3:45 PM Abstract No. 96 CT-fluoroscopy in subcentimeter lung nodule biopsy: does it make a difference?

Abstract

Percutaneous lung nodule biopsy plays a critical role in the diagnosis, staging and therapeutic planning of primary and metastatic lung malignancies. However, sampling of subcentimeter lesions remains technically challenging and often leads to increased rate of diagnostic failure. We retrospectively reviewed our subcentimeter lung nodule biopsies using CT-fluoroscopy (CTF) to evaluate diagnostic accuracy, radiation dose and complication rate in the context of anatomical location, imaging features and technical intraprocedural data. We determined the diagnostic accuracy of CTF-guided biopsy of nodules 9-10 mm and 6-8 mm in size, respectively, using core sampling or core sampling plus fine-needle aspiration (FNA). Location of the nodule, nodule imaging characteristics, presence of known malignancy, and associated complications were recorded. Independent risk factors for diagnostic accuracy, radiation dose and complications were determined with multivariate logistic regression analysis. After IRB approval, search on our PACS yielded 791 lung biopsies in the past 5 years, 58 of which were subcentimeter. With exclusion criteria, 46 cases are recruited for diagnostic accuracy analysis and 52 for radiation dose and associated complication. Overall the diagnostic accuracy is 84.8%. However, the cohort (14 cases) with both core and FNA samples has higher accuracy of 92.9%, vs. 81.3% with only core samples (32 cases), in par with reported literature. Logistic regression did not reveal any significant difference in biopsy accuracy or radiation doses against nodule characteristics, location or depth. However, the increased true positive yield with each 1 mm increase in size of nodule has an odds ratio (OR) up to 1.20 (95% CI: 0.73-2.00). The minor and major complication rate was 32.7% and 21.2%, per SIR criteria, respectively. Particularly, there is increased risk of major complication for upper lobe nodules, with OR of 2.9 (95% CI: 0.68-7.86) vs. other lobes. CTF-guided percutaneous subcentimeter lung nodule biopsy in the range of 6-10 mm offers high diagnostic accuracy. However, there is relatively high risk for major complications, particularly for the upper lobar nodules.