First-in-human results of targeted intraoperative molecular imaging for visualization of ground glass opacities during robotic pulmonary resection

Abstract

Background: Identifying ground glass opacities (GGOs) is challenging during robot-assisted thoracic surgery (RATS). Intraoperative molecular imaging (IMI) using tumor-targeted fluorescent tracers may address this clinical problem, but has never been evaluated in RATS. In a pilot study, we sought to determine whether IMI during RATS (RIMI) can localize GGOs. Methods: Ten patients with a cT1 GGO were enrolled. Prior to resection, participants received a folate-receptor targeted fluorescent tracer (OTL38). During RATS, a white-light robotic scope was utilized to identify tumors. RIMI was then conducted using a RATS thoracoscope with a wavelength-specific camera. Finally, a video-assisted thoracic surgery (VATS) thoracoscope designed to detect OTL38 was used as a control to compare to RIMI. The lesions were then resected under RIMI guidance. Results: By white-light robotic scope, 7/10 (70%) GGOs were visually identifiable by pleuroparenchymal distortions. RIMI identified tumor-specific fluorescence in all (100%) subjects. RIMI clearly located the three nodules that could not be seen by robotic white-light imaging. The mean fluorescence intensity (MFI) of tumors was 99.48 arbitrary units (A.U.) (IQR, 75.72-130.49 A.U.), which was significantly higher than background tissue with mean MFI 20.61 A.U. (IQR, 13.49-29.93 A.U., P<0.0001). Mean signal-to-background ratio was 5.71 (range, 2.28-10.13). When compared to VATS-IMI as a control, there were no significant differences in MFI of tumors, background tissue, or signal-to-background ratios. In summary, RIMI compared favorably to VATS-IMI by all measured imaging characteristics. Conclusions: RIMI is feasible for identification of GGOs during robotic resection as compared to white light thoracoscopy and compares favorably to VATS-IMI.