Feasibility and accuracy of rapid on-site evaluation of touch imprint cytology during transbronchial biopsy

BACKGROUND: Rapid on-site evaluation (ROSE) of cytologic material is widely performed because it provides clinicians with instant diagnostic information. However, the utility of ROSE of touch imprint cytology (ROSE-TIC) during transbronchial biopsy (TBB) remains unclear. The aim of this study was to evaluate the feasibility and accuracy of ROSE-TIC for TBB. METHODS: A retrospective study was performed on patients who underwent diagnostic bronchoscopy combined with ROSE-TIC. The results of ROSE-TIC, diagnosed as either positive or negative for malignancy, were compared with the histological findings and final diagnosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated. The success rate of molecular testing on TBB specimens was also assessed. RESULTS: Overall, 460 patients underwent bronchoscopy with ROSE-TIC. Of these, 377 cases (82.0%) were malignant and 83 cases (18.0%) were non-malignant in the final diagnosis. Compared with the histological findings, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 91.1%, 90.4%, 94.8%, 84.0%, and 90.9%, respectively. Compared with the final diagnosis, ROSE-TIC showed sensitivity, specificity, PPV, NPV, and diagnostic accuracy values of 75.3%, 91.6%, 97.6%, 45.0%, and 78.3%, respectively. Seven discordant cases (1.5%) were positive on ROSE-TIC and negative on final diagnosis. The success rates for molecular analysis from TBB samples were 96.6% for EGFR mutation, 87.3% for ALK rearrangement, 93.1% for ROS1 rearrangement, and 96.2% for PD-L1 expression. CONCLUSIONS: The accuracy of ROSE-TIC is high. It can be useful for obtaining instant diagnosis, contributing to a high success rate of molecular analysis for targeted therapy.