A multimodal bronchoscopic approach for diagnosing peripheral ground-glass nodules using Cone-Beam computed tomography and cryobiopsy: a preliminary study.

BACKGROUND

Ground-glass nodules (GGNs) remain challenging to diagnose using endobronchial ultrasound-guided transbronchial biopsy (EBUS-TBB) due to limited visibility and low tissue yield. We evaluated a multimodal bronchoscopic approach and investigated a radiographic predictor of EBUS invisibility to guide the use of cone-beam computed tomography (CBCT).

METHODS

In this single-center retrospective study, patients with GGNs (consolidation-to-tumor ratio <50%) who underwent EBUS-TBB followed by transbronchial cryobiopsy (TBC) using ultrathin bronchoscopy with intraprocedural CBCT between January 2022 and December 2024 were included. The primary endpoint was diagnostic accuracy.

RESULTS

Ninety patients were included. Diagnostic accuracy was 68.9% for EBUS-TBB with CBCT and 76.7% for TBC (p = 0.241). Combined biopsy improved accuracy  over TBB alone (85.6% vs. 68.9%, p = 0.008), with higher diagnostic accuracy across predefined subgroups. After Bonferroni correction, statistically significant remained only for lesions not visible on chest radiography. TBC yielded larger samples (16.8 vs. 3.7 mm2, p < 0.001). Lower HU values were independently associated with EBUS invisibility (adjusted odds ratio per 10-HU decrease, 1.30; 95% CI, 1.08-1.57; p = 0.006). Receiver operating characteristic analysis demonstrated excellent discrimination (area under the curve, 0.94), with an optimal cutoff of -541.95 HU. No life-threatening bleeding, mortality, intensive care unit admission, or surgical intervention occurred.

CONCLUSION

A multimodal bronchoscopic approach provides favorable diagnostic yield for GGNs, and the combined use of forceps biopsy and TBC improves diagnostic performance and tissue acquisition. Lower HU values predict EBUS invisibility and may help guide the selective use of CBCT.