Background: Electromagnetic navigation bronchoscopy (ENB) is a relatively new and technically demanding procedure for the guidance of bronchoscopic biopsy to help locate small lung lesions. The results in experienced hands are well described. However, we do not know the results in unexperienced hands-in other words, we have no knowledge about how fast you can learn the procedure.Aim: The aim of this study was to draw learning curves for beginners in ENB using Cumulated Sum (CUSUM) analysis, a method for quantitative evaluation of the learning curves for clinical procedures.Methods: Four operators from 3 centers without prior ENB experience were enrolled. The outcome of consecutive ENB procedures was assessed and classified as either diagnostic or nondiagnostic based on sample adequacy. Learning curves were drawn based on diagnostic yield.Results: A total of 215 procedures were assessed. For 2 of the operators (operators 1 and 4), at least 25 to 30 procedures were necessary to obtain competency whereas operators 2 and 3 showed more horizontal learning curves indicating an overweight of diagnostic procedures from the beginning.Conclusion: Operators achieve competences in ENB at different paces. This must be taken in account when beginners start to learn the procedure. There is a huge need for a structured educational program and a validated test to determine competences.

Predicting factors of diagnostic yield in electromagnetic navigation bronchoscopy (ENB) have been explored in a number of previous studies based on data from experienced operators. However, little is known about predicting factors when the procedure is carried out by operators in the beginning of their learning curve. We here aim to identify the role of operators’ experience as well as lesion– and procedure characteristics on diagnostic yield of ENB procedures in the hands of novice ENB operators. Four operators from three centers without prior ENB experience were enrolled. The outcome of consecutive ENB procedures was assessed and classified as either diagnostic or non-diagnostic and predicting factors of diagnostic yield were assessed. A total of 215 procedures were assessed. A total of 122 (57%) of the ENB procedures resulted in diagnostic biopsies. Diagnostic ENB procedures were associated with a minor yet significant difference in tumor size compared to non-diagnostic/inconclusive ENB procedures (28 mm vs. 24 mm; p = 0.03). Diagnostic ENB procedures were associated with visible lesions at either fluoroscopy (p = 0.003) or radial endobronchial ultrasound (rEBUS), (p = 0.001). In the logistic regression model, lesion visibility on fluoroscopy, but none of operator experience, the presence of a bronchus sign, lesion size, or location nor visibility on rEBUS significantly impacted the diagnostic yield. In novice ENB operators, lesion visibility on fluoroscopy was the only factor found to increase the chance of obtaining a diagnostic sample.