Local lymph node recurrence after central neck dissection in papillary thyroid cancers: A meta analysis

The impact of intraoperative neural monitoring during papillary thyroid cancer surgery on completeness of thyroidectomy and thyroglobulin response: a propensity-score matched study

BACKGROUND

Intraoperative neural monitoring (IONM) has been utilized for a variety of thyroid pathologies, including papillary thyroid carcinoma (PTC). Remnant thyroid tissue following total thyroidectomy (TT) in patients with PTC is associated with increased recurrence. The aim of this study is to investigate whether the use of IONM in PTC surgery has an impact on the completeness of thyroidectomy.

METHODS

Retrospectively, patients with preoperative diagnosis of PTC, who underwent TT in a tertiary center were reviewed. They were grouped based on the IONM usage, and 1:1 propensity-score match was performed. Primary outcome was the completeness of thyroidectomy, determined by measuring postoperative stimulated thyroglobulin levels (sTg).

RESULTS

Among 274 clinically node-negative PTC patients who underwent TT and ipsilateral prophylactic central lymph-node dissection, a total of 170 patients (85:85) were matched. Postoperative sTg levels were significantly lower in the IONM group (1 ng/dL vs. 0.4 ng/dL; p < 0.01) with higher percentage of the patients with sTg levels <1 ng/ml (50.6% vs. 69.4%; p = 0.01). More patients in the no-IONM group received RAI ablation with significantly higher doses (mean mci: 120 vs. 102; p = 0.02).

CONCLUSION

The use of IONM during thyroidectomy provides improvement in the completeness of thyroidectomy and reduction in postoperative sTg levels which can be used as a guide by clinicians to avoid RAI ablation in selected PTC patients and to adjust low ablative doses in patients who are scheduled for remnant ablation.

Two Rare Cases of Metastatic Occult Thyroid Carcinoma Without Primary Cancer in the Thyroid Gland

Papillary thyroid cancer (PTC) contributes to the majority of all thyroid malignancies. In this case report, we detail two cases of occult thyroid carcinoma (OTC), which presents with thyroid metastasis to locoregional lymph nodes without having an initial primary tumor detected in the thyroid gland. OTC may be found incidentally on biopsy, surgery, or imaging. Advancements in diagnostic technology have allowed physicians to identify and treat OTC at an earlier stage. We present two patients who were found to have metastases to cervical lymph nodes without a primary identification in the thyroid gland. The first patient was a 67-year-old female who noticed an enlarging mass in her right neck at levels III and IV. Fine needle aspiration (FNA) revealed the presence of PTC. The patient underwent a total thyroidectomy, central nodal dissection, and right-modified radical neck dissection. Final pathology confirmed the presence of PTC metastasis to cervical lymph nodes, but no primary tumor was identified within the thyroid gland. The second patient was a 79-year-old male who presented with a painless mass of the left parotid gland. The FNA of the patient revealed PTC metastasis to his left parotid gland. The patient underwent a total thyroidectomy, ipsilateral central nodal dissection, ipsilateral modified radical neck dissection, and inferior superficial and deep lobe parotidectomy. No malignancy was detected within the thyroid gland or central or lateral neck lymph nodes on final pathology. Carcinoma was confined to an intra-parotid node in the deep lobe of the parotid gland. OTC is a rare phenomenon in PTC. One proposed theory for OTC includes spontaneous regression of the primary tumor and genetic mutations to the BRAF gene. Due to the fact that it is easy for this rare condition to be misdiagnosed, more studies should be conducted to standardize diagnostic and treatment plans for OTC.

Cervical lymph node metastasis prediction from papillary thyroid carcinoma US videos: a prospective multicenter study

BACKGROUND

Prediction of lymph node metastasis (LNM) is critical for individualized management of papillary thyroid carcinoma (PTC) patients to avoid unnecessary overtreatment as well as undesired under-treatment. Artificial intelligence (AI) trained by thyroid ultrasound (US) may improve prediction performance.

METHODS

From September 2017 to December 2018, patients with suspicious PTC from the first medical center of the Chinese PLA general hospital were retrospectively enrolled to pre-train the multi-scale, multi-frame, and dual-direction deep learning (MMD-DL) model. From January 2019 to July 2021, PTC patients from four different centers were prospectively enrolled to fine-tune and independently validate MMD-DL. Its diagnostic performance and auxiliary effect on radiologists were analyzed in terms of receiver operating characteristic (ROC) curves, areas under the ROC curve (AUC), accuracy, sensitivity, and specificity.

RESULTS

In total, 488 PTC patients were enrolled in the pre-training cohort, and 218 PTC patients were included for model fine-tuning (n = 109), internal test (n = 39), and external validation (n = 70). Diagnostic performances of MMD-DL achieved AUCs of 0.85 (95% CI: 0.73, 0.97) and 0.81 (95% CI: 0.73, 0.89) in the test and validation cohorts, respectively, and US radiologists significantly improved their average diagnostic accuracy (57% vs. 60%, P = 0.001) and sensitivity (62% vs. 65%, P < 0.001) by using the AI model for assistance.

CONCLUSIONS

The AI model using US videos can provide accurate and reproducible prediction of cervical lymph node metastasis in papillary thyroid carcinoma patients preoperatively, and it can be used as an effective assisting tool to improve diagnostic performance of US radiologists.

TRIAL REGISTRATION

We registered on the Chinese Clinical Trial Registry website with the number ChiCTR1900025592.

Role of computed tomography in the evaluation of regional metastasis in well-differentiated thyroid cancer

Background

Accurate neck staging is essential for performing appropriate surgery and avoiding undue morbidity in thyroid cancer. The modality of choice for evaluation is ultrasonography (US), which has limitations, particularly in the central compartment, that can be overcome by adding a computed tomography (CT).

Methods

A total of 314 nodal levels were analyzed in 43 patients with CT, and US; evaluations were done between January 2013 and November 2015. The images were reviewed by two radiologists independently who were blinded to histopathological outcomes. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of US, CT, and US + CT were calculated using histology as the gold standard.

Results

The overall sensitivity, specificity, PPV, and NPV for US, CT, and US + CT were 53.9%, 88.8%, 74.1%, and 76.4%; 81.2%, 68.0%, 60.1%, and 85.9%; and 84.6%, 66.0%, 59.6%, and 87.8%, respectively. The overall accuracy of the US was 75.80%, the CT scan was 72.93%, and the US + CT scan was 72.93%. For the lateral compartment, the sensitivity, specificity, PPV, and NPV for the US, CT, and US + CT were 56.6%, 91.4%, 77.1%, and 80.5%; 80.7%, 70.6%, 58.3%, and 87.8%; and 84.3%, 68.7%, 57.9%, and 89.6%, respectively. The accuracy of the US was 79.67%, the CT scan was 73.98%, and the US + CT scan was 73.98% for the lateral compartment. For the central compartment, the sensitivity, specificity, PPV, and NPV for the US, CT, and US + CT were 47.1%, 76.5%, 66.7%, and 59.1%; 82.4%, 55.9%, 65.1%, and 76.0%; and 85.3%, 52.9%, 64.4%, and 78.3%, respectively. The accuracy of the US was 61.76%, the CT scan was 69.12%, and the US + CT scan was 69.12% for the central compartment.

Conclusions

This study demonstrated that CT has higher sensitivity in detecting nodal metastasis; however, its role is complementary to US due to low specificity.

Prediction of Cervical Lymph Node Metastasis in Clinically Node-Negative T1 and T2 Papillary Thyroid Carcinoma Using Supervised Machine Learning Approach

Papillary thyroid carcinoma (PTC) is generally considered an indolent cancer. However, patients with cervical lymph node metastasis (LNM) have a higher risk of local recurrence. This study evaluated and compared four machine learning (ML)-based classifiers to predict the presence of cervical LNM in clinically node-negative (cN0) T1 and T2 PTC patients. The algorithm was developed using clinicopathological data from 288 patients who underwent total thyroidectomy and prophylactic central neck dissection, with sentinel lymph node biopsy performed to identify lateral LNM. The final ML classifier was selected based on the highest specificity and the lowest degree of overfitting while maintaining a sensitivity of 95%. Among the models evaluated, the k-Nearest Neighbor (k-NN) classifier was found to be the best fit, with an area under the receiver operating characteristic curve of 0.72, and sensitivity, specificity, positive and negative predictive values, F1 and F2 scores of 98%, 27%, 56%, 93%, 72%, and 85%, respectively. A web application based on a sensitivity-optimized kNN classifier was also created to predict the potential of cervical LNM, allowing users to explore and potentially build upon the model. These findings suggest that ML can improve the prediction of LNM in cN0 T1 and T2 PTC patients, thereby aiding in individual treatment planning.

Recent Advances in the Surgical Management of Thyroid Cancer

A growing incidence of differentiated thyroid cancer (DTC) has been reported in most developed countries, corresponding mainly to incidentally discovered small papillary thyroid carcinomas. Given the excellent prognosis of most patients with DTC, optimal therapeutic management, minimizing complications, and preserving patient quality of life are essential. Thyroid surgery has a central role in both the diagnosis, staging, and treatment of patients with DTC. Thyroid surgery should be integrated into the global and multidisciplinary management of patients with DTC. However, the optimal surgical management of DTC patients is still controversial. In this review article, we discuss the recent advances and current debates in DTC surgery, including preoperative molecular testing, risk stratification, the extent of thyroid surgery, innovative surgical tools, and new surgical approaches.

Modification and application of "zero-line" incision design in total endoscopic gasless unilateral axillary approach thyroidectomy: A preliminary report

Introduction

Gasless unilateral trans-axillary approach (GUA) thyroidectomy has witnessed rapid development in technologies and applications. However, the existence of surgical retractors and limited space would increase the difficulty of guaranteeing the visual field and disturb safe surgical manipulation. We aimed to develop a novel zero-line method for incision design to access optimal surgical manipulation and outcomes.

Methods

A total of 217 patients with thyroid cancer who underwent GUA were enrolled in the study. Patients were randomly classified into two groups (classical incision and zero-line incision), and their operative data were collected and reviewed.

Results

216 enrolled patients underwent and completed GUA; among them, 111 patients were classified into the classical group, and 105 patients were classified into the zero-line group, respectively. Demographic data, including age, gender, and the primary tumor side, were similar between the two groups. The duration of surgery in the classical group was longer (2.66 ± 0.68 h) than in the zero-line group (1.40 ± 0.47 h) (p < 0.001). The counts of central compartment lymph node dissection were higher in the zero-line group (5.03 ± 3.02 nodes) than that in the classical group (3.05 ± 2.68 nodes) (p < 0.001). The score of postoperative neck pain was lower in the zero-line group (1.0 ± 0.36) than that in the classical group (3.3 ± 0.54) (p < 0.05). The difference in cosmetic achievement was not statistically significant (p > 0.05).

Conclusion

The "zero-line" method for GUA surgery incision design was simple but effective for GUA surgery manipulation and worth promoting.

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.

Genetic Changes in Thyroid Cancers and the Importance of Their Preoperative Detection in Relation to the General Treatment and Determination of the Extent of Surgical Intervention—A Review

Carcinomas of the thyroid gland are some of the most common malignancies of the endocrine system. The causes of tumor transformation are genetic changes in genes encoding cell signaling pathways that lead to an imbalance between cell proliferation and apoptosis. Some mutations have been associated with increased tumor aggressiveness, metastatic lymph node spread, tendency to dedifferentiate, and/or reduced efficiency of radioiodine therapy. The main known genetic causes of thyroid cancer include point mutations in the BRAF, RAS, TERT, RET, and TP53 genes and the fusion genes RET/PTC, PAX8/PPAR-γ, and NTRK. Molecular genetic testing of the fine needle aspiration cytology of the thyroid tissue in the preoperative period or of the removed thyroid tissue in the postoperative period is becoming more and more common in selected institutions. Positive detection of genetic changes, thus, becomes a diagnostic and prognostic factor and a factor that determines the extent of the surgical and nonsurgical treatment. The findings of genetic research on thyroid cancer are now beginning to be applied to clinical practice. In preoperative molecular diagnostics, the aggressiveness of cancers with the most frequently occurring mutations is correlated with the extent of the planned surgical treatment (radicality of surgery, neck dissection, etc.). However, clear algorithms are not established for the majority of genetic alterations. This review aims to provide a basic overview of the findings of the most commonly occurring gene mutations in thyroid cancer and to discuss the current recommendations on the extent of surgical and biological treatment concerning preoperatively detected genetic changes.

A novel tool for predicting the risk of central lymph node metastasis in patients with papillary thyroid microcarcinoma: a retrospective cohort study

Introduction

Central lymph node status in papillary thyroid microcarcinoma (PTMC) plays an important role in treatment decision-making clinically, however, it is not easy to predict central lymph node metastasis (CLNM). The present work focused on finding the more rational alternative for evaluating central lymph node status while identifying influencing factors to construct a model to predict CLNM incidence.

Methods

In this study, we retrospectively analyzed the typical sonographic and clinicopathologic features of 546 PTMC patients who underwent surgery, among which, the data of 382 patients were recruited in the training cohort and that of 164 patients in the validation cohort. Based on the outcome of the training cohort, significant influencing factors were further identified through univariate analysis and were considered as independent variables in multivariable logistic regression analysis and incorporated in and presented with a nomogram.

Results

In total, six independent predictors, including the age, sex, tumor size, multifocality, capsular invasion, Hashimotos thyroiditis were entered into the nomogram. Both internal validation and external validation revealed the favorable discrimination of our as-constructed nomogram. Calibration curves exhibited high consistency. As suggested by decision-curve analyses, the as-constructed nomogram might be applied in clinic. Besides, the model also distinguished patients according to risk stratification.

Conclusions

The novel nomogram containing remarkable influencing factors for CLNM cases was established in the present work. The nomogram can assist clinicians in clinical decision-making.

Relationship between subgroups of central and lateral lymph node metastasis in clinically node-negative papillary thyroid carcinoma

BACKGROUND

Lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) has a certain regularity and occurs first to the central lymph node and then to the lateral lymph node. The pathway of PTC LNM can guide surgical prophylactic lymph node dissection (LND) for clinical surgeons.

AIM

To investigate the relationship between subgroups of central LNM and lateral LNM in unilateral clinically node-negative PTC (cN0-PTC).

METHODS

Data were collected for 1089 PTC patients who underwent surgical treatment at the Department of Endocrine and Breast Surgery of the First Hospital of Chongqing Medical University from January 2016 to December 2017. A total of 388 unilateral cN0-PTC patients met the inclusion criteria and were enrolled in this study. The clinical and pathological data for these 388 patients who underwent total thyroidectomy + central LND + lateral LND were retrospectively analyzed. The relationship between the central LNM and lateral LNM subgroups was investigated.

RESULTS

The coincidence rate of cN0-PTC was only 30.0%.Optimal scaling regression analysis showed that sex (57.1% vs 42.9%, P = 0.026), primary tumor size (68.8% vs 31.2%, P = 0.008), tumor location (59.7% vs 40.3%, P = 0.007), extrathyroid extension (ETE) (50.6% vs 49.9%, P = 0.046), and prelaryngeal LNM (57.1% vs 42.9%, P = 0.004) were significantly associated with ipsilateral level-II LNM. Their importance levels were 0.122, 0.213, 0.172, 0.110, and 0.227, respectively. Primary tumor size (74.6% vs 30.2%, P = 0.016), pretracheal LNM (67.5% vs 32.5%, P < 0.001), and paratracheal LNM (71.4% vs 28.6%, P < 0.001) were significantly associated with ipsilateral level-III LNM. Their importance levels were 0.120, 0.408, and 0.351, respectively. Primary tumor size (72.1% vs 27.9%, P = 0.003), ETE (70.4% vs 29.6%, P = 0.016), pretracheal LNM (68.3% vs 31.7%, P=0.001), and paratracheal LNM (80.8% vs 19.2%, P < 0.001) were significantly associated with ipsilateral level-IV LNM. Their importance levels were 0.164, 0.146, 0.216, and 0.472, respectively.

CONCLUSION

The LNM pathway of thyroid cancer has a certain regularity. For unilateral cN0-PTC patients with a tumor diameter > 2 cm and pretracheal or ipsilateral paratracheal LNM, LND at ipsilateral level III and level IV must be considered. When there is a tumor in the upper third of the thyroid with prelaryngeal LNM, LND at level II, level III and level IV must be considered.

Clinicopathologic predictors of central lymph node metastases in clinical node-negative papillary thyroid microcarcinoma: a systematic review and meta-analysis

Background

The presence of central lymph node metastases (CLNM) has been suggested as a risk factor for poorer prognosis and recurrence in papillary thyroid microcarcinoma (PTMC). However, the clinicopathologic factors for CLNM in clinical node-negative (CN0) PTMC were not well defined. This study aimed to perform a systematic review and meta-analysis to investigate the significant clinicopathologic predictors of CLNM in CN0 PTMC.

Methods

A systematic literature search was performed in PubMed, Embase, Cochrane Library, and Web of Science. Case-control studies on the association of clinicopathologic risk factors with CLNM in CN0 PTMC were included.

Results

Thirteen eligible studies involving 6068 patients with CN0 PTMC were included. From the pooled analyses, male (odds ratio [OR]: 2.07, 95% CI: 1.49–2.87, P < 0.001), multifocality (OR: 1.88, 95% CI: 1.54–2.29, P < 0.001), tumor size > 5 mm (OR: 1.84, 95% CI: 1.55–2.18, P < 0.001), and extrathyroidal extension (OR: 1.96, 95% CI: 1.30–2.95, P = 0.001) are significantly associated with increased risk of CLNM in CN0 PTMC. A sample size with a cutoff point of 200 was identified as the source of heterogeneity for sex according to meta-regression (t = 3.18, P = 0.033). Then, the subgroup analysis of male was performed, which illustrated that male increased the risk of CLNM in the small sample group (SG) and the large sample group (LG) by 6.11-folds and 2.01-folds, respectively (SG: OR, 6.11, 95% CI, 3.16–11.81, P < 0.001; LG: OR, 2.01, 95% CI, 1.65–2.46, P < 0.001).

Conclusions

Male, multifocality, tumor size > 5 mm, and extrathyroidal extension may be reliable clinical predictors of CLNM in CN0 PTMC. Moreover, prophylactic central lymph node dissection should be considered in surgical decision-making for CN0 PTMC patients, who are male, multifocal, with tumor size > 5 mm, and with extrathyroidal extension.

Trial registration

CRD42021242211 (PROSPERO)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02573-7.

Clinicopathological Findings Associated With Cervical Lymph Node Metastasis in Papillary Thyroid Microcarcinoma: A Retrospective Study in China

Objective

The incidence of papillary thyroid microcarcinoma (PTMC) has increased sharply during the past decades. Yet, whether or not nodal dissection should be performed remains controversial. This article aims to assess the high-risk factors associated with cervical lymph node metastasis (LNM) in patients with PTMC, which may potentially guide clinical management decision-making.

Methods

Medical records of 449 PTMC patients who underwent thyroidectomy in our hospital from August 2016 to July 2017 were retrospectively reviewed. Clinical and pathological factors of the patients were anonymously extracted from the charts and analyzed.

Result

The patients were classified into two subgroups according to maximum tumor size measured through post-surgical pathology: smaller PTMC group (≤5 mm) and larger PTMC group (>5 mm). Larger tumor size was found to be associated with a higher rate of LNM (P = .001), particularly central lymph node metastasis (CLNM) (P = .001). Tumor size was also associated with extrathyroidal tumor extension (ETE) (P < .001), bilateral lesions (P = .015), and BRAF^v600e mutation (P = .004). LNM was found to be more common in older patients (>55 y) (P = .030), and those with multifocal cancer (P < .001). In PTMC patients with unilateral lesions without ETE, tumor size was not significantly associated with LNM (P = .121).

Conclusions

For the PTMC population, tumor size was an independent risk factor for LNM, particularly for patients of old age (>55 y), and multifocality. However, in PTMC patients with unilateral lesions without extrathyroidal extension, tumor size was not related to the risk of LNM. These findings may potentially guide clinical decision-making in terms of cervical nodal dissection.

Establishing a Predictive Nomogram for Cervical Lymph Node Metastasis in Patients With Papillary Thyroid Carcinoma

Objectives

The purpose of this study was to establish a nomogram for predicting cervical lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC).

Materials and Methods

A total of 418 patients with papillary thyroid carcinoma undergoing total thyroidectomy with cervical lymph node dissection were enrolled in the retrospective study from January 2016 to September 2019. Univariate and multivariate Logistic regression analysis were performed to screen the clinicopathologic, laboratory and ultrasound (US) parameters influencing cervical lymph nodes metastasis and develop the predicting model.

Results

CLNM was proved in 34.4% (144/418) of patients. In the multivariate regression analysis, Male, Age < 45 years, Tumor size > 20mm, multifocality, ambiguous boundary, extracapsular invasion and US-suggested lymph nodes metastasis were independent risk factors of CLNM (p < 0.05). Prediction nomogram showed an excellent discriminative ability, with a C-index of 0.940 (95% confidence interval [CI], 0.888-0.991), and a good calibration.

Conclusion

The established nomogram showed a good prediction of CLNM in patients with PTC. It is conveniently used and should be considered in the determination of surgical procedures.

Prophylactic central neck dissection for well-differentiated thyroid carcinoma: results and methodological assessment of systematic reviews

OBJECTIVE

The aim was to assess the methodological quality of systematic reviews evaluating the effectivness of prophylactic central neck dissection plus thyroidectomy to decrease locoregional recurrence in patients with thyroid carcinoma.

INTRODUCTION

Many systematic reviews have been published concerning prophylactic central neck dissection in well-differentiated thyroid carcinoma, finding inconsistent results regarding the risk of locoregional recurrence. Because systematic reviews are considered the best source on which to base clinical decisions, the assessment of methodological quality is important.

INCLUSION CRITERIA

This paper included studies that mentioned that a systematic review was performed in adult patients with confirmed diagnosis of well-differentiated thyroid carcinoma without evidence of nodal metastatic disease who underwent total thyroidectomy. Reviews evaluated prophylactic central neck dissection compared with no neck diessection for decreasing locoregional recurrence.

METHODS

A systematic search was performed using MEDLINE, Embase, the Cochrane Database of Systematic Reviews, LILACS, Web of Science, CNKI, and Google Scholar. PROSPERO was searched for unpublished studies and gray literature. Data regarding the study characteristics, patient types, numbers of patients, and locoregional recurrence by group were extracted. Methodological characteristics, type of statistical analysis and summary estimator, heterogeneity, and publication bias were recorded. The methodological quality was measured using the AMSTAR 2 tool.

RESULTS

The search identified 12 systematic reviews. Only four systematic reviews reported adherence to methodological guidelines. The AMSTAR 2 critical criteria classified all the studies as critically low quality. The pooled risk difference for locoregional recurrence varied among studies from -5% to 0%. Most of the studies were published in high-impact journals.

CONCLUSIONS

The published systematic reviews that assessed prophylactic central neck dissection as an intervention to decrease the rate of locoregional recurrence have a critically low methodological quality. The results and recommendations based on these studies should be used with caution. The evaluation of methodological quality by peer reviewers must be improved.

Prevalence of Central Compartment Lymph Node Metastases in Papillary Thyroid Micro-Carcinoma: A Retrospective Evaluation of Predictive Preoperative Features

Simple Summary

The present study focused on patients affected by stage pT1a papillary thyroid micro-carcinomas that were treated with surgery and central lymph node dissection. In this study, male sex, low age, and sub-capsular carcinoma localization resulted as independent predictive factors for central lymph node metastases.

Abstract

Papillary thyroid micro-carcinomas are considered relatively indolent carcinomas, often occult and incidental, with good prognosis and favorable outcomes. Despite these findings, central lymph node metastases are common, and are related to a poor prognosis for the patient. We performed a retrospective analysis on patients treated with surgery for stage pT1a papillary thyroid micro-carcinomas. One hundred ninety-five patients were included in the analyses. The presence of central lymph node metastases was identified and studied. A multivariate analysis employing binary logistic regression was used to calculate adjusted odds ratios with 95% confidence intervals of possible central lymph node metastases risk factors. In the performed multivariate analysis, male gender, younger age, and histopathological characteristics, such as a tumor sub-capsular localization, were significantly associated with central lymph node metastases in pT1a patients. Central compartment lymph node metastases are present in a non-negligible number of cases in patients with papillary thyroid micro-carcinoma undergoing surgical resection. Studying these factors could be an effective tool for predicting patients’ central lymph node metastases in papillary thyroid micro-carcinomas, defining a tailored surgical treatment in the future.

Prophylactic Central Neck Dissection for Clinically Node-Negative Papillary Thyroid Carcinoma

OBJECTIVE

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) that scrutinized the oncological benefits and postsurgical complications of total thyroidectomy (TT) plus prophylactic central neck dissection (pCND) versus TT alone among clinically node-negative (cN0) papillary thyroid cancer (PTC) patients.

METHODS

We screened five databases from inception to September 4, 2021 and evaluated the risk of bias of the eligible studies. We pooled dichotomous outcomes using the risk ratio (RR) with 95% confidence interval (CI).

RESULTS

Overall, we included 5 RCTs with low risk of bias comprising 795 patients (TT plus pCND = 410 and TT alone = 385). With regard to efficacy endpoint, the rate of structural loco-regional recurrence did not significantly differ between both groups (n = 4 RCTs, RR = 0.49, 95% CI [0.19, 1.27], P = .14). With regard to safety endpoints, the rates of hypoparathyroidism (n = 5 RCTs, RR = 1.48, 95% CI [0.73, 2.97], P = .27), recurrent laryngeal nerve injury (n = 5 RCTs, RR = 1.34, 95% CI [0.59, 3.03], P = .48), and bleeding (n = 3 RCTs, RR = 1.75, 95% CI [0.42, 7.26], P = .44) did not significantly differ between both groups.

CONCLUSION

For cN0 PTC patients, there was no significant difference between TT plus pCND and TT alone with regard to the rate of structural loco-regional recurrence or frequency of postsurgical complications. Adaptation of pCND in cN0 PTC patients should be contemplated by taking into consideration the clinical oncological benefits and rate of postsurgical adverse events.

LEVEL OF EVIDENCE

1 Laryngoscope, 2021.

Risk Factors of Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma and the Value of Sentinel Lymph Node Biopsy

Objective: The present study aims to investigate the risk factors of central lymph node metastasis (CNM) in papillary thyroid microcarcinoma (PTMC) and evaluate the predictive value of sentinel lymph node biopsy (SLNB) during surgery.

Methods: The clinicopathological data of 179 patients with PTMC staging in cN0 and with SLNB performed were analyzed retrospectively. Positive sentinel lymph node ratio (PSLNR) and additional positive lymph node (APLN) were analyzed in cases with positive SLNB. The efficiency of SLNB was investigated. ROC curves were plotted to evaluate the predictive value of PSLNR for APLN.

Results: Cumulative maximum diameter of tumors (CMD) (P = 0.041) and capsule involvement (CI) (P = 0.014) were independent risk factors for central lymph node metastasis. The SLNB success rate was 97.28%, and the incidence of CNM was 31.28%. The sensitivity, specificity, false positive rate (FPR), false negative rate (FNR), positive predictive value (PPV), and negative predictive value (NPV) of SLNB to evaluate CNM and APLN were 82.14 vs. 61.54%, 100 vs. 80.39%, 0 vs. 19.61%, 17.86 vs. 38.46%, 100 vs. 34.78%, and 92.48 vs. 92.48%, respectively. For cases with positive SLNB, subgroup analysis was performed according to APLN. The PSLNRs of true and false positive groups were 0.4620 ± 0.1744 and 0.2425 ± 0.1355, respectively (P < 0.001). Analyzing the predictive value of PSLNR by the ROC curve, the optimal diagnostic cutoff point was 0.2917 [AUC = 0.861 (95% CI: 0.757, 0.966), P < 0.001], and the sensitivity, specificity, FPR, FNR, PPV, and NPV of PSLNR were 87.50, 73.33, 26.67, 12.50, 63.64, and 91.67%, respectively.

Conclusion: CMD and CI are independent risk factors for central lymph node metastasis in PTMC. SLNB has good predictive value for CNM. For cases with positive SLNB, PSLNR could be used to predict the presence of APLN, which may provide a theoretical basis for intraoperative lymph node dissection.

Management of the Neck in Well-Differentiated Thyroid Cancer

PURPOSE OF REVIEW

In this narrative review, we discuss the indications for elective and therapeutic neck dissections and the postoperative surveillance and treatment options for recurrent nodal disease in patients with well-differentiated thyroid cancer.

RECENT FINDINGS

Increased availability of advanced imaging modalities has led to an increased detection rate of previously occult nodal disease in thyroid cancer. Nodal metastases are more common in young patients, large primary tumors, specific genotypes, and certain histological types. While clinically evident nodal disease in the lateral neck compartments has a significant oncological impact, particularly in the older age group, microscopic metastases to the central or the lateral neck in well-differentiated thyroid cancer do not significantly affect outcome. As patients with clinically evident nodal disease are associated with worse outcomes, they should be treated surgically in order to reduce rates of regional recurrence and improve survival. The benefit of elective neck dissection remains unverified as the impact of microscopic disease on outcomes is not significant.

Prophylactic Central Lymph Node Dissection Improves Disease-Free Survival in Patients with Intermediate and High Risk Differentiated Thyroid Carcinoma: A Retrospective Analysis on 399 Patients

The role of prophylactic central lymph node dissection (pCLND) in the treatment of differentiated thyroid cancer (DTC) is controversial and still a matter of debate. The primary outcome of our study was to assess whether pCLND is effective in reducing the incidence of recurrent disease, and the secondary goal was to estimate the incidence of postoperative complications in patients who underwent pCLND and to evaluate the prognostic value of occult node metastases. In this retrospective study, we included patients with preoperative diagnosis of DTC and clinically uninvolved lymph nodes (cN0). The patients were divided into two groups, depending on the surgical approach: total thyroidectomy alone (TT group) or total thyroidectomy and pCLND (pCLND group). Three hundred and ninety-nine patients were included in this study, 320 (80.2%) in the TT group and 79 (19.8%) in the pCLND group. There were no significant differences in morbidity among the two groups. Histopathological evaluation demonstrated a similar distribution of aggressive features, especially regarding multicentricity, extrathyroidal extension, and angioinvasivity between the two groups. Occult lymph node metastases were found in 20 (25.3%) patients in the pCLND group. Prophylactic CLND was effective in improving disease-free survival in patients with intermediate and high risk of disease recurrence (p = 0.0392); occult lymph node metastases resulted as a significant negative prognostic factor (p < 0.001).

The effectiveness of prophylactic ipsilateral central neck dissection in selected patients who underwent total thyroidectomy for clinically node-negative unilateral papillary thyroid carcinoma

Background

Prophylactic central neck dissection (CND) in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) remains controversial. The purpose of this study was to evaluate the benefits of prophylactic ipsilateral CND compared with bilateral CND in total thyroidectomy for cN0 unilateral PTC.

Methods

We retrospectively enrolled 174 patients who underwent total thyroidectomies with prophylactic CND for cN0 unilateral PTC between January 2009 and May 2010. The prophylactic CND patients were divided into group 1, the ipsilateral CND group (n=74), and group 2, the bilateral CND group (n=100). The incidence of central lymph node metastasis (CLNM) and postoperative complications, such as hypoparathyroidism, recurrent laryngeal nerve injury, and recurrence were assessed.

Results

CLNM was found in 22 (29.8%) in group 1 and 69 (69%) in group 2. The incidence of postoperative severe hypocalcemia less than 7.0 was also significantly different (six patients [8.1%] in group 1 and 23 [23%] in group 2; p=0.009). Permanent hypoparathyroidism was significantly more frequent in group 2 (4.1% vs. 19%; p=0.005). However, the incidence of transient hypoparathyroidism, recurrence, and recurrent laryngeal nerve injury was not significantly different.

Conclusion

Prophylactic ipsilateral CND has advantage not only to reduce incidence of some complications but also to have similar recurrence rate compared with bilateral CND. We suggest that prophylactic ipsilateral CND may be safe and effective for selected patients undergoing total thyroidectomy for cN0 unilateral PTC.