Diagnostic Yield Vs Diagnostic Accuracy for Lung Nodule Biopsy Evaluation: Evidence Supporting a Pragmatic End Point for Future Studies

ABSTRACT

SESSION TITLE Lung Nodule Biopsy Yield and Accuracy SESSION TYPE Original Investigations PRESENTED ON 10/16/2022 1030 am - 1130 am PURPOSE: A variety of endpoints have been used to evaluate the diagnostic performance of navigational bronchoscopy for sampling peripheral pulmonary lesions (PPLs), including diagnostic yield (rate of biopsies with a specific diagnosis that facilitates clinical decisions) and diagnostic accuracy (yield plus a follow-up to assess for false negative/positive initial results). There is also significant variation in what non-malignant findings are considered diagnostic, especially regarding nonspecific inflammatory changes. We hypothesized a diagnostic yield definition excluding nonspecific findings as diagnostic would lead to few false negative PPL biopsies. METHOD(S) Our center maintains a prospective cohort of consecutive PPLs targeted via navigational bronchoscopy. Diagnostic yield was defined as specific findings readily explaining the presence of a PPL (malignancy, organizing pneumonia, granulomatous inflammation, frank purulence, other specific finding) permitting management without immediate additional diagnostic intervention. "Other specific finding" required pulmonologist and lung pathologist agreement. All other findings were considered non-diagnostic. RESULT(S) A total of 450 PPLs biopsied 2017-2019 with complete two-year follow-up were included in the analysis. Ultimately, 274 of 450 (60.9%) PPLs were determined to be malignant. Diagnostic biopsies were obtained in 331 cases (73.6%). There was a single false-positive among 228 malignant biopsies (0.4%, carcinoid tumor on cytopathology, alveolar adenoma on resection surgical pathology). Among 223 PPLs without malignant diagnosis at initial bronchoscopy, 48 were later determined to be malignant. Most (n=39) exhibited nonspecific abnormalities on initial pathology. Two of 104 specific benign biopsies were false negative (1.9%). Both demonstrated organizing pneumonia on initial pathology but re-biopsy months after index bronchoscopy revealed Hodgkin's lymphoma and metastatic renal cell carcinoma, respectively. The sensitivity, specificity, and positive predictive value of specific benign findings for an ultimately benign nodule were 58% (95% CI, 51-66%), 95% (86-99%), and 90% (70-97%). The sensitivity, specificity, and positive predictive value of nonspecific benign findings for an ultimately benign PPL diagnosis were 32% (95% CI, 25-39%), 19% (9-33%), and 20% (16-24%). CONCLUSION(S) A definition of diagnostic yield excluding nonspecific benign findings had low false positive/negative rates. If bronchoscopy is not diagnostic of malignancy, a specific benign finding was highly predictive of an ultimately benign PPL, while nonspecific findings poorly predicted benignity. CLINICAL IMPLICATIONS This definition of diagnostic yield could be used as the primary outcome in future studies, permitting distribution of reliable diagnostic results without requiring years of follow-up. DISCLOSURES No relevant relationships by Joyce Johnson No relevant relationships by Robert Lentz No relevant relationships by Kaele Leonard No relevant relationships by See-Wei Low PI ofan investigator-initiated study relationship with Medtronic Please note >$100000 by Fabien Maldonado, value=Grant/Research Support PI on investigator-initiated relationship with Erbe Please note $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Consulting relationship with Medtronic Please note $5001 - $20000 by Fabien Maldonado, value=Honoraria co-I industry-sponsored trial relationship with Lung Therapeutics Please note $5001 - $20000 by Fabien Maldonado, value=Grant/Research Support Board of director member relationship with AABIP Please note $1-$1000 by Fabien Maldonado, value=Travel Consultant relationship with Medtronic/Covidien Please note $1001 - $5000 by Otis Rickman, value=Consulting fee No relevant relationships by Briana Swanner Copyright © 2022 American College of Chest Physicians