Related Experiment Video For calcitonin assays in fine-needle aspiration washout fluid (FNA-CT)
Updated: Aug 20, 2025

Computer-Aided Three-Dimensional Visualization in the Treatment of Locally Advanced Thyroid Cancer
Published on: June 9, 2023
Diagnostic value and cost-effectiveness of FNA-CT versus FNAC for medullary thyroid carcinoma
Mingjun Wang1, Hedan Chen1, Yichao Wang1
1Thyroid and Parathyroid Surgery Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Objective:
To evaluate the diagnostic performance and cost-effectiveness of calcitonin assays in fine-needle aspiration washout fluid (FNA-CT) compared to fine-needle aspiration cytology (FNAC) for medullary thyroid carcinoma (MTC).
Methods:
A total of 27,404 patients from three medical centres between January 2020 and May 2022 were screened for serum calcitonin (sCT). Of whom, 223 patients met endpoints and were enroled for analyses. Based on sCT levels, patients were divided into two groups (group 1: 10 pg/ml< sCT ≤100 pg/ml and group 2: sCT > 100 pg/ml). The diagnostic performance and cost-effectiveness of FNA-CT and FNAC were compared.
Results:
Most patients (N = 25,228; 92.1%) with thyroid nodules had normal sCT levels. In group 1, 24 and 167 nodules were diagnosed as MTC and non-MTC lesions, respectively. FNA-CT showed better performance in diagnosing MTC than FNAC in terms of sensitivity (100.0% vs. 58.3%), negative predictive value (100.0% vs. 94.3%), and overall accuracy (100.0% vs. 94.7%). In group 2, 67 and 7 nodules were diagnosed as MTC and non-MTC lesions, respectively. The diagnostic performance of FNA-CT was superior to FNAC in terms of sensitivity (100.0% vs. 64.2%), negative predictive value (100.0% vs. 22.6%), and overall accuracy (100.0% vs. 67.6%). Furthermore, analysis from the decision tree model showed that FNA-CT was a cost-effective tool for diagnosing MTC lesions.
Conclusions:
FNA-CT can serve as an auxiliary and cost-effective approach for patients with indeterminate sCT levels to detect occult MTC lesions. FNA-CT can be recommended for patients with sCT >100 pg/ml to overcome the high false-negative rate of FNAC.

