# Core needle biopsy as a first-line diagnostic tool for selected thyroid nodules: a real-world evaluation of diagnostic performance and safety

## TL;DR

This study shows that core needle biopsy is an effective and safe first-line diagnostic tool for thyroid nodules with suspicious features.

## Contribution

The study provides real-world evidence supporting the use of core needle biopsy as a primary diagnostic method for thyroid nodules.

## Key findings

- Core needle biopsy achieved 98.2% diagnostic accuracy and 100% sensitivity for thyroid nodules.
- The non-diagnostic and inconclusive rates were 1.9% and 10.4%, respectively.
- The rate of unnecessary surgeries was 6.3% among the studied cases.

## Abstract

This study aimed to evaluate the diagnostic performance and safety of core needle biopsy (CNB) as a first-line diagnostic tool for selected thyroid nodules with suspicious imaging features or other high-risk characteristics in a real-world setting.

The protocol for this observational study was approved by the Review Board of Tianjin Medical University Cancer Institute and Hospital. All the medical records of patients who underwent ultrasound (US)-guided CNB of thyroid nodules were searched between 1 January 2022 and 30 April 2023. US-guided CNB was performed using a disposable 18-gauge needle, and the pathological results of CNB were divided into six categories: nondiagnostic, benign, indeterminate, follicular neoplasms (FN) or suspected follicular neoplasms (SFN), suspicion of malignancy, and malignancy. The diagnostic performance and complications of CNB and the risk factors associated with inconclusive results were also assessed.

A total of 286 patients with 316 nodules were included. Of the 199 cases of malignant nodules, 72 were confirmed by surgery after CNB, and 127 were managed as malignant based on definitive CNB findings in conjunction with clinical and imaging correlation, without surgical confirmation. Among the 78 benign nodules, eight were confirmed by surgery, 50 cases were confirmed by CNB plus contrast-enhanced ultrasound (CEUS), and 20 cases were confirmed by CNB with no change in follow-up for more than 1 year. The non-diagnostic and inconclusive rates were 1.9% and 10.4%, respectively. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CNB were 98.2%, 100.0%, 93.6%, 97.5%, and 100.0%, respectively. The rate of unnecessary surgeries was 6.3%.

CNB is an effective diagnostic tool for thyroid nodules, demonstrating high diagnostic accuracy and a low rate of non-diagnostic results. It may serve as a viable alternative or complementary first-line diagnostic option for selected nodules, particularly those with suspicious ultrasound features or larger sizes, by providing reliable histological architectural assessment.