Study design and rationale: A multicenter, prospective trial of electromagnetic bronchoscopic and electromagnetic transthoracic navigational approaches for the biopsy of peripheral pulmonary nodules

Background: Pulmonary nodules are a common but difficult issue for physicians as most identified on imaging are benign but those identified early that are cancerous are potentially curable. Multiple diagnostic options are available, ranging from radiographic surveillance, minimally invasive biopsy (bronchoscopy or transthoracic biopsy) to more invasive surgical biopsy/resection. Each technique has differences in diagnostic yield and complication rates with no established gold standard. Currently, the safest approach is bronchoscopic but it is limited by variable diagnostic yields. Percutaneous approaches are limited by nodule location and complications. With the recent advent of electromagnetic navigation (EMN), a combined bronchoscopic and transthoracic approach is now feasible in a single, staged procedure. Here, we present the study design and rationale for a single-arm trial evaluating a staged approach for the diagnosis of pulmonary nodules. Methods: Participants with 1–3 cm, intermediate to high-risk pulmonary nodules will undergo a staged approach with endobronchial ultrasound (EBUS) followed by EMN-bronchoscopy (ENB), then EMN-transthoracic biopsy (EMN-TTNA) with the procedure terminated at any stage after a diagnosis is made via rapid onsite cytopathology. We aim to recruit 150 EMN participants from eight academic and community settings to show significant improvements over other historic bronchoscopic guided techniques. The primary outcome is overall diagnostic yield of the staged approach. Conclusion: This is the first study designed to evaluate the diagnostic yield of a staged procedure using EBUS, ENB and EMN-TTNA for the diagnosis of pulmonary nodules. If effective, the staged procedure will increase minimally invasive procedural diagnostic yield for pulmonary nodules.