Adequacy and complications of computed tomography-guided core needle biopsy on non-small cell lung cancers for epidermal growth factor receptor mutations demonstration: 18-gauge or 20-gauge biopsy needle

Introduction: To compare adequacy of tissue acquisition for EGFR DNA mutation analysis and the resulting complications in CT-guided lung biopsy cases with either 18-gauge or 20-gauge core biopsy needle. Methods: Forty-seven patients with advanced staged non-small cell lung cancers who were failure-treated by conventional chemotherapy were retrospectively reviewed. All had received CT-guided core needle lung biopsy for histology diagnosis and freshly frozen for EGFR mutation analysis before targeted therapy. We compared the complications resulting from these CT-guided lung biopsies and the specimen assessment using 18-gauge (32 patients) or 20-gauge (15 patients) biopsy needle via 17-gauge or 19-gauge coaxial needle. Results: With an overall pneumothorax rate of 12.8%, pneumothorax occurred in 12.5% and 13.3% of patients by 17-gauge and 19-gauge coaxial needles respectively. The overall rate of hemoptysis was 6.4%, with 6.3% by 18-gauge biopsy needle and 6.6% by 20-gauge biopsy needle. Large peritumoral hemorrhage revealed only in 2 cases of those completed with 18-gauge biopsy needles. 18-gauge biopsy needle obtained larger specimens with heavier weight (average 10.15 mg vs 9 mg) and higher DNA concentration (average 47.13 ng/ul vs 35.92 ng/ul) than 20-gauge biopsy needle. Otherwise, the range of optical density (1.67-2.09) was more constant in the specimens by 20-gauge biopsy needles. Mutation demonstration was achieved for all samples. Conclusion: CT-guided core needle biopsy is a feasible technique in acquisition of fresh cancer tissues for EGFR gene mutation analysis. The specimen is adequate for gene demonstration either using 18-gauge or 20-gauge tru-cut biopsy needles via 17-gauge or 19-gauge coaxial needles.