The identification of sub-centimetre nodules by near-infrared fluorescence thoracoscopic systems in pulmonary resection surgeries.

OBJECTIVES: Current surgical procedures lack high-sensitivity intraoperative imaging guidance, leading to undetected micro tumours. In vivo near-infrared (NIR) fluorescence imaging provides a powerful tool for identifying small nodules. The aim of this study was to examine our experience of using 2 different NIR devices in pulmonary resection surgery.

METHODS: From August 2015 to October 2016, 36 patients with lung nodules underwent NIR fluorescence imaging thoracoscopic surgery. Two NIR devices: a D-Light P system and a SUPEREYE system were used. Patients were administered an injection of indocyanine green (ICG) through the peripheral vein 24 h preoperatively. During surgery, traditional white-light thoracoscopic exploration was performed first, followed by ICG-fluorescent-guided exploration. All detected nodules were resected and examined by a pathologist.

RESULTS: Of the 36 patients, 76 nodules were resected. ICG-fluorescent imaging identified 68 nodules during in vivo exploration. The mean signal-to-background ratio of lung nodules in NIR exploration was 3.29 ± 1.81. The application of NIR devices led to the detection of 9 additional nodules that were missed using traditional detection methods (1 mm computed tomography scan and white-light thoracoscopic exploration) in 7 patients (19.4%). Four of the 9 nodules were confirmed as malignant or atypical adenomatous hyperplasia (44.4%). The other 5 nodules were confirmed as false-positive nodules. The sensitivities and positive predictive values of the ICG-fluorescent imaging for lung tumours were 88.7% and 92.6%, respectively.

CONCLUSIONS: This study demonstrated the feasibility and safety of using ICG-fluorescent imaging for multiple lung nodules identification in video-assisted thoracoscopic surgery pulmonary resection.

Clinicaltrial.gov number: NCT02611245.