Thyroglobulin level in fine-needle aspirates for preoperative diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma: two different cutoff values according to serum thyroglobulin level

Metastatic differentiated thyroid cancer with negative serum stimulated Tg but positive post-therapeutic 131I-SPECT/CT scintigraphy: a single-center retrospective study

PURPOSE

This study aimed to describe the characteristics of patients with metastatic differentiated thyroid carcinoma (DTC) who had positive 131I-scintigraphy but negative stimulated thyroglobulin (sTg), and to evaluate their short-term response to radioiodine therapy (RAI).

METHODS

A total of 2250 consecutive postoperative DTC patients, who underwent RAI treatment from July 2019 to June 2022, were analyzed retrospectively. The target group was defined as stimulated Tg < 2 ng/mL with TgAb < 100 IU/mL but with post-therapeutic 131I-SPECT/CT metastases. The characteristics of these patients were analyzed and the metastatic profiles were compared with TgAb positive or sTg positive ones. A cross-sectional efficacy was evaluated 6-12 months after the RAI therapy and the treatment course until the end of the study was recorded.

RESULTS

105 (4.67%) DTC patients were post-therapeutic 131I-SPECT/CT positive and sTg negative (target group). Metastatic profiles were found significant differences between sTg negative and sTg positive ones (P < 0.001). Excellent response (ER) was achieved in 72.4% of the target group between 6-12 months of cross-sectional efficacy assessment, compared with only 12.8% in sTg positive ones (P < 0.001). The majority of the target group didn't require aggressive treatment in short-term follow-up compared with sTg positive group (P < 0.001).

CONCLUSION

The percentage of DTCs with negative sTg but positive post-therapeutic 131I-SPECT/CT was relatively low, but still significant. Moreover, the majority of these patients showed an ER to RAI and may not require the next course of therapy. Long-term follow-up is still necessary to assess recurrence and adapt surveillance in these patients.

Long-term follow-up result of antithyroid drug treatment of Graves' hyperthyroidism in a large cohort

OBJECTIVE

This study evaluated the efficacy of antithyroid drugs (ATDs) and risk factors associated with the recurrence of Graves' hyperthyroidism using a comprehensive retrospective cohort.

METHODS

We included 1829 patients newly diagnosed with Graves' hyperthyroidism, with sufficient follow-up data. Clinical outcomes of the patients and risk factors associated with recurrence-free survival, including the changes in thyrotropin receptor antibody, were evaluated.

RESULTS

The median age of the patients was 44.5 years, and 69% were female. Among the patients, 1235 had a chance to withdraw ATD after a median of 23 (interquartile range (IQR) 17.0-35.5) months of treatment. The first remission rate was 55.6% during a median of 72.7 months of follow-up. After the first recurrence, 95% of patients underwent the second course of ATD treatment for a median of 21.1 (IQR 14.8-31.7) months, and the remission rate was 54.1%. During a median of 67 months of follow-up, 7.7% of patients underwent surgery, and 10.5% underwent radioactive iodine therapy. Approximately 30% were still on ATD therapy for recurrent disease or prolonged low-dose maintenance. Younger age (<45 years), male sex, and fluctuating or smoldering of TRAb levels were independent risk factors of the first recurrence after ATD treatment.

CONCLUSIONS

ATD treatment is an acceptable option for the initial treatment of Graves' hyperthyroidism as well as for recurrent disease. The optimal treatment period for ATD treatment needs to be determined using the individual risk factors of recurrence.

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.

Detection of thyroglobulin in fine-needle aspiration for diagnosis of metastatic lateral cervical lymph nodes in papillary thyroid carcinoma: A retrospective study

Objective

We analysed the diagnostic performance of thyroglobulin in fine-needle aspiration (FNA-Tg) in the suspicious lateral cervical lymph nodes (CLNs) in patients with papillary thyroid cancer (PTC), proposed the best cutoff value and discussed the factors that may affect the diagnostic value of FNA-Tg.

Methods

In the present study, a retrospective analysis of 403 patients with PTC with 448 suspected lateral CLNs metastasis from October 2019 to May 2021 was performed. The cutoff value according to the receiver operating characteristic (ROC) curve was determined, and the Wilcoxon rank-sum test was used to evaluate the correlation between FNA-Tg and factors.

Results

According to the ROC curve, the cutoff value of FNA-Tg was 3.69 ng/ml (sensitivity, 92.48%; specificity, 75.00%). Patients who underwent total thyroidectomy were excluded. Compared with US and FNAC, the diagnostic performance of FNA-Tg was the greatest, especially for small CLNs (diameter ≤ 1 cm), cystic CLNs, and patients with Hashimoto’s thyroiditis (HT). Moreover, FNA-Tg levels were correlated with the presence of HT (p = 0.003), the anti-thyroglobulin antibody (Tg-Ab) (p < 0.001), the ratio of metastatic lateral CLNs (p = 0.004) and Tg assay kits (p < 0.001).

Conclusions

FNA-Tg measurement is sensitive enough for diagnosing lateral CLN metastases from PTC, but its diagnostic value is compromised by a number of factors.

The Role of Thyroglobulin in Preoperative and Postoperative Evaluation of Patients With Differentiated Thyroid Cancer

Thyroglobulin (Tg) is secreted by thyroid follicular cells and stored in the thyroid follicular lumen as a component of thyroid hormone. It is known that both benign and well-differentiated malignant thyroid tissue can secrete Tg. In recent years, growing lines of evidence have shown that Tg plays an important role in the diagnosis and metastasis of preoperative differentiated thyroid carcinoma (DTC). The levels of Tg, whether in the serum or in a fine-needle aspiration washout fluid, are usually viewed as an excellent indicator in the monitoring of postoperative DTC, including the guidance and evaluation of radioactive iodine ablation. Nevertheless, some factors limit the application of Tg, such as the method used to measure Tg and the presence of Tg antibodies. This review aimed to summarize the role of Tg in the preoperative and postoperative evaluation of patients with DTC, and the factors influencing Tg. This review could provide a reference for a more accurate application of Tg in patients with DTC.

A New Dynamic Response to Therapy Assessment in Postoperative Patients With Low-Risk Differentiated Thyroid Cancer Treated Without Radioactive Iodine

Background

Total thyroidectomy (TT) or lobectomy without radioactive iodine (RAI) is becoming a common management for patients with low-risk differentiated thyroid cancer (DTC). However, the assessment of response to therapy for these patients remains controversial. The aim of this study was to propose and validate a new dynamic evaluation strategy to assess the response to therapy in patients with low-risk DTC treated with TT or lobectomy but without RAI.

Methods

We performed a retrospective analysis of 543 adult patients with low-risk DTC who underwent TT or lobectomy without RAI therapy. Follow-up consisted of trends of serum thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb) levels and neck ultrasonography (US) were conducted every 6-24 months. Response to therapy assessments were defined as excellent response, biochemical incomplete response, structural incomplete response, and indeterminate response according to the follow-up findings.

Results

At a median follow-up of 51 months (range 33-66 months), 517 (95%) had excellent response, while the other 26 had either biochemical incomplete response (an increasing trend of suppressed serum Tg levels, n=9; an increasing trend of TgAb levels, n=3) or indeterminate response (a stable or decreasing trend of suppressed serum Tg levels, but a stable positive trend of TgAb levels, n=14). No patients had structural incomplete response or no deaths related to thyroid cancer. The risk of incomplete response was significantly higher in lobectomy than in TT (p<0.001).

Conclusion

Our study proposed and validated a new dynamic response to therapy assessment depending on trends of suppressed serum Tg, TgAb levels, and neck US findings which could be an appropriate tool for postoperative follow-up in low-risk DTC patients without RAI therapy. Our findings provided further evidence to support no routine recommendation of RAI after surgery in low-risk DTC.

Measurement of thyroglobulin level in lateral neck lymph node fine needle aspiration washout fluid in papillary thyroid cancer

Background

Thyroglobulin (Tg) level of fine needle aspiration (FNA) washout fluid (FNA-Tg) is useful to detect cervical lymph node (LN) metastasis in patients with papillary thyroid cancer (PTC). The objective of this study was to determine appropriate cutoff values of serum Tg (S-Tg) and FNA-Tg levels for diagnosis of lateral neck LN metastasis and investigate their diagnostic performance.

Methods

A total of 169 patients with PTC who underwent modified radical neck dissection (mRND) were retrospectively reviewed at Seoul St. Mary's Hospital (Seoul, Korea) from December 2011 to September 2019. Diagnostic performance of FNA-Tg, Tg ratio (FNA-Tg level/S-Tg level), and FNA-Tg combined with Tg ratio was evaluated by correlation with FNA cytology results.

Results

FNA-Tg level ≥20 ng/mL exhibited 86.6% sensitivity, 66.7% specificity, and 81.7% accuracy. Tg ratio ≥3 exhibited lower sensitivity but higher specificity (82.7% and 73.8%, respectively) than FNA-Tg level ≥20 ng/mL. FNA-Tg level ≥20 ng/mL combined with Tg ratio ≥3 had 81.9% sensitivity, 80.5% accuracy, and an integrated area under the curve (iAUC) of 0.790.

Conclusions

Measurement of FNA-Tg level increases preoperative diagnostic accuracy for the detection of metastatic LNs in patients with PTC. Diagnostic accuracy is higher using a 20 ng/mL FNA-Tg cutoff level. Tg ratio is also valuable and FNA-Tg combined with Tg ratio shows promise.

The diagnostic value of thyroglobulin in fine-needle aspiration of metastatic lymph nodes in patients with papillary thyroid cancer and its influential factors

Thyroglobulin (Tg) measurement in fine-needle aspiration (FNA-Tg) has proved to be an excellent tool to identify metastatic cervical lymph nodes (CLN) before or after surgery for papillary thyroid cancer (PTC). The diagnostic value of FNA-Tg for metastatic CLN in PTC patients is higher than that of ultrasound (US) and fine-needle aspiration cytology (FNAC), especially for small or cystic LN. The combination of FNAC and FNA-Tg can provide nearly 100% diagnostic sensitivity and specificity for CLN metastasis. However, the cutoff values of FNA-Tg for metastatic CLN have not been standardized, and the reported cutoff values of FNA-Tg range from 0.2 ng/ml to 77 ng/ml because of the differences in study samples, Tg measurement methods, Tg assays kits, etc. Serum anti-thyroglobulin antibody level, serum thyroglobulin level, the presence or absence of thyroid glands, and the characteristics of CLN may be factors affecting the accuracy of FNA-Tg. This review summarizes the recent research on the application of FNA-Tg in the diagnosis of metastatic LN in PTC and provides a reliable basis for the clinical diagnosis of cervical lymph node metastasis.

Lateral neck multilevel fine-needle aspiration cytology and thyroglobulin estimation in papillary thyroid carcinoma

OBJECTIVE

To assess the accuracy of preoperative ultrasound-guided multilevel fine-needle aspiration (FNA) cytology and thyroglobulin (Tg) estimation in mapping metastatic levels in the lateral neck, in patients with papillary thyroid carcinoma (PTC).

METHODS

Patients with PTC clinically metastasizing to the lateral neck who were initially treated at the Peking University Cancer Hospital from June 2018 to September 2020 were included. FNA was performed preoperatively in each suspicious neck level; cytological examination (FNA-C) and Tg measurement of the needle-washout fluid (FNA-Tg) were combined to determine metastasis. FNA-Tg cutoff value was calculated, and the accuracy of FNA at different levels were evaluated.

RESULTS

In total, 111 patients underwent 124 lymph node dissections. The best cutoff value of FNA-Tg for the diagnosis of metastatic level was 1.0 ng/mL. Multilevel FNA showed sensitivity, specificity, positive predictive value, and negative predictive value in predicting single-level metastasis of 100%, 61.0%, 43.9%, and 100%, respectively. In 64 (51.6%) cases, the involved levels diagnosed by FNA were consistent with that diagnosed by postoperative pathology.

CONCLUSION

FNA-Tg improves the diagnostic performance of FNA-C in lateral neck lymph node metastases. However, limited accuracy was obtained for preoperative multilevel FNA in predicting the extent of metastasis in the lateral compartment.

A practical individualized radiation precaution based on the dose rate at release time after inpatient 131I ablation therapy

Introduction

Retained radioactivity of ¹³¹I after ablation therapy largely differs in each patient according to factors including the amount of remnant thyroid tissue, renal function, and use of recombinant human thyroid-stimulating hormone. To reduce unnecessary restriction of patient’s daily life after inpatient ¹³¹I ablation therapy, we propose a practical individualized method for radiation precaution based on dose rate at release time.

Methods

We evaluated 215 patients with differentiated thyroid cancer who underwent inpatient ¹³¹I ablation therapy following total thyroidectomy. Effective dose equivalent rates at 1-m distance were measured upon release (EDR_R) on day 2 and during delayed whole-body scan (EDR_D) visits on day 6‒8 after ¹³¹I administration. The biexponential model was designed to estimate total effective dose equivalent to others. To assess conservativeness of our model, EDR_D estimated by our model was compared with measured EDR_D. EDR_R-based periods of precaution not to receiving 1 mSv of radiation exposure were estimated and compared with those based on administered radioactivities on American Thyroid Association (ATA) recommendations.

Results

The EDR_R ranged from 1.0–48.9 μSv/hr. The measured EDR_D were equal to or lower than estimated EDR_D in all patients, except for one, indicating that our model is sufficiently conservative. According to our model, no subjects needed additional daytime restriction after release. The maximum permissible times for public transportation use were longer in all patients compared with those based on administered radioactivities. Nighttime restriction periods were significantly shorter than those based on administered radioactivity; median periods requiring sleeping apart were 0 (range, 0‒5), 4 (range, 1‒14), and 3 (range, 2‒13) days after release in patients treated with radioactivity doses of 2.96, 5.50, and 7.40 GBq, respectively, needing 8, 16, and 19 additional days, respectively, based on administered radioactivity.

Conclusions

Radiation safety instructions using proposed method based on EDR_R of individual patient could safely reduce the burden of radiation precaution.

Clinical outcomes of a conservative approach in cervical lymph node metastases of thyroid cancer

CONTEXT

Lymph node metastases (LNM) can be present in 35% of patients with differentiated thyroid cancer (DTC), and the management of persistent/recurrent nodal disease has been controversial. Watchful waiting may be a reasonable approach in selected patients, but uncertainty about clinical outcomes remains a concern.

OBJECTIVE

To investigate the outcomes of patients with DTC with recurrent/persistent confirmed LNM under surveillance.

METHODS

Patients with LNM from DTC were selected from databases of needle washout thyroglobulin measurements and fine-needle aspiration biopsies performed in our institution. Patients with confirmed metastases, in whom active surveillance was initially proposed, were selected. Main clinical outcomes were analysed.

RESULTS

We found 89 patients with LNM under surveillance. Classic papillary was the most frequent variant (44%). During a median follow-up of 3 (0.5-17.2) years, different treatments were needed in 35 (39.3%) patients: radioactive iodine (RAI) in 23 (25.8%), surgery in 9 (10.1%) and radiotherapy (RT) in 3 (3.4%). From those submitted initially to RAI, progression of disease was observed in 8 patients, 4 requiring other treatment modalities: surgery (n = 2), RT (n = 1) and RAI (n = 1). The remaining 54 (60.7%) patients maintained surveillance. In this group, progression of disease was observed in 26 (48.1%), due to increase in the number and/or volume of metastases, but further treatments were not required.

CONCLUSION

In a group of patients with cervical LNM under active surveillance, only 16.9% (n = 15) required invasive intervention (surgery or RT).

Long-Term Oncological Outcome Comparison between Intermediate- and High-Dose Radioactive Iodine Ablation in Patients with Differentiated Thyroid Carcinoma: A Propensity Score Matching Study

BACKGROUND

Radioactive iodine (RAI) ablation is recommended for most patients with differentiated thyroid carcinoma (DTC) after total thyroidectomy (TT). We aimed to compare long-term outcomes between intermediate-dose (100 mCi) and high-dose (150 mCi) RAI ablation therapy in patients with DTC using propensity score matching analysis.

METHODS

This was a retrospective study of 1448 patients with DTC who underwent RAI ablation after TT. Propensity score matching was performed using the extent of operation, tumor size, extrathyroidal extension, multifocality, lymphatic invasion, vascular invasion, perineural invasion, number of positive lymph nodes (LNs), ATA risk stratification system, T stage, N stage, TNM stage, preoperative serum Tg and TgAb levels, and post-RAI serum Tg and TgAb levels.

RESULTS

Recurrence rates in the intermediate- and high-dose groups were 3.1% and 5.6%, respectively. After propensity score matching, LN ratio >0.22 (HR, 2.915; 95% CI, 1.228-6.918; p=0.015) and serum Tg >10 ng/mL after RAI (HR, 3.976; 95% CI, 1.839-8.595; p < 0.001) were significant predictors of recurrence. Kaplan-Meier analysis showed no significant difference in DFS before or after propensity score matching (p=0.074 and p=0.378, respectively).

CONCLUSIONS

Intermediate-dose RAI ablation for the adjuvant treatment of DTC is sufficient as compared to high-dose RAI ablation. Further prospective or multicenter studies should be conducted to clarify the prognosis of intermediate-dose RAI ablation.

Evaluating the risk of re-recurrence in patients with persistent/recurrent thyroid carcinoma after initial reoperation

BACKGROUND

Although the 2015 American Thyroid Association guidelines proposed initial and response-to-therapy risk stratifications were adequately validated in untreated papillary thyroid cancer patients, it is still unknown how they work in persistent/recurrent papillary thyroid cancer patients. This study aimed to evaluate and revise the stratifications in these patients.

METHODS

This retrospective study included patients who received the first reoperation with complete thyroid resection but without radioactive iodine ablation. Stratifications were performed considering the persistent/recurrent tumor characteristics and thyroglobulin levels 1 to 6 months after reoperation and then revised with new prognostic factors and adjusted thyroglobulin cutoff values, respectively. Prognostic performance was evaluated with Kaplan-Meier curves, proportion of variation explained, and Harrell's concordance index.

RESULTS

Among a total of 232 patients, 5-year re-recurrence free survival rates were 92.4%, 86.2%, and 74.5% in low-, intermediate-, and high-risk patients, respectively (all P > .05) and 97.0%, 96.3%, and 81.6% in excellent response, intermediate response, and biochemical incomplete response groups, respectively (excellent response versus intermediate response, P > .05; intermediate response versus biochemical incomplete response, P < .05). After incorporating age at reoperation, recurrent primary size, and recurrent lymph node number, the high-risk group had significantly compromised re-recurrence free survival versus the intermediate-risk group (76.2% vs 91.6%). After adjusting thyroglobulin values, 5-year re-recurrence free survival rates were 96.4%, 85.9%, and 75.8% in excellent response (<1 ng/mL), intermediate response (1-10 ng/mL), and biochemical incomplete response (≥10 ng/mL) groups, respectively (all P < .05), with a higher proportion of variation explained (12.8% vs 10.1%) and concordance index (0.669 vs 0.615) compared with the American Thyroid Association version.

CONCLUSION

The revised American Thyroid Association initial and response-to-therapy risk stratifications have acceptable predictive value for persistent/recurrent papillary thyroid cancer patients.

Thyroglobulin Measurement in Needle Aspiration for Detection of Recurrences and Neck Metastases in Patients with Differentiated Thyroid Carcinoma: Significance of Anti-Tg Antibodies

The worldwide incidence of differentiated thyroid cancer (DTC) has increased in recent decades, likely due to frequent use of cervical ultrasonography (US) and US-guided fine needle aspiration biopsy (FNA)., US is performed during follow-up after thyroidectomy, and US-guided FNA with cytology is used if suspicious cervical lymph nodes (LN) or thyroid bed masses are detected. Knowing that serum anti-Tg antibodies (sTgAb) affect the use of serum Tg (sTg) as a tumor marker, the aim of our study was to assess the usefulness of Tg determination in needle aspirates (FNA-Tg) in presence of sTgAb. This retrospective study included 149 patients with DTC and 159 aspirations of suspicious LN and thyroid bed masses. As expected, there was a negative correlation between sTg and sTgAb levels (p<0.05), while FNA-Tg levels had a positive correlation with FNA-TgAb levels (p<0.05). Furthermore, we found a positive correlation between sTg and FNA-Tg levels (p<0.05), but not between sTgAb and FNA-TgAb or sTgAb and FNA-Tg. In conclusion, these results show that FNA-Tg values were not affected by sTgAb and that FNA-Tg measurement were highly effective in detecting cervical DTC metastases. However, combined use with cytology is suggested for neck evaluation because cytology could reveal metastases from other tumor sites.

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.

When should antithyroid drug therapy to reduce the relapse rate of hyperthyroidism in Graves' disease be discontinued?

OBJECTIVE

The use of antithyroid drug (ATD) therapy in patients with Graves' disease (GD) hyperthyroidism has been increasing, but ATD therapy is associated with a higher relapse rate. We aimed to evaluate clinical factors for predicting relapse of GD after ATD therapy.

METHODS

Patients (n = 149) with newly diagnosed GD who achieved remission of hyperthyroidism after ATD therapy (≥6 months) were followed up for >18 months after ATD withdrawal. We evaluated the predictive factors of relapse during a median of 6.9 years of follow-up.

RESULTS

Disease relapse occurred in 52 patients (34.9%). By multivariate analyses, a duration of the minimum maintenance dose therapy (MMDT) of <6 months was a significant factor in disease relapse (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.47-4.52; p < 0.001), and a T3/free T4 (fT4) ratio > 120 at ATD withdrawal was significantly more frequent in patients with relapse (HR 2.43; 95% CI, 1.36-4.34; p = 0.002). In the prediction-of-relapse model, the likelihood of relapse was greater in the high-risk group, which had a short MMDT duration and a T3/fT4 ratio ≥120 (HR, 5.81; 95% CI, 2.52-13.39; p < 0.001) and the intermediate-risk group, which had a short MMDT duration or a T3/fT4 ratio < 120 (HR, 2.77; 95% CI, 1.26-6.13; p < 0.001), than in the low-risk group, which had a long MMDT duration and a T3/fT4 ratio < 120.

CONCLUSION

An MMDT longer than 6 months and a high T3/fT4 ratio at ATD withdrawal were independent predictors of relapse in patients who achieved initial remission after ATD for GD. These factors could be used to determine the optimal time to withdraw ATD during the treatment of GD hyperthyroidism.

Ultrasonography, Cytology, and Thyroglobulin Measurement Results of Cervical Nodal Metastasis in Patients With Unclear Papillary Thyroid Carcinoma

Objective: This study aimed to evaluate the ultrasonography (US), cytology, and thyroglobulin (Tg) measurement results of nodal metastasis in patients showing unclear US or cytology results of primary papillary thyroid carcinoma (PTC). Methods: From January 2016 to December 2018, 179 patients underwent US-guided fine-needle aspiration (FNA) to diagnose lymphadenopathy in the neck. Among them, 36 patients underwent subsequent total thyroidectomy and nodal dissection, and cervical lymph node (LN) metastasis from PTC was confirmed. However, two patients were excluded because of mismatch between the US and pathological findings of LNs. US images and cytological slides for metastatic LNs were retrospectively analyzed, and serum and FNA Tg levels for metastatic LNs were investigated using data from the electric medical records. Primary PTC patients with suspicious results on both US and cytology were classified as the clear group, and the remaining patients were classified as the unclear group. Results: Of the 34 patients, 24 had clear results of primary PTC on both US and cytology (clear group), whereas 10 had unclear results of primary PTC on US or cytology (unclear group). Of the 10 patients in the unclear group, seven had suspicious nodal metastasis from PTC on cytology after US-guided FNA of the cervical LN, and the remaining three had negative cytology but a positive Tg measurement. Metastatic LNs with cystic change tended to show a positive Tg measurement but negative cytology. Conclusions: The combination of US, cytology, and Tg measurement is necessary for diagnosing nodal metastasis from PTC. In cases with unclear primary PTC on US or cytology, the detection of nodal metastasis may be helpful for assessing primary PTC.

Changes in Serum Thyroglobulin Levels After Lobectomy in Patients with Low-Risk Papillary Thyroid Cancer

BACKGROUND

Low-risk patients with differentiated thyroid cancer can be treated with thyroid lobectomy. Serial measurements of serum thyroglobulin (Tg) are recommended for surveillance, but the cutoff values indicating recurrence are not known. This study documented the natural course of serum Tg levels during follow-up after lobectomy for low-risk papillary thyroid carcinoma (PTC) and evaluated whether changes in serum Tg levels predict disease recurrence.

METHODS

This historical cohort study included 208 patients with low-risk PTC who underwent lobectomy but did not require hormone replacement. Postoperative serum Tg levels and Tg/thyrotropin (TSH) ratios and neck ultrasound were evaluated during a follow-up period with a median of 6.9 years.

RESULTS

The serum Tg levels increased gradually, and the proportion of patients with levels >10 ng/dL increased annually by 13.9%, 18.8%, 22.1%, 21.9%, 28.4%, and 28.9% during the six-year follow-up period (β = 0.574, p = 0.027). The relative serum Tg levels increased by 10% annually (β = 0.105, p < 0.001), and the levels of Tg and Tg/TSH ratios in 19 patients with recurrent disease did not differ significantly (β = 0.150, p = 0.090). Patients without recurrent disease were more likely to have serum Tg levels increased by >20% (p = 0.022). There were no significant differences in the proportions of patients with serum Tg levels increased by ≥50% or ≥100% in terms of the disease recurrence.

CONCLUSIONS

Serum Tg levels and the Tg/TSH ratio increased gradually after lobectomy in patients with and without recurrences, without any significant differences. Periodic measurements of serum Tg levels seem to have limited value in predicting recurrent PTCs after lobectomy.

Impact of Serum TSH and Anti-Thyroglobulin Antibody Levels on Lymph Node Fine-Needle Aspiration Thyroglobulin Measurements in Differentiated Thyroid Cancer Patients

BACKGROUND

Thyroglobulin measurements in the washout of fine needle aspiration (FNA-Tg) are an excellent tool to detect lymph node (LN) metastases of differentiated thyroid carcinoma (DTC). Nevertheless, how to define the best cutoffs and the influence of potential confounders are still being discussed.

OBJECTIVE

To evaluate the accuracy of FNA-Tg measurement to detect DTC metastases and the influence of thyroid status and anti-thyroglobulin antibodies (TgAb).

METHODS

One hundred thirty-eight patients with DTC and suspicious cervical LN were included. Patients underwent ultrasound (US)-guided FNA for cytological examination and FNA-Tg measurements. Final diagnoses were confirmed by histological examination or clinical and US follow-up for at least 1 year.

RESULTS

Data from 119 subjects with suspicious LN were evaluated. The median value of FNA-Tg in patients with metastatic LN (n = 65) was 3,263.0 ng/mL (838.55-12,507.5), while patients without LN metastasis (n = 54) showed levels of 0.2 ng/mL (0.2-0.2). According to the ROC curve analysis, the best cutoff value to predict metastasis was 4.41 ng/mL for FNA-Tg, with a sensitivity of 98% and specificity of 96%. There were no differences in the median of FNA-Tg measurements between those on (TSH 0.16 mUI/mL) and those off levothyroxine (TSH 99.41 mUI/mL) therapy (47.94 vs. 581.15 ng/mL, respectively; p = 0.79). Interestingly, the values of FNA-Tg in patients with LN metastasis (n = 65) did not differ between patients with positive and those with negative TgAb (88.8 vs. 3,263.0 ng/mL, respectively; p = 0.57).

CONCLUSION

US-guided FNA-Tg proved to be a useful examination in the follow-up of patients with DTC, independently of TSH status and the presence of TgAb.

Intraoperative measurement of thyroglobulin in lymph node aspirates for the detection of metastatic papillary thyroid carcinoma

Background

Among patients with papillary thyroid carcinoma (PTC), 30%–80% have cervical lymph node (LN) metastases, which are most commonly located in the central compartment. However, preoperative ultrasonography identifies malignant central compartment LNs in only 20%–30% of cases. We aimed to evaluate the diagnostic value of intraoperative thyroglobulin (Tg) measurement in fine-needle aspirates (FNA-Tg) of suspicious metastatic LNs.

Methods

In total, 75 patients (75 LNs) with PTC or suspected PTC were enrolled in this study. Suspicious metastatic LNs were isolated intraoperatively, and FNA-Tg was performed. Then, the Tg values were compared with the corresponding pathological results and preoperative ultrasonography.

Results

In total, 37 LNs were diagnosed as malignant, and 38 were benign. According to the receiver operating characteristic (ROC) curve, the optimal cutoff value of intraoperative FNA-Tg was 147.5 ng/mL (sensitivity, 81.1%; specificity, 100%; p=0.000). The sensitivity and specificity for detecting central compartment LN metastasis were 77.78% (21/27) and 100% (36/36), respectively. The corresponding sensitivity of preoperative ultrasonography was lower than that of FNA-Tg (p=0.000). Serum Tg-antibody (Ab), thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (TPO-Ab) were not significantly associated with FNA-Tg values. There was no statistical correlation between preoperative serum Tg and intraoperative FNA-Tg (p=0.451).

Conclusion

Intraoperative FNA-Tg levels of suspicious metastatic cervical LNs can be useful for diagnosing metastatic PTC. Intraoperative LN-FNA-Tg may have an important role in determining which surgical procedure to perform.

The Role of Intraoperative Thyroglobuline Level of Lymph Node in the Management of Papillary Thyroid Cancer (Determination of a Cutoff Point)

Background:

Some studies have shown that a preoperative high concentration of thyroglobulin (Tg) in wash out of fine-needle aspiration cytology of cervical lymph nodes mandate therapeutic lymph node dissection. However, there is disagreement about the minimum concentration of Tg which could have diagnostic value. Hence, according to our literature review, this study is the first one which designed to do intraoperatively. Therefore, this study was conducted and aimed to determine the clinical diagnostic value of Tg lymph nodes in the diagnosis of metastatic thyroid cancer.

Methods:

In a cross-sectional study, 65 patients with papillary thyroid carcinoma (PTC) who were thyroidectomy candidates were chosen and during surgery, before the removal of lymph nodes in the neck, fine-needle sampling was performed and the level of Tg in the samples, nature of the sample sent for biopsy and Tg levels in affected and unaffected lymph nodes were determined.

Results:

The mean levels of washout Tg in malignant and nonmalignant lymph nodes were 622.1 ± 66.2 and 1.38 ± 0.43 ng/ml, respectively, and the difference between the two groups was significant (P < 0.001). The Tg cut-off point for the detection of lymph node metastases was 0.7 ng/dl, and according to it, Tg washout sensitivity was 93.8%, specificity of 92.4%, false positives 7.76%, false negatives 6.3%, positive predictive value was 92.3%, and negative predictive value was 93.8% and accuracy was 93.1%.

Conclusion:

Based on the results, Tg level of cervical lymph nodes in patients with PTC is a suitable criterion for the diagnosis of lymph node which can be determined through fine-needle biopsy. Therefore, it is suggested that in patients with suspicion of lymph nodes involvement during surgery, fine-needle biopsy and determination of the Tg level performed.

Thyrotropin Suppressive Therapy for Low-Risk Small Thyroid Cancer: A Propensity Score-Matched Cohort Study

BACKGROUND

Thyrotropin (TSH) suppression has improved the clinical outcomes of patients with differentiated thyroid cancer (DTC). However, the efficacy of TSH suppressive therapy (TST) is unclear in patients with low-risk DTC. This study aimed to evaluate the efficacy of TST and optimal TSH levels of patients with low-risk DTC.

METHODS

This retrospective propensity score-matched cohort study included DTC patients (n = 446) who underwent lobectomy from 2002 to 2008 with or without TST (TST group and No-TST group). Disease-free survival (DFS) and dynamic risk stratification were compared between both groups using serum TSH levels.

RESULTS

Approximately 74% of TST patients and 11% of No-TST patients had suppressed serum TSH levels (<2 mIU/L). The median follow-up period was 8.6 years. During follow-up, the disease recurred in 10 (2.7%) patients, with no significant difference in DFS between the groups (p = 0.63). The proportion of patients with excellent treatment response was similar between the TST (65.2%) and No-TST (64.4%) groups. Incomplete biochemical response was noted in 17.2% of the TST group patients and 9.4% of the No-TST group patients. No significant difference was observed in the DFS between both groups by comparing serum TSH level (p = 0.57).

CONCLUSIONS

TST did not improve clinical outcomes, and serum TSH levels were not associated with recurrence in patients with low-risk small DTC. No clinical benefits were shown for TSH suppression in low-risk patients who underwent lobectomy. Thus, levothyroxine is not necessary for patients without evidence of hypothyroidism.

Lack of Efficacy of Radioiodine Remnant Ablation for Papillary Thyroid Microcarcinoma: Verification Using Inverse Probability of Treatment Weighting

BACKGROUND

Most of the increase in thyroid cancer in recent decades has been due to papillary thyroid microcarcinoma (PTMC). We evaluated the efficacy of radioiodine remnant ablation (RRA) in patients with PTMC.

METHODS

This historical cohort study included 1932 PTMC patients without lateral cervical lymph node (LN) or distant metastasis who underwent total thyroidectomy (TT) during the median 8.3 years of follow-up. The clinical outcomes of patients with or without RRA were compared using weighted logistic regression models with the inverse probability of treatment weighting (IPTW) method and considering risk factors, including age, sex, primary tumor size, extrathyroidal extension, multifocality, and central cervical LN metastasis.

RESULTS

The median primary tumor size of the RRA group was significantly larger than that of the no-RRA group (0.7 vs. 0.5 cm, P < 0.001). There were significantly more patients with multifocality, extrathyroidal extension, and cervical LN metastasis in the RRA group compared with the no-RRA group. There was no significant difference in recurrence-free survival between the two groups (P = 0.11). Cox proportional-hazard analysis with IPTW by adjusting for clinicopathological risk factors demonstrated no significant difference in recurrence of PTMC according to RRA treatment (hazard ratio [HR] 2.02; 95% confidence interval [CI] 0.65-6.25; P = 0.2).

CONCLUSIONS

RRA had no therapeutic effect on the clinical outcomes of patients with PTMC who underwent TT. Surgical treatment without RRA could be applicable for patients with PTMC if there is no evidence of lateral cervical LN metastasis or distant metastasis.

Active Surveillance for Patients With Papillary Thyroid Microcarcinoma: A Single Center's Experience in Korea

CONTEXT

Papillary thyroid microcarcinoma (PTMC) usually has an excellent prognosis.

OBJECTIVE

To evaluate the three-dimensional structures of PTMCs, using serial neck ultrasonography (US) in patients under active surveillance.

DESIGN AND SETTING

A retrospective cohort study.

PARTICIPANTS

In total, 192 patients diagnosed with PTMC under active surveillance for >1 year were included in a median 30-month follow-up. Changes in tumor size were evaluated not only using the maximal tumor diameter but also the tumor volume.

RESULTS

The median age of patients was 51.3 years and 145 patients (76%) were female. The median initial maximal tumor diameter and tumor volume were 5.5 mm and 48.8 mm3, respectively. The tumor size increased in 27 patients (14%); 23 patients showed a tumor volume increase >50% without a maximal diameter increase of ≥3 mm. The other four patients had both an increasing tumor volume and increasing maximal tumor diameter ≥3 mm. One patient (0.5%) had newly appeared cervical lymph node (LN) metastasis at 3 years after the initial diagnosis. There were no significant risk factors associated with increased tumor size, such as age, sex, or Hashimoto thyroiditis. Twenty-four patients (13%) underwent delayed thyroid surgery at a median of 31.2 months and seven (29%) had cervical LN metastasis on pathologic examination.

CONCLUSION

Some PTMCs could grow significantly after a relatively short period of active surveillance. We also found that the change in tumor volume was more sensitive to detect tumor progression than the change in the maximal tumor diameter.

Clinical Features of Early and Late Postoperative Hypothyroidism After Lobectomy

CONTEXT

Lobectomy is preferred in thyroid cancer to decrease surgical complications and avoid lifelong thyroid-hormone replacement. However, postoperative hypothyroidism, requiring thyroid-hormone replacement, may occur.

OBJECTIVE

We aimed to identify the incidence and risk factors of postoperative hypothyroidism to develop a surveillance strategy after lobectomy for papillary thyroid microcarcinoma (PTMC).

METHODS

This historical cohort study involved 335 patients with PTMC treated by lobectomy. Postoperative thyroid functions were measured regularly, and patients were prescribed levothyroxine according to specific criteria. Patients not satisfying hormone-replacement criteria were closely followed up.

RESULTS

Postoperative hypothyroidism occurred in 215 patients (64.2%) including 5 (1.5%) with overt hypothyroidism and 210 (62.7%) with subclinical hypothyroidism. Forty patients (11.9%) were required thyroid hormone replacement. One hundred nineteen patients (33.5%) experienced temporary hypothyroidism and spontaneously recovered to euthyroid state. High preoperative thyroid-stimulating hormone (TSH) was the most important factor predicting postoperative hypothyroidism and failure of recover from hypothyroidism (odds ratio [OR], 2.82 and 1.77; 95% confidence interval [CI], 2.07 to 3.95 and 1.22 to 2.63; P < 0.001 and 0.002, respectively). Of the 215 patients eventually developing postoperative hypothyroidism, 70 (32.6%) developed hypothyroidism after the first postoperative year. Postoperative 1-year TSH levels were able to differentiate patients developing late hypothyroidism or euthyroidism (OR, 2.29; 95% CI, 1.68 to 3.26; P < 0.001).

CONCLUSIONS

Preoperative and postoperative TSH levels might be predictive for patients who develop postlobectomy hypothyroidism and identify those requiring long-term surveillance for hypothyroidism. Additionally, mild postoperative hypothyroidism cases should be followed up without immediate levothyroxine replacement with the expectation of spontaneous recovery.

Dynamic Risk Stratification for Predicting Recurrence in Patients with Differentiated Thyroid Cancer Treated Without Radioactive Iodine Remnant Ablation Therapy

BACKGROUND

Increased incidence of small differentiated thyroid cancer (DTC) has emphasized the need for risk stratification and individualized disease management for these low risk DTCs. The aim of this study was to validate a new dynamic risk stratification (DRS) system for the prediction of structural recurrent/persistent disease in patients with DTC treated without radioactive iodine (RAI) remnant ablation therapy.

METHODS

This historical cohort study included 357 patients with DTC treated with lobectomy or total thyroidectomy without RAI therapy. We stratified patient response to initial treatment as excellent, indeterminate, biochemical incomplete, and structural incomplete according to the DRS system.

RESULTS

During a median follow-up of 8.6 years, 3.6% patients had structural recurrent DTC. The response was excellent in 71.7% patients, indeterminate in 18.5%, biochemical incomplete in 8.4%, and structural incomplete in 1.4%. There were significant differences in DFS among the DRS groups (p < 0.001). The hazard ratio (HR) of recurrent/persistent disease was significantly higher in the biochemical incomplete group (HR = 20.8, p < 0.001) and structural incomplete group (HR = 243.3, p < 0.001) compared with the excellent group. However, the Tumor Node Metastasis staging system and the American Thyroid Association initial risk classification did not effectively predict recurrence of DTC.

CONCLUSIONS

The new DRS system was effective for predicting risk of recurrent/persistent disease in patients with DTC who underwent lobectomy or total thyroidectomy without RAI remnant ablation.

ENDOCRINE TUMOURS: Imaging in the follow-up of differentiated thyroid cancer: current evidence and future perspectives for a risk-adapted approach

The clinical and epidemiological profiles of differentiated thyroid cancers (DTCs) have changed in the last three decades. Today's DTCs are more likely to be small, localized, asymptomatic papillary forms. Current practice is, though, moving toward more conservative approaches (e.g. lobectomy instead of total thyroidectomy, selective use of radioiodine). This evolution has been paralleled and partly driven by rapid technological advances in the field of diagnostic imaging. The challenge of contemporary DTCs follow-up is to tailor a risk-of-recurrence-based management, taking into account the dynamic nature of these risks, which evolve over time, spontaneously and in response to treatments. This review provides a closer look at the evolving evidence-based views on the use and utility of imaging technology in the post-treatment staging and the short- and long-term surveillance of patients with DTCs. The studies considered range from cervical US with Doppler flow analysis to an expanding palette of increasingly sophisticated second-line studies (cross-sectional, functional, combined-modality approaches), which can be used to detect disease that has spread beyond the neck and, in some cases, shed light on its probable outcome.

Surgical Management of Lymph Node Compartments in Papillary Thyroid Cancer

Although papillary thyroid cancer (PTC) commonly metastasizes to cervical lymph nodes, prophylactic central neck dissection is controversial. The primary treatment for lymph node metastases is surgical resection. Patients diagnosed with PTC should be assessed preoperatively by cervical ultrasound to evaluate central and lateral neck lymph node compartments. Sonographically suspicious lymph nodes in the lateral neck should be biopsied for cytology or thyroglobulin levels. Any compartment (central or lateral) that has definitive proof of nodal metastases should be formally dissected at the time of thyroidectomy.

Usefulness of Measuring Thyroid Stimulating Antibody at the Time of Antithyroid Drug Withdrawal for Predicting Relapse of Graves Disease

BACKGROUND

Hyperthyroidism relapse in Graves disease after antithyroid drug (ATD) withdrawal is common; however, measuring the thyrotropin receptor antibody (TRAb) at ATD withdrawal in order to predict outcomes is controversial. This study compared measurement of thyroid stimulatory antibody (TSAb) and thyrotropin-binding inhibitory immunoglobulin (TBII) at ATD withdrawal to predict relapse.

METHODS

This retrospective study enrolled patients with Graves disease who were treated with ATDs and whose serum thyroid-stimulating hormone levels were normal after receiving low-dose ATDs. ATD therapy was stopped irrespective of TRAb positivity after an additional 6 months of receiving the minimum dose of ATD therapy. Patients were followed using thyroid function tests and TSAb (TSAb group; n=35) or TBII (TBII group; n=39) every 3 to 6 months for 2 years after ATD withdrawal.

RESULTS

Twenty-eight patients (38%) relapsed for a median follow-up of 21 months, and there were no differences in baseline clinical characteristics between groups. In the TSAb group, relapse was more common in patients with positive TSAb at ATD withdrawal (67%) than patients with negative TSAb (17%; P=0.007). Relapse-free survival was shorter in TSAb-positive patients. In the TBII group, there were no differences in the relapse rate and relapse-free survivals according to TBII positivity. For predicting Graves disease relapse, the sensitivity and specificity of TSAb were 63% and 83%, respectively, whereas those of TBII were 28% and 65%.

CONCLUSION

TSAb at ATD withdrawal can predict the relapse of Graves hyperthyroidism, but TBII cannot. Measuring TSAb at ATD withdrawal can assist with clinical decisions making for patients with Graves disease.