fluorescence intensity ≥1.67 times SBR. ICG results were compared to final pathology and surgeon’s clinical impression.

Results: Among 51 participants with bone (n = 11) or soft tissue (n = 40) sarcomas, pathology reported 15 (29.4%) positive margins, whereas surgeons predicted 8 (15.7%). When compared to pathological findings, surgeons correctly identified 4 out of 15 positive margins (sensitivity: 26.7%) and 32 out of 36 negative margins (specificity: 88.9%). Using an SBR of 1.67, ICG correctly identified 14/15 positive margins (sensitivity: 93.3%).

Conclusion: ICG shows promise for intraoperative margin assessment in sarcoma surgery. As surgeons are very specific (88.9%) and ICG is very sensitive (93.3%), we posit that these strengths could be combined to decrease local recurrence rates to the benefit of sarcoma patients. As ICG imaging platforms are used by many institutions and surgical specialties, this research suggests an opportunity for a multi-institutional clinical trial.