Intraoperative molecular imaging to identify lung adenocarcinomas.

Intraoperative molecular imaging is a promising new technology with numerous applications in lung cancer surgery. Accurate identification of small nodules and assessment of tumor margins are two challenges in pulmonary resections for cancer, particularly with increasing use of video-assisted thoracoscopic surgery (VATS). One potential solution to these problems is intraoperative use of a fluorescent contrast agent to improve detection of cancer cells. This technology requires both a targeted fluorescent dye that will selectively accumulate in cancer cells and a specialized imaging system to detect the cells. In several studies, we have shown that intraoperative imaging with indocyanine green (ICG) can be used to accurately identify indeterminate pulmonary nodules. The use of a folate-tagged fluorescent molecule targeted to the folate receptor-α (FRα) further improves the sensitivity and specificity of detecting lung adenocarcinomas. We have demonstrated this technology can be used as an "optical biopsy" to differentiate adenocarcinoma versus other histological subtypes of pulmonary nodules. This strategy has potential applications in assessing bronchial stump margins, identifying synchronous or metachronous lesions, and rapidly assessing lymph nodes for lung adenocarcinoma.