The Role of Computed Tomography Studies in Navigation Bronchoscopy for Differential Diagnosis of Peripheral Pulmonary Lesions

Abstract

Aim: to study radiological semiotics of peripheral pulmonary lesions (PPLs) detected by CT of the chest, and establish radiological patterns, which significantly increase effectiveness of navigation bronchobiopsies. Materials and methods. A cohort retrospective study included 278 patients with PPLs with verified diagnoses established by invasive diagnostic procedures (navigation bronchoscopy with a complex of biopsies and/or diagnostic thoracic surgery). The study included 162 (58.3%) women aged 13 to 80 yrs. (average age – 46.21 ± 5.23) and 116 (41.7%) men aged 14 to 85 yrs. (average age – 46.05 ± 3.49). The patients were divided into 4 nosological groups: pulmonary TB patients – 158 (56.8%), neoplastic patients – 79 (28.4%), nontuberculous pulmonary mycobacteriosis (NTPM) patients – 21 (7.6%), and protracted course community-acquired pneumonia (CAP) patients (presentations of PPLs) – 20 (7.2%). Results. According to chest CT data, PPLs had three major radiological sings, defined as “infiltrate”, “rounded shadow”, and “focus”. Rounded shadows prevailed in NTPM patients and neoplastic patients. Statistically significant differences between the groups were as follows: the medium maximum size and contour of PPLs (focus / rounded shadow / infiltrate), the presence of bronchiectasis and the type of foci (lobular/sublobular/acinar) in the lung parenchyma surrounding PPLs, the presence of calcification, cavitation, or air bronchograms inside PPLs. The total effectiveness of bronchoscopic verification of PPLs in patients with “CT bronchus sign” was 79.4%, which significantly exceeded diagnosis verification in patients without it (17.9%) (р < 0.001). The effectiveness of diagnosis verification by bronchobiopsy in patients with PPLs less than 20 mm (CT data) achieved 50% irrespective of etiology. The most effective bronchoscopic verification of diagnoses was observed in TB and NTPM patients with PPLs ≥ 20 mm – 83.3% and 100.0% respectively, and in neoplastic patients with PPLs ≥ 30 mm it reached 93.0%. The lobar localization of the process did not affect the diagnostic effectiveness of bronchobiopsies. Conclusion. The highest effectiveness of bronchobiopsies was observed in patients with the CT bronchus sign and with PPLs ≥ 20 mm or ≥ 30 mm (CT data). The volume of diagnostic biopsies obtained by navigation bronchoscopy or surgical resection should be determined by radiological morphology of PPLs with estimation of malignancy or benign signs revealed by CT of the chest.