Radial probe endobronchial ultrasound for the diagnosis of peripheral lung cancer: systematic review and meta-analysis

Improved diagnostic sensitivity of bronchsocopy for the investigation of peripheral pulmonary lesions (PPLs) with the use of radial probe endobroncial ultrasound (EBUS) has been reported, although diagnostic performance varies considerably. A systematic review of published literature evaluating radial probe EBUS accuracy was performed to determine point sensitivity and specificity, and to construct a summary receiver-operating characteristic curve. Sub-group analysis and linear regression was used to identify possible sources of study heterogeneity. 16 studies with 1,420 patients fulfilled inclusion criteria. Significant inter-study variation in EBUS method was noted. EBUS had point specificity of 1.00 (95% CI 0.99-1.00) and point sensitivity of 0.73 (95% CI 0.70-0.76) for the detection of lung cancer, with a positive likelihood ratio of 26.84 (12.60-57.20) and a negative likelihood ratio of 0.28 (0.23-0.36). Significant inter-study heterogeneity for sensitivity was observed, with prevalence of malignancy, lesion size and reference standard used being possible sources. EBUS is a safe and relatively accurate tool in the investigation of PPLs. Diagnostic sensitivity of EBUS may be influenced by the prevalence of malignancy in the patient cohort being examined and lesion size. Further methodologically rigorous studies on well-defined patient populations are required to evaluate the generalisability of our results.