Endobronchial Ultrasound-guided Transbronchial Needle Aspiration without Rapid On-site Evaluation: A Retrospective Study with Cytologic-Histologic Correlation

Summary: Introduction: Endobronchial ultrasound–guided transbronchial needle aspiration (EBUS-TBNA) is the most commonly used approach for both diagnosing and staging lung cancers with several advantages, including minimally-invasive approach, safe, cost-effective, real-time image guidance, broad sampling capability, and rapid on-site evaluation (ROSE). However, utility of ROSE during EBUS-TBNA has been a matter of debate, in terms of diagnostic efficacy. Currently at our institution, EBUS is being performed without ROSE due to subspecialization and limited availability of our staff for multiple operating sites. Materials and Methods: EBUS specimens from all passes were fixed in Saccomanno, the sediment was used to prepare a cell block, the supernatant was used to prepare one ThinPrep slide for cytologic evaluation. We reviewed the cytological profile of 400 patients, including 140 lymph node only cases, 45 lung only cases, and 215 cases of both lymph node and lung sampling. Our aims:1) Compare the non-diagnostic rates between our method with the EBUS+ROSE method. 2) Establish sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of our method and compare with EBUS+ROSE method. Results: Of cases of lymph node sampling, 169 nodes (48%) were diagnosed as malignant, 577 nodes (61%) as benign process, and 18 nodes (0.05%) as atypical cells. Of the lung lesion sampling, 123 cases (51%) were diagnosed as malignant, 79 cases (35%) as benign process, 4 cases (0.02%) as suspicious for malignancy, and 37 cases (15%) as atypical cells. The lymph node nondiagnostic rate was 6.1%, whereas the nondiagnostic rate for lung lesions was 16.3%. 154 patients had corresponding core biopsies or follow-up surgery. Using histology as the gold standard, the sensitivity, specificity, and positive and negative predictive values for EBUS-TBNA were 85.0%, 96%, and 98% and 91%, respectively. Conclusions: Although ROSE has been successfully introduced into daily practice, considering the cost, staffing issues, and distance between different sites, we used a method which does not utilize ROSE but is time saving, cost effective, and felt to be comparable in terms of performance.