Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in the Nodal Staging of Stereotactic Ablative Body Radiotherapy Patients

Abstract

Patients with non-small cell lung cancer (NSCLC) being evaluated for stereotactic ablative body radiotherapy (SABR) are typically staged noninvasively with positron emission tomography/computed tomography (PET/CT). Incorporating endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) into the staging workup of these patients has not been evaluated. Our primary objective was to compare the performance of PET/CT with EBUS-TBNA for intrathoracic nodal assessment among SABR-eligible patients. This was a retrospective study consisting of two parts. First, we assessed the concordance for nodal metastasis of PET/CT and EBUS-TBNA. Second, we evaluated clinical outcomes among patients who underwent SABR with and without a prior EBUS-TBNA. We identified 246 eligible patients. Compared with PET/CT, EBUS-TBNA led to a stage shift in 48 of 246 patients (19%). Of 174 N0 patients by PET/CT, 6 (3.4%) had nodal metastasis on EBUS-TBNA. Among 72 clinical N1 patients, 36 (50%) were downstaged to N0 after EBUS-TBNA, therefore becoming eligible for SABR. Concordance between PET/CT and EBUS-TBNA for nodal metastasis was 83% (κ= 0.53). Clinical outcomes of patients who underwent SABR with or without a prior EBUS-TBNA did not differ significantly. Concordance of PET/CT and EBUS-TBNA for nodal disease was only moderate. Incorporating EBUS-TBNA into the staging workup was beneficial in identifying occult nodal metastasis that would otherwise be left untreated with SABR and in expanding the pool of potentially SABR-eligible patients.