Robotic bronchoscopic needle-based confocal laser endomicroscopy to diagnose peripheral lung nodules

Abstract

Background and objective: Robotic bronchoscopy has demonstrated high navigational success in small peripheral lung nodules but the diagnostic yield is discrepantly lower. Needle based confocal laser endomicroscopy (nCLE) enables real-time microscopic imaging at the needle tip. We aim to assess feasibility, safety and needle repositioning based on real-time nCLE-guidance during robotic bronchoscopy in small peripheral lung nodules.

Methods: Patients with suspected peripheral lung cancer underwent fluoroscopy and radial EBUS assisted robotic bronchoscopy. After radial EBUS nodule identification, nCLE-imaging of the target area was performed. nCLE-malignancy and airway/lung parenchyma criteria were used to identify the optimal sampling location. In case airway was visualized, repositioning of the biopsy needle was performed. After nCLE tool-in-nodule confirmation, needle passes and biopsies were performed at the same location.

Measurements and main results: Twenty patients were included (final diagnosis n = 17 (lung) cancer) with a median lung nodule size of 14.5 mm (range 8-28 mm). No complications occurred. In 19/20 patients, good quality nCLE-videos were obtained. In 9 patients (45%), real-time nCLE-imaging revealed inadequate positioning of the needle and repositioning was performed. After repositioning, nCLE-imaging provided tool-in-nodule-confirmation in 19/20 patients. Subsequent ROSE demonstrated representative material in 9/20 patients (45%) and overall diagnostic yield was 80% (16/20). Of the three patients with malignant nCLE-imaging but inadequate pathology, two were diagnosed with malignancy during follow-up.

Conclusion: Robotic bronchoscopic nCLE-imaging is feasible and safe. nCLE-imaging in small, difficult-to-access lung nodules provided additional real-time feedback on the correct needle positioning with the potential to optimize the sampling location and diagnostic yield.

Trial registration: ClinicalTrials.gov NCT04441749.

Keywords: cytology; lung cancer; needle based confocal laser endomicroscopy; peripheral lung nodule; rapid onsite evaluation; robotic bronchoscopy.