Probe-based confocal laser endomicroscopy for pleural malignancies diagnosis

Use of medical thoracoscopy in managing pleural malignancy

Local anaesthetic "medical" thoracoscopy is an important tool for the diagnosis and management of a unilateral pleural effusion. It is performed under conscious sedation and has a high diagnostic yield. Clinical experience has demonstrated that thoracoscopy is a safe procedure. This article is an expert review of various aspects of the procedures from two experienced practitioners and we suggest areas for potential future research.

Advances in the diagnosis and follow-up of pleural lesions: a scoping review

INTRODUCTION

Pleural lesions may have heterogeneous presentation and causes. In recent years, there have been significant advances in pleural lesions diagnostics. The aim of this review is to provide an overview of the state-of-the-art, and recent updates for diagnostic modalities and monitoring regimes for pleural lesions.

AREAS COVERED

A literature search was conducted through PubMed and Web of Science for relevant articles published from 1 January 2000- 1 March 2023. This article critically appraises the radiological modalities and biopsy techniques that are employed in pleural lesions diagnostics, including chest radiography, thoracic ultrasound, computed tomography, F-fluorodeoxyglycose positron emission tomography, magnetic resonance imaging, percutaneous, and thoracoscopic pleural biopsies with reference to their strengths, limitations, and clinical use. The review asserts also the available literature regarding monitoring algorithms.

EXPERT OPINION

Despite the recent advances in the field, there are several key areas for improvement, including the development and validation of minimal invasive methods and tools for risk stratification, the integration of multi-omics technologies, the implementation of standardized, evidence-based diagnostic and monitoring guidelines and increased focus on research and patient-centric approaches. The broad establishment of dedicated pleural clinics may significantly assist toward this direction.

[Probe based confocal laser endomicroscopy in thoracic endoscopy]

INTRODUCTION

Probe based confocal laser endomicroscopy (pCLE) is a new endoscopic imaging technology. It uses mini probes which can be introduced through the working channels of endoscopes. Whenever applied on the tissue of interest, they allow imaging of tissue at a cellular level.

STATE OF ART

In the filed of pleuropulmonary malignancies, pCLE showed mostly its ability to guide biopsies samplings. Those results need to be validated in larger prospective studies. In interstitial lung diseases, pCLE provides information complementary to other clinical and paraclinical data. The valuability of these informations need to be investigated further, prospectively in randomized trials. In obstructive pulmonary diseases, pCLE is able to investigate the structural and functional relationships between pulmonary structures. pCLE showed good ability in the identification of acute cellular rejection after lung transplantation.

PERSPECTIVES AND CONCLUSION

For the time being, pCLE is not part of routine clinical practice. The data available need to be validated in larger randomized prospective trials, before it can be recommended as a guiding tool for biopsies or as a diagnostic tool for pathologic process. New fluorophores are now available. They are specific of some molecular sequences, allowing the enhancement of specific targets within the sample studied.

Advances in bronchoscopic optical coherence tomography and confocal laser endomicroscopy in pulmonary diseases

PURPOSE OF REVIEW

Imaging techniques play a crucial role in the diagnostic work-up of pulmonary diseases but generally lack detailed information on a microscopic level. Optical coherence tomography (OCT) and confocal laser endomicroscopy (CLE) are imaging techniques which provide microscopic images in vivo during bronchoscopy. The purpose of this review is to describe recent advancements in the use of bronchoscopic OCT- and CLE-imaging in pulmonary medicine.

RECENT FINDINGS

In recent years, OCT- and CLE-imaging have been evaluated in a wide variety of pulmonary diseases and demonstrated to be complementary to bronchoscopy for real-time, near-histological imaging. Several pulmonary compartments were visualized and characteristic patterns for disease were identified. In thoracic malignancy, OCT- and CLE-imaging can provide characterization of malignant tissue with the ability to identify the optimal sampling area. In interstitial lung disease (ILD), fibrotic patterns were detected by both (PS-) OCT and CLE, complementary to current HRCT-imaging. For obstructive lung diseases, (PS-) OCT enables to detect airway wall structures and remodelling, including changes in the airway smooth muscle and extracellular matrix.

SUMMARY

Bronchoscopic OCT- and CLE-imaging allow high resolution imaging of airways, lung parenchyma, pleura, lung tumours and mediastinal lymph nodes. Although investigational at the moment, promising clinical applications are on the horizon.

Probe-based confocal laser endomicroscopy for pleural malignancies diagnosis

Probe based confocal laser endomicroscopy (pCLE) is an optical imaging tool allowing live imaging of tissues at a cellular level. It remains experimental but its clinical value as a diagnostic/guiding tool is apparent. To address the lack of data in thoracic oncology and pleural diseases, we show the ability of pCLE during medical thoracoscopy to distinguish benign from malignant pleural involvement.

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Background and objective

Probe based confocal laser endomicroscopy (pCLE) is an optical imaging technique allowing live tissue imaging at a cellular level. Currently, this tool remains experimental. Two studies regarding pleural disease have been published and suggest that pCLE could be valuable for pleural disease investigations. However, normal and malignant pleural pCLE features remain unknown. Therefore, we conducted a prospective trial of pCLE during medical thoracoscopy to study and describe the malignant and benign pleural pCLE features.

Methods

Every patient >18 years referred to our department for medical thoracoscopy was eligible. Medical thoracoscopy was performed under sedation, allowing spontaneous breathing. Five millilitres of fluorescein (10%) was intravenously administrated 5 min before image acquisition. The pCLE was introduced through the working channel of the thoracoscope and gently placed on the parietal pleura to record videos. Afterwards, biopsies were performed on the corresponding sites. Malignant and benign pleural pCLE features were precisely described and compared using 11 preselected criteria.

Results

A total of 62 patients were included in the analysis including 36 benign and 26 malignant pleura. Among our preselected criteria, ‘abnormal tissue architecture’ and ‘dysplastic vessels’ were strongly associated with malignancies (100% and 85% ss, 721% and 74% sp, respectively) whereas, the ‘full chia seeds sign’ and ‘cell shape homogeneity’ were associated with benignity (36% and 56% ss, 100% and 70% sp, respectively). No study‐related adverse events occurred.

Conclusion

Benign and malignant pleural involvement have clearly distinct pCLE features.