Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

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.

Radiologic and histopathologic features of hydrogel sealant after lung resection in participants of a prospective randomized clinical trial

PURPOSE

To summarize imaging and histopathologic characteristics of hydrogel sealant (plug) in lung parenchyma and assess their correlation with time since deployment of sealant.

MATERIALS AND METHODS

Among a total of 208 participants randomized to the hydrogel sealant arm of a lung biopsy prospective randomized clinical trial, 51 underwent resection of the biopsied lesion. In 34 participants sealant material was present on histopathologic sections (n = 22), or they had cross-sectional imaging of chest between biopsy and resection (n = 23) or they had both imaging and histopathology (n = 11). Histopathologic and imaging findings were described. The association of these findings with time since sealant deployment was evaluated using the Wilcoxon rank sum test.

RESULTS

The mean time since sealant deployment for histopathology was 45.7 days (median 36, range 14-181) and for imaging studies was 99 days (median 32, range 4-527). The sealant was infiltrated by inflammatory cells in 20 (91%) participants. The main general histopathologic pattern of sealant was foamy in 12 (57%) and mesh in 8 (38%) participants. Imaging appearance of sealant was serpiginous in 18 (60%), linear in 10 (33%) or lobulated in 2 (6.7%) participants. In 2 participants the sealant was hypermetabolic with no histopathologic evidence of tumor. No correlation was found between time since sealant deployment and imaging or histopathologic appearances.

CONCLUSION

Hydrogel sealant appears as a serpiginous, linear, or lobulated opacity on cross-sectional imaging which can be metabolically active. It is associated with an inflammatory reaction with a foamy or mesh general pattern on histopathological assessment. No correlation was found between time since sealant deployment and imaging or histopathologic appearances.