Cone beam computed tomography virtual navigation-guided transthoracic biopsy of small (≤ 1 cm) pulmonary nodules: impact of nodule visibility during real-time fluoroscopy

Objective: To evaluate the impact of nodule visibility during real-time fluoroscopy and other biopsy-related variables on the diagnostic accuracy and complication rates of cone beam CT (CBCT) virtual navigation (VN)-guided percutaneous transthoracic needle biopsies (PTNBs) of small (<1 cm) pulmonary nodules. Methods: Patients (99 males and 114 females: age, 62.1 +/- 11.1 years) who underwent CBCT VN-guided biopsies for lung nodules <= 1 cm were retrospectively reviewed. The visibility of target nodules was assessed on the captured fluoroscopy images. Diagnostic accuracies were calculated and logistic regression analyses were performed to determine independent influencing factors for the correct diagnosis and complications (pneumothoraxes and hemoptysis) in CBCT VN-guided PTNBs, respectively. Results: Among 213 nodules, 63 (29.6%) were invisible on real-time fluoroscopy during VN. The diagnostic accuracy of CBCT VN-guided PTNBs for the invisible nodules was 76.7%, while for the visible nodules was 89.1% (p = 0.042). In the logistic regression analysis, the visibility of a target nodule (odds ratio = 2.49, p = 0.047) was the only independent influencing factor for a correct diagnosis. As regards complication rates, nodule visibility was not a significant factor for the occurrence of a pneumothorax or hemoptysis. Conclusion: Although nodule visibility on real-time fluoroscopy was an affecting factor for the correct diagnosis, CBCT VN-guided PTNB was feasible for the invisible nodules with diagnostic accuracy of 76.7%. Advance in knowledge: CBCT VN-guided PTNB can be tried safely for the subcentimeter-sized pulmonary nodules regardless of their fluoroscopic visibility.