Intraoperative Molecular Imaging of Lung Adenocarcinoma Can Identify Residual Tumor Cells at the Surgical Margins

Purpose: During lung surgery, identification of surgical margins is challenging. We hypothesized that molecular imaging with a fluorescent probe to pulmonary adenocarcinomas could enhance residual tumor during resection. Procedures: Mice with flank tumors received a contrast agent targeting folate receptor alpha. Optimal dose and time of injection was established. Margin detection was compared using traditional methods versus molecular imaging. A pilot study was then performed in three humans with lung adenocarcinoma. Results: The peak tumor-to-background ratio (TBR) of murine tumors was 3.9. Fluorescence peaked at 2 h and was not improved beyond 0.1 mg/kg. Traditional inspection identified 30 % of mice with positive margins. Molecular imaging identified an additional 50 % of residual tumor deposits (p < 0.05). The fluorescent probe visually enhanced all human tumors with a mean TBR of 3.5. Conclusions: Molecular imaging is an important adjunct to traditional inspection to identify surgical margins after tumor resection.