Diagnostic accuracy of preoperative ultrasonography-guided fine-needle aspiration biopsy in distinguishing malignancy in large thyroid nodules: A systematic review, meta-analysis, and meta-regression

Abstract

Controversy persists regarding the effectiveness of ultrasonography-guided fine-needle aspiration biopsy (US-FNAB) in distinguishing malignancies in large thyroid nodules. The prevailing belief that larger thyroid nodules inherently pose a higher risk of malignancy has led to a common practice of suggesting thyroidectomy for large thyroid nodules. Herein, the aim of this study was to assess the diagnostic accuracy of preoperative US-FNAB for distinguishing malignancy in large thyroid nodules. A search for published records was carried out on October 20, 2023, utilizing the search feature available on PubMed, Scopus, Embase, and Google Scholar. Patients with large thyroid nodules (3 cm or larger) who underwent preoperative US-FNAB and postoperative histopathological tests were included. Related outcomes, including false positive, false negative, true negative, true positive, specificity, and sensitivity, were extracted from each study. Pooled specificity and sensitivity were estimated, and the summarized receiver operating characteristic (sROC) curve, along with the summarized area under the curve (sAUC), was calculated. Out of 133 articles identified across four databases, ten studies with a total sample of 2752 patients were included. The overall diagnostic sensitivity was 72% (95%CI: 50-86%; p=0.00) and specificity was 96% (95%CI: 87-90%; p=0.00). The positive predictive value (PPV) and negative predictive value (NPV) were 93% (95%CI: 89-98%) and 75% (95%CI: 72-79%), respectively. sAUC was 93%, suggesting the diagnostic tool is accurate. Meta-regression analysis revealed that factors such as the number of samples, country (high-income vs upper-middle income), demographic characteristics (age and sex), and different thyroid size cut-off values did not significantly impact the sensitivity or specificity of US-FNAB. In conclusion, the present study confirms the reliability of US-FNAB in distinguishing malignancy in large thyroid nodules, emphasizing its role in reducing unnecessary thyroidectomy by identifying high-risk patients and challenging the conventional practice of routine thyroidectomy for large thyroid nodules.

Keywords: Large thyroid nodule; accuracy; fine-needle aspiration; histopathology; review.

Figure 1.

PRISMA flowchart of the included studies

Figure 2.

Quality assessment of the included studies based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 assessment tool.

Figure 3.

Plots for goodness-of-fit (A) and bivariate normality test (B). (A) Goodness-of-fit analysis: Mahalanobis D-squared statistic and Chi-squared quantile test assess the data's symmetry and distribution. (B) Bivariate normality test: The plot illustrates the relationship between variables, supporting the normal distribution assumption and confirming the model's accuracy.

Figure 4.

Forest plots for sensitivity and specificity of ultrasonography-guided fine-needle aspiration biopsy (US-FNAB) in distinguishing malignancy in large thyroid nodules.

Figure 5.

Summarized receiver operating characteristic (sROC) curve demonstrates the diagnostic accuracy of ultrasonography-guided fine-needle aspiration biopsy (US-FNAB) in distinguishing malignancy in large thyroid nodules.

Figure 6.

Probability modifying plot illustrates the predictive values (positive predictive value (PPV) and negative predictive value (NPV)) of ultrasonography-guided fine-needle aspiration biopsy (US-FNAB) in distinguishing malignancy in large thyroid nodules.

Figure 7.

Cook distance (A) and outlier detection plots (B) of ultrasonography-guided fine-needle aspiration biopsy (US-FNAB) in distinguishing malignancy in large thyroid nodules. Deeks’ funnel plot of diagnostic odds ratio of US-FNAB in distinguishing malignancy in large thyroid nodules (C).