Ultrasound-guided lung biopsy for small (≤2 cm) subpleural lung lesions: comparison of diagnostic yield and safety with larger lesions.

Background: Ultrasound (US)-guided percutaneous core needle biopsy (PCNB) has been used to diagnose subpleural lung lesions with high diagnostic performance and acceptable complication rates. However, with regard to the role of US-guided needle biopsy for the diagnosis of small (≤2 cm) subpleural lesions, limited information is available.

Methods: From April 2011 to October 2021, a total of 572 US-guided PCNBs in 572 patients were retrospectively reviewed. The lesion size, pleural contact length (PCL), lesion location, and operator's experience were analyzed. Computed tomography features including peri-lesional emphysema, air-bronchogram, and cavitary change were also included in image analysis. The patients were divided into three groups according to lesion size (lesions ≤2 cm 2 cm< lesions ≤5 cm lesions >5 cm). The sample adequacy, diagnostic success rate, diagnostic accuracy, and complication rate was calculated. For statistical analysis, one-way ANOVA, Kruskal-Wallis test, or the chi-square test were used.

Results: The overall sample adequacy, diagnostic success rate, and diagnostic accuracy were 96.2%, 82.9%, and 90.4%, respectively. In the subgroup analysis, sample adequacy (93.1% 96.1% 96.9%, P=0.307), diagnostic success rate (75.0% 81.6% 85.7%, P=0.079), and diagnostic accuracy (84.7% 90.8% 90.5%, P=0.301) were not significantly different. Operator's experience (OR, 0.64; 95% CI: 0.49-0.80; P<0.001), lesion size (OR, 0.68; 95% CI: 0.54-0.83; P<0.001), PCL (OR, 0.68; 95% CI: 0.52-0.84; P=0.001), and presence of air-bronchogram (OR, 14.36; 95% CI: 4.18-48.53; P<0.001) were independently associated with complication rate.

Conclusions: US-guided PCNB performed by an experienced radiologist could be an effective and safe diagnostic approach for subpleural lesions, even in small lesions.