Prognosis of Patients with Papillary Thyroid Carcinoma Showing Postoperative Recurrence to the Central Neck

Ultrasound-based nomogram to predict the recurrence in papillary thyroid carcinoma using machine learning

BACKGROUND AND AIMS

The recurrence of papillary thyroid carcinoma (PTC) is not unusual and associated with risk of death. This study is aimed to construct a nomogram that combines clinicopathological characteristics and ultrasound radiomics signatures to predict the recurrence in PTC.

METHODS

A total of 554 patients with PTC who underwent ultrasound imaging before total thyroidectomy were included. Among them, 79 experienced at least one recurrence. Then 388 were divided into the training cohort and 166 into the validation cohort. The radiomics features were extracted from the region of interest (ROI) we manually drew on the tumor image. The feature selection was conducted using Cox regression and least absolute shrinkage and selection operator (LASSO) analysis. And multivariate Cox regression analysis was used to build the combined nomogram using radiomics signatures and significant clinicopathological characteristics. The efficiency of the nomogram was evaluated by receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA). Kaplan-Meier analysis was used to analyze the recurrence-free survival (RFS) in different radiomics scores (Rad-scores) and risk scores.

RESULTS

The combined nomogram demonstrated the best performance and achieved an area under the curve (AUC) of 0.851 (95% CI: 0.788 to 0.913) in comparison to that of the radiomics signature and the clinical model in the training cohort at 3 years. In the validation cohort, the combined nomogram (AUC = 0.885, 95% CI: 0.805 to 0.930) also performed better. The calibration curves and DCA verified the clinical usefulness of combined nomogram. And the Kaplan-Meier analysis showed that in the training cohort, the cumulative RFS in patients with higher Rad-score was significantly lower than that in patients with lower Rad-score (92.0% vs. 71.9%, log rank P < 0.001), and the cumulative RFS in patients with higher risk score was significantly lower than that in patients with lower risk score (97.5% vs. 73.5%, log rank P < 0.001). In the validation cohort, patients with a higher Rad-score and a higher risk score also had a significantly lower RFS.

CONCLUSION

We proposed a nomogram combining clinicopathological variables and ultrasound radiomics signatures with excellent performance for recurrence prediction in PTC patients.

Predicting central lymph node metastasis in patients with papillary thyroid carcinoma based on ultrasound radiomic and morphological features analysis

OBJECTIVES

To build a combined model based on the ultrasound radiomic and morphological features, and evaluate its diagnostic performance for preoperative prediction of central lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC).

METHOD

A total of 295 eligible patients, who underwent preoperative ultrasound scan and were pathologically diagnosed with unifocal PTC were included at our hospital from October 2019 to July 2022. According to ultrasound scanners, patients were divided into the training set (115 with CLNM; 97 without CLNM) and validation set (45 with CLNM; 38 without CLNM). Ultrasound radiomic, morphological, and combined models were constructed using multivariate logistic regression. The diagnostic performance was assessed by the area under the curve (AUC) of the receiver operating characteristic curve, accuracy, sensitivity, and specificity.

RESULTS

A combined model was built based on the morphology, boundary, length diameter, and radiomic score. The AUC was 0.960 (95% CI, 0.924-0.982) and 0.966 (95% CI, 0.901-0.993) in the training and validation set, respectively. Calibration curves showed good consistency between prediction and observation, and DCA demonstrated the clinical benefit of the combined model.

CONCLUSION

Based on ultrasound radiomic and morphological features, the combined model showed a good performance in predicting CLNM of patients with PTC preoperatively.

Guidelines from the Brazilian society of surgical oncology regarding indications and technical aspects of neck dissection in papillary, follicular, and medullary thyroid cancers

Objective

The purpose of these guidelines is to provide specific recommendations for the surgical treatment of neck metastases in patients with papillary, follicular, and medullary thyroid carcinomas.

Materials and methods

Recommendations were developed based on research of scientific articles (preferentially meta-analyses) and guidelines issued by international medical specialty societies. The American College of Physicians' Guideline Grading System was used to determine the levels of evidence and grades of recommendations. The following questions were answered: A) Is elective neck dissection indicated in the treatment of papillary, follicular, and medullary thyroid carcinoma? B) When should central, lateral, and modified radical neck dissection be performed? C) Could molecular tests guide the extent of the neck dissection?

Results and conclusion

Recommendation 1: Elective central neck dissection is not indicated in patients with cN0 well-differentiated thyroid carcinoma or in those with noninvasive T1 and T2 tumors but may be considered in T3-T4 tumors or in the presence of metastases in the lateral neck compartments. Recommendation 2: Elective central neck dissection is recommended in medullary thyroid carcinoma. Recommendation 3: Selective neck dissection of levels II-V should be indicated to treat neck metastases in papillary thyroid cancer, an approach that decreases the risk of recurrence and mortality. Recommendation 4: Compartmental neck dissection is indicated in the treatment of lymph node recurrence after elective or therapeutic neck dissection; "berry node picking" is not recommended. Recommendation 5: There are currently no recommendations regarding the use of molecular tests in guiding the extent of neck dissection in thyroid cancer.

Clinical Significance of the Lymph Node Ratio of the Second Operation to Predict Re-Recurrence in Thyroid Carcinoma

The purpose of this study was to establish the risk factors for re-recurrences and disease-specific mortality (DSM) in recurrent thyroid cancer. Patients with recurrent thyroid cancer who underwent initial thyroid surgery from January 2000 to December 2019 at Seoul St. Mary's Hospital (Seoul, Korea) were assessed. Clinicopathological characteristics and long-term oncologic outcomes were compared between patients with one recurrence (n = 202) and patients with re-recurrences (n = 44). Logistic regression and cox-regression analyses were conducted to determine the risk factors for re-recurrences and DSM, respectively. Receiver-operating characteristic curve analysis was performed to determine the cutoff value for lymph node ratio (LNR) as a predictor of re-recurrences. DSM was significantly higher in the re-recurrence group compared with the single-recurrence group (6.8% vs. 0.5%, p = 0.019). Surgical treatment at the first recurrence significantly lowered the risk of re-recurrences. Age (≥55), male sex, and LNR (≥0.15) were independent significant risk factors for re-recurrences in patients who underwent surgery at the first recurrence. Surgical resection is the optimal treatment for initial thyroid cancer recurrence. LNR at re-operation is more effective in predicting re-recurrence than the absolute number of metastatic LNs.

Active Surveillance of Small Metastatic Lymph Nodes as an Alternative to Surgery in Selected Patients with Low-Risk Papillary Thyroid Cancer: A Retrospective Cohort Study

Background: It has been suggested that small metastatic lymph nodes (LNs) detected after initial surgery in patients with differentiated thyroid cancer (DTC) can be managed with active surveillance (AS). However, there is still concern regarding the clinical outcomes of these patients. The main aims of our study were as follows: (1) to assess the frequency of growth and the need of additional treatment in a group of patients with LN recurrences selected for AS, and (2) to determine predictive factors of LN progression. Methods: We retrospectively reviewed 856 clinical records from our DTC patient's database (May 2010 to January 2022). Eighty patients had suspicious cervical LNs on consecutive ultrasound (US) after initial surgery, but we included 50 patients with cytological confirmation of metastatic disease and at least 12 months follow-up. Exclusion criteria were as follows: any LN ≥2 cm or multiple LNs ≥1.5 cm in size, proximity to vital structures, PET-positive disease (standard uptake value ≥5), aggressive histology, and distant metastasis. Patients were followed with thyroglobulin (Tg) and thyroglobulin antibodies measurements on suppressive therapy and neck US every 6-12 months. LN growth was defined as an increase of ≥3 mm in any of its diameters. Results: A total of 50 patients had a median age of 41 years (range, 18-75). Most patients were women (80%) and had classical papillary thyroid cancer (86%). The mean size of the LNs was 10.1 ± 4.4 mm. After a median follow-up of 29 months (range, 12-144), 12 patients (24%) had an increase in size of the metastatic LN, 7 (58%) of whom were surgically removed. None of these seven patients had a structural incomplete response at the end of follow-up. The only variable that predicted an increase in LN size was a rise in Tg levels ≥0.5 ng/mL (p = 0.016). Based on a multivariate analysis, patients with increase in Tg levels ≥0.5 ng/mL had a significantly higher chance of developing LN growth (odds ratio [OR] 16.2 [confidence interval, CI 1.5-120.2], p = 0.020). The median progression-free survival rate was 6.6 years [CI 5.6-9.5]. Conclusion: AS of small LNs could be a feasible alternative to immediate surgery in properly selected patients.

Contrast-enhanced ultrasound characteristics of preoperative central cervical lymph node metastasis in papillary thyroid carcinoma

This study evaluated the preoperative diagnostic value of lymph node ultrasonography in distinguishing between benign and malignant central cervical lymph nodes (CCLNs) in patients with papillary thyroid carcinoma (PTC). A total of 176 patients who had PTC with 216 CCLNs (49 benign and 155 malignant) were enrolled in this study and preoperatively imaged by ultrasonography, including conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS). We evaluated the ultrasonography parameters for each lymph node. Binary logistic regression analysis indicated that multifocality of PTC and the absence of Hashimoto's thyroiditis are independent clinical features related to patients with PTC who also have malignant CCLNs. For preoperative ultrasonography features, heterogeneous enhancement and centripetal perfusion are independent ultrasonographic features to identify malignant and benign CCLNs. This study demonstrated that preoperative CEUS characteristics help to distinguish malignant CCLNs from benign CCLNs.

Personalized Dosimetry in the Context of Radioiodine Therapy for Differentiated Thyroid Cancer

The most frequent thyroid cancer is Differentiated Thyroid Cancer (DTC) representing more than 95% of cases. A suitable choice for the treatment of DTC is the systemic administration of 131-sodium or potassium iodide. It is an effective tool used for the irradiation of thyroid remnants, microscopic DTC, other nonresectable or incompletely resectable DTC, or all the cited purposes. Dosimetry represents a valid tool that permits a tailored therapy to be obtained, sparing healthy tissue and so minimizing potential damages to at-risk organs. Absorbed dose represents a reliable indicator of biological response due to its correlation to tissue irradiation effects. The present paper aims to focus attention on iodine therapy for DTC treatment and has developed due to the urgent need for standardization in procedures, since no unique approaches are available. This review aims to summarize new proposals for a dosimetry-based therapy and so explore new alternatives that could provide the possibility to achieve more tailored therapies, minimizing the possible side effects of radioiodine therapy for Differentiated Thyroid Cancer.

Correlation between low expression of protein disulfide isomerase A3 and lymph node metastasis in papillary thyroid carcinoma and poor prognosis: a clinicopathological study of 1,139 cases with long-term follow-up

The incidence of papillary thyroid carcinoma (PTC) is increasing worldwide. The biomarkers to identify aggressive types of PTC are limited, illustrating the need to establish reliable novel biomarkers. Protein disulfide isomerase A3 (PDIA3) is a chaperone protein that modulates the folding of newly synthesized glycoproteins and stress-responsive proteins in the endoplasmic reticulum. Although the role of PDIA3 in various cancers such as breast, uterine cervix, head and neck, and gastrointestinal tract has been examined, its expression in thyroid cancer has not been reported. We retrospectively reviewed accumulated data with long-term follow-up of 1,139 PTC patients, and investigated the correlation between immunohistochemical expression of PDIA3 in PTC patients and clinicopathological features and prognosis. PDIA3 expression was significantly lower in PTCs compared to normal thyroid tissues (NTT; n = 80, p = 0.002). In PTCs, correlation between low PDIA3 expression and lymph node metastasis (p = 0.018) and the number of positive nodes (p = 0.004) was observed. Patients with low PDIA3 expression exhibited worse cause-specific survival compared to those with high PDIA3 expression (p = 0.013). Our findings indicate that low PDIA3 expression is related to poor clinical outcome in PTC patients, and that PDIA3 may potentially be a novel ancillary biomarker. Further clarification of the biological role of PDIA3 in PTC is warranted for the future clinical application.

Value of Contrast-Enhanced Ultrasound for Evaluation of Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma

The aim of the study was to evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) in distinguishing between benign and malignant cervical lymph nodes (LNs) in patients with papillary thyroid carcinoma (PTC). Two hundred and one cervical LNs (157 metastatic from PTC and 44 benign) were evaluated using conventional ultrasonography (US) and CEUS before biopsy or surgery. Histopathology was used as the gold standard. We evaluated the size, long axis/short axis ratio (L/S), fatty hilum, hyper-echogenicity, calcification, cystic change, peripheral vascularity and CEUS parameters for each lymph nodule. The CEUS parameters included enhancement type, homogeneity, perfusion type, ring enhancement, peak intensity (PI) index and area under the curve (AUC) index. Univariate analysis demonstrated that compared with benign LNs, malignant LNs more frequently had L/S < 2, absence of a fatty hilum, presence of hyper-echogenicity, presence of calcification, peripheral vascularity, hyper-enhancement, heterogeneous enhancement, centripetal perfusion, ring enhancement, PI index > 1 and AUC index > 1 on preoperative US and CEUS. Binary logistic regression analysis demonstrated that hyper-enhancement, centripetal perfusion, and ring enhancement are independent CEUS characteristics related to malignant LNs for their differentiation from benign LNs (all p < 0.05). Our study indicated that preoperative CEUS characteristics may serve as a useful tool to identify malignant cervical LNs from benign cervical LNs.

Prediction of central compartment nodal metastases in papillary thyroid cancer using TI-RADS score, blood flow, and multifocality

BACKGROUND

The relationship between the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the risk of lymph node metastases in papillary thyroid cancer (PTC) could improve the detection rate of lymph node metastases in thyroid cancer and provide a scientific basis for clinical diagnosis.

PURPOSE

To evaluate the risk of lymph node metastases of PTC associated with the score from ACR TI-RADS adjusted for other correlative factors.

MATERIAL AND METHODS

A total of 560 patients with pathologically confirmed PTC were included in the study and classified into a metastases group and a non-metastases group. Clinical and pathological manifestations of the patients were collected.

RESULTS

The median TI-RADS score was 13 (p₂₅-p₇₅ = 11-14) among the patients with lymph node metastases, higher than those without metastases 9 (8-10) (P < 0.001). Multiple logistic regression indicated that TI-RADS score (odds ratio [OR] = 2.204), male sex (OR = 2.376), multifocality (OR = 4.170), and rich blood flow (OR = 3.656) were risk factors for lymph node metastases in patients with thyroid carcinoma. Some related factors such as TI-RADS score, age(<45years old), male, multifocality and rich blood flow were related to lymph node metastases in the central area of the neck which could provide therapeutic strategy for further treatment.

CONCLUSION

it is not just the TI-RADS score but also multifocality, blood flow, and sex that influence the prediction of the risk of PTC central lymph node metastases.

Machine learning-based prediction model using clinico-pathologic factors for papillary thyroid carcinoma recurrence

This study analyzed the prognostic significance of clinico-pathologic factors, including the number of metastatic lymph nodes (LNs) and lymph node ratio (LNR), in patients with papillary thyroid carcinoma (PTC), and attempted to construct a disease recurrence prediction model using machine learning techniques. We retrospectively analyzed clinico-pathologic data from 1040 patients diagnosed with PTC between 2003 and 2009. We analyzed clinico-pathologic factors related to recurrence through logistic regression analysis. Among the factors that we included, only sex and tumor size were significantly correlated with disease recurrence. Parameters such as age, sex, tumor size, tumor multiplicity, ETE, ENE, pT, pN, ipsilateral central LN metastasis, contralateral central LNs metastasis, number of metastatic LNs, and LNR were input for construction of a machine learning prediction model. The performance of five machine learning models related to recurrence prediction was compared based on accuracy. The Decision Tree model showed the best accuracy at 95%, and the lightGBM and stacking model together showed 93% accuracy. Among those factors mentioned above, LNR and contralateral LN metastasis were used as important features in all machine learning prediction models. We confirmed that all machine learning prediction models showed an accuracy of 90% or more for predicting disease recurrence in PTC. LNR and contralateral LN metastasis were used as important features for constructing a robust machine learning prediction model. In the future, we have a plan to perform large-scale multicenter clinical studies to improve the performance of our prediction models and verify their clinical effectiveness.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

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.

Value of Qualitative and Quantitative Contrast-Enhanced Ultrasound Analysis in Preoperative Diagnosis of Cervical Lymph Node Metastasis From Papillary Thyroid Carcinoma

OBJECTIVES

To investigate the qualitative and quantitative characteristics of contrast-enhanced ultrasound (CEUS) in assessing cervical lymph node metastasis from papillary thyroid carcinoma (PTC) and to evaluate its value in the preoperative diagnosis of cervical lymph node metastasis from PTC.

METHODS

A total of 55 lymph nodes in 46 patients were enrolled retrospectively, including 29 metastases from PTC and 26 normal/reactive ones. All lymph nodes were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. A receiver operating characteristic curve analysis was used to analyze the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of US and CEUS features in the diagnosis of lymph node metastasis as well as the overall diagnostic performance of US, CEUS, and a combination of the two.

RESULTS

Significant differences were found in the enhancement direction, enhancement type, and enhancement range between metastatic and normal/reactive lymph nodes on CEUS (P < .05). Quantitative CEUS parameters were not statistically significant (P > .05). The combination of US and CEUS had the highest diagnostic accuracy (92.7%) compared with US (80.8%) and CEUS (89.1%) alone in the diagnosis of lymph node metastasis from PTC.

CONCLUSIONS

The characteristics of cervical lymph node metastasis from PTC on CEUS include centripetal perfusion, peripheral or mixed enhancement, and an enlarged range on CEUS compared with US, and the first feature was the most meaningful. The combination of CEUS and US is a promising imaging tool for the preoperative diagnosis of cervical metastatic lymph nodes in patients with PTC.

The features of contrast enhanced ultrasound and BRAF V600E in papillary thyroid carcinoma

Background

BRAF V600E mutation was proved to be associated with thyroid cancer. Papillary thyroid carcinoma (PTC) with positive BRAF mutation might have a more aggressive behavior. We investigated the correlation of the contrast-enhanced ultrasound (CEUS) features with BRAF 600VE in PTC.

Methods

The medical records of 1,199 patients with 1,315 nodules who underwent CEUS prior to fine needle aspiration (FNA) from January 2016 to March 2018 were retrospectively reviewed. The features of their enhancement were assessed from eight aspects: degree of enhancement, method of enhancement, homogeneity of enhancement, completeness of enhancement, boundary of the enhanced lesions, shape of the enhanced lesions, size of the enhanced lesions, and wash out period of the enhanced lesions. The patients then examined for the BRAF V600E mutation using specimens obtained from FNA.

Results

BRAF mutations were found in 888 of 1,315 nodules. The CEUS features were significantly different between BRAF-positive and BRAF-negative nodules. The BRAF mutation positive nodules were more often with larger size, hypo-enhancement, centripetal enhancement, inhomogeneous enhancement, complete enhancement, blurred boundary, irregular shape, and with wash out period at preoperative CEUS than those without BRAF mutations (P<0.001). However, no significant correlation was showed in Spearman's rank correlation between the CEUS features and BRAF mutation, except for degree of enhancement, method pattern of enhancement, and completeness of complete enhancement. Multivariate analysis showed that centripetal (OR: 1.465, 95% CI: 1.129-1.903) and no significant enhancement (OR: 0.790, 95% CI: 0.639-0.977) were predictive for the presence of BRAF mutations. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of no significant enhancement and centripetal enhancement of CEUS for predicting BRAF mutation were 68.3%, 40.0%, 91.6%, 11.7%, and 72.4%, 35.1%, 37.8%, 70.0%, respectively.

Conclusions

Our study indicated that preoperative thyroid nodule characteristics on CEUS might serve as a useful tool to BRAF mutation in PTC.

The usefulness of fine-needle aspirates for detection of recurrent carcinoma in the thyroid bed

INTRODUCTION

Locoregional recurrence of thyroid carcinoma has a negative impact on patient prognosis. In the current study, we retrospectively reviewed cases of thyroid bed lesions in the last 3 years, correlating cytologic diagnoses with clinical findings and, whenever available, final surgical diagnosis.

MATERIALS AND METHODS

Cytologic results and needle wash thyroglobulin results from patients with fine-needle aspiration (FNA) of thyroid bed lesions were retrospectively collected from our electronic files. Additional retrieved data included sex, age at diagnosis, previous thyroidectomy diagnosis, time lapse since surgery, and corresponding surgical diagnosis (whenever available).

RESULTS

A total of 91 cases from 72 patients (54 F, 18 M) were retrieved from the electronic files, with a median age of 49 years. Average interval between surgery and thyroid bed FNA was 5 years. Thyroglobulin levels were available for 60 (65.2%) cases. The average level was 276.2 ug/mL, with a range of <0.1 to 4720 ug/mL. Information on final surgical diagnosis was available for 31 samples. Complete agreement between final cytologic and histologic diagnoses was achieved in 28 of 31 (90.3%) of the cases, with 1 false negative and 2 false positives. Cytology sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.2%, 71.4%, 90.9%, 83.3%, and 89.1%, respectively.

CONCLUSIONS

Ultrasound-guided FNA is an accurate and minimally invasive diagnostic method for suspicious thyroid bed lesions, with high sensitivity and positive predictive value.

Predictors of Neck Reoperation and Mortality After Initial Total Thyroidectomy for Differentiated Thyroid Cancer

BACKGROUND

In an era of rising differentiated thyroid cancer incidence, the rate and impact of neck reoperation may inform the intensity of earlier interventions and surveillance. This study sought to define predictors of neck reoperation and to assess its impact on survival.

METHODS

Using the California Cancer Registry linked to the California Office of Statewide Health Planning and Development records, a retrospective cohort study was performed of 24,230 patients with total or near-total thyroidectomy for papillary or follicular thyroid cancer between 1991 and 2008 and follow-up through 2013. The primary outcome was neck reoperation 91 days to 5 years after the initial thyroid surgery. Using logistic and Cox proportional hazards regression, the impact of sociodemographics, tumor staging, and hospital thyroid cancer surgery volume on neck reoperation and survival was determined.

RESULTS

Neck reoperation was identified in 1231 (5.1%) patients in increasing odds from 1991 to 2008. In multivariable models, male sex, papillary thyroid cancer, and advancing tumor stage were associated with neck reoperation. Among men, neck reoperation was associated with Asian/Pacific Islander (odds ratio [OR] = 1.44 [confidence interval (CI) 1.07-1.94]) race/ethnicity. Among women, neck reoperation was associated with younger age (15-34 years; OR = 1.50 [CI 1.17-1.92] versus ≥55 years), and Asian/Pacific Islander (OR = 1.24 [CI 1.02-1.51]) or Hispanic (OR = 1.20 [CI 1.00-1.44]) race/ethnicity. After controlling for baseline characteristics, neck reoperation predicted worse thyroid cancer-specific survival (hazard ratio = 4.26 [CI 3.50-5.19]). The effect differed between men and women, and was most pronounced among women who received radioiodine in initial treatment (hazard ratio = 8.32 [CI 6.14-11.27]).

CONCLUSIONS

Neck reoperation is becoming increasingly frequent and is strongly predictive of mortality. Advancing tumor stage, Asian/Pacific Islander race/ethnicity, male sex, as well as younger age and Hispanic ethnicity among women predict a higher risk for neck reoperation and subsequent mortality, reflecting a higher risk of persistent or more biologically aggressive disease.

Second Radioiodine Treatment: Limited Benefit for Differentiated Thyroid Cancer With Locoregional Persistent Disease

OBJECTIVES

Radioactive iodine (RAI) treatment is often indicated after total thyroidectomy in differentiated thyroid cancer (DTC). However, its role in biochemical or locoregional persistent DTC is unclear. We aimed to investigate the effect of a second RAI treatment in patients with incomplete response to initial treatment and no evidence of distant metastases.

METHODS

Patients who underwent at least two RAI treatments over a 20-year period at a tertiary hospital were identified. Thyroglobulin levels and neck imaging were compared before and 1 to 2 years after RAI retreatment and evaluated at the last visit.

RESULTS

The cohort included 164 patients (103 female; mean age, 46.6 ± 17 years). Of 114 patients retreated without prior reoperation, 53 had structural disease. At 1 to 2 years after RAI retreatment, 10 of the 41 patients with sufficient data had structural progression, 5 resolution/shrinkage, and 26 stable disease. Stimulated thyroglobulin (stTg) measured 93.7.1 ± 108 ng/mL before and 102.2 ± 124 ng/mL after retreatment (P = NS). The other 61 patients had biochemical-only persistence. Their stTg levels decreased from 41.9 ± 56 to 24.6 ± 54 ng/mL (P = 0.003). The 50 patients who underwent neck reoperation before RAI retreatment showed no substantial change in stTg; 21 (42%) still had imaging findings 1 to 2 years later. At final follow-up, despite additional treatment in 63/164 patients (38.4%), only 56/164 (34.1%) had no evidence of disease.

CONCLUSIONS

This comprehensive study showed limited benefit of second RAI treatment in DTC patients with biochemical or locoregional structural persistent disease. Prospective studies are needed to distinguish patients for whom repeated RAI may be indicated to avoid unnecessary exposure.

Management and outcome of clinically evident neck recurrence in patients with papillary thyroid cancer

BACKGROUND

The aim of this study was to report our incidence of clinically evident neck recurrence, salvage neck management and subsequent outcomes in patients with papillary thyroid cancer. This is important to know so that patients with thyroid cancer can be properly counselled about the implications of recurrent disease and subsequent outcome.

METHODS

An institutional database of 3664 patients with thyroid cancer operated between 1986 and 2010 was reviewed. Patients with nonpapillary histology and gross residual disease and those with distant metastases at presentation or distant metastases prior to nodal recurrence were excluded from the study. Of these, 99 (3.0%) patients developed clinically evident nodal recurrence. Details of recurrence and subsequent therapy were recorded for each patient. Subsequent disease-specific survival (sDSS), distant recurrence-free survival (sDRFS) and nodal recurrence-free survival (sNRFS) were determined from the date of first nodal recurrence using the Kaplan-Meier method.

RESULTS

Of the 99 patients, 59% were female and 41% male. The median age was 41 years (range 5-91). The majority of patients had pT3/4 primary tumours (63%) and were pN+ (78%) at initial presentation. The median time to clinically evident nodal recurrence was 28 months (range: 3-264). Nodal recurrence occurred in the central neck in 15 (15%) patients, lateral neck in 74 (75%) patients and both in 10 (10%) patients. After salvage treatment, the 5-year sDSS was 97.4% from time of nodal recurrence. The 5-year sDRFS and sNRFS were 89.2% and 93.7%, respectively.

CONCLUSION

In our series, isolated clinically evident nodal recurrence occurred in 3.0% of patients. Such patients are successfully salvaged with surgery and adjuvant therapy with sDSS of 97.4% at 5 years.

Role of Contrast-Enhanced Ultrasound in the Pre-operative Diagnosis of Cervical Lymph Node Metastasis in Patients with Papillary Thyroid Carcinoma

The objective of this study was to prospectively evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating between benign and metastatic cervical lymph nodes in patients with papillary thyroid cancer (PTC). Three hundred nineteen cervical lymph nodes (162 metastatic from PTC and 157 benign) were evaluated using conventional ultrasonography (US) and CEUS before biopsy or surgery. Metastatic lymph nodes more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, perfusion defects and ring-enhancing margins than benign lymph nodes at pre-operative CEUS (all p values < 0.001). The area under the receiver operating characteristic curve (AUC) for the combination of conventional US and CEUS (0.983, 95% confidence interval [CI]: 0.971-0.994) was higher than that of conventional US alone (0.929, 95% CI: 0.899-0.958) and CEUS (0.911, 95% CI: 0.876-0.947). In conclusion, CEUS is a promising tool in conjunction with conventional US for the pre-operative prediction of metastatic cervical lymph nodes in patients with PTC.

Management of the central compartment in differentiated thyroid carcinoma

Management of differentiated thyroid carcinoma (DTC) is gradually evolving with considerations of de-escalation of treatment and/or active surveillance in a significant proportion of patients on the basis of an improved understanding of the long-term disease and functional outcomes from both surgical and non-surgical approaches. This is fueled by improved risk stratification using clinicopathologic prognostic factors as determined through high resolution ultrasound and fine needle aspiration cytology. This paper discusses general recommendations for preoperative decision-making in the management of the central compartment in DTC with particular reference to micropapillary thyroid carcinoma and encapsulated follicular variant papillary thyroid carcinoma. Given the multitude of specific factors that must be considered for each patient, therapeutic decisions should occur in a multidisciplinary setting weighing the risks of treatment morbidity against the risks of disease progression or recurrence. Recurrent/persistent disease merits special attention with regard to pre-operative planning and surgical risk, and should be managed by high-volume thyroid surgeons.

Post-treatment surveillance of thyroid cancer

An increased incidence of differentiated thyroid cancer (DTC) has resulted in an increased population of thyroid cancer survivors requiring ongoing disease surveillance. Our institution's risk-adapted surveillance strategy is based on a contemporary understanding of disease biology, guided by analysis of prognostic factors and balanced application of available surveillance modalities. The goal of this strategy is to detect recurrent disease early, identify patients who would benefit from further treatment and reduce over investigation of low-risk patients. This article describes our center's risk-stratified approach to the postoperative surveillance of patients with differentiated thyroid cancer with reference to the recent 2015 American Thyroid Association management guidelines.

Association of patient age with high-risk pathologic features in papillary thyroid cancer

BACKGROUND

Certain patient demographics and histopathologic features are risk factors for papillary thyroid cancer (PTC) recurrence after initial treatment. Our objective was to determine whether very young age is associated with aggressive pathologic features in patients with PTC.

MATERIALS AND METHODS

A retrospective analysis was performed for PTC patients who underwent surgical treatment at the University of Michigan between 2006 and 2012. Patients with known distant metastases were excluded. Demographics, high-risk pathologic features (capsular or vascular invasion, extrathyroidal extension, lymph node metastases, and extranodal extension), and disease recurrence were analyzed.

RESULTS

632 PTC patients were included in the analysis. Median age was 49 y (range 10-87). Tumors in patients aged <25 y had higher rates of extranodal extension (P = 0.002) compared with patients aged 25-44 y. Patients aged <25 y had more vascular invasion (P < 0.001) and lymph node metastasis (P = 0.001) than tumors in patients aged between 45-75 y. Patients aged >75 y had higher rates of vascular invasion (P < 0.001) and extrathyroidal extension (P = 0.001) compared with patients aged 45-75 y and more extrathyroidal extension (P < 0.001) than patients aged 25-44 y. There were no differences in tumor characteristics between the <25 and >75 age groups.

CONCLUSIONS

PTC patients aged <25 y of age or older than 75 y exhibit higher rates of aggressive histopathologic features compared to PTC patients aged between 25-75 y.

Current Guidelines for Postoperative Treatment and Follow-Up of Well-Differentiated Thyroid Cancer

Well-differentiated thyroid cancer is increasing in incidence but the disease-specific mortality remains very low. The only effective adjuvant treatment is radioactive iodine ablation. Guidelines regarding the use and dosage of radioactive iodine depend on pathologic features of the primary and metastatic tumor that define risk. Long-term treatment includes thyroid-stimulating hormone suppression and surveillance with serum thyroglobulin and radiologic assessment for nodal recurrence.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Effectiveness of routine ultrasonographic surveillance of patients with low-risk papillary carcinoma of the thyroid

BACKGROUND

Over the last 15 years, there has been a change in clinical practice for the detection of recurrence in all patients with papillary thyroid cancer (PTC). In the past, recurrence was detected by clinical examination supplemented with fine-needle aspiration cytology; however, routine neck ultrasonography (US) and measurements of serum thyroglobulin were introduced for follow-up in 2000 and are now used widely for recurrence surveillance. The aim of this study was to describe the effectiveness of this changing trend in the use of routine surveillance ultrasonography for the detection of recurrence in low-risk PTC at a single institution.

METHODS

Patients undergoing total thyroidectomy for PTC between January 2000 and December 2010 were identified from an institutional database. Of these, 752 (43.1%) were categorized as low risk by the risk stratification of the American Thyroid Association and included for analysis. The number of US examinations per patient per year of follow-up was then determined. The number of recurrences and deaths from disease was recorded similarly.

RESULTS

The median age was 48 years (range, 16-83) and the median follow-up was 34 months (range, 1-148). Between 2003 and 2012, the number of US examinations per patient-year of follow-up increased by 5.3-fold. Over the same time period, 3 structural recurrences (clinically evident neck masses or nodes) were detected with no disease-related deaths.

CONCLUSION

At our institution, the annual rate of neck US examination increased by 5.3-fold per low-risk PTC patients between 2003 and 2012. Despite this increase, only 3 structural recurrences were detected. The routine use of neck US for surveillance of low-risk PTC patients requires review.

Cost-effectiveness analysis of papillary thyroid cancer surveillance

BACKGROUND

The recent overdiagnosis of subclinical, low-risk papillary thyroid cancer (PTC) coincides with a growing national interest in cost-effective health care practices. The aim of this study was to measure the relative cost-effectiveness of disease surveillance of low-risk PTC patients versus intermediate- and high-risk patients in accordance with American Thyroid Association risk categories.

METHODS

Two thousand nine hundred thirty-two patients who underwent thyroidectomy for differentiated thyroid cancer between 2000 and 2010 were identified from the institutional database; 1845 patients were excluded because they had non-PTC cancer, underwent less than total thyroidectomy, had a secondary cancer, or had <36 months of follow-up. In total, 1087 were included for analysis. The numbers of postoperative blood tests, imaging scans and biopsies, clinician office visits, and recurrence events were recorded for the first 36 months of follow-up. Costs of surveillance were determined with the Physician Fee Schedule and Clinical Lab Fee Schedule of the Centers for Medicare and Medicaid Services.

RESULTS

The median age was 44 years (range, 7-83 years). In the first 36 months after thyroidectomy, there were 3, 44, and 22 recurrences (0.8%, 7.8%, and 13.4%) in the low-, intermediate-, and high-risk categories, respectively. The cost of surveillance for each recurrence detected was US $147,819, US $22,434, and US $20,680, respectively.

CONCLUSIONS

The cost to detect a recurrence in a low-risk patient is more than 6 and 7 times greater than the cost for intermediate- and high-risk PTC patients. It is difficult to justify this allocation of resources to the surveillance of low-risk patients. Surveillance strategies for the low-risk group should, therefore, be restructured.

Cost-Effectiveness of Long-Term Every Three-Year Versus Annual Postoperative Surveillance for Low-Risk Papillary Thyroid Cancer

BACKGROUND

Patients with low-risk papillary thyroid cancer (PTC) who demonstrate an excellent response to initial therapy have a 2% recurrence rate and 100% disease-specific survival within 10 years. Thus, annual surveillance may be excessive. We hypothesized that less frequent postoperative surveillance in these patients is cost effective.

METHODS

A Markov discrete time state transition model was created to compare postoperative surveillance tapered to 3-year intervals after 5 years of annual surveillance versus conventional annual surveillance in low-risk PTC patients with negative neck ultrasound and stimulated thyroglobulin less than 2 ng/mL 1 year postoperatively. Outcome probabilities, utilities, and costs were determined via literature review, the Medicare Physician Fee Schedule, and Healthcare Cost and Utilization Project data. Sensitivity analyses were performed to assess areas of uncertainty.

RESULTS

The cost of annual surveillance was $5,239 per patient and yielded 22.49 quality-adjusted life-years (QALYs). The 3-year strategy cost $2,601 less, but also yielded 0.01 less QALYs. Thus, the incremental cost per QALY of annual surveillance was $260,100. Probabilistic sensitivity analysis demonstrated that less frequent surveillance was more cost effective in 99.98% of 10,000 simulated patients. One-way sensitivity analysis revealed that annual surveillance would be cost effective if the total cost of neck ultrasound could be reduced to $23 or less.

CONCLUSION

Extending postoperative surveillance to 3-year intervals after 5 years of annual surveillance in patients with low-risk PTC with excellent response to therapy is more cost effective than annual surveillance.

Conventional US, elastography, and contrast enhanced US features of papillary thyroid microcarcinoma predict central compartment lymph node metastases

Lymph node metastases at the time of diagnosis have a major impact on both therapeutic strategy and tumor recurrence for patients with papillary thyroid microcarcinoma (PTMC). Our objective was to evaluate the usefulness of PTMC characteristics on ultrasonography for predicting central compartment lymph node metastases (CCLNM) of PTMC. One hundred twenty seven patients who underwent surgery for PTMC were enrolled in this study. The relationship between the CCLNM and the characteristics on conventional US, elastographic, and contrast enhanced ultrasound (CEUS) were investigated. Univariate analysis indicated that PTMCs with CCLNM were more often nodule irregular shape, microcalcifications, hyperenhancing or isoenhancing parametric maps, and peak index ≥1 at preoperative US and CEUS than those without CCLNM (P< 0.01, 0.05, 0.01 and 0.05 respectively). Multivariate analysis showed that microcalcification (OR:2.378, 95% CI: 1.096–5.158) and hyperenhancement or isoenhancement (OR:2.8, 95% CI: 1.287–6.094) were predictive for the presence of CCLNM. Elastography score was not significantly different between the groups. Our study indicated that preoperative thyroid nodule characteristics on conventional US and CEUS may serve as a useful tool to predict central compartment lymph node metastases in PTMC.

Management of recurrent cervical papillary thyroid cancer

Papillary thyroid cancer is one of the most common endocrine malignancies, and it is often associated with an excellent prognosis. However, it has been shown to recur in the lymph nodes in the neck. The management of these lymph nodes remains controversial, and current treatment strategies include observation, surgery, radioactive iodine ablation, and percutaneous ethanol injection. These various treatment modalities are discussed in this article.

Update in utility of secondary node dissection for papillary thyroid cancer

BACKGROUND

Detection of recurrent/persistent thyroid cancer has improved significantly in the past decade. Disease is detected earlier in recently treated patients and localized in patients long out from initial treatment. This update reviews recent literature regarding the utility of secondary node dissection for papillary thyroid carcinoma. Outcomes include disease-free status measured biochemically and clinically.

RESULTS

The utility of secondary node dissection as measured by clinically detectable disease exceeds 70% for all series and 90% for most. The utility as measured biochemically is more modest, with rates of biochemical cure ranging from 27-81% depending upon strictness of definition and patient selection. In predominately radioiodine scan-negative patients, using the strictest definition of biochemical cure, undetectable stimulated thyroglobulin (Tg) of less than 0.5 ng/ml, a rate of 27% is reported. Biochemical cure rates are reportedly 30-51% for stimulated Tg of less than 2 ng/ml and 56-71% for basal Tg of less than 2 ng/ml, with higher preoperative Tg levels less likely to achieve biochemical cure. Radioiodine-avid disease appears more amenable to cure, with 81% of patients achieving negative stimulated Tg after repeat I131 treatment and radio-assisted surgery. Complication rates of secondary nodal surgery appear similar to initial surgery in experienced hands; however, bilateral reoperative central neck dissection is associated with significantly higher complication rates than unilateral.

SUMMARY

Surgical resolution of clinically detectable disease is likely. Biochemical cure rates are more modest, with the greatest likelihood of biochemical cure occurring in patients with radioiodine-avid disease. In radioiodine-negative patients, there may be a higher likelihood of biochemical cure for those with lower preoperative detectable Tg levels.

The Evaluation of Microcarcinoma in Differentiated Thyroid Cancers According to Old and New TNM Classification

Objective: In this study, we aimed to evaluate the tumor size for proximal and distant metastases when the new and old TNM classification is taken into account in differentiated thyroid cancers.

Material and Methods: Two hundred sixty eight patients diagnosed with thyroid carcinoma, undergoing bilateral total or subtotal thyroidectomy treated with high doses of I-131 were examined retrospectively. The data of these patients were compared after classification, according to tumor size <1 cm and <2 cm, lymph node metastases thyroid and tumor capsule invasion at the time of diagnosis, and accumulation of abnormal activity in post I-131 treatment whole-body scan. I-131 uptakes besides physiological and thyroid bed were considered as abnormal activity uptakes.

Results: A total of 268 patients with average age of 19-82 yrs (mean: 47.0±13.8 yrs) were included in the study. At postoperative histopathological evaluation, 228 (85.1%) of patients were reported as papillary, 13 (4.9%) as follicular, 23 (8.6%) as well differentiated tumor of unknown malignant potential, 2 (0.7%) as insular and 2 (0.7%) as Hürthle-cell carcinoma. In patients with known tumor size, 96 of 207 (46.4%) patients' tumor size was <1 cm and in 111 (53.6%) >1 cm. In the same group, according to the revised TNM classification, in 149 of 207 patients (72%) the tumor size was <2 cm, whereas in 58 (28%) >2 cm. Of 187 patients with negative lymph nodes, 15 (8%) showed abnormal activity accumulation in the first post I-131 treatment whole-body scan and 10 (40% of 25 patients) positive lymph node (p<0.05) involvement.

Conclusion: Since the treatment of patients with microcarcinoma is controversial, tumor size should not be the only factor considered in patients with differentiated thyroid cancer Tissue tumor invasion, age, gender and multifocality should also be taken into account.

Conflict of interest:None declared.