Imaging Findings Related to Lung Tract Sealant Use in Percutaneous CT-guided Lung Biopsy

This study examines the imaging findings and malignancy suspicion associated with hydrogel lung tract sealants (h-LTS) used after CT-guided lung biopsy (CTLB).

Charts of patients who underwent CTLB from 01/2016 to 01/2020 were reviewed for biopsy date, h-LTS use, resection, and imaging follow-up. Exclusion criteria included resection <3 months postbiopsy, no imaging ≥3 months, and pleural nodules. Postbiopsy imaging was analyzed for abnormalities at the biopsy tract. Out of 164 patients who underwent CTLB with h-LTS, a random subset of 64 patients (Group A) was anonymized and compared with another randomly selected, anonymized group of 64 patients who underwent CTLB without h-LTS during the study period (Group B) to assess inter-reader agreement. Two cardiothoracic radiologists reviewed the anonymized intraprocedural biopsy CT and follow-up imaging at multiple intervals (3-6, 6-12, 12-24, >24months) for abnormalities along the biopsy tract and associated malignancy suspicion (Categories 1-5 [low-high]).

A serpiginous lesion was observed along the biopsy tract in 60% (99/164) of patients who received h-LTS, lasting an average of 23.3 months (Range: 3-67). Moderate inter-reader agreement was seen for abnormalities in Group A patients at all follow-up intervals. FDG-PET/CT showed mild uptake for up to 5 years in 46% of patients. At initial follow-up, 17% of h-LTS scars were rated Category 3 or higher suspicion for malignancy. Most h-LTS scars maintained or decreased in suspicion in later follow-ups.

h-LTS is associated with a serpiginous scar, which may be mildly hypermetabolic and last up to 5 years.