Fig 1.
Subjects were recruited from either one of the two centers of the NODIVEM study. Inclusion criteria in the NODIVEM study included a final diagnosis of malignant SPN with histopathology confirmation and successful location of the SPN with r-EBUS. All of the patients signed a written informed consent before the pCLE procedure, which was performed with topical lidocaine but without conscious sedation.
Fig 2.
probe-based confocal endomicroscopy probe in the r-EBUS guide sheath, and examples of alveolar pCLE imaging.
A, A stopper is first used to determine that the tip of the confocal miniprobe. B, coincides with the distal tip of the external guide sheath. C&D. Endomicroscopic images of the distal lung (autofluorescence, 488 nm excitation, Cell-vizio Lung-488) showing: C, normal axial elastic backbone of an alveolar duct in a non-smoking subject; and D, a blood vessel with cellular infiltration by fluorescent cells, presumably alveolar macrophages.
Fig 3.
A&B: Image of the USAF 1951 pattern obtained under 488 nm excitation with AlveoFlex (A) and CholangioFlex (B) confocal miniprobes. Element 3 group 1 with frequency 151 lp/mm can be clearly identified, which corresponds to a bar width of 3.3 μm. These results are consistent with the design specification for resolution of CholangioFlex Miniprobes (3.5 μm). C&D: In order confirm reliability of measures with the two different probes, we imaged ex-vivo a well-preserved lung sample, fixed in glutaraldehyde at 20 cmH2O pressure, with the AlveoFlex (C) and CholangioFlex (D). On the images obtained with the two different probes, diameters of twelve pulmonary alveolar capillaries were measured, and the comparison showed no difference between the two probes.
Fig 4.
Example of one case with radiologic images of a solitary pulmonary nodule, a respectively r-EBUS image, the pCLE image and corresponding histology.
A: 15 mm solitary pulmonary nodule of the lingula, located at 10 mm of the pleura. B: radial-EBUS signal in this nodule shows a tangential signal on the left part of the image (white arrow). C: pCLE image of this nodule shows a solid pattern on the whole field of view using the 0.6mm CholangioFlex® confocal miniprobe (scale bar: 20 μm). D: H&E staining of the biopsy performed during the procedure shows a pulmonary adenocarcinoma (Magnification x 40; scale bar: 40 μm).
Table 1.
Characteristics of SPNs imaged by AlveoFlex® and CholangioFlex® miniprobes.
Fig 5.
Confocal fluorescence endomicroscopy of SPN (autofluorescence, 488 nm excitation, Cell-vizio Lung 488) demonstrating: A, axial elastic backbone of an alveolar duct and B, cellular infiltration by fluorescent cells, presumably alveolar macrophages using (i) AlveoFlex® miniprobe and (ii) CholangioFlex® miniprobe.
Fig 6.
Confocal fluorescence endomicroscopy of SPN (autofluorescence, 488 nm excitation, Cell-vizio Lung 488) demonstrating A, solid pattern in less than 50% of the field view, and B, solid pattern in more than 50% of the field view and C, increased fibres in SPNs with confirmed adenocarcinoma using (i) AlveoFlex® miniprobe and (ii) CholangioFlex® miniprobe.
Table 2.
Characteristics of confocal images of SPNs by AlveoFlex and CholangioFlex miniprobes detected by at least one of the two observers.
Table 3.
Interobserver agreement (κ).