Bronchoscopic needle based confocal laser endomicroscopy (nCLE) as a real-time detection tool for peripheral lung cancer

Introduction: Diagnosing peripheral lung cancer is challenging with near miss of the target lesion as major obstacle. Needle-based confocal laser endomicroscopy (nCLE) enables real-time microscopic analysis at the needle tip. Aim: Assess feasibility and safety of bronchoscopic nCLE guided transbronchial needle aspiration of peripheral lung lesions. Methods: Patients with suspected peripheral lung cancer based on (PET-)CT scan underwent radial EBUS and fluoroscopy guided flexible bronchoscopy. After lesion detection, an 18G needle loaded with the CLE probe inserted the lesion. Lesion CLE-imaging was followed by TBNA and biopsies. CLE videos were reviewed using published CLE lung cancer criteria and compared to final diagnoses. Results: nCLE-imaging was performed in 15 patients (adenocarcinoma n=10, squamous cell carcinoma n=2, sarcoma n=1, urothelial carcinoma n=1, organizing pneumonia n=1). No complications occurred. In 13 patients (87%) good to high quality videos were obtained. All malignant lesions scored at least 2/3 malignant CLE criteria. Two patients with a malignant CLE pattern but negative bronchoscopic sampling, were diagnosed with adenocarcinoma after lobectomy. In 1 patient only an alveolar CLE pattern was shown. Conclusion: Bronchoscopic needle based CLE-imaging of peripheral lung lesions is feasible and safe and can serve as a real-time guidance tool to improve lung cancer diagnostics.