Influence of thyroid gland status on the thyroglobulin cutoff level in washout fluid from cervical lymph nodes of patients with recurrent/metastatic papillary thyroid cancer

Ultrasound-guided fine needle aspiration thyroglobulin in the diagnosis of lymph node metastasis of differentiated papillary thyroid carcinoma and its influencing factors

Background

Ultrasound-guided fine needle aspiration thyroglobulin (FNA-Tg) is recommended for the diagnosis of lymph node metastasis (LNM) in differentiated thyroid cancer (DTC), but its optimal cutoff value remains controversial, and the effect of potential influencing factors on FNA-Tg levels is unclear.

Method

In this study, a retrospective analysis was conducted on 281 patients diagnosed with DTC, encompassing 333 lymph nodes. We analyze the optimal cutoff value and diagnostic efficacy of FNA-Tg, while also evaluating the potential influence of various factors on FNA-Tg.

Results

For FNA-Tg, the optimal cutoff value was 16.1 ng/mL (area under the curve (AUC)= 0.942). The optimal cutoff value for FNA-Tg/sTg was 1.42 (AUC = 0.933). The AUC for FNA combined with FNA-Tg yielded the highest value compared to other combined diagnostic methods (AUC = 0.955). It has been found that serum thyroglobulin (sTg) is positively correlated with FNA-Tg (Rs = 0.318), while serum thyroglobulin antibodies (sTgAb) is negatively correlated with FNA-Tg (Rs = -0.147). In cases where the TNM stage indicated N1b, the presence of large or high volume lymph node metastasis(HVLNM), lymph node lateralization/suspicion (L/S) ratio ≤ 2, ultrasound findings indicating lymph node liquefaction, calcification, and increased blood flow, patients with coexisting Hashimoto's thyroiditis (HT), a tumor size ≥10 mm, and postoperative pathology confirming invasion of the thyroid capsule, higher levels of FNA-Tg were observed. However, the subgroup classification of DTC and the presence or absence of thyroid tissue did not demonstrate any significant impact on the levels of FNA-Tg.

Conclusion

The findings of this study indicate that the utilization of FNA in conjunction with FNA-Tg is a crucial approach for detecting LNM in DTC. TNM stage indicated N1b, the presence of HVLNM, the presence of HT, lymph node L/S ratio, liquefaction, calcification, tumor diameter, sTg and sTgAb are factors that can impact FNA-Tg levels.In the context of clinical application, it is imperative to individualize the use of FNA-Tg.

Diagnostic Efficacy of FNA-Tg in DTC Cervical LN Metastasis and its Impact Factors: A Large Retrospective Study

CONTEXT

Thyroglobulin in needle washout fluid (FNA-Tg) has the advantage of compensating for the low sensitivity of cytological analysis (FNAC) in differentiated thyroid carcinoma (DTC) lymph node (LN) metastasis. However, studies of large data sets to support this view and identify the best cutoff of FNA-Tg are lacking.

OBJECTIVE

Our study aimed to determine the best cutoff of FNA-Tg and explore the impact factors of FNA-Tg.

METHOD

A total of 1106 suspicious LNs from patients treated at West China Hospital from October 2019 to August 2021 were included. Parameters were compared between metastatic and benign LNs, and the best cutoff value of FNA-Tg was identified by ROC curves. The impact factors of FNA-Tg were analyzed.

RESULTS

In the nonsurgery group, after correcting for the effect of age and short diameter of LN, FNA-Tg was the independent risk factor for cervical LN metastasis of DTC (odds ratio [OR]: 1.048; 95% CI, 1.032-1.065). In the surgery group, after correcting for the effects of serum thyrotropin, serum Tg, long diameter of LN, and short diameter of LN, FNA-Tg was the independent risk factor for cervical LN metastasis of DTC (OR: 1.019; 95% CI, 1.006-1.033). The best cutoff value of FNA-Tg was 25.17 μg/L, and the area under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.944, 0.847, 0.978, 0.982, 0.819, and 0.902, respectively. FNA-Tg highly correlated with FNA-TgAb (P < .01; Spearman correlation coefficient = 0.559), but FNA-TgAb positivity did not undermine the diagnostic efficacy of FNA-Tg for DTC LN metastasis.

CONCLUSION

The best cutoff value of FNA-Tg was 25.17 μg/L in diagnosing DTC cervical LN metastasis. FNA-Tg highly correlated with FNA-TgAb, but FNA-TgAb had no influence on the diagnostic efficacy of FNA-Tg.

Diagnostic value of multiple diagnostic methods for lymph node metastases of papillary thyroid carcinoma: A systematic review and meta-analysis

OBJECTIVE

This study compared the diagnostic value of various diagnostic methods for lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) through network meta-analysis.

METHODS

In this experiment, databases such as CNKI, Wanfang, PubMed, and Web of Science were retrieved according to the Cochrane database, Prisma, and NMAP command manual. A meta-analysis was performed using STATA 15.0, and the value of the surface under the cumulative ranking curve (SUCRA) was used to determine the most effective diagnostic method. Quality assessments were performed using the Cochrane Collaboration's risk of bias tool, and publication bias was assessed using Deeks' funnel plot.

RESULTS

A total of 38 articles with a total of 6285 patients were included. A total of 12 diagnostic methods were used to study patients with LNM of PTC. The results showed that 12 studies were direct comparisons and 8 studies were indirect comparisons. According to the comprehensive analysis of the area of SUCRA, US+CT(86.8) had the highest sensitivity, FNAC had the highest specificity (92.4) and true positive predictive value (89.4), and FNAC+FNA-Tg had higher negative predictive value (99.4) and accuracy (86.8). In the non-invasive method, US+CT had the highest sensitivity, and the sensitivity (SEN) was [OR=0.59, 95% confidence interval (CI): (0.30, 0.89]. Among the invasive methods, the combined application of FNAC+FNA-Tg had higher diagnostic performance. The sensitivity was [OR=0.62, 95% CI: (0.26, 0.98)], the specificity (SPE) was [OR=1.12, 95% CI: (0.59, 1.64)], the positive predictive value was [OR=0.98, 95% CI: (0.59, 1.37)], the negative predictive value was [OR=0.64, 95% CI (0.38, 0.90)], and the accuracy was [OR=0.71, 95% CI: (0.31, 1.12)].

CONCLUSION

In the non-invasive method, the combined application of US+CT had good diagnostic performance, and in the invasive method, the combined application of FNAC+FNA-Tg had high diagnostic performance, and the above two methods were recommended.

A Combination of Contrast-Enhanced Ultrasound and Thyroglobulin Level in Fine-Needle Aspirates Improves Diagnostic Accuracy for Metastatic Lymph Nodes of Papillary Thyroid Carcinoma

OBJECTIVE

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) combined with thyroglobulin (Tg) levels in fine-needle aspirates (FNA) washout fluid (FNA-Tg) in diagnosing cervical lymph node (LN) metastasis in papillary thyroid cancer (PTC) patients.

METHODS

Data from 190 LNs in 167 patients suspected of metastasis from the US between November 2018 and September 2020 were included. All subjects underwent FNA, CEUS, and FNA-Tg examinations. The final outcomes were confirmed by histopathological or cytological examination or follow-up imaging. Data were analyzed using the Wilcoxon rank-sum or chi-squared test. The diagnostic efficacy of FNA, CEUS, and FNA-Tg in diagnosing LNs was compared.

RESULTS

A cutoff value of 6.15 ng/ml (AUC 0.925, 95% confidence interval (CI) 0.885-0.966) successfully identified metastatic LNs. FNA missed 58 LN metastases, of these, 94.8% (55/58) were correctly diagnosed using the combination of CEUS and FNA-Tg. FNA-Tg showed higher sensitivity (90.2%), NPV (86.1%) and accuracy (88.9%) than either FNA (48.2, 57.4 and 69.5%, respectively) or CEUS (82.1, 67.7 and 70.5%, respectively) alone. The combination of CEUS, FNA and FNA-Tg resulted in maximal sensitivity (100%) and NPV (100%) but reduced specificity (51.3%) and overall diagnostic accuracy (80.0%). After adding FNA-Tg to discordant samples between CEUS and FNA, 81.9% of LNs (77/94) were correctly diagnosed.

CONCLUSIONS

The combination of FNA, FNA-Tg and CEUS was found to be a promising imaging tool in detecting metastatic LNs in PTC patients.

The influence of thyroid status, serum Tg, TSH, and TgAb on FNA-Tg in cervical metastatic lymph nodes of papillary thyroid carcinoma

OBJECTIVE

Papillary thyroid carcinoma is treated in China mostly with surgery, including total ablation, lobectomy, and lobe and isthmus resection. Therefore, whether thyroid status affects the FNA-Tg cutoff value in the diagnosis of cervical lymph node metastasis deserves our attention. In addition, we investigated the influence of serum Tg, TSH, and TgAb on the accuracy of using FNA-Tg for diagnosis.

METHODS

Our retrospective analysis included 189 suspected cervical lymph nodes, and we determined whether the cutoff value of FNA-Tg was affected by thyroid status, sTg, sTSH, and sTgAb.

RESULTS

In thyroid present cases, the optimal cutoff value of FNA-Tg was 2.3 ng/ml (sensitivity 96.2%, specificity 100%), and in the thyroid absent cases, the optimal cutoff value of FNA-Tg was 0.7 ng/ml (sensitivity 97.6%, specificity 96.0%). Although serum Tg, TSH, and TgAb were weakly correlated with FNA-Tg values, they did not affect the diagnostic performance of the optimal cutoff value of FNA-Tg according to thyroid status.

CONCLUSIONS

The optimal cutoff value of FNA-Tg should be selected according to the thyroid status (2.3 ng/ml for thyroid present cases and 0.7 ng/ml for thyroid absent cases) to ensure the efficient diagnosis of cervical metastatic lymph nodes of papillary thyroid carcinoma. It was determined that sTg, sTSH, and sTg-Ab cannot influence the diagnostic performance of FNA-Tg. The combination method of FNA-Tg and FNAC is the most optimal choice for the diagnosis of lymph nodes metastasis.

Impact of Thyroid Tissue Status on the Cut-Off Value of Lymph Node Fine-Needle Aspiration Thyroglobulin Measurements in Papillary Thyroid Cancer

Objective: To study the optimal cut-off value of thyroglobulin measurement in a fine-needle aspiration (FNA-Tg) in diagnosing malignant lymph nodes and benign lymph nodes (LNs) according to the thyroid tissue status.

Methods: A total of 517 LNs were aspirated: 401 preoperative LNs, 42 LNs after subtotal thyroidectomy and 74 suspected LNs after total thyroidectomy. The cut-off value of FNA-Tg was obtained from receiver operating characteristic (ROC) analysis. The cut-off value with the best diagnostic performance was then obtained by comparing different cut-off values from other studies.

Results: LN FNA-Tg levels differed between preoperative and total thyroid disease (p < 0.001) and subtotal thyroidectomy and total thyroidectomy (p = 0.03), but not between preoperative and subtotal thyroidectomy (p = 1.00). Accordingly, those 443 LNs with preoperative and subtotal thyroidectomy were compared to those 74 without thyroid tissue. The optimal cut-off value in thyroid tissue group was 19.4 ng/ml and the area under the ROC curve (AUC) was 0.95 (95% CI 0.92–0.97). The optimal cut-off value in thyroid tissue absence group was 1.2 ng/ml and the AUC was 0.93 (0.85–0.98). After the analysis and comparison of multiple cut-off values, the optimal diagnostic performance was still found to be 19.4 ng/ml and 1.2 ng/ml.

Conclusion: The influential factors of FNA-Tg are still controversial, and the optimal cut-off value of FNA-Tg can be determined based on the presence or absence of thyroid tissue. FNA-Tg can be used as an important auxiliary method for diagnosing cervical metastatic LNs of thyroid cancer.

Predictive Value of FNA-Tg and TgAb in Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma

Objectives: To analyze whether thyroglobulin (Tg) and anti-Tg antibody (TgAb) detection in fine-needle aspiration (FNA) of cervical lymph node (LN; LN-FNA-Tg and LN-FNA-TgAb) can predict LN metastasis and obtain the best cutoff value. Methods: The patients admitted to our hospital from January 2020 to March 2021 were prospectively enrolled. The LNs were sampled by FNA. All patients underwent thyroid surgery and neck dissection. LN-FNA-Tg, LN-FNA-TgAb, and blood Tg and TgAb were measured. The receiver operating characteristic curve analysis was used to determine the best cutoff points for positive LN. Results: There were 29 participants in the LN metastasis group and 42 in the nonmetastasis group. Compared with the nonmetastasis group, the participants in the metastasis group had higher LN-FNA-Tg (median: 1897 vs 7.74 ng/mL, P < .001), higher LN-FNA-TgAb (median: 15.65 vs 8.21 IU/mL, P < .001), and higher serum Tg (median: 25.4 vs 18.81 ng/mL); there were no differences in serum TgAb (median: 26.6 vs 28.6 IU/mL, P = .477). The best accuracy (87.5%) was observed with LN-FNA-Tg of >227.1 ng/mL, resulting in an area under the curve of 0.927, 84.5% sensitivity, and 89.5% specificity. LN-FNA-TgAb >10.85 IS/mL had an accuracy of 79.6%, sensitivity 64.8%, and specificity 89.5%. Serum Tg and TgAb had the lowest accuracy, with 64.2% and 57.4%, respectively, sensitivity of 53.5% and 67.6%, and specificity of 71.4% and 50.5%. Similar results were observed in first-operation participants and postoperative participants. Conclusions: LN-FNA-Tg has high accuracy, sensitivity, and specificity for detecting cervical LN in patients with papillary thyroid cancer.

Thyroglobulin Measurement Through Fine-Needle Aspiration for Optimizing Neck Node Dissection in Papillary Thyroid Cancer

BACKGROUND

Thyroglobulin measurement in fine-needle aspiration (FNA-Tg) is an additional diagnostic tool of lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC). However, its performance as a preoperative indicator of lateral neck LNM in PTC is unclear. We evaluated the use of FNA cytology and FNA-Tg to detect neck LNM presurgery using a simple methodology, and established a cut-off value for diagnosing LNM in PTC.

METHODS

We performed a retrospective cohort study based on hospital records, including 299 FNA-Tg measurements from 228 patients with PTC. The cut-off value for FNA-Tg was obtained through a receiver operating characteristic (ROC) curve analysis. The relationships between various parameters and FNA-Tg were analyzed using Spearman's correlation.

RESULTS

Of 299 lymph nodes (LNs) from 228 patients following surgery, 151 were malignant and 148 were benign. The median FNA-Tg levels were 414.40 ng/mL and 6.36 ng/mL in the metastatic and benign LNs, respectively. An FNA-Tg cut-off value of 28.3 ng/mL had the best diagnostic performance (93.38% sensitivity, 70.27% specificity, area under the ROC curve [AUC] 0.868) in the whole cohort. The diagnostic value performed better in the lateral neck group (level II-V, n = 163) than in the central neck group (level VI, n = 136); in the lateral neck group, the sensitivity and specificity of the FNA-Tg cut-off (16.8 ng/mL) were 96.25% and 96.36%, respectively.

CONCLUSIONS

FNA-Tg is a useful technique for the diagnosis of LNM before surgery, especially in lateral neck dissection.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR1900028547.

Excellent diagnostic performance of FNA-Tg in detecting lymph nodes metastases from papillary thyroid cancer

Background: Thyroglobulin washout of fine needle aspiration (FNA-Tg) has proved to be useful in detecting lymph node metastases from papillary thyroid cancer; however, the influences of thyroid gland, Hashimoto thyroiditis, serum thyroglobulin (Tg) and anti-TG antibody on the diagnostic performance of FNA-Tg are controversial. Patients & methods: We retrospectively collected the FNA-Tg results of 176 preoperative or postoperative patients (356 lymph nodes) who finally were diagnosed with papillary thyroid cancer. The diagnostic abilities of FNA-Tg were evaluated and compared under different circumstances. Results: The diagnostic performance of FNA-Tg was uninfluenced irrespective of the status of thyroid gland or serum anti-TG antibody. However, high serum Tg was positively correlated with FNA-Tg (Exp(B) = 1.57; 95% CI: 1.209-2.309; p = 0.001). Conclusion: FNA-Tg was an excellent diagnostic tool, but it should be interpreted with caution only if serum Tg is higher than 10 ng/ml.

Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review

Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.

The utility of thyroglobulin washout studies in predicting cervical lymph node metastases: One academic medical center's experience

BACKGROUND

Fine-needle aspiration cytology (FNAC) is useful for evaluating cervical lymph nodes for metastases from thyroid carcinomas. Reports have illustrated that with application of standardized technique and appropriate cutoffs, thyroglobulin (TG) washout studies increase the sensitivity and specificity of FNAC in identifying lymph node metastases. This project describes our experience at an academic medical center utilizing needle wash thyroglobulin analyses as an ancillary to FNAC.

MATERIALS AND METHODS

We reviewed cases at our institution where thyroglobulin analysis was performed in conjunction with FNA of lymph nodes in patients with thyroid carcinoma. Thyroglobulin levels were measured on needle rinses from each FNA biopsy that appeared negative or equivocal at the time of immediate assessment. These results were compared with surgical pathology results from neck dissections, when performed.

RESULTS

168 FNA biopsies were performed on suspicious lymph nodes from 97 patients with known or suspected thyroid malignancy between April 2013 and present. Using a cutoff of 1.0 ng TG/ml, thyroglobulin studies performed at our institution were found to have sensitivity and specificity results of 0.95. Surgical pathology results were used as the gold standard. When surgical pathology results are not available, FNAC is used as the mode of comparison. False positive T_g results occurred in two prethyroidectomy patients suggesting that sample contamination with blood may influence this method's specificity. A false-negative T_g result occurred in a lymph node with <1 mm focus of metastatic PTC, indicating that T_g results may not be sensitive in cases with few tumor cells.

CONCLUSIONS

Our results suggest that thyroglobulin washout studies improve the quality of our biopsy diagnoses when used in conjunction with FNA in the assessment of metastatic disease in the context of established thyroid malignancy in post-thyroidectomy patients. Thyroglobulin values close to the cutoff of 1.0 ng/ml should be interpreted with caution, as these may represent a minute focus of metastatic tumor. T_g values in prethyroidectomy patients should also be interpreted with caution, as contamination with blood may cause its elevation. Diagn. Cytopathol. 2016;44:964-968. © 2016 Wiley Periodicals, Inc.