Original Abstract
BACKGROUND: Less-invasive, lower-risk alternatives to surgical lung biopsy (SLB) have emerged for interstitial lung disease (ILD) diagnosis, such as transbronchial lung cryobiopsy (TBLC) and Envisia Genomic Classifier (EGC), but suffer from limited sampling and simplified binomial classification, respectively. Endobronchial optical coherence tomography (EB-OCT) is a low-risk, large-volume bronchoscopic imaging modality with microscopic resolution, which accurately detects features and patterns for ILD diagnosis as previously validated against SLB. RESEARCH QUESTION: How does EB-OCT contribute to ILD diagnosis and diagnostic confidence at multidisciplinary discussion (MDD) when paired with clinically indicated TBLC and EGC? STUDY DESIGN AND METHODS: Patients with low-confidence ILD diagnosis clinically referred for both TBLC with EGC were enrolled to undergo concurrent EB-OCT imaging. Each modality was interpreted independently by blinded pathologists. Separate MDD sessions were conducted at two independent sites, including one without prior EB-OCT experience. RESULTS: Fifteen patients were included (9 male; mean age: 70.6 years) with final diagnoses of UIP/IPF (n=5), secondary UIP (n=2), and various non-UIP ILDs (n=8) in agreement at both MDDs. EB-OCT provided diagnostic data that was in agreement with final MDD diagnosis for 100% of subjects (15/15), including in the 40% of subjects (6/15) where TBLC was non-diagnostic. In the subjects where TBLC yielded diagnostic data (60%, 9/15), EB-OCT diagnosis was in agreement. EB-OCT combined with TBLC/EGC increased diagnostic confidence and/or narrowed the differential diagnosis from baseline clinical/radiologic data review in all subjects, with replication across both independent MDDs. INTERPRETATION: In this pilot study, we demonstrate EB-OCT is a safe, large-volume imaging method that detects microscopic features and patterns for ILD diagnosis, which increases diagnostic confidence in the context of MDD and complements TBLC and EGC. Future multicenter studies are needed to further validate these findings.