Accuracy of convex probe EBUS-TBNA versus FDG-PET/CT imaging in diagnosis and mediastinal staging of lung cancer patients; an Egyptian Experience

Abstract

Appropriate staging of lung cancer is of paramount importance, as it customizes treatment and predicts prognosis. Both Fludeoxyglucose-18 (FDG) positron emission tomography (PET) combined with contrast computed tomography (CT) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are two widely used diagnostic modalities in the field of staging & diagnosis of lung malignancies, the former depends on image analysis while the later enables real-time sampling of lymph nodes under sonographic guidance. To compare the diagnostic and staging accuracy of convex probe EBUS-TBNA versus FDG – PET/CT as two modalities in diagnosis & mediastinal staging of lung cancer patients. This prospective, observational (daignostic accuracy) research was performed on 40 cases with lung malignancies. All cases were examined via FDG-PET/CT followed by convex probe EBUS-TBNA for diagnosis & staging of concurrent mediastinal lymphadenopathy (MLN). The diagnostic yield of EBUS-TBNA reached 92.5% (37/40) compared to 70% (28/40) for FDG-PET/CT. There was poor agreement between EBUS-TBNA & FDG-PET/CT regarding (MLN) staging (k = 0.043), in 16/40 patients (40%), EBUS MLN staging matched that of FDG-PET/CT, while in 24/40(60%) there were discrepancies between the two diagnostic modalities; 18/40(45%) were up-staged after EBUS while 6/40(15%) were down staged after EBUS. In addition, EBUS-TBNA confirmed occult mediastinal nodal involvement in 9/10 FDG-PET/CT negative scans (N0). The overall diagnostic accuracy of EBUS-TBNA was significantly greater than FDG-PET/CT in staging of lung cancer (97.37% & 70% respectively, p < 0.001). EBUS-TBNA is a minimally invasive procedure that we currently recommend as a first choice for MLN staging. ClinicalTrials.gov, NCT06479798. Registered 26 June 2024—Retrospectively registered, https://clinicaltrials.gov/study/NCT06479798 .