Diagnostic efficacy, performance and safety of side-cut core needle biopsy for thyroid nodules: comparison of automated and semi-automated biopsy needles

Purpose This study was performed to compare the utility of the semi-automated and automated side-cut core biopsy needles for thyroid nodules. Methods Between January 2014 and March 2020, biopsy was performed for 278 thyroid nodules using the semi-automated core needle and for 225 nodules using the automated core needle. Nondiagnostic rate, inconclusive rate, diagnostic performance and complication rates were evaluated and compared between two core needle types. Results There were 1.2% (6/503) nondiagnostic results and 15.9% (80/503) inconclusive results. Nondiagnostic rate between two needle types was not significantly different. The semi-automated type (33/278, 11.9%) showed lower inconclusive rate than the automated type (47/225, 20.9%) ( p = 0.006). The sensitivity, specificity, PPV, NPV and diagnostic accuracy for diagnosis of malignancy of the semi-automated type were 70.18, 100, 100, 84.96 and 88.89%, respectively; the corresponding rates of automated type were 70.45, 100, 100, 86.6, and 89.84%. There were 12 minor complications: four hematomas (4/278, 1.4%) for the semi-automated type and eight hematomas (8/225, 3.6%) for the automated type, which difference was not statistically significant. Conclusion Core needle biopsy for thyroid nodules using either the semi-automated or automated needle is a safe diagnostic tool. Semi-automated needle has lower inconclusive rate than automated needle.