Pulmonologists frequently encounter lung nodules, >50% of which are benign. This poses a diagnostic challenge when nodules with worrisome features are found in areas of the lung that are not easily accessible by conventional bronchoscopy or transthoracic biopsy. Triage of nodules to observation, biopsy, and/or resection is influenced by nodule location and size, patient comorbidities, and technological limitations. Conventional bronchoscopy can reach the fifth generation bronchi, but nodules in the peripheral third of the lung are inaccessible. Diagnostic yield with conventional bronchoscopy is poor for small peripheral lesions, especially those <2cm in size. While the advent of electromagnetic navigation bronchoscopy significantly improved this yield, it has been further augmented with the use of robotic-assisted navigation bronchoscopy. Here, we describe our experience evaluating high-risk lesions using the Ion platform, specifically to prove malignancy or definitive benign disease. Proving benign disease avoids unnecessary resection, alleviates concern for cancer, and minimizes the need for follow up imaging.METHODS: All patients undergoing robotic navigation bronchoscopy using the Ion platform beginning August 1 st , 2020 were enrolled in an IRB-approved registry. Radial EBUS and fluoroscopy were used for all cases to confirm proximity to the nodule. Patient demographics, nodule characteristics, diagnostic yield, complications, and pathology were recorded for all patients.
RESULTS:The Ion was used to evaluate 64 nodules in 51 patients. Median number of nodules per person was 1 (range 1-3). Median size of nodules was 14mm (range 5-44mm). A total of 34 benign nodules with a mean size of 16mm were diagnosed in 25 patients. Twenty-one nodules were solid, 9 were subsolid, and 4 were groundglass. Seventeen patients (26 nodules) were evaluated with PET/CT, 20 nodules were PET-avid. Definitive diagnoses included the following: granulomatous disease (7), inflammation (6), fibrosis (2), necrosis (1), organizing pneumonia (1), multinucleated giant cells (1), radiation effect (1), and infection (3), including Streptococcus, Aspergillus, and NTM. Benign tissue was isolated from the remaining 12 nodules, but for our purposes this was considered non-diagnostic and ongoing surveillance was recommended.CONCLUSIONS: Small peripheral nodules are increasingly identified, especially with new lung cancer screening guidelines that capture a larger patient cohort. Many have high-risk features despite being benign, therefore it is essential to have a safe method of tissue sampling that allows both access to and accuracy in diagnosing these lesions. Using the Ion we were able to definitively prove benign disease in 34% of nodules, thus alleviating patient anxiety and eliminating the need for future surveillance and resection.CLINICAL IMPLICATIONS: Using the Ion we were able to definitively prove benign disease in 34% of nodules, thus alleviating patient anxiety and eliminating the need for future surveillance and resection.