A novel minimally invasive near-infrared thoracoscopic localization technique of small pulmonary nodules: A phase I feasibility trial

Abstract

Objectives: Localization and resection of nonvisible, nonpalpable pulmonary nodules during video-assisted thoracoscopic surgery are challenging. Our study was to determine the feasibility and safety of indocyanine green fluorescence localization and resection of small nodules using a near-infrared fluorescence thoracoscope.

Methods: Twenty patients with undiagnosed peripheral nodules smaller than 3 cm scheduled for computed tomography-guided microcoil placement followed by video-assisted thoracoscopic surgery wedge resection were enrolled. After microcoil deployment, 100 to 150 μL of diluted indocyanine green was injected percutaneously near the nodule. The nodule initially was localized solely by using a near-infrared thoracoscope to visualize indocyanine green fluorescence. Thoracoscopic instruments were used to determine the staple line. Wedge resection was performed after confirmation of the location of the microcoil using fluoroscopy.

Results: Twenty patients underwent near-infrared, image-guided, video-assisted thoracoscopic surgery resection. The median computed tomography tumor size was 1.2 cm. The median depth from the pleural surface was 1.4 cm (range, 0.2-4.8 cm). The median computed tomography-guided intervention time was 35 minutes, and video-assisted thoracoscopic surgery procedural time was 54 minutes. Indocyanine green fluorescence was clearly identified in 18 of 20 patients (90%). The surgical margins were all negative on final pathology without the need for additional resection. The final diagnoses included 18 primary lung cancers, 1 metastatic lung cancer, and 1 benign lung tumor.

Conclusions: Computed tomography-guided percutaneous indocyanine green injection and intraoperative near-infrared localization of small nodules are safe and feasible. These offer surgeons the ease of localization through direct indocyanine green fluorescence imaging without the use of fluoroscopy and may be a complementary technique to preoperative microcoil placement for nonvisible, nonpalpable intrapulmonary nodules.

Keywords: fluorescence; image-guided surgery; indocyanine green; lung cancer; near-infrared; staging.