# Radial Endobronchial Ultrasound for the Diagnosis of Peripherally Located Pulmonary Lesions

## TL;DR

Radial endobronchial ultrasound is a safe and effective method for diagnosing peripheral lung lesions, with high accuracy and agreement with imaging results.

## Contribution

The study evaluates the diagnostic yield and agreement of radial EBUS-guided biopsy for peripheral pulmonary lesions.

## Key findings

- Radial EBUS had a 77.5% diagnostic yield for peripheral pulmonary lesions.
- Adenocarcinoma was the most common malignant lesion diagnosed.
- Radial EBUS showed substantial agreement with CT in classifying lesions as benign or malignant.

## Abstract

Introduction

Peripheral pulmonary lesions (PPLs) pose a significant diagnostic challenge for the clinician as they are not visualized within the bronchial tree during flexible bronchoscopy. Radial endobronchial ultrasound (EBUS) is a minimally invasive bronchoscopic technique that expands the view of the bronchoscopist beyond the lumen of the airway, offering a promising diagnostic modality for PPLs.

Objectives

To assess the types of different peripheral pulmonary lesions diagnosed by radial endobronchial ultrasound-guided biopsy, and also to assess the agreement between the findings of radiological imaging and radial EBUS-guided biopsy in determining benign and malignant peripheral pulmonary lesions.

Methodology

This was a cross-sectional study performed on 40 patients aged ≥18 years with radiological evidence of PPLs who attended the respiratory medicine outpatient department (OPD) of the Regional Institute of Medical Sciences (RIMS), Imphal, Manipur, from April 2023 to March 2025.

Results

This study determined the diagnostic yield of radial EBUS to be 77.5%. Among the malignant lesions diagnosed, adenocarcinoma (15 patients, 37.5%) was the most common histopathological type followed by squamous cell carcinoma (eight patients, 20%) and small cell carcinoma (one patient, 2.5%) while benign lesions included pulmonary tuberculosis (five patients, 12.5%) and pulmonary aspergillosis (two patients, 5%). Substantial agreement (Kappa=0.674, p<0.001) was found between CT diagnosis and radial EBUS transbronchial lung biopsy (TBLB) findings in classifying lesions as benign or malignant.

Conclusion

In this study, radial EBUS-guided TBLB was found to be a safe and effective diagnostic modality for PPLs, offering high diagnostic yield and strong concordance with imaging findings, reinforcing its value in clinical decision-making.