Assessing the feasibility of confocal laser endomicroscopy in solitary pulmonary nodules for different part of the lungs, using either 0.6 or 1.4 mm probes.

Tidi Hassan,Florian Guisier,Luc Thiberville,Samy Lachkar,Christophe Hermant,Mathieu Salaun,Nicolas Piton,Baktiar Hasan

doi:10.1371/journal.pone.0189846

Abstract

BackgroundMalignant solitary pulmonary nodules (SPN) have become more prevalent, with upper lobes predilection. Probe-based confocal laser endomicroscopy (pCLE) provides in-vivo imaging of SPN. However, the stiffness of the 1mm confocal probe (AlveoFlex) causes difficult accessibility to the upper lobes. A thinner 600μm probe designed for bile duct exploration (CholangioFlex) has the potential to reach the upper lobes.ObjectivesTo examine the accessibility of malignant SPNs in all segments of the lungs using either the 0.6mm or 1.4 mm probe and to assess the quality and inter observer interpretation of SPN confocal imaging obtained from either miniprobes.MethodsRadial(r)-EBUS was used to locate and sample the SPN. In-vivo pCLE analysis of the SPN was performed using either CholangioFlex (apical and posterior segments of the upper lobes) or AlveoFlex (other segments) introduced into the guide sheath before sampling. pCLE features were compared between the two probes.ResultsFourty-eight patients with malignant SPN were included (NCT01931579). The diagnostic accuracy for lung cancer using r-EBUS coupled with pCLE imaging was 79.2%. All the SPNs were successfully explored with either one of the probes (19 and 29 subjects for CholangioFlex and AlveoFlex, respectively). A specific solid pattern in the SPN was found in 30 pCLE explorations. Comparison between the two probes found no differences in the axial fibers thickness, cell size and specific solid pattern in the nodules. Extra-alveolar microvessel size appeared larger using CholangioFlex suggesting less compression effect. The kappa test for interobserver agreement for the identification of solid pattern was 0.74 (p = 0.001).ConclusionThis study demonstrates that pCLE imaging of SPNs is achievable in all segments of both lungs using either the 0.6mm or 1.4mm miniprobe.

Highlights

Probe-based confocal laser endomicroscopy is an emerging technology that complements standard white-light bronchoscopy to provide in-vivo and real-time imaging of the lungs [1,2,3]
This study demonstrates that Probe-based confocal laser endomicroscopy (pCLE) imaging of solitary pulmonary nodules (SPN) is achievable in all segments of both lungs using either the 0.6mm or 1.4mm miniprobe
This is a pilot, exploratory study to conduct a comparative analysis of pCLE with the AlveoFlex1 and CholangioFlex1 minprobes, in which subjects were selected from the cohort prospectively enrolled in the NODIVEM (Assessment of Probe Based Confocal Laser Endo-microscopy for In-vivo Diagnosis of Peripheral Lung Nodules and Masses) trial (S1 and S2 Files)

Summary

Introduction

Probe-based confocal laser endomicroscopy (pCLE) is an emerging technology that complements standard white-light bronchoscopy to provide in-vivo and real-time imaging of the lungs [1,2,3]. In-vivo confocal microscopic imaging of the distal lung fluorescent structures in response to 488nm blue light excitation resulted in the description of pCLE imaging of the normal alveolar ducts, extra-alveolar microvessels and alveolar cells in both non-smoking and actively smoking subjects [4]. Solitary pulmonary nodules (SPN) have become more prevalent and have resulted in diagnostic challenges in clinical practice, especially due to the increasing reports of peripheral lung adenocarcinoma [9, 10]. Malignant solitary pulmonary nodules (SPN) have become more prevalent, with upper lobes predilection. Probe-based confocal laser endomicroscopy (pCLE) provides in-vivo imaging of SPN. A thinner 600μm probe designed for bile duct exploration (CholangioFlex) has the potential to reach the upper lobes

Objectives

Methods

Results