Extent of prophylactic lymph node dissection in the central neck area of the patients with papillary thyroid carcinoma: comparison of limited versus comprehensive lymph node dissection in a 2-year safety study

Comparison of actual prognosis between unilateral and bilateral central neck dissection in modified radical neck dissection patients with no clinical central lymph node metastasis: a retrospective cohort study

Purpose

This study aimed to evaluate the long-term prognosis of contralateral central neck dissection (CND) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We compared the actual recurrence rate according to the extent of CND-ipsilateral and contralateral sides.

Methods

A total of 708 PTC patients who underwent total thyroidectomy and concomitant ipsilateral or bilateral CND with ipsilateral lateral neck dissection between January 1997 and December 2022 at Samsung Medical Center were retrospectively analyzed.

Results

The median follow-up time was 118 months. Locoregional recurrence was observed in 26 patients (7.9%) and 30 patients (7.9%) in the ipsilateral and bilateral CND groups, respectively. There were 6 contralateral recurrence cases (1.8%) in the ipsilateral CND group and 6 cases (1.6%) in the bilateral CND group. There was only 1 contralateral central neck recurrence in the ipsilateral CND group. The incidence of hypocalcemia (P = 0.007) was higher in the bilateral CND group compared to the ipsilateral CND group.

Conclusion

Surgeons may consider performing only unilateral CND-the side where tumor is for therapeutic purposes to reduce surgical complications.

Machine learning algorithms for identifying contralateral central lymph node metastasis in unilateral cN0 papillary thyroid cancer

Purpose

The incidence of thyroid cancer is growing fast and surgery is the most significant treatment of it. For patients with unilateral cN0 papillary thyroid cancer whether to dissect contralateral central lymph node is still under debating. Here, we aim to provide a machine learning based prediction model of contralateral central lymph node metastasis using demographic and clinical data.

Methods

2225 patients with unilateral cN0 papillary thyroid cancer from Wuhan Union Hospital were retrospectively studied. Clinical and pathological features were compared between patients with contralateral central lymph node metastasis and without. Six machine learning models were constructed based on these patients and compared using accuracy, sensitivity, specificity, area under the receiver operating characteristic and decision curve analysis. The selected models were then verified using data from Differentiated Thyroid Cancer in China study. All statistical analysis and model construction were performed by R software.

Results

Male, maximum diameter larger than 1cm, multifocality, ipsilateral central lymph node metastasis and younger than 50 years were independent risk factors of contralateral central lymph node metastasis. Random forest model performed better than others, and were verified in external validation cohort. A web calculator was constructed.

Conclusions

Gender, maximum diameter, multifocality, ipsilateral central lymph node metastasis and age should be considered for contralateral central lymph node dissection. The web calculator based on random forest model may be helpful in clinical decision.

Long-term impact of prophylactic central neck dissection in non-invasive classic papillary thyroid carcinoma

BACKGROUND

The utilization of prophylactic central neck dissection (pCND) in cases of non-invasive clinical node-negative (cN0) papillary thyroid carcinoma (PTC) remains a topic of debate, with a dearth of long-term evidence.

MATERIALS AND METHODS

We retrospectively reviewed 1181 cN0 PTC patients from 1997 to 2011. Of these, 641 underwent pCND (pCND + group) and 540 did not (pCND-group). Propensity score matching (PSM) was used to identify similar patients. Event-free survival and long-term complications including permanent hyperparathyroidism and permanent recurrent laryngeal nerve (RLN) paralysis were analyzed after PSM.

RESULTS

The pCND + group had more aggressive characteristics. In the matched cohort after PSM, the 5-year, 10-year, and 15-year EFS rates were 98.9 %, 98.2 %, and 97.1 % for the pCND + group, and 97.7 %, 97.1 %, and 97.1 % for the pCND-group, respectively. There was no statistically significant difference in EFS rates between the two groups (Log Rank P = 0.38). There was no statistically significant difference in the incidence of permanent hyperparathyroidism (3.3 % vs. 1.5 %, P = 0.08) and permanent RLN paralysis (1.7 % vs. 0.9 %, P = 0.13) between the pCND+ and pCND- groups.

CONCLUSION

Our study, with a median follow-up duration of 107 months, indicates that pCND does not lead to a significant reduction in nodal recurrence among non-invasive cN0 PTC patients.

Evaluation of the role of prophylactic bilateral central neck lymph node dissection in patients with papillary thyroid carcinoma: a case controlled study

Thyroid cancer is the most common malignancy in the endocrine system. Papillary thyroid carcinoma (PTC) is the most common differentiated thyroid cancer. There are considerable discrepancies regarding the role and extent of prophylactic central lymph node dissection (PCLND) for patients with PTC. Our primary goal was the evaluation of CLN involvement based on the tumor features and staging on the eight version of the American Joint Committee on Cancer and also the TNM method. Our secondary aim was to evaluate the features of the CLNs with tumoral features and also features associated with the development of transient hypoparathyroidism. This prospective case-controlled study was performed among PTC patients. Total thyroidectomy and bilateral dissection of the CLNs of the central compartment of the neck was performed, and samples were sent for pathological evaluation. CLN involvement, tumoral features and transient hypoparathyroidism were cross-evaluated and analyzed with SPSS version 26.0. In this study, out of 61 patients, 11 (18%) were male, the average age was 37.3 ± 13.7 years, based on AJCC staging, 53 (86.9%) were stage I and 8 (13.1%) were stage II, and based on TNM staging, 39 patients (66.1%) were T1, including 13 (22.0%) T1a and 26 (44.1%) T1b, 15 patients (25.4%) were T2, and five patients (8.5%) were T3. Based on permanent pathology evaluation, the majority of patients (n = 48; 78.7%) had CLN involvement. None of the preoperative and tumor features had a significant association with CLN involvement. 75% of stage I and 100% of stage two cases, while 76.9% of T1, 86.7% of T2, and 80.0% of T3 cases had CLN involvement. There was no significant association between the involvement of CLN and the AJCC staging (P = 0.184) or TNM staging (P = 0.875). The involved to dissected CLN ratio was significantly higher in stage II patients compared to stage I (72.5 vs. 34.8%; P = 0.006), and also with higher T staging (0.009). There was a statistically significant association between the larger CLN size and older patients' age, higher postoperative thyroglobulin levels, and smaller tumor size. Higher postoperative thyroglobulin level was significantly associated with larger tumors size and thyroid capsule invasion. Also, 26 (44.8%) of patients developed transient hypoparathyroidism, which was significantly associated with vascular invasion (P = 0.048), bilateral location of tumor (P = 0.048) or on the right side (0.005), and larger size of the tumor (P = 0.016). Tumor features and staging were not associated with CLN involvement features. Therefore, full extent PCLND should be carried out to avoid reoperation or metastasis in PTC patients.

Total thyroidectomy can be overtreatment in cN1a papillary thyroid carcinoma patients whose tumor is smaller than 1 cm

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines recommend pursuing total thyroidectomy with therapeutic central lymph-node dissection (CND) in patients with clinically apparent nodal disease (cN1a), regardless of tumor size. The aim of this study was to investigate whether total thyroidectomy is necessary for thyroid papillary microcarcinoma (PTMC) patients with preoperative unilateral cN1a.

METHODS

This study included 295 papillary thyroid microcarcinoma patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2015.

RESULTS

The median follow-up time was 42.5 months. Locoregional recurrence (LRR) was observed in only two (0.9%) patients. Among 70 cN1a patients, only 19 (27.1%) were at intermediate risk for disease recurrence and required total thyroidectomy per the ATA guidelines. Lobectomy can be considered as a treatment option for the remaining patients (72.9%).

CONCLUSIONS

Our study showed that more than two-thirds of PTMC patients with clinical nodal disease who underwent total thyroidectomy and CND were actually lobectomy candidates. Total thyroidectomy as the first surgical option for cN1a, especially in PTMC patients, should be reconsidered.

Analyze and compare the predictors of ipsilateral central lymph node metastasis in papillary thyroid carcinoma with cT1a and cT1b stage

PURPOSE

Central lymph node metastasis (CLNM) is common in papillary thyroid carcinoma (PTC). The aim of this study was to compare the cT1a and cT1b stages of PTC and to analyze the predictive factors of ipsilateral central lymph node metastasis (CLNM).

METHODS

In total, 212 PTC (cT1N0) patients underwent hemi-thyroidectomy with ipsilateral central lymph node dissection (CLND) between 2019 and 2020 in our hospital. Univariate and multivariate analyses identified the predictive factors for CLNM of PTC (cT1aN0 and cT1bN0), and compared the differences between the two stages.

RESULTS

The total rate of ipsilateral CLNM was 31.13% (66/212), and the ipsilateral CLNM rate in cT1b stage was higher than that in cT1a stage (48.84% vs. 26.63%), with significant differences (p = 0.005). cT1b stage was more prone to capsule invasion than cT1a stage (41.86% vs. 2.37%), with significant differences (p‹0.001). The multivariate analysis showed that tumor size (n > 5 mm) was an independent predictive factor for CLNM in cT1a stage (p = 0.002), with an odds ratio (OR) of 0.228 (95% confidence interval (95% CI): 0.079-0.655). Capsular invasion (p = 0.048) and tumors located in the middle and lower parts (p = 0.022) were independent predictive factors for CLNM in cT1b stage, with ORs of 0.157 (95% CI: 0.034-0.724) and 0.075 (95% CI: 0.007-0.847), respectively.

CONCLUSIONS

The rate of CLNM increases with increase of tumor size. Patients in cT1b stage are more prone to capsule invasion and CLNM. For the cT1b stage of PTC, predictive factors should be correctly evaluated to guide surgical treatment for PTC patients.

A Prediction Model for Contralateral Central Neck Lymph Node Metastases in Unilateral Papillary Thyroid Cancer

The health problems caused by the frequent relapse of papillary thyroid carcinoma (PTC) remain a worldwide concern since the morbidity rate of PTC ranks the highest among thyroid cancers. Residues from contralateral central lymph node metastases (con-CLNM) are the key reason for persistence or recurrence of unilateral papillary thyroid carcinoma (uni-PTC); however, the ability to assess the status of con-CLNM in uni-PTC patients is limited. To clarify the risk factors of con-CLNM, a total of 250 patients with uni-PTC who underwent total thyroidectomy and bilateral central lymph node dissection were recruited in this study. We compared the clinical, sonographic, and pathological characteristics of patients with con-CLNM to those without con-CLNM and established a nomogram for con-CLNM in uni-PTC. We found that male sex, without Hashimoto's thyroiditis, present capsular invasion, with ipsilateral lateral lymph node metastases, and the ratio of ipsilateral central lymph node metastases ≥0.16 were independent con-CLNM predictors of uni-PTC (ORs: 2.797, 0.430, 2.538, 2.202, and 26.588; 95% CIs: 1.182-6.617, 0.211-0.876, 1.223-5.267, 1.064-4.557, and 7.596-93.069, respectively). Additionally, a preoperative nomogram for the prediction of con-CLNM based on these risk factors showed good discrimination (C-index 0.881; 95% CI: 0.840-0.923; sensitivity 85.3%; specificity 76.0%) and good agreement via the calibration plot. Our study provided a way to quantitatively and accurately predict whether con-CLNM occurred in patients with uni-PTC, which may guide surgeons to evaluate the nodal status and perform tailored therapeutic central lymph node dissection.

High-risk factors for lymph node metastasis in contralateral central compartment in unilateral papillary thyroid carcinoma（cT1N0）

OBJECTIVE

The incidence of papillary thyroid carcinoma (PTC) increases yearly. Central lymph node metastasis (CLNM) is common in PTC. Many studies have addressed ipsilateral CLNM; however, few studies have evaluated contralateral CLNM. The purpose of this study is to investigate the high-risk factors of lymph node metastasis in the contralateral central compartment of cT1 stage in PTC.

METHODS

In total, 369 unilateral PTC (cT1N0) patients who underwent total-thyroidectomy with bilateral central lymph node dissection (CLND) between 2013 and 2016 in our hospital were retrospectively enrolled. Univariate and multivariate analyses identified the high-risk factors for contralateral CLNM of PTC.

RESULTS

The total metastasis rate of the ipsilateral central neck compartment was 31.71% (117/369). The total metastasis rate of the contralateral central neck compartment was 8.13% (30/369). The multivariate analysis showed that multifocality (p = 0.009), ipsilateral CLNM (p＜0.001), number of ipsilateral CLNM ＞2 (p = 0.006), tumor located at the inferior pole (p = 0.032) and tumor diameter ＞ 1 cm (p = 0.029) were independent risk factors for contralateral CLNM at cT1 stage in PTC, with odds ratios (ORs) of,4.132 (95% confidence intervals (CI): 1.430-11.936) ，8.591 (95% CI: 3.200-23.061) ，0.174 (95% CI: 0.050-0.601) ，0.353 (95% CI: 0.136-0.917)and 0.235 (95% CI: 0.064-0863), respectively.

CONCLUSION

The combinational use of these risk factors will help surgeons devise an appropriate surgical plan preoperatively. This information could provide reference for the readers who are interested and help to determine the optimal extent of CLND in patients with PTC, especially for cT1b patients.

Quality Indicators of Central Compartment Neck Dissection in Thyroid Surgery

OBJECTIVES

Quality metrics are an increasingly important means of improving patient care. Variability in the number of lymph nodes removed during central compartment lymph node dissection (CCLND) at the time of thyroidectomy has not been studied.

STUDY DESIGN

A retrospective cohort study was performed using American College of Surgeons National Quality Improvement Program (ACS-NSQIP) data.

SETTING

Centers in North America and worldwide contributing data to ACS-NSQIP and performing thyroidectomy on adults in inpatient and outpatient settings were included.

SUBJECTS AND METHODS

Adult patients undergoing thyroidectomy with or without CCLND were included. Outcomes of interest were number of nodes removed during CCLND and risks of postoperative hypocalcemia.

RESULTS

In total, 6108 patients met inclusion criteria (1565 with CCLND). The median number of lymph nodes removed during CCLND was 2. There was no statistically significant association between postoperative hypocalcemia and CCNLD, regardless of number of nodes removed. However, we were underpowered to detect this association based on the overall low nodal yield of many CCLNDs performed.

CONCLUSION

In many cases where CCLND is documented as part of thyroidectomy, very few lymph nodes are removed. Our ability to draw conclusions regarding the effect of CCLND on postoperative hypocalcemia is restricted due to the limited nature of many CCLNDs performed.

Central Compartment Nodal Bulk: A Predictor of Permanent Postoperative Hypocalcaemia

Central compartment clearance (CCC) for Papillary thyroid cancers (PTC) is one of the factors causing postoperative hypocalcaemia. We aimed to examine determinants of this major sequela. 41 patients treated for PTCs between 2014 and 2016 were studied. Surgical details, tumour and nodal characteristics, incidence of transient, temporary and permanent hypocalcaemia were noted. Central clearance was done bilaterally in 24 (58.5%) cases, ipsilaterally in 17 (41.6%). Central nodes were involved in 26 (63.4%) cases, unilaterally in 15 (36.6%), bilaterally in 11 (26.8%). Transient hypocalcaemia developed in 10 (24.4%) cases, temporary hypocalcaemia in 6 (14.6%) cases, and permanent hypocalcaemia in 2 (4.9%) cases. 17 (41%) patients were symptomatic. 9 (21.9%) patients received intravenous calcium. The only factor consistently associated with development of hypocalcaemia of all patterns, was the presence of matted central compartment nodes (p = 0.021). Matted nodes also related to a longer length of stay (p = 0.04) and requirement of intravenous calcium (p = 0.000). Extent of CCC, nodal yield, nodal positivity, perinodal extension, number of parathyroids identified, gender or pT size were not significantly associated. Symptomatic patients did not necessarily become permanently hypocalcaemic (p = 0.8). Patients requiring intravenous calcium were more likely to take oral calcium after discharge (p = 0.002). Postoperative hypocalcaemia is more likely in cases with bulky involved central nodes where extensive clearance is done. In routine CCC, even if done bilaterally, preservation of parathyroid function is possible. Permanent hypocalcaemia after CCC need not be taken as inevitable.

The extent of lymph node yield in central neck dissection can be affected by preoperative and intraoperative assessment and alter the prognosis of papillary thyroid carcinoma

Background

Lymph node yield (LNY) was implemented in the stratification of papillary thyroid cancer (PTC) patients. The effect of LNY may be related to the extent of surgery. This study aims to identify influencing factors for LNY in central compartment neck dissection (CND).

Methods

Data of 13 712 consecutive PTC patients were analyzed retrospectively. Risk factors for LNY in CND and distribution characteristics of LNY were evaluated. Its relationship with prognosis was studied in another cohort of 136 cases.

Results

LNY in therapeutic CND was significantly higher than prophylactic CND (Unilateral: 5.55 ± 3.79 vs 3.41 ± 2.77; Bilateral: 8.90 ± 5.10 vs 6.47 ± 4.17, P < .001). Other independent factors included extranodal extension (ETE), tumor size, and concurrent Hashimoto's thyroiditis. The inconsistency distribution of LNY in bilateral CND was associated with preoperative and intraoperative assessment. Patients with significant difference between major and minor LNY suffered from poorer prognosis (10y‐RFS: 58.3% vs 92.0%; HR = 6.719, 95%, P < .0001).

Conclusions

CND surgical procedure, ETE, and Hashimoto's thyroiditis were independent factors of LNY. Inconsistent distribution of LNY was associated with prognosis of bilateral PTC patients. The impact of preoperative and intraoperative assessment on the actual extent of CND can be used to explain the relationship between LNY and PTC prognosis.

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

BACKGROUND

Prophylactic central neck dissection (CND) at the time of total thyroidectomy (TT) remains controversial in clinically node-negative (cN0) papillary thyroid carcinoma (PTC). This systematic review and meta-analysis was performed to compare the local recurrence between patients who underwent TT plus CND and those who underwent TT alone.

METHODS

The publicly available literature published from January 1990 to October 2017 concerning TT plus prophylactic CND versus TT for PTC was retrieved by searching the national and international online databases. Meta-analysis was performed after the data extraction process.

RESULTS

Twenty-five studies with comparison between TT+CND and TT alone were eligible and included in this meta-analysis. For both PTC and papillary thyroid microcarcinoma (PTMC), the overall recurrence in TT+CND group was significantly lower than that in TT alone group. The central compartment recurrence was significantly higher in TT alone group than TT+CND group (OR=3.41, 95% Cl [2.00∼5.80], P<0.00001), while no significant difference of lateral compartment recurrence was observed between the two groups (OR=1.19, 95%Cl [0.81∼1.77], P=0.38). We compared ipsilateral CND+TT with TT alone and found that the recurrence was not significantly different between the two groups (OR=1.44, 95%Cl [0.74∼2.81], P=0.28). On the other hand, bilateral CND+TT showed significantly low recurrence (OR=2.48, 95%Cl [1.75∼3.53], P<0.00001).

CONCLUSIONS

The addition of CND to TT resulted in a greater reduction in risk of local recurrence than TT alone, especially preventing central neck recurrences. Additionally, we discovered that bilateral CND in patients with PTC>1cm was necessary.

Randomized trial of prophylactic ipsilateral central lymph node dissection in patients with clinically node negative papillary thyroid microcarcinoma

PURPOSE

This study aimed to evaluate the role of prophylactic ipsilateral central neck dissection (pCND) in patients with clinically node-negative (cN0) papillary thyroid microcarcinoma (PTMC).

METHODS

In this randomized control trial, a total of 164 consecutive patients were enrolled. By double-blinded randomization protocol, patients were allocated into hemithyroidectomy with pCND (n = 82) or without pCND (n = 82). With intention-to-treat analysis, post-surgical pathological and clinical course, surgery-related complications, causes and clinical course of protocol-violated cases and 5-year recurrence-free survival were compared.

RESULTS

Operation time, hospital stay, and post-surgical complication were not significantly different between the two groups. In the pCND (+) group, occult lymph node metastasis rate was 50.0%, and lymph node ratio (metastatic/harvested lymph nodes) was 45.2%. Ten patients in the pCND (+) group had converted to undergo onsite or staged completion total thyroidectomy due to the presence of metastatic central lymph nodes and/or positive resection margin. Until last follow-up (mean 73.4 months), one regional recurrence developed in the pCND (-) group, and three regional recurrences occurred in the pCND (+) group. Five-year recurrence-free survival was similar between the two groups.

CONCLUSION

Although ipsilateral pCND could clear occult lymph node metastasis in the central compartment, it failed to provide any oncological benefit for cN0 PTMC patients.

Fluorescence imaging-guided robotic thyroidectomy and central lymph node dissection

BACKGROUND

The purpose of this study was to evaluate the feasibility of complete central compartment node dissection (CCND) using fluorescence imaging (FI) during robotic thyroidectomy.

METHODS

A total of 110 patients underwent robotic thyroidectomy and CCND from August 2015 to June 2016; 55 patients underwent robotic surgery using FI (FI group) and the other 55 patients without it (control group). The FI group was injected with indocyanine green into the thyroid to enhance the identification of lymph nodes (LNs).

RESULTS

Indocyanine green-stained LNs were easily detected using FI. The number of harvested LNs was 7.0 in the FI group and 4.8 in the control group (P = 0.004). There was lower rate of transient hypocalcemia in the FI group (18.5%) than control group (26.7%), but there was no significant difference (P = 0.417). There were no other significant differences between the two groups.

CONCLUSIONS

The use of FI during robotic thyroidectomy facilitated the identification of LNs and guided complete CCND.

Rationality in prophylactic central neck dissection in clinically node-negative (cN0) papillary thyroid carcinoma: Is there anything more to say? A decade experience in a single-center

AIM

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Despite its extremely favorable prognosis, cervical lymph node metastases are a common feature of PTC and a known independent risk factor for local recurrence. However, the role of prophylactic central neck dissection (PCND) remains a matter of debate in patients with clinically node-negative (cN0) PTC. To better clarify the current role of PCND in the surgical treatment of PTC, evaluating advantages and disadvantages of PCND and outcome of cN0 PTC patients who have been treated with either total thyroidectomy alone or in combination with PCND. A review of recent literature data is performed.

METHODS

Between January 2000 and December 2015, 186 consecutive patients with cN0 PTC were identified to be included in the present study. 74 of these underwent total thyroidectomy associated with PCND, while 112 patients underwent total thyroidectomy alone. The epidemiological and clinical-pathological data of all patients included were collected at diagnosis and during follow-up.

RESULTS

Overall complication rate was significantly higher in the group of patients undergoing PCND (39.2% vs. 17.8%, p = 0.0006). To be specific, they presented a considerably increased risk of temporary recurrent laryngeal nerve injury (p = 0.009) and of permanent hypothyroidism (p = 0.016). Overall survival and recurrence rates did not differ between those undergoing PCND and those undergoing total thyroidectomy alone (p = 1.000 and p = 0.715, respectively).

CONCLUSIONS

The results of the present study do not support the routine use of PCND in the treatment of cN0 PTC patients.

A nomogram predicting contralateral central neck lymph node metastasis for papillary thyroid carcinoma

BACKGROUND AND OBJECTIVES

Central compartment neck dissection (CCND) is recommended for patients with papillary thyroid carcinoma (PTC). However, whether to perform contralateral CCND remains unclear. An individualized estimation of the contralateral central neck metastasis (CNM) risk would assist in the tailoring of treatment for PTC patients.

METHODS

Consecutive patients who underwent bilateral CCND for unilateral PTC between 2012 and 2014 in a tertiary center were identified. The clinicopathological data of 142 patients were analyzed retrospectively. The variables that had clinical significance in the final multivariate logistic regression model were built into a nomogram to assess the risk of metastasis of the contralateral central compartment. This model was internally validated using bootstrap resampling.

RESULTS

This nomogram demonstrated good calibration and discrimination, with a concordance index of 0.834 (bootstrap corrected, 0.824). The variables with the greatest influence on the risk of contralateral CNM in this model included tumor size, the number of positive lymph nodes, and extranodal extension in the ipsilateral central neck.

CONCLUSIONS

This nomogram integrates three variables to estimate an individualized risk of contralateral CNM in unilateral PTC patients. This model may assist in individual decision-making regarding contralateral CCND and help avoid the over- and under-treatment of PTC. J. Surg. Oncol. 2016;114:703-707. © 2016 Wiley Periodicals, Inc.

Prophylactic "First-Step" Central Neck Dissection (Level 6) Does Not Increase Morbidity After (Total) Thyroidectomy

BACKGROUND

In terms of morbidity, prophylactic central neck dissection (CND; level 6) in potentially malignant thyroid disease is discussed controversially. The rates of (transient and permanent) hypoparathyroidism and palsy of the recurrent laryngeal nerve (RLN) after "first-step" (FS-)CND are analyzed in this study.

METHODS

Bilateral and unilateral FSCND, i.e., lymph node dissection along the RLN before (total) thyroidectomy, was performed bilaterally in 68 (group 1) and unilaterally in 44 patients (group 2), respectively. The rates of hypoparathyroidism and palsy of the RLN were documented prospectively and were compared to 237 patients of group 3 (controls) who underwent (total) thyroidectomy only.

RESULTS

Fifteen of 68 patients (22 %) of group 1 developed transient and one patient had permanent hypoparathyroidism. Transient unilateral palsy of the RLN was observed in ten patients (15 %); none were permanent. Transient hypoparathyroidism was monitored in 10 of 44 patients (23 %) of group 2 and permanent hypoparathyroidism in 1 (2 %). Six patients (14 %) developed temporary palsy of the RLN; one remained permanent. Palsy was seen in 3 patients on the contralateral side of unilateral FSCND. Transient and permanent hypoparathyroidism was observed in 50 (21 %) and 2 (1 %) of 237 controls. Transient palsy of the RLN was documented in 22 (9 %) of 237 controls and permanent palsy of the RLN in 4 (2 %).

CONCLUSIONS

In this single-center series, the overall permanent morbidity was low (1 %). Therefore, FSCND may be recommended (even prophylactically) for experienced high-volume surgeons in patients with thyroid nodules suspicious for malignancy.

Optimal Cut-Off Values of Lymph Node Ratio Predicting Recurrence in Papillary Thyroid Cancer

Regional lymph node (LN) metastasis has a significant impact for prediction of recurrence in patients with papillary thyroid cancers (PTC); however, the prognostic value of the lymph node ratio (LNR), which is defined as the ratio of the number of metastatic LNs to the total number of investigated LNs, is controversial. In this study, we determined the optimal cut-off values of LNRs for the prediction of recurrence in PTC patients.This large cohort study retrospectively evaluated 2294 patients who had undergone total thyroidectomy for PTC at a single institution from October 1985 to June 2009. The prediction probability of central LNR (cLNR, level VI) and total LNR (tLNR, levels II-VI) were estimated by binominal logistic regression analysis. Hazard ratios of the cut-off LNR values for cancer recurrence were calculated for relevant covariates using multivariate Cox regression analyses. Kaplan-Meier analyses were also utilized to assess the effects of estimated LNR cut-off values on recurrence-free survival (RFS).Of the 2294 patients, 138 (6.0%) presented cancer recurrence during the follow-up period (median duration = 107.1 months). The prediction probability indicated that LNRs of 0.4 and 0.5 for central LN and total LN, respectively, are optimal cut-off values for precise prediction with minimization of outliers. Multivariate Cox regression analyses revealed that cLNR ≥0.4 was independently predictive of recurrence in patients with N0 and N1a PTCs (hazard ratio [HR]: 7.016, 95% confidence interval [CI]: 3.72-12.986, P < 0.001) and that tLNR ≥0.5 indicated a significantly increased risk of recurrence in patients with N1b PTCs (HR: 2.372, 95% CI: 1.458-3.860, P < 0.001). In addition, Kaplan-Meier analyses clearly demonstrated that these LNR cut-off values are precisely operational in RFS estimation.The cut-off LNR values of 0.4 and 0.5 for cLNR and tLNR, respectively, were identified. Risk stratification combined with these LNR cut-off values may prove useful to determine treatment and follow-up strategies for PTC patients.

Quantification of lymph nodes in the central compartment of the neck: a cadaveric study

Differentiated thyroid cancer (DTC) accounts for over 90 % of thyroid malignancies, and is frequently associated with central neck compartment nodal metastasis that requires a therapeutic central compartment neck dissection (CCND) for clinically evident nodes. Current knowledge on the expected lymph node yield from a CCND is limited, compared with data on the lateral neck. The aim of our study was to accurately quantify nodal yield from the cadaveric central neck compartment. Twenty-eight cadaveric necks were dissected and the central neck compartment was subdivided into four regions: pre-laryngeal (delphian), pre-tracheal, right and left para-tracheal regions. Each cadaver had a thyroid gland, which was also removed, and the CCND tissue in each compartment was processed and examined by a consultant histopathologist. Only lymphoid tissue with a defined microscopic fibrous capsule and subcapsular sinus was included in the node count. The median total lymph node count per cadaver was four (range 1-16), with a median of one node detectable in each para-tracheal region (range 0-7) and the pre-tracheal region (range 0-8). The median pre-laryngeal node count was 0 (range 0- 2). The average lymph node size across all compartments was 2.9 mm. This is the first European study to assess cadaveric central neck lymph nodes and establish baseline counts for nodal yield. If a prophylactic or therapeutic CCND is required during thyroid surgery, those involved in DTC management must recognise that there is a wide range, and low median yield of central neck compartment lymph nodes.

Surgical morbidity of cervical lymphadenectomy for thyroid cancer: A retrospective cohort study over 25 years

INTRODUCTION

Prognosis of thyroid cancer is strictly related to loco-regional metastases. Cervical lymphadenectomy has a specific oncologic role but may lead to significant increase of morbidity. Aim of the study is the analysis of surgical morbidity in cervical lymphadenectomy for thyroid cancer.

METHODS

We retrospectively analyzed 1.765 thyroid cancers operated over a period of 25 years at S. Maria University Hospital, Terni, University of Perugia, Italy. Type of lymphadenectomy, histology and complications were analysed.

RESULTS

A prevalence of differentiated and medullary cancers was observed (respectively 88% and 7.2%). Central lymphadenectomy was carried out in 425 patients, lateral modified and radical lymphadenectomy respectively in 651 and 17 cases. Following central neck dissection we observed: bilateral and unilateral temporary recurrent nerves palsy respectively of 0.7% and 3.5%, unilateral permanent palsy in 1.6% of cases, temporary and permanent hypoparathyroidism respectively in 17.6% and 4.4%. After lateral neck dissection we observed: intra and post-operative haemorrhage respectively in 2% and 0.29%, respiratory distress in 0.29%, lesions of facial nerve in 0.44%, of vagus in 0.14%, of phrenic nerve in 0.14%, of hypoglossal nerve in 0.29%, of the accessory nerve, transient in 1.34% and permanent in 0.29%, permanent lesion of cervical plexus in 0.29%, salivary fistula in 0.14% and chylous fistula in 1.04% of patients. Student's t test was used to compare groups when appliable.

CONCLUSION

Central and lateral cervical lymph node dissection are associated to severe morbidity. Correct indication, surgical expertise, high volume of patients and early multidisciplinary management of complications is the key of an acceptable balance between oncologic benefits and surgical morbidity.

The clinical prognosis of patients with cN0 papillary thyroid microcarcinoma by central neck dissection

BACKGROUND

Central lymph node metastasis of papillary thyroid microcarcinoma (PTMC) is common; however, prophylactic central lymph node dissection (CLND) is still controversial because of the possible increased morbidity. The purpose of this study is to determine the clinical outcome of patients with cN0 PTMC by central neck dissection.

METHODS

A retrospective cohort study was conducted on patients with PTMC without preoperative evidence of lymph node disease (cN0), and the outcomes were compared between patients undergoing total thyroidectomy (TT) alone (group A) and patients undergoing TT with CLND (group B).

RESULTS

In this study, 242 patients with cN0 PTMC were included. Group A had 108 patients and group B had 134 patients. During a follow-up of over 60 months, the long-term postoperative complications were equivalent between the two groups. In group B, the presence of involved central neck lymph nodes upstaged 16% of patients to stage III disease, which necessitated additional postoperative radioactive iodine treatment. More patients had recurrences in group A. The rate of reoperation in the central compartment was higher in group A than in group B (8.3% vs 2.2%, P < 0.01).

CONCLUSIONS

Prophylactic CLND does not increase long-term postoperative complications and reduces the risk of recurrence in the central compartment.

Predictive factors of contralateral paratracheal lymph node metastasis in unilateral papillary thyroid carcinoma

BACKGROUND

Most of unilateral papillary thyroid carcinoma (PTC) metastasize to ipsilateral paratracheal lymph nodes (LNs) while some had contralateral paratracheal LN involved. The aim of this study was to analyze the predictive factors of contralateral paratracheal LN metastasis in unilateral PTC.

METHODS

Data on 332 patients with unilateral PTC who underwent total/near total thyroidectomy and bilateral central neck dissection (CND) with/without lateral neck dissection were collected retrospectively. Patients' demographics, the extent of surgeries, and the pathological status of LNs and primary tumor were analyzed.

RESULTS

A total of 332 patients (67 male and 265 female) were included. Contralateral paratracheal LN metastasis was found in 68 (68/332, 20.5%) patients. Tumor size (>1 cm) (P < .001), capsular/extracapsular invasion (P < .001), pretracheal/prelaryngeal LN metastasis (P < .001), lateral neck LN metastasis (P < .001) and ipsilateral paratracheal LN metastasis (P < .001) was significantly associated with contralateral paratracheal LN metastasis on univariate analysis. Multivariate analysis showed that tumor size (>1 cm) (P = .013), capsular/extracapsular invasion (P = .009), pretracheal/prelaryngeal LN metastasis (P = .021) and lateral neck LN metastasis (P = .002) were independent risk factors of contralateral paratracheal LN metastasis.

CONCLUSION

Primary tumor size >1 cm, capsular/extracapsular invasion, pretracheal/prelaryngeal LN metastasis and lateral neck LN metastasis are predictive factors of contralateral paratracheal LN metastasis in unilateral PTC, which may help to determine the optimal extent of CND in patients with PTC.

The role of carbon nanoparticles in identifying lymph nodes and preserving parathyroid in total endoscopic surgery of thyroid carcinoma

AIM

To evaluate the efficacy of carbon nanoparticles (CNs) in identifying lymph nodes and preserving parathyroids in endoscopic total thyroidectomy (ETT) with central neck dissection (CND), and to further explore the role of CNs in recovering postoperative parathyroid function.

METHOD

Fifty-five patients with papillary thyroid carcinoma were randomized to either CN group (n = 28) or control group (n = 27). The primary outcome measures were pathological results (e.g., amount of incidental removed parathyroids and lymph nodes dissected) and follow-up results [e.g., recovery of serum calcium and parathyroid hormone (PTH) levels]. The secondary end-points were the rates of neuromuscular symptoms, in-hospital postoperative hormonal assay, and lymph node metastases.

RESULTS

A total of 193 lymph nodes in the CN group and 123 lymph nodes in the control group were detected. The mean number of detected lymph nodes was significantly higher in the CN group than in the control group (P = 0.009). Parathyroids were present in the thyroid or central nodal specimens of five patients, which were all in the control group. The control group had a relatively higher incidence of incidental parathyroidectomy compared to the CN group (P = 0.023). Compared to the CN group, the incidence of paresthesia was higher in the control group even if not statistically significant. During follow-up, the serum calcium levels were higher in the CN group than in the control group; however, there was no statistically significant difference. For the serum PTH levels, the CN group recovered rapidly to the preoperative levels, whereas the control group climbed steadily to the normal range. The serum PTH levels in the CN group were apparently higher than in the control group at 1 week and 1 month postoperatively.

CONCLUSION

CNs play an important role in protecting parathyroid glands, dissecting lymph nodes thoroughly, and promoting rapid recovery of parathyroid in ETT with CND (ChiCTR-TRC-14005042).

The total number of prelaryngeal and pretracheal lymph node metastases: is it a reliable predictor of contralateral central lymph node metastasis in papillary thyroid carcinoma?

BACKGROUND

Central lymph node (CLN) metastasis in papillary thyroid carcinoma (PTC) is common and being able to predict CLN metastasis helps surgeons determine individualized therapy. However, the relationship between contralateral CLN metastasis and the total number of positive lymph nodes (LNs) in the combined prelaryngeal and pretracheal region remains unclear. This study aimed to investigate whether the total number of positive LNs in the combined prelaryngeal and pretracheal region has clinical significance as a predictor for contralateral CLN metastasis.

METHODS

We prospectively enrolled 153 consecutive patients with unifocal PTC >1.0 cm without ultrasonographic evidence of nodal metastasis who underwent total thyroidectomy and prophylactic bilateral CLN dissection from July 2011-May 2013. Patients were divided into three groups according to the total number of positive LNs in the combined prelaryngeal and pretracheal region.

RESULTS

Rates of metastasis to ipsilateral and contralateral central compartments in PTC >1.0 cm were 84.3% and 24.2%, respectively. Multivariate analysis showed that ≥3 positive LNs in the combined prelaryngeal and pretracheal region were an independent predictive factor of contralateral CLN metastasis (P < 0.001; odds ratio, 8.585). After a mean follow-up of 24.1 mo, none of these patients had a recurrence in the central or lateral compartment.

CONCLUSIONS

Occult metastasis is highly prevalent in the ipsilateral central neck of patients with PTC >1.0 cm, and the total number of prelaryngeal and pretracheal LNs metastases may be a useful indicator to predict contralateral CLN metastasis in patients with unifocal PTC.

Ipsilateral Central Neck Dissection Plus Frozen Section Examination Versus Prophylactic Bilateral Central Neck Dissection in cN0 Papillary Thyroid Carcinoma

BACKGROUND

Ipsilateral central compartment node dissection (IpsiCCD) can reduce the morbidity of prophylactic bilateral central compartment node dissection (BilCCD) in papillary thyroid carcinoma (PTC) but it carries the risk of contralateral metastases being overlooked. Frozen section examination (FSE) of removed ipsilateral nodes has been proposed to intraoperatively assess nodal status. We compared IpsiCCD plus FSE and BilCCD in clinically unifocal and node negative PTC.

METHODS

One hundred patients were prospectively assigned to undergo total thyroidectomy (TT) plus BilCCD or TT plus IpsiCCD. In the IpsiCCD group, removed lymph nodes were sent for FSE. If FSE was positive for metastases, a BilCCD was accomplished.

RESULTS

The two groups included 50 patients each. Overall, occult lymph node metastases were found in 41 patients-20 in the IpsiCCD group and 21 in the BilCCD group. FSE correctly identified occult node metastases in 13 of 20 pN1a patients in the IpsiCCD group (overall accuracy 86 %). Seven node metastases were not detected at FSE-five were micrometastases (≤2 mm). Six of 13 patients in the IpsiCCD group who underwent BilCCD and 6 of 21 BilCCD pN1a patients had bilateral metastases. More patients in the BilCCD group showed transient hypocalcemia (27/50 vs. 18/50, respectively) [p = NS]. No patient experienced recurrent disease.

CONCLUSIONS

FSE of ipsilateral nodes is accurate in determining nodal status, allowing the extension of the central neck clearance to be reliably modulated. Routine IpsiCCD plus FSE of the ipsilateral nodes could be a valid alternative to prophylactic BilCCD since it allows accurate staging and may reduce morbidity.

Effectiveness of preventative and other surgical measures on hypocalcemia following bilateral thyroid surgery: a systematic review and meta-analysis

BACKGROUND

A variety of measures have been proposed to reduce the incidence of post-thyroidectomy hypocalcemia. The aim of this study was to perform a systematic review and meta-analysis of preventive and other surgical measures on post-thyroidectomy hypocalcemia as reported in the literature.

METHODS

Comprehensive searches of the PubMed, EMBASE, and Cochrane databases were performed, and the quality of included papers was assessed using the Cochrane risk of bias tool or a modified Newcastle-Ottawa Scale (NOS). The results of all included studies were summarized, and meta-analyses were performed where appropriate.

RESULTS

Thirty-nine randomized controlled trials (RCTs) and 37 observational studies were included. Measures studied included hemostatic techniques, extent of thyroidectomy and central neck dissection, surgical approach, calcium/vitamin D/thiazide diuretic supplements, parathyroid gland autotransplantation (PGAT) and intraoperative parathyroid gland (PG) identification, truncal ligation of inferior thyroid artery (ITA), preoperative magnesium infusion, and use of magnification loupes and Surgicel. Measures associated with significantly lower rates of transient hypocalcemia in meta-analysis were postoperative calcium and vitamin D supplementation compared to either calcium supplements alone (odds ratio (OR) 0.66; p=0.04) or no supplements (OR 0.34; p=0.007), and bilateral subtotal thyroidectomy (BST) compared to Hartley Dunhill (HD) procedure (OR 0.35; p=0.01). Meta-analyses did not demonstrate any measure to be significantly associated with a reduction in permanent hypocalcemia.

CONCLUSION

This review identified postoperative calcium and vitamin D supplementation and bilateral subtotal thyroidectomy (over HD) as being effective in prevention of transient hypocalcemia. However, the majority of RCTs were of low quality, primarily due to a lack of blinding. The wide variability in study design, definitions of hypocalcemia, and methods of assessment prevented meaningful summation of results for permanent hypocalcemia.

Routine prophylactic central neck dissection for low-risk papillary thyroid cancer is not cost-effective

BACKGROUND

The role of routine prophylactic central neck dissection (CND) in papillary thyroid cancer (PTC) remains controversial. The aim of this study was to evaluate the cost utility of the addition of routine CND in patients with low-risk PTC compared with total thyroidectomy (TT) alone.

METHODS

A Markov model for low-risk PTC was constructed with a treatment algorithm based on the American Thyroid Association guidelines for well-differentiated thyroid carcinoma. Utilities and outcome probabilities were derived from published medical literature. US 2010 costs were examined from a society perspective using Medicare reimbursement rates and opportunity loss based on published US government data. Monte Carlo simulation and sensitivity analysis were used to examine the uncertainty of probability, cost and utility estimates.

RESULTS

Initial TT alone is more cost-effective than TT with CND, resulting in a cost savings of US $5763 per patient with slightly higher effectiveness per patient (0·03 QALY) for a cost savings of $285 per QALY. Sensitivity analysis shows that TT alone offers no advantage when radioactive iodine (RAI) becomes more detrimental to a patient's state of health, when the incidence of non-neck recurrence increases above 5% in patients undergoing TT alone or decreases below 3·9% in patients undergoing TT with CND or when the rate of permanent hypocalcaemia rises above 4%.

CONCLUSIONS

TT with CND is not a cost-effective strategy in low-risk PTC. Initial TT alone is favourable because of the low complication rates and low recurrence rates associated with the initial surgery. Alternative strategies such as unilateral prophylactic neck dissection require additional study to assess their cost-effectiveness.

Total thyroidectomy without prophylactic central neck dissection in clinically node-negative papillary thyroid cancer: is it an adequate treatment?

Background

Cervical lymph node metastases in papillary thyroid cancer are common. Although central neck dissection is indicated in clinically nodal-positive disease, it remains controversial in patients with no clinical evidence of nodal metastasis. The aim of this retrospective study was to determine the outcomes of clinically lymph node-negative patients with papillary thyroid cancer who underwent total thyroidectomy without a central neck dissection, in order to determine the rates of recurrence and reoperation in these patients compared with a group of patients submitted to total thyroidectomy with central neck dissection.

Methods

Two-hundred and eighty-five patients undergoing total thyroidectomy with preoperative diagnosis of papillary thyroid cancer, in the absence of suspicious nodes, were divided in two groups: those who underwent a thyroidectomy only (group A; n = 220) and those who also received a central neck dissection (group B; n = 65).

Results

Six cases (2.1%) of nodal recurrence were observed: 4 in group A and 2 in group B. Tumor histology was associated with risk of recurrence: Hürthle cell-variant and tall cell-variant carcinomas were associated with a high risk of recurrence. Multifocality and extrathyroidal invasion also presented a higher risk, while smaller tumors were at lower risk.

Conclusions

The role of prophylactic central lymph node dissection in the management of papillary thyroid cancer remains controversial. Total thyroidectomy appears to be an adequate treatment for clinically node-negative papillary thyroid cancer. Prophylactic central neck dissection could be considered for the more appropriate selection of patients for radioiodine treatment and should be reserved for high-risk patients only. No clinical or pathological factors are able to predict with any certainty the presence of nodal metastasis. In our experience, tumor size, some histological types, multifocality, and locoregional infiltration are related to an increased risk of recurrence. The potential use of molecular markers will hopefully offer a further strategy to stratify the risk of recurrence in patients with papillary thyroid cancer and allow a more tailored approach to offer prophylactic central neck dissection to patients with the greatest benefit. Multi-institutional larger studies with longer follow-up periods are necessary to draw definitive conclusions.

Prophylactic central compartment neck dissection for papillary thyroid cancer

Prophylactic central compartment neck dissection (pCCND) is a CCND in patients with thyroid cancer who have no clinical, sonographic, or intraoperative evidence of abnormal lymph nodes. Whether pCCND should be performed in all patients with clinically node-negative papillary thyroid cancer (PTC) is controversial. Existing data reveal that for patients with clinically node-negative PTC there is no difference between treatment with total thyroidectomy plus pCCND and total thyroidectomy alone. The potential increased risk of hypoparathyroidism associated with CCND is not offset by any measurable oncologic benefit. Risk/benefit balance favors total thyroidectomy alone for patients with clinically node-negative PTC.

Predictive Factors of Contralateral Paratracheal Lymph Node Metastasis in Papillary Thyroid Cancer

Objective

To analyze patterns of central lymph node (LN) metastasis to specific compartments in the neck and predictive factors of contralateral paratracheal LN metastasis in patients who underwent prophylactic bilateral central LN dissection for papillary thyroid cancer (PTC).

Study Design

Prospective study.

Setting

Multitertiary centers.

Subjects and Methods

One hundred forty consecutive patients underwent total thyroidectomy and prophylactic bilateral central LN dissection for unilateral PTC without evidence of central LN metastatic disease based on preoperative ultrasound imaging. The central LN compartment was divided into prelaryngeal, ipsilateral/contralateral paratracheal, and pretracheal regions. The patterns of central LN metastasis and clinicopathologic variables for predicting contralateral metastasis were analyzed.

Results

Fifty-one (36.4%) of 140 patients had nodal involvement in the central compartment. Twelve (23.5%) patients had ipsilateral paratracheal LN metastasis, 17 (33.3%) had ipsilateral paratracheal and pretracheal LN metastasis, 14 (27.5%) had bilateral paratracheal LN metastasis, 9 (17.6%) had pretracheal-only LN metastasis, and 8 (15.7%) had prelaryngeal LN metastasis. Ipsilateral paratracheal LN metastasis was found to independently predict contralateral paratracheal LN metastasis in patients without central LN metastatic disease.

Conclusions

Contralateral paratracheal LN metastasis is associated with ipsilateral paratracheal LN metastasis. This information may help to determine the optimal extent of prophylactic central LN dissection in patients with PTC.

Risk factors and clinical indication of metastasis to lymph nodes posterior to right recurrent laryngeal nerve in papillary thyroid carcinoma: a single-center study in China

BACKGROUND

Lymph nodes posterior to right recurrent laryngeal nerve (PRRLN) may be frequently overlooked during central compartment dissection (CCD) for papillary thyroid carcinoma (PTC). The purpose of this study was to investigate risk factors of lymph node PRRLN metastasis in right-sided PTC, thereby to identify the indications for lymph node PRRLN dissection.

METHODS

We conducted a retrospective study of patients with right-sided PTC who underwent a thyroidectomy plus lymph node PRRLN dissection during ipsilateral CCD.

RESULTS

Overall, 108 patients (26.7%) had lymph node PRRLN metastases, including 26 (6.4%) who presented with solely lymph node PRRLN positivity. Factors of extrathyroidal extension, multifocality, larger tumor (≥1 cm), level VIa positivity (p < .0001 for each), and lateral compartments positivity (p = .0002) significantly predicted lymph node PRRLN metastasis in right-sided PTC.

CONCLUSION

Lymph node PRRLN should be routinely explored during CCD because of the possibility of only involvement in PTC. Factors of tumors larger than 1 cm, multifocality, and extrathyroidal extension were independent predictors of lymph node PRRLN metastasis in right-sided PTC, and suggested the clinical indications of lymph node PRRLN dissection.

Total thyroidectomy, without prophylactic central lymph node dissection, in the treatment of differentiated thyroid cancer. Clinical retrospective study on 221 cases

Total thyroidectomy (TT) is the standard of care for differentiated thyroid cancer (DTC), but still there is no consensus about the role of routine use of prophylactic central lymph node dissection. The aim of this study was to analyze our results of TT without prophylactic central lymphadenectomy in the treatment of DTC. Clinical records, between January 1998 and December 2005, of 221 patients undergoing TT, without prophylactic central lymph node dissection, were retrospectively evaluated. Two hundred and eleven patients (95.47 %) also underwent radioiodine (RAI) ablation followed by thyroid stimulating hormone (TSH) suppression therapy. In patients with loco-regional lymph nodal recurrence, lateral and central lymph node dissection was performed. The incidence of permanent hypoparathyroidism (iPTH <10 pg/ml) and permanent vocal fold paralysis were, respectively, 0.91 and 0.91 %. After a 9.6 ± 3.5 years mean follow-up, the rate of loco-regional recurrence, with positive cervical lymph nodes, was 3.16 % (7/221 patients). In these cases a lateral and central lymphadenectomy was carried out without significant complications. Our results showed that TT without prophylactic central lymph node dissection, followed by RAI ablation, was associated with low morbidity and low loco-regional recurrence rate, even if the lack of a control group treated with TT plus prophylactic central lymphadenectomy suggests caution against generalization of our assumption. Such last combined procedure could be indicated in high-risk patients, in whom loco-regional recurrence is more frequent. However, given the trend in the literature toward prophylactic lymphadenectomy and the avoidance of RAI treatment, prospective randomized trials should be conducted to better clarify this issue.

Differentiated thyroid cancer: indications and extent of central neck dissection--our experience

The aim of this retrospective study was to determine the rate of metastases in the central neck compartment and examine the morbidity and rate of recurrence in patients with differentiated thyroid cancer treated with or without a central neck dissection. Two hundred and fifteen patients undergoing total thyroidectomy with preoperative diagnosis of differentiated thyroid cancer, in the absence of suspicious nodes, were divided in two groups: those who underwent a thyroidectomy only (group A; n = 169) and those who also received a central neck dissection (group B; n = 46). Five cases (2.32%) of nodal recurrence were observed: 3 in group A and 2 in group B. Tumor histology was associated with a risk of recurrence: Hürthle cell-variant and tall cell-variant carcinomas were associated with a high risk of recurrence. Multifocality and extrathyroidal invasion also presented a higher risk, while smaller tumors were at lower risk. The results of this study suggest that prophylactic central neck dissection should be reserved for high-risk patients only. A wider use of immunocytochemical and genetic markers to improve preoperative diagnosis and the development of methods for the intraoperative identification of metastatic lymph nodes will be useful in the future for the improved selection of patients for central neck dissections.

Predictive factors for different subgroups of central lymph node metastasis in unilateral papillary thyroid carcinoma

AIMS

We aimed to investigate the incidence rates and risk factors for different subgroups of central neck lymph node (LN) metastasis (prelaryngeal, ipsilateral paratracheal, pretracheal, and contralateral paratracheal) in unilateral papillary thyroid carcinoma (PTC) patients with clinically negative neck nodes (cN0).

METHODS

We evaluated 184 patients from 2007 to 2009. The relationships between different subgroups of LN metastasis and clinical pathological factors were analyzed.

RESULTS

The incidence rates of different central LN metastases were diverse. Multivariate analysis indicated that lymphovascular invasion, perithyroidal invasion, and tumor size were risk factors for ipsilateral paratracheal central LN metastasis; tumor size was an independent risk factor for pretracheal central LN metastasis, and pretracheal or/and ipsilateral paratracheal central LN metastasis were risk factors for contralateral paratracheal central LN metastasis.

CONCLUSION

The extent of elective central LN dissection (CLND) should be decided based on different clinical pathological factors in cN0 PTC patients. Moreover, elective prelaryngeal CLND may be unnecessary.

A meta-analysis of the effect of prophylactic central compartment neck dissection on locoregional recurrence rates in patients with papillary thyroid cancer

BACKGROUND

It is not known whether prophylactic central compartment neck dissection (pCCND) in conjunction with total thyroidectomy decreases rates of locoregional recurrence in patients with papillary thyroid cancer (PTC).

METHODS

A meta-analysis was performed of reported recurrence rates of clinically node-negative PTC in patients treated with total thyroidectomy (TT) alone, or TT and pCCND. The primary outcome was locoregional recurrence of PTC.

RESULTS

Eleven studies capturing 2,318 patients met the inclusion criteria. Overall, the recurrence rate for patients undergoing TT/pCCND was 3.8 % [95 % confidence interval (CI) 2.3-5.8]. In the six comparative studies, which included 1,740 patients, 995 patients undergoing TT and 745 patients undergoing TT/pCCND, the overall recurrence rate was 7.6:7.9 % in the TT group and 4.7 % in the TT/pCCND group. The relative risk of recurrence was 0.59 (95 % CI 0.33-1.07), favoring a lower recurrence rate in the TT/pCCND arm. The number of patients that would need to be treated (NNT) in order to prevent a single recurrence is 31. The relative risk for permanent hypocalcemia was 1.82 (95 % CI 0.51-6.5) and for permanent recurrent laryngeal nerve injury was 1.14 (95 % CI 0.46-2.83).

CONCLUSIONS

There was no difference in recurrence or long-term complication rates between patients undergoing TT or TT/pCCND. There was a trend toward lower recurrence rates in TT/pCCND patients, with a NNT of 31 patients. On the basis of these data, routine pCCND might be considered in the hands of high-volume surgeons treating patients with clinically node-negative PTC.

Clinical analysis of prophylactic central neck dissection for papillary thyroid carcinoma

Purpose

The need of prophylactic central neck dissection (PCND) in patients with papillary thyroid carcinoma (PTC) is still controversial. The major restriction of PCND is the potential complications. We undertook a retrospective study to discuss its necessity in PTC patients.

Methods

A total of 188 patients with PTC who underwent total thyroidectomy and PCND were involved. In all of these, central lymph nodes were pathologic examined. Univariate and multivariate analyses were performed based on tumor location and size, etc.

Results

Overall, node metastases were found in 44.1 % (83/188) of patients. Tumor size was the independent positive predictor for lymph node metastasis, while gender, age, tumor multifocality, tumor location, and capsular infiltration were not independent predictors of central lymph node metastases. Postoperative complications happened in 5.3 % (10/188) of patients, which 4.8 % (9/188) had temporary hypocalcemia and 0 % (0/188) had permanent hypocalcemia. Rates of temporary and permanent recurrent laryngeal nerve injury were 0.5 % (1/188) and 0 % (0/188), respectively.

Conclusions

PCND is recommended in all patients with PTC.

Experience and analysis of Delphian lymph node metastasis in patients with papillary thyroid carcinoma

Background

Recently, lymph node metastasis (LNM) has been regarded as an important factor influencing loco-regional recurrence and survival rate in papillary thyroid cancer (PTC) patients. The aims of this study were to investigate the detection rate and metastasis rate of the Delphian lymph node (DLN) and clinical patterns related to regional LNM, and to examine how DLN metastasis affects PTC treatment.

Methods

We reviewed the medical records of 413 patients with pathologically confirmed PTC from among 452 patients who underwent thyroid surgery between January 2010 and October 2010 in the Department of Endocrine Surgery at Kosin University Gospel Hospital in Busan, South Korea.

Results

Multivariate analyses revealed a significantly higher proportion of cases with lymphovascular invasion (56.6% vs. 12.5%, P <0.001), central neck node metastasis (88.6% vs. 34.5%, P <0.001) and lateral neck node metastasis (47.2% vs. 10.2%, P <0.005) among cases with DLN metastasis compared to those without. The negative predictive value (NPV) of DLN metastasis with regard to the presence of contralateral central LNM for cases with a tumor size 1 cm or smaller than 1 cm was found to be 93.3% (127/136).

Conclusion

When DLN metastasis is not detected in papillary thyroid microcarcinomas (PTMC), thyroid lobectomy on the affected side and ipsilateral central neck lymph node dissection should be sufficient. In addition, even in cases where lateral neck LNM is not detected on preoperative examination, if DLN metastasis is detected postoperatively, more careful attention should be paid to the lateral neck nodes during follow-up.

Complications of central neck dissection in patients with papillary thyroid carcinoma: results of a study on 1087 patients and review of the literature

BACKGROUND

Prophylactic central neck dissection (CND) has been proposed in the treatment of patients affected by papillary thyroid carcinoma (PTC) with clinically negative neck lymph nodes. The procedure allows pathologic staging of lymph nodes of the central compartment and treatment of the micrometastases. Nevertheless, the morbidity that its routine use adds to the total thyroidectomy must be taken into account. The aim of this study was to characterize the morbidity that CND adds to the total thyroidectomy.

METHODS

This was a retrospective study of 1087 patients with PTC and clinically negative neck lymph nodes. Patients were divided into three study groups: Group A, total thyroidectomy; Group B, total thyroidectomy and ipsilateral CND; Group C, total thyroidectomy and bilateral CND. Primary endpoints of the study were evaluated by comparing the rates of transient and permanent recurrent laryngeal nerve (RLN) injury and hypoparathyroidism in the three study groups.

RESULTS

Analysis of data showed no significant differences in the rate of transient (Group A: 3.6%, Group B: 3.9%, and Group C: 5.5%; p=0.404) and permanent (Group A: 1%, Group B: 0.5%, and Group C: 2.3%; p=0.099) RLN injury between the three study groups. Both ipsilateral CND and bilateral CND were associated with a higher rate of transient hypoparathyroidism (Group: A 27.7%, Group B: 36.1%, and Group C: 51.9%; p=0.014; odds ratio [OR]: 1.477; 95% confidence interval [CI]: 1.091-2.001; p<0.001; OR: 2.827; 95% CI: 2.065-3.870, respectively). Bilateral CND had a higher rate of permanent hypoparathyroidism (Group A: 6.3%, Group B: 7%, and Group C: 16.2%; p<0.001; OR: 2.860; 95% CI: 1.725-4.743).

CONCLUSIONS

The increased rates of transient and permanent hypoparathyroidism in our series suggest a critical review of indications for the routine use of prophylactic CND for PTC. Prophylactic CND ipsilateral to the tumor associated with total thyroidectomy may represent an effective strategy for reducing the rate of permanent hypoparathyroidism. Concomitant completion contralateral paratracheal lymph node neck dissection should be performed in presence of lymph node metastasis on intraoperative frozen-section pathology. This approach limits the use of bilateral CND to patients with intraoperative pathological findings of lymph node metastases.

Central cervical lymph node metastases in papillary thyroid cancer: a systematic review of imaging-guided and prophylactic removal of the central compartment

BACKGROUND

Papillary thyroid cancer (PTC) is a common endocrine cancer and commonly presents with lymph node (LN) metastases. The role of surgical removal of the central cervical LN compartment is poorly defined. There are no prospective randomized controlled trials addressing the relevance to the extent of the initial surgical approach.

DESIGN AND METHODS

A systematic review of studies of patients with PTC undergoing either prophylactic or therapeutic lymphadenectomy of the central LNs was carried out. Studies involving imaging modalities in the detection of LNs in PTC were also analysed.

RESULTS

Twenty-one studies contained data on 4188 patients undergoing prophylactic or imaging-guided removal of the central compartment. Imaging-guided surgery retrieved cancerous central LNs in 346 or 30% of eligible patients, whilst prophylactic central neck dissection yielded histopathological proof of cancer in 898 or 26·2% of patients. Five imaging studies revealed data on the use of ultrasound (US) and/or computerized tomography (CT). The sensitivity of US and CT was poor, ranging from 50% to 70% when accurately calculated.

CONCLUSION

Metastatic central LNs are found in nearly half of all patients with PTC when prophylactic central lymph node dissection (CLND) is performed. With unreliable imaging modalities, prophylactic CLND should be performed on all patients with PTC.

Pattern and risk factors of central compartment lymph node metastasis in papillary thyroid cancer: a prospective study from an endocrine surgery centre

Lymphatic metastasis in papillary thyroid cancer (PTC) is eminent; however, the extent of central compartment lymph nodes dissection (CCD) is controversial and requires the knowledge of pattern and risk factors for central compartment lymph nodes metastasis (CCM). We did a prospective study of 47 cases with PTC who underwent total thyroidectomy (TT) with CCD with/without lateral lymph nodes dissection (LND). Clinicopathological profile including CCM as ipsilateral and contralateral was documented. On histopathology, the mean tumour size was 3.57 ± 2.42 cm 59.6% had CCM, which was bilateral in the majority (60.72%). The tumour-size was the most important predictor for lymph nodes metastasis-(P=0.018) whereas multicentricity-(P=0.002) and ipsilateral CCM-(P=0.001) were the predictors for contralateral CCM. The long-term morbidity of CCD done in primary setting is comparable with TT-alone. Bilateral CCD should be done with thyroidectomy in PTC, otherwise the risk of residual diseases and subsequent recurrence is high. The long-term morbidity is comparable in experienced hands.

The role of prophylactic central neck dissection in differentiated thyroid carcinoma: issues and controversies

Prophylactic central neck dissection (pCND) in differentiated thyroid carcinoma (DTC) is one of the most controversial surgical subjects in recent times. To date, there is little evidence to support the practice of pCND in patients with DTC undergoing total thyroidectomy. Although the recently revised American Thyroid Association (ATA) guideline has clarified many inconsistencies regarding pCND and has recommended pCND in “high-risk” patients, many issues and controversies surrounding the subject of pCND in DTC remain. The recent literature has revealed an insignificant trend toward lower recurrence rate in patients with DTC who undergo total thyroidectomy and pCND than those who undergo total thyroidectomy alone. However, this was subjected to biases, and there are concerns whether pCND should be performed by all surgeons who manage DTC because of increased surgical morbodity. Performing a unilateral pCND may be better than a bilateral pCND given its lower surgical morbidity. Further studies in this controversial subject are much needed.