The Role of Central Neck Lymph Node Dissection in the Management of Papillary Thyroid Cancer

Disease-free survival and response to therapy of clinically node- negative Papillary Thyroid Cancer treated without central neck dissection: Retrospective study of 321 patients

BACKGROUND AND OBJECTIVE

Nodal metastases in the central compartment are frequent in papillary thyroid cancer (PTC). However, they are mostly micrometastases with no impact on survival and their relevance on the risk of locoregional relapse is controversial. There is no consensus regarding optimal management of the central neck in patients with PTC cN0. In our center, we do not perform prophylactic central neck dissection (pCND). The objective of this study is to review our long-term results and compare them with the most recent literature.

PATIENTS AND METHODS

Retrospective review of patients with PTC who underwent total thyroidectomy (TT) without CND between 2005 and 2017. Primary result was disease-free survival in the neck (DFS).

RESULTS

321 patients were identified, mostly T1-T2 tumors (94.1%). Median follow-up was 90 months. DFS in the central compartment was excellent (96.1% at 10 year's follow-up). 19 patients had cervical recurrence, of which 15 underwent salvage surgery. On their last visit, including salvage surgery when appropriate, 77% of patients had excellent response, 18.7% had indeterminate response, 3.1% had biochemically incomplete response and 1.2% had morphologically incomplete response. Recurrent laryngeal nerve (RLN) paralysis after TT was transient in 4.7% of patients and permanent in 0.9% of patients. There were no RLN paralysis after salvage surgery. Permanent hypoparathyroidism occurred in 3.4% of patients. Only one patient had hypoparathyroidism after salvage surgery and it was permanent.

CONCLUSIONS

Based on long-term results and low rate of complications associated with salvage surgery in our experience, we consider routine pCND is not justified.

The model for predicting the central lymph node metastasis in cN0 papillary thyroid microcarcinoma with Hashimoto's thyroiditis

Background

The relationship between Hashimoto's thyroiditis (HT) and papillary thyroid microcarcinoma (PTMC) is controversial. These include central lymph node metastasis (CLNM), which affects the prognosis of PTMC patients. This study aimed to establish a predictive model combining ultrasonography and clinicopathological features to accurately evaluate latent CLNM in PTMC patients with HT at the clinical lymph node-negative (cN0) stage.

Methods

In this study, 1102 PTMC patients who received thyroidectomy and central cervical lymph node dissection (CLND) from the First Affiliated Hospital of Shandong First Medical University from January 2021 to December 2022 and the 960th Hospital of PLA from January 2021 to December 2022 were jointly collected. The clinical differences between PTMCs with HT and those without HT were compared. A total of 373 PTMCs with HT in cN0 were randomly divided into a training cohort and a validation cohort. By analyzing and screening the risk factors of CLNM, a nomogram model was established and verified. The predictive performance was measured by the receiver operating characteristic (ROC) curve, calibration curve, and clinical decision curve analysis (DCA).

Results

The ratio of central lymph node metastasis (CLNMR) in PTMCs with HT was 0.0% (0.0%, 15.0%) and 7.7% (0.0%, 40.0%) in the non-HT group (P<0.001). Multivariate logistic regression analysis showed that age, gender, calcification, adjacent to trachea or capsule, and TPOAB were predictors of CLNM in PTMCs with HT. The areas under the curve (AUC) of the prediction models in the training cohort and the validation cohort were 0.835 and 0.825, respectively, which showed good differentiation ability. DCA indicates that the prediction model also has high net benefit and clinical practical value.

Conclusion

This study found that CLN involvement was significantly reduced in PTMC patients with HT, suggesting that different methods should be used to predict CLNM in PTMC patients with HT and without HT, to more accurately assist preoperative clinical evaluation. The actual CLNM situation of PTMCs with HT in cN0 can be accurately predicted by the combination of ultrasonography and clinicopathological features.

Added value of arterial enhancement fraction derived from dual-energy computed tomography for preoperative diagnosis of cervical lymph node metastasis in papillary thyroid cancer: initial results

OBJECTIVES

To explore the added value of arterial enhancement fraction (AEF) derived from dual-energy computed tomography CT (DECT) to conventional image features for diagnosing cervical lymph node (LN) metastasis in papillary thyroid cancer (PTC).

METHODS

A total of 273 cervical LNs (153 non-metastatic and 120 metastatic) were recruited from 92 patients with PTC. Qualitative image features of LNs were assessed. Both single-energy CT (SECT)-derived AEF (AEFS) and DECT-derived AEF (AEFD) were calculated. Correlation between AEFD and AEFS was determined using Pearson's correlation coefficient. Multivariate logistic regression analysis with the forward variable selection method was used to build three models (conventional features, conventional features + AEFS, and conventional features + AEFD). Diagnostic performances were evaluated using receiver operating characteristic (ROC) curve analyses.

RESULTS

Abnormal enhancement, calcification, and cystic change were chosen to build model 1 and the model provided moderate diagnostic performance with an area under the ROC curve (AUC) of 0.675. Metastatic LNs demonstrated both significantly higher AEFD (1.14 vs 0.48; p < 0.001) and AEFS (1.08 vs 0.38; p < 0.001) than non-metastatic LNs. AEFD correlated well with AEFS (r = 0.802; p < 0.001), and exhibited comparable performance with AEFS (AUC, 0.867 vs 0.852; p = 0.628). Combining CT image features with AEFS (model 2) and AEFD (model 3) could significantly improve diagnostic performances (AUC, 0.865 vs 0.675; AUC, 0.883 vs 0.675; both p < 0.001).

CONCLUSIONS

AEFD correlated well with AEFS, and exhibited comparable performance with AEFS. Integrating qualitative CT image features with both AEFS and AEFD could further improve the ability in diagnosing cervical LN metastasis in PTC.

CLINICAL RELEVANCE STATEMENT

Arterial enhancement fraction (AEF) values, especially AEF derived from dual-energy computed tomography, can help to diagnose cervical lymph node metastasis in patients with papillary thyroid cancer, and complement conventional CT image features for improved clinical decision making.

KEY POINTS

• Metastatic cervical lymph nodes (LNs) demonstrated significantly higher arterial enhancement fraction (AEF) derived from dual-energy computed tomography (DECT) and single-energy CT (SECT)-derived AEF (AEFS) than non-metastatic LNs in patients with papillary thyroid cancer. • DECT-derived AEF (AEFD) correlated significantly with AEFS, and exhibited comparable performance with AEFS. • Integrating qualitative CT images features with both AEFS and AEFD could further improve the differential ability.

Central Neck Lymph Node Size Measured by Ultrasound Significantly Predicts Central Neck Lymph Node Metastasis of Papillary Thyroid Carcinoma

Objective: The aim of this study was to investigate whether Central lymph node (CLN) size as measured by an ultrasound can significantly predict CLN metastasis of papillary thyroid carcinoma (PTC). Materials and methods: This retrospective chart review of patients diagnosed with PTC who underwent ultrasound and central neck dissection (CND). We excluded patients who received previous thyroid surgery or radiation. We analyzed the correlation between CLN size and characteristics by ultrasound and histopathologic findings among positive CLN patients. Results: Of the 48 patients who underwent preoperative ultrasound and CND, 34 patients had positive CLN identified by ultrasound. The positive predictive value, negative predictive value, sensitivity, specificity, and accuracy of ultrasound in this diagnostic setting was 88.0%, 21.0%, 73.2%, 42.9%, and 68.7%, respectively. The risk of CLN metastasis of PTC was 67.7% and 85.7% for lymph node size 3.1 to 4 mm and 4.1 to 5 mm, respectively. The risk increased to 100% when the lymph node size was >5 mm. Positive preoperative ultrasound of lateral neck lymph node was found to be a significant risk factor for CLN metastasis (P = .003). Conclusion: Ultrasound was found to be an effective preoperative evaluation in patients with PTC to determine the likelihood of CLN metastasis and whether CND is indicated, especially in the ultrasound-positive central lymph node. A high risk of metastasis was found in CLN size >3 mm by ultrasound, and the risk dramatically increased in CLN size >5 mm. We also found positive lateral neck node from preoperative ultrasound to be a significant risk factor for CLN metastasis.

Nomogram to predict the risk of biochemical recurrence and structural recurrence in patients with stage cN1 papillary thyroid carcinoma

INTRODUCTION

Although papillary thyroid carcinoma (PTC) is thought to be the least aggressive thyroid cancer, it has a significant recurrence rate. Therefore, we aimed to develop a nomogram to estimate the probability of biochemical recurrence (BIR) and structural recurrence (STR) in patients with stage cN1 PTC.

METHODS

We studied the relationship between the characteristics of patients with stage N1a PTC and the risk of recurrence by analysing the data of 617 inpatients (training cohort) and 102 outpatients (validation cohort) in our hospital. We used the least absolute shrinkage and selection operator regression model to identify prognostic indicators to construct nomograms to predict the risk of BIR and STR.

RESULTS

There were 94 (15.24%) BIR cases in the training cohort and 36 (35.29%) in the validation cohort. There were 31 (5.02%) STR cases in the training cohort and 23 (22.55%) cases in the validation cohort. The variables included in the BIR nomogram were sex, age at diagnosis, tumour size, extrathyroidal infiltration, and lymph node ratio (LNR). While the variables included in the STR nomogram were tumour size, extrathyroidal infiltration, BRAF state, metastatic lymph nodes, and LNR. Both the prediction models demonstrated good discrimination ability. The results showed the calibration curve of the nomogram was near the optimum diagonal line, and the decision curve analysis showed a noticeably better benefit.

CONCLUSION

The LNR may be a valid prognostic indicator for patients with stage cN1 PTC. The nomograms could help clinicians identify high-risk patients and choose the best postsurgical therapy and monitoring.

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.

SLP-2 regulates the generation of reactive oxygen species and the ERK pathway to promote papillary thyroid carcinoma motility and angiogenesis

Although papillary thyroid cancer (PTC) has a generally decent prognosis, approximately 10% of patients experience recurrence, which is frequently associated with distant metastasis. Stomatin-like protein 2 (SLP-2), a protein located in the mitochondrial intermembrane space, is thought to be a possible cancer promoter. This study aimed to discover the involvement of SLP-2 in PTC motility and angiogenesis, and to initially explore its mechanism. According to the CCLE database, SLP-2 was universally increased in various cancers. Then SLP-2 expression in PTC cell lines was evaluated. Thereafter the influences of SLP-2 knockdown on cell migration, invasion, epithelial-mesenchymal transition (EMT), and angiogenesis were assessed, respectively. The mediated roles of reactive oxygen species (ROS) and MAPKs in the SLP-2 regulation were likewise determined. SLP-2 was discovered to be upregulated in PTC cells, and its knockdown could suppress cell migration, invasion, EMT, and angiogenesis. Declined SLP-2 expression also facilitated ROS generation and inhibited phosphorylation of MAPKs. Moreover, ERK agonist and ROS scavenger treatment partially reversed the impacts of SLP-2 knockdown on cells, indicating SLP-2 regulated generation of ROS and ERK pathway to promote PTC motility and angiogenesis. Generally, SLP-2 appears to be one of the major genes in the pathogenesis of PTC. Silencing its expression may have an impact on the onset and evolution of PTC. The fact that SLP-2 has a considerable influence on ROS levels implies that PTC can be treated by boosting ROS levels.

A clinical and molecular pathology prediction model for central lymph node metastasis in cN0 papillary thyroid microcarcinoma

BACKGROUND

The frequency of thyroid cancer has rapidly increased in recent years globally. Thus, more papillary thyroid microcarcinoma (PTMC) patients are being diagnosed, including clinical lymph node-negative (cN0) patients. Our study attempted to develop a prediction model for assessing the probability of central lymph node metastasis (CLNM) in cN0 PTMC patients.

METHODS

A total of 595 patients from the Affiliated Hospital of Qingdao University (training cohort: 456 patients) and the Affiliated Hospital of Jining Medical University (verification cohort: 139 patients) who underwent thyroid surgery between January 2020 and May 2022 were enrolled in this study. Their clinical and molecular pathology data were analyzed with multivariate logistic regression to identify independent factors, and then we established a prediction model to assess the risk of CLNM in cN0 PTMC patients.

RESULTS

Multivariate logistic regression analysis revealed that sex, Hashimoto's thyroiditis (HT), tumor size, extrathyroidal extension, TERT promoter mutations and NRAS mutation were independent factors of CLNM. The prediction model demonstrated good discrimination ability (C-index: 0.757 and 0.753 in the derivation and validation cohorts, respectively). The calibration curve of the model was near the optimum diagonal line, and decision curve analysis (DCA) showed a noticeably better benefit.

CONCLUSION

CLNM in cN0 PTMC patients is associated with male sex, tumor size, extrathyroidal extension, HT, TERT promoter mutations and NRAS mutation. The prediction model exhibits good discrimination, calibration and clinical usefulness. This model will help to assess CLNM risk and make clinical decisions in cN0 PTMC patients.

Differential diagnosis of non-diffuse primary thyroid lymphoma and papillary thyroid carcinoma by ultrasound combined with computed tomography

Background

Primary thyroid lymphoma (PTL) and papillary thyroid carcinoma (PTC) are both thyroid malignancies, but their therapeutic methods and prognosis are different. This study aims to explore their sonographic and computed tomography(CT)features, and to improve the early diagnosis rate.

Methods

The clinical and imaging data of 50 patients with non-diffuse PTL and 100 patients with PTC confirmed by pathology were retrospectively analysed.

Results

Of the 150 patients, from the perspective of clinical data, between non-diffuse PTL and PTC patients existed significant difference in age, maximum diameter of nodule, asymmetric enlargement and Hashimoto’s thyroiditis (P < 0.001), but not in gender ratio, echo texture, cystic change and anteroposterior-to-transverse ratio (P > 0.05). With respect to sonographic feature, non-diffuse PTL patients had a higher proportion than PTC patients in markedly hypoechoic, internal linear echogenic strands, posterior echo enhancement, rich vascularity, lack of calcification and homogeneous enhancement, with statistically significant difference (P < 0.05), while PTC patients had a higher proportion than non-diffuse PTL patients in irregular border, circumscribed margin, capsular invasion and significant enhancement, with statistically significant difference (P < 0.001). With respect to CT feature, non-diffuse PTL patients were significantly different from PTC patients in the non-contrast CT value mean, venous phase CT value mean, enhanced intensity and homogeneity of nodules (P < 0.05). Multivariate logistic regression analysis showed that age (OR = 1.226, 95%CI:1.056 ~ 1.423, P = 0.007), posterior echo enhancement (OR = 51.152, 95%CI: 2.934 ~ 891.738, P = 0.007), lack of calcification (OR = 0.013, 95%CI: 0.000 ~ 0.400, P = 0.013) and homogeneous enhancement (OR = 0.020, 95%CI: 0.001 ~ 0.507, P = 0.018) were independent risk factors.

Conclusions

Sonographic and CT features of the presence of posterior echo enhancement, lack of calcification and homogeneous enhancement were valuable to distinguishing non-diffuse PTL from PTC.

The incidence and features of Delphian lymph node involvement in patients with papillary thyroid carcinoma

Introduction

In papillary thyroid cancer patients, the extent of dissection is still a matter of debate. Evaluating Delphian lymph nodes (DLNs) during the surgery has been speculated as a valuable tool to determine the extent of dissection. Herein, we aimed to evaluate the incidence and features of DLNs involvement in patients with papillary thyroid carcinoma.

Method

We conducted this cross-sectional study among surgical cases of papillary thyroid cancer. Patients were divided based on their DLNs involvement status. Their age, gender, location of the mass, lymphatic involvement, tumor size, tumor characteristics, pathology report, and operation note features were compared between the two groups. Definitive pathology slides of the patients were evaluated regarding DLN features.

Results

Of the 61 patients (mean age: 38.2 ± 12.0), 45 (73.8%) were females. In 13 (21.3%) patients, DLNs involvement was reported. A statistically significant relationship was noted between DLNs involvement and other lymph nodes' involvement on the same side of the mass (P < 0.001), the opposite side (P = 0.041), and also central lymph nodes (P < 0.001). Vascular invasion was also significantly higher among patients with DLNs involvement (P = 0.012).

Conclusion

Since DLNs involvement is significantly associated with extensive nodal involvement, intraoperative evaluation of DLNs is recommended to establish the extent to which dissection should be performed.

Post-operative Horner's Syndrome Following Total Thyroidectomy: A Case Report

The oculosympathetic chain is a three-neuron pathway responsible for sympathetic innervation to the eye, which follows a complex anatomical course through the head and neck. Neck surgery may cause injury to this pathway, causing loss of sympathetic innervation producing the eponymous Horner's syndrome (ipsilateral ptosis, miosis and anhidrosis), but this is rare in the reported literature. We present the case of a 23-year-old female who underwent total thyroidectomy for a right-sided, metastatic papillary thyroid carcinoma. Following surgery, in the immediate postoperative period, she was noted to have unilateral ptosis and miosis. This patient was assessed by an ophthalmologist due to persistent unilateral ocular symptoms following thyroidectomy. She was subsequently diagnosed with right-sided Horner's syndrome. The diagnosis was confirmed following the observed reversal of her ocular symptoms using apraclonidine 1% minims. The management of Horner's syndrome following thyroidectomy is conservative if no evidence of compressive hematoma or seroma is identified as in this case. The patient was followed up at six weeks following thyroidectomy and a partial improvement in ptosis was noted. The patient also reported blurred vision secondary to increased refractive error due to reduced pupillary function in her right eye. Prognosticating recovery from Horner's syndrome following thyroidectomy is challenging due to limited evidence. Horner's syndrome as a possible complication of thyroidectomy should be counselled to patients pre-operatively. A residual deficit from Horner's syndrome may cause functional impairment in addition to the poor cosmetic outcome.

A Narrative Review of Preventive Central Lymph Node Dissection in Patients With Papillary Thyroid Cancer - A Necessity or an Excess

Objective

This review article summarises the latest evidence for preventive central lymph node dissection in patients with papillary thyroid cancer taking into account the possible complications and risk of recurrence.

Background

Papillary thyroid cancer is the most frequent histological variant of malignant neoplasms of the thyroid gland. It accounts for about 80-85% of all cases of thyroid cancer. Despite good postoperative results and an excellent survival rate in comparison with many other malignant diseases, tumor metastases to the cervical lymph nodes are frequent. Most researchers agree that the presence of obvious metastases in the lymph nodes requires careful lymph node dissection. It was suggested to perform preventive routine lymphadenectomy in all patients with malignant thyroid diseases referred to surgery.

Methods

It was performed the literature review using the “papillary thyroid cancer”, “central lymph node dissection”, “hypocalcemia”, “recurrent laryngeal nerve paresis”, “metastasis”, “cancer recurrence” along with the MESH terms. The reference list of the articles was carefully reviewed as a potential source of information. The search was based on Medline, Scopus, Google Scholar, eLibrary engines. Selected publications were analyzed and their synthesis was used to write the review and analyse the role of preventive central lymph node dissection in patients with papillary thyroid cancer.

Conclusions

The necessity of preventive central lymph node dissection in patients with differentiated papillary thyroid carcinoma is still controversial. There is much evidence that it increases the frequency of transient hypocalcemia. Due to the fact that this complication is temporary, its significance in clinical practice is debatable. It can also be assumed that an extant of surgery in the neck area is associated with an increased risk of recurrent laryngeal nerve injury. However, most studies indicate that this injury is associated more with thyroidectomy itself than with lymph node dissection. Recurrent laryngeal nerve dysfunction is also a temporary complication in the vast majority of cases. At the same time, a large amount of data shows that central lymph node dissection reduces the risk of thyroid cancer recurrence in two times.

Extracellular Volume Fraction Derived From Dual-Layer Spectral Detector Computed Tomography for Diagnosing Cervical Lymph Nodes Metastasis in Patients With Papillary Thyroid Cancer: A Preliminary Study

Objectives

The current study evaluates the performance of dual-energy computed tomography (DECT) derived extracellular volume (ECV) fraction based on dual-layer spectral detector CT for diagnosing cervical lymph nodes (LNs) metastasis from papillary thyroid cancer (PTC) and compares it with the value of ECV derived from conventional single-energy CT (SECT).

Methods

One hundred and fifty-seven cervical LNs (81 non-metastatic and 76 metastatic) were recruited. Among them, 59 cervical LNs (27 non-metastatic and 32 metastatic) were affected by cervical root artifact on the contrast-enhanced CT images in the arterial phase. Both the SECT-derived ECV fraction (ECV_S) and the DECT-derived ECV fraction (ECV_D) were calculated. A Pearson correlation coefficient and a Bland–Altman analysis were performed to evaluate the correlations between ECV_D and ECV_S. Receiver operator characteristic curves analysis and the Delong method were performed to assess and compare the diagnostic performance.

Results

ECV_D correlated significantly with ECV_S (r = 0.925; p <0.001) with a small bias (−0.6). Metastatic LNs showed significantly higher ECV_D (42.41% vs 22.53%, p <0.001) and ECV_S (39.18% vs 25.45%, p <0.001) than non-metastatic LNs. By setting an ECV_D of 36.45% as the cut-off value, optimal diagnostic performance could be achieved (AUC = 0.813), which was comparable with that of ECV_S (cut-off value = 34.99%; AUC = 0.793) (p = 0.265). For LNs affected by cervical root artifact, ECV_D also showed favorable efficiency (AUC = 0.756), which was also comparable with that of ECV_S (AUC = 0.716) (p = 0.244).

Conclusions

ECV_D showed a significant correlation with ECV_S. Compared with ECV_S, ECV_D showed comparable performance in diagnosing metastatic cervical LNs in PTC patients, even though the LNs were affected by cervical root artifacts on arterial phase CT.

Evaluation of the clinical value of carbon nanoparticles in endoscopic thyroidectomy and prophylactic central neck dissection through total mammary areolas approach for thyroid cancer

Background

Carbon nanoparticles (CNs) are tracers used in thyroid surgery of patients with thyroid cancer (TC) to help remove lymph nodes and protect the parathyroid gland. The facilitative effect of carbon nanoparticles in endoscopic thyroidectomy and prophylactic central neck dissection (pCND) has not been reported.

Methods

The protective effect on parathyroid gland (PG) function and the numbers of identified parathyroid glands and central lymph nodes in endoscopic thyroid surgery through the total mammary areolas approach were compared between the CN and control groups.

Results

All endoscopic thyroidectomies were successfully completed. No difference was found in either group regarding the general characteristics or operative complications. The mean number of superior PGs and inferior PGs identified in situ or in the dissected central lymph tissues was not different between the groups. The mean number of lymph nodes removed by unilateral CND was greater in the CN group than in the control group. However, there was no difference in the number of harvested lymph nodes when excluding the LNs less than 5 mm, which exhibit an extremely low metastatic rate.

Conclusion

Carbon nanoparticles do not improve the protective effect on the parathyroid gland, especially the inferior glands, in endoscopic thyroid surgery through the total mammary areolas approach. There is no need to use CNs to facilitate the lymph node harvest in endoscopic prophylactic unilateral CND.

Construction and validation of a nomogram for predicting cervical lymph node metastasis in classic papillary thyroid carcinoma

PURPOSE

Patients with papillary thyroid carcinoma (PTC) frequently present a relatively poor prognosis when they coexist with cervical lymph node metastasis (LNM). Moreover, it remains controversial whether prophylactic lymph node dissection (LND) should be performed for patients without clinically lymph node metastasis. Thus, we hereby develop a nomogram for predicting the cervical LNM (including central and lateral LNM) in patients with PTC.

METHODS

We retrospectively reviewed the clinical characteristics of adult patients with PTC in the surveillance, epidemiology, and end results (SEER) database between 2010 and 2015 and in our Department of Breast and Thyroid Surgery in the Second Affiliated Hospital of Chongqing Medical University between 2019 and 2020.

RESULT

A total of 21,972 patients in the SEER database and 747 patients in our department who met the inclusion criteria were enrolled in this study. Ultimately, six clinical features including age, gender, race, extrathyroidal invasion, multifocality, and tumor size were identified to be associated with cervical LNM in patients with PTC, which were screened to develop a nomogram. This model had satisfied discrimination with a concordance index (C-index) of 0.733, supported by both internal and external validation with a C-index of 0.731 and 0.716, respectively. A decision curve analysis was subsequently made to evaluate the feasibility of this nomogram for predicting cervical LNM. Besides, a positive correlation between nomogram score and the average number of lymph node metastases was observed in all groups.

CONCLUSION

This visualized multipopulational-based nomogram model was successfully established. We determined that various clinical characteristics were significantly associated with cervical LNM, which would be better helping clinicians make individualized clinical decisions for PTC patients.

Development and validation of a population-based model for predicting the regional lymph node metastasis in adolescent differentiated thyroid carcinoma

BACKGROUND

Adolescent differentiated thyroid carcinoma (DTC) is a rare type of thyroid cancer that represents a special entity of all endocrine-related cancer. This study aims to establish the first nomogram for predicting the regional (central and lateral) lymph node metastasis (LNM) in the adolescent population for better surgical management.

METHOD

We retrospectively reviewed the clinicopathology characteristics of adolescent patients with DTC in the Surveillance, Epidemiology, and End Results database between 2010 and 2015.

RESULTS

A total of 1,930 adolescent patients between the ages of 10 and 24 years from the SEER database were enrolled in this study. Six predictive factors including age, race, histology, multifocality, extrathyroidal invasion (EI) and tumor size were identified to be significantly associated with the regional LNM via univariate and multivariate logistic regression analyses. These indicators were used to construct a nomogram for predicting the regional LNM in adolescent patients with DTC. Moreover, a satisfied predictive ability of the model was determined with a C-index of 0.794, supported by an internal validation group with a C-index of 0.776. The Decision Curve Analysis and calibration curve further conducted a great agreement in our model.

CONCLUSION

The first predictive model containing multiple factors has been successfully established with good discrimination for predicting the regional LNM in adolescent patients with DTC. This nomogram could effectively help surgeons to make better individualized surgical decision intraoperatively, especially in terms of whether cervical lymph node dissection (LND) is warranted.

Predictive Factors for Occult Bilateral Papillary Thyroid Carcinoma

BACKGROUND

Bilateral papillary thyroid carcinoma (PTC) requires aggressive treatment, such as total thyroidectomy (TT). If there is only an isolated PTC focus in one lobe that can be diagnosed preoperatively, and it is unknown whether there are foci in the contralateral lobe that are too small to be detected, it is difficult to know whether to perform TT or to remove only the lobe with the isolated PTC focus. Here, we investigated the prevalence of and predictive factors for occult bilateral PTC that was only diagnosed unilaterally before surgery.

METHODS

This retrospective study involved 586 patients with unilateral PTC who were diagnosed preoperatively by ultrasound. They underwent TT and cervical lymph node dissection. According to the pathology, they were divided into unilateral PTC and bilateral (Bil)-PTC groups. Student's t test, chi-squared test, and multivariate analysis were performed to identify features of the malignant tumor that increased the likelihood of malignancy in the contralateral lobe. The prevalence of occult Bil-PTC was calculated.

RESULTS

Bil-PTC was found in 70 of 586 (11.95%) PTC patients. Multivariate analysis showed that vascularity (odds ratio[OR]: 2.180, 95% confidence interval [CI]: 1.142-4.162, p = 0.018) and ultrasound diagnosis of lymph node metastasis (USLNM) (OR: 2.056, 95% CI: 1.056-4.004, p = 0.034) were independent predictors of occult Bil-PTC.

CONCLUSION

The prevalence of occult PTC in the contralateral lobe was only 11.95%. Vascularity and USLNM were risk factors for Bil-PTC. In terms of these preoperative risk factors for PTC, TT should be cautiously performed in patients with preoperative diagnosis of PTC with isolated focus.

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).

Preoperatively Predicting the Central Lymph Node Metastasis for Papillary Thyroid Cancer Patients With Hashimoto's Thyroiditis

BACKGROUND

The preoperative distinguishment of lymph nodes with reactive hyperplasia or tumor metastasis plays a pivotal role in guiding the surgical extension for papillary thyroid carcinoma (PTC) with Hashimoto's thyroiditis (HT), especially in terms of the central lymph node (CLN) dissection. We aim to identify the preparative risk factors for CLN metastasis in PTC patients concurrent with HT.

MATERIALS AND METHODS

We retrospectively reviewed and analyzed the data including the basic information, preoperative sonographic characteristics, and thyroid function of consecutive PTC patients with HT in our medical center between Jan 2019 and Apr 2021. The Chi-square and Fisher's exact tests were used for comparison of qualitative variables among patients with or without CLN metastasis. Univariate and multivariate logistic regression analyses were used to determine the risk factors for CLN metastasis. The nomogram was constructed and further evaluated by two cohorts produced by 1,000 resampling bootstrap analysis.

RESULTS

A total of 98 in 214 (45.8%) PTC patients were identified with CLN metastasis. In multivariate analysis, four variables including high serum thyroglobulin antibody (TgAb) level (>1,150 IU/ml), lower tumor location, irregular margin of CLN, and micro-calcification in the CLN were determined to be significantly associated with the CLN metastasis in PTC patients with HT. An individualized nomogram was consequently established with a favorable C-index of 0.815 and verified via two internal validation cohorts.

CONCLUSIONS

Our results indicated that preoperatively sonographic characteristics of the tumor and lymph node condition combined with serum TgAb level can significantly predict the CLN in PTC patients with HT and the novel nomogram may further help surgeons to manage the CLN in this subpopulation.

Lymph node metastasis prediction of papillary thyroid carcinoma based on transfer learning radiomics

Non-invasive assessment of the risk of lymph node metastasis (LNM) in patients with papillary thyroid carcinoma (PTC) is of great value for the treatment option selection. The purpose of this paper is to develop a transfer learning radiomics (TLR) model for preoperative prediction of LNM in PTC patients in a multicenter, cross-machine, multi-operator scenario. Here we report the TLR model produces a stable LNM prediction. In the experiments of cross-validation and independent testing of the main cohort according to diagnostic time, machine, and operator, the TLR achieves an average area under the curve (AUC) of 0.90. In the other two independent cohorts, TLR also achieves 0.93 AUC, and this performance is statistically better than the other three methods according to Delong test. Decision curve analysis also proves that the TLR model brings more benefit to PTC patients than other methods.

An Ultrasound Radiomics Nomogram for Preoperative Prediction of Central Neck Lymph Node Metastasis in Papillary Thyroid Carcinoma

Purpose: This study aimed to establish and validate an ultrasound radiomics nomogram for the preoperative prediction of central lymph node (LN) metastasis in patients with papillary thyroid carcinoma (PTC).

Patients and Methods: The prediction model was developed in 609 patients with clinicopathologically confirmed unifocal PTC who received ultrasonography between Jan 2018 and June 2018. Radiomic features were extracted after the ultrasonography of PTC. Lasso regression model was used for data dimensionality reduction, feature selection, and radiomics signature building. The predicting model was established based on the multivariable logistic regression analysis in which the radiomics signature, ultrasonography-reported LN status, and independent clinicopathologic risk factors were incorporated, and finally a radiomics nomogram was established. The performance of the nomogram was assessed with respect to the discrimination and consistence. An independent validation was performed in 326 consecutive patients from July 2018 to Sep 2018.

Results: The radiomics signature consisted of 23 selected features and was significantly associated with LN status in both primary and validation cohorts. The independent predictors in the radiomics nomogram included the radiomics signature, age, TG level, TPOAB level, and ultrasonography-reported LN status. The model showed good discrimination and consistence in both cohorts: C-index of 0.816 (95% CI, 0.808–0.824) in the primary cohort and 0.858 (95% CI, 0.849–0.867) in the validation cohort. The area under receiver operating curve was 0.858. In the validation cohort, the accuracy, sensitivity, specificity and AUC of this model were 0.812, 0.816, 0.810, and 0.858 (95% CI, 0.785–0.930), respectively. Decision curve analysis indicated the radiomics nomogram was clinically useful.

Conclusion: This study presents a convenient, clinically useful ultrasound radiomics nomogram that can be used for the pre-operative individualized prediction of central LN metastasis in patients with PTC.

Elective Central Compartment Lymph Node Dissection Does not Increase the Risk of Postoperative Hypoparathyroidism in Patients Treated for Differentiated Thyroid Cancer

Aim

The aim of this study was to compare the incidence of postoperative hypoparathyroidism in two groups of patients who were treated for differentiated thyroid cancer.

Methods

A retrospective analysis of 179 patients who were treated for differentiated thyroid cancer in our institution from January 2011 until December 2018 was performed. Only patients initially treated with total thyroidectomy and those who did not have preoperatively confirmed central compartment and lateral neck lymph node metastases were included in this study. Two main groups of patients were analysed. The patients who were treated with total thyroidectomy and elective central compartment lymph node dissection simultaneously were included in the first group. The patients who were treated only with total thyroidectomy were included in the second group. The rate of transitory and persistent postoperative hypoparathyroidism was compared between the two groups.

Results

A total of 117 patients (65.4%) underwent total thyroidectomy and elective central compartment lymph node dissection simultaneously (TT + CCLNd group). The remaining 62 patients (34.6%) underwent total thyroidectomy only (TT group). A total of 22.6% patients in the TT group developed postoperative hypoparathyroidism compared with 25.6% in the TT + CCLNd group. The rate of persistent hypoparathyroidism in the TT and TT + CCLNd groups was 3.2% and 6.0%, respectively. The difference in the rate of transient and persistent postoperative hypoparathyroidism was not statistically significant between the two groups. Within the TT + CCLNd group, 82.9% of patients underwent ipsilateral paratracheal lymph node dissection and 17.1% underwent bilateral paratracheal lymph node dissection. The rate of postoperative hypoparathyroidism was analysed in those two subgroups of patients and did not prove to be statistically significant.

Discussion

While its impact on the local recurrence rate is still controversial, elective central compartment lymph node dissection could be a great tool for selection of patients who could profit from adjuvant radioiodine treatment. On the other hand, central compartment lymph node dissection could potentially increase the risk of hypoparathyroidism due to involuntary injury to parathyroid glands and/or their blood supply. Our study did not find a statistically significant difference regarding postoperative hypoparathyroidism between patients who underwent central compartment lymph node dissection compared with patients who underwent total thyroidectomy only. Our data are not in accordance with some of the previously published studies.

Conclusion

Our results demonstrated that elective central compartment lymph node dissection is a safe procedure and does not significantly increase the risk of postoperative hypoparathyroidism when it is performed simultaneously with total thyroidectomy.

Clinical Analysis of Risk Factors for Cervical Lymph Node Metastasis in Papillary Thyroid Microcarcinoma: A Retrospective Study of 3686 Patients

Purpose

To investigate the risk factors for cervical lymph node metastasis (LNM) in papillary thyroid microcarcinoma (PTMC).

Patients and Methods

In total, 3686 patients with PTMC who underwent initial surgery in Shanghai Jiao Tong University affiliated Sixth People’s Hospital from January 2010 to December 2019 were retrospectively analyzed. Univariate and multivariate analyses were conducted to identify risk factors associated with cervical LNM.

Results

Male gender [odds ratio (OR) =1.420, P <0.001], age <55 years (OR =2.128, P <0.001), tumor size >6.5 mm (OR =2.112, P <0.001), lymphovascular invasion (LVI) (OR =2.110, P =0.016), multifocality (OR =1.358, P =0.022), extrathyroidal extension (ETE) (OR =1.598, P <0.001), and lateral LNM (LLNM) (OR =6.383, P <0.001) served as independent risk factors for central LNM (CLNM). Moreover, male gender (OR =1.668, P =0.001), tumor size >6.5 mm (OR =2.223, P <0.001), chronic lymphocytic thyroiditis (OR =1.402, P =0.021), LVI (OR =4.582, P <0.001), ETE (OR =1.393, P=0.023), and CLNM (OR =6.212, P <0.001) served as independent risk factors for LLNM. Furthermore, solitary PTMC with lesions in the upper third of the thyroid gland were more associated with LLNM than lesions in the other regions.

Conclusion

This study suggests that meticulous evaluation of risk factors associated with LNM is required in order to guide the surgical treatment of PTMC patients in clinical practice.

Lymph Node Metastasis and Extrathyroidal Extension in Papillary Thyroid Microcarcinoma in Cyprus: Suspicious Subcentimeter Nodules Should Undergo FNA When Multifocality is Suspected

OBJECTIVE

To determine the prevalence of lymph node (LN) metastasis and extrathyroidal extension (ETE) in patients with papillary thyroid microcarcinoma (PTMC) in Cyprus and to evaluate the role of preoperative ultrasound (U/S) examination.

METHODS

A retrospective study of 102 patients who underwent thyroidectomy for PTMC in a 2-year period. Preoperatively, all patients had a thyroid and neck U/S examination with LN mapping. Tumor size according to the largest diameter, number of foci, LN metastasis, and ETE data was collected from the histopathological report and was compared to the preoperative U/S reports.

RESULTS

LN metastasis was present in 23.5% of patients. 15.7% had central, 3.9% had lateral, and 3.9% had both central and lateral LN metastasis. ETE was present in 27.5% of patients. 21.6% had multifocal disease, and in this group, 40.9% had LN metastasis and 36.4% had ETE. Multifocality (p = 0.03), size of tumor (p = 0.05), and ETE (p ≤ 0.001) were significantly associated with LN metastasis. The prevalence of LN metastasis in multifocal PTMC ≤5 mm was the same with multifocal PTMC >5 mm. The preoperative U/S sensitivity for the suspicious lateral neck and central LN was 100%, and the specificity was 100%. The preoperative U/S sensitivity for nodules suspicious for ETE was 53.6%, and the specificity was 100%.

CONCLUSION

The presence of LN metastasis and ETE in our PTMC patients in Cyprus is frequent. Neck U/S mapping is a highly reliable and accurate tool in identifying metastatic nodes. LN metastasis is associated with ETE and multifocality. Suspicious subcentimeter nodules should undergo FNA irrespective of size when multifocality is suspected.

PBX3 Promotes Tumor Growth and Angiogenesis via Activation of AT1R/VEGFR2 Pathway in Papillary Thyroid Carcinoma

PBX3 (Pre-B-cell leukemia homeobox 3) had been considered to be a multifunctional oncogene which involved in tumor growth, invasion, and metastasis in leukemia and some solid tumors. However, the contribution of PBX3 to papillary thyroid carcinoma (PTC) remains unclear. In this study, we found that PBX3 expression was significantly upregulated in PTC tissues compared to adjacent normal tissues, and high levels of PBX3 were correlated with tumor size, lymphatic metastasis, TMN stage, and poor prognosis of PTC patients. Overexpression of PBX3 in PTC cell lines promoted cell proliferation. Consistently, knockdown of PBX3 by shRNA induced cell cycle arrest at G0/G1 phase, and inhibited angiogenesis and tumor growth in vitro and in vivo. Furthermore, PBX3 promoted PTC cell proliferation and angiogenesis through activation of AT1R/VEGFR2 pathway while overexpression of AT1R and treatment with VEGFA reversed PBX3-shRNA-induced decreased phosphorylation of VEGFR2 and its downstream (ERK1/2, AKT and Src). It demonstrated that PBX3 could be used as a potential prognostic biomarker and therapeutic target for PTC.

The role of thymus preservation in parathyroid gland function and surgical completeness after bilateral central lymph node dissection for papillary thyroid cancer: A randomized controlled study

BACKGROUND

The clinical value of thymus preservation during thyroid carcinoma surgery remains unclear. The aim of this study is to explore the role of bilateral thymus preservation in parathyroid glands (PGs) function and surgical completeness in total thyroidectomy (TT) with bilateral central lymph node dissection (CLND).

MATERIALS AND METHODS

Fifty-four consecutive patients who underwent TT and bilateral CLND were assigned to the thymus preservation (TP) group (n = 27) and the bilateral thymectomy (BT) group (n = 27). Surgical completeness was evaluated by the number of lymph nodes dissected, serum Tg level and ultrasound findings postoperatively.

RESULTS

Incidental parathyroidectomy was more common in the BT group (29.6% vs 7.4%, p = 0.038). Patients in the BT group had higher risks of neuromuscular symptoms (63.0% vs 29.6%, P = 0.014) and transient hypoparathyroidism (70.4% vs 25.9%, P = 0.001). The incidence of persistent hypoparathyroidism failed to show a significant difference between the TP and BT groups (0 vs 14.8%, P = 0.111). However, those with transient hypoparathyroidism in the BT group had a lower level of serum PTH at 3 weeks postoperatively (p = 0.001). There was no significant difference in the number of lymph nodes dissected (5.89 ± 3.12 vs 8.56 ± 6.93, P = 0.077) and preablation sTg level (1.82 ± 2.18 vs 1.42 ± 1.56 ng/ml, P = 0.775) between the TP and BT groups. No metastatic lymph nodes were found on sonography at 3 months postoperatively in both groups.

CONCLUSION

Thymus preservation had benefits on protecting PGs and promoting rapid clinical resolution of hypoparathyroidism. It had no effects on oncologic completeness of TT with bilateral CLND.

Differentiated thyroid cancer theranostics: radioiodine and beyond

The term theranostics is the combination of a diagnostic tool that helps to define the right therapeutic tool for specific disease. It signifies the "we know which sites require treatment (diagnostic scan) and confirm that those sites have been treated (post-therapy scan)" demonstrating the achievable tumor dose concept. This term was first used by John Funkhouser at the beginning of the 90s, at the same time the concept of personalized medicine appeared. In nuclear medicine, theranostics is easy to apply and understand because of an easy switch from diagnosis to therapy with the same vector. It helps in maximizing tumor dose and sparing normal tissue with high specific and rapid uptake in metastasis. The oldest application of this concept is radioactive iodine I-131 (RAI). The first treatment based on the theranostic concept was performed on thyroid cancer patients with RAI in 1946. From then on management of differentiated thyroid cancer (DTC) has evolved on the multimodality concept. We now use the term "our" patient instead of "my" patient to signify this. However, the initial surgical management followed by RAI as per the theranostics has remained the mainstay in achieving a cure in most of DTC patients. The normal thyroid cells metabolise iodine, the principle of which is utilized in imaging of the thyroid gland with isotopes of iodine. RAI treatment of DTC is based on the principle of sodium iodide symporter (NIS) expressing thyroid cells with DTC cells having the ability of trapping circulating RAI successfully helping in treatment of residual and metastatic disease. NIS is usually negative in poorly differentiated cells and is inversely proportional to Glucose transporter receptor Type 1 expression. Both positive and negative NIS are the key components of the theranostic approach in treatment of DTC. Presence or absence of NIS is documented by either whole body iodine scintigraphy (WBS) or 2-deoxy-2(18F) fludeoxyglucose (FDG) positron emission tomography computed tomography (PET-CT). Currently, single photon emission CT and CT (SPECT-CT) has significantly improved the precision and sensitivity of whole body iodine scintigraphy with its capability of accurate localization of disease foci whether iodine avid or non-avid. This has helped in a more personalized approach in treatment. This review will give an overview of the role of NIS in the theranostic approach to management with RAI, its current status and also the molecular approach to treatment in RAI refractory disease.