Supplementary Material for: Enhanced multimodal diagnosis of peripheral lung lesions using Iriscope and radial endobronchial ultrasonography: results from a randomized controlled trial.

Introduction. Iriscope, a novel ultra-thin video probe designed to be inserted through the bronchoscope working channel enables direct visualization of peripheral lung lesions. However, its diagnostic value in comparison or in combination with established bronchoscopic guidance techniques remains unclear. This study aims to evaluate the added benefit of combining Iriscope with radial endobronchial ultrasonography (R-EBUS) compared to R-EBUS alone for the diagnosis of peripheral lung lesions sized 20–50 mm. Methods. 81 patients were randomized into two groups: bronchoscopy guided by R-EBUS or bronchoscopy guided by both Iriscope and R-EBUS. Fluoroscopic guidance and forceps biopsy were used in both groups. In the combined group, the Iriscope was used first, followed by insertion of the ultrasound probe through the working channel for lesion visualization. Biopsies were taken in case of abnormal lesion visualized by R-EBUS. The primary outcome was diagnostic yield. Secondary outcomes included yield stratified by lesion size, presence of bronchus sign, and lesion visualization on fluoroscopy. Results. The diagnostic yield was higher in the combined group (32/40, 80%) compared to R-EBUS alone (23/41, 55%, p=0.036). The improved yield in the combined approach was consistent regardless of lesion size, bronchus sign presence, or fluoroscopic visualization. Conclusion. Combining Iriscope with R-EBUS significantly improves diagnostic yield compared to R-EBUS alone in patients with peripheral lung lesions sized 20–50 mm.