Factors that affect the diagnostic yield of endobronchial ultrasonography-assisted transbronchial lung biopsy

Endobronchial ultrasound (EBUS) is a relatively noninvasive procedure used to diagnose and stage lung cancer. Although EBUS-guided transbronchial lung biopsy (TBLB) procedures for peripheral lesions have higher diagnostic yields than traditional TBLB or fluoroscopy-assisted TBLB, the diagnostic yield is not 100%, and the reasons for this are not clear.

This retrospective study assessed what characteristics influence the diagnostic yield of EBUS-guided TBLB. EBUS was used to locate a single peripheral lung nodule or mass, and the lesion was biopsied and pathologically characterized. Parameters that were evaluated included patient demographics, lesion location, ease of tumor sampling, location of the EBUS probe relative to the lesion, pathological volume, tumor cell type, and whether physicians were under supervision.

Thirty-nine patients received EBUS-guided TBLB, which correctly identified 76.9% of the patients as having lung cancer. For the remaining patients, subsequent surgery indicated their tumors were malignant. Univariate logistic regression modeling indicated that only the location of the probe relative to the lesion was significantly associated with diagnostic yield of EBUS-guided TBLB. When the probe was directly within the lesion, it was 8.17 times (odds ratio 8.17; 95% confidence interval 1.41, 47.22; P=.019) more likely to have a successful TBLB than when the probe was adjacent to the lesion.

In this study, the position of the probe relative to a peripheral lung lesion was associated with the diagnostic yield of EBUS-guided TBLB. Larger prospective studies are required to further assess what influences the diagnostic yield of this technology.