Incidence and features of pulmonary track nodules after CT-guided lung biopsy with track sealing using gelatin sponge slurry

Background Track sealing (TS) with gelatin sponge slurry (GSS) is efficient in reducing pneumothorax after CT-guided lung biopsy. Nodule appearance along the pulmonary track after TS with GSS is a potential issue that has not been previously evaluated. Methods A secondary analysis of two studies evaluating the efficacy of lung TS in 710 patients in reducing post-biopsy pneumothorax was performed. Among these patients, 377 had a follow-up CT within 2 months post-biopsy and were retrospectively included in this study (187 had TS with GSS, 83 with saline, and 107 no TS). Imaging findings of the pulmonary track were described. Binary logistic regression was used to determine factors associated with lung track nodules. Results Median time between biopsy and follow-up CT was 29 days (range, 1-61). A pulmonary track nodule was detected on follow-up CT in 65/377 (17.2%) patients. Sixty three out of these 65 nodules (97%) were observed in the GSS group. Factors significantly associated with nodules on multivariate analysis were GSS use (odds ratio: 47.4, 95%CI:11.8-189.5; p < .0001) and track length (odds ratio: 1.03, 95%CI:1.01-1.05; p = .009). Nodules were solid in 100%, ovoid in 83.1%, well-defined in 87.7%, and had smooth borders in 96.9%. Thirty-three nodules were still visible on imaging > 6 weeks after the biopsy. Conclusion A pulmonary nodule along the biopsy track was detected on follow-up CT in 34% of cases when TS with GSS was performed. Recognition of these nodules on chest imaging is essential to avoid misinterpretation. Clinical Trial Number Not applicable.