Routine level VI lymph node dissection for papillary thyroid cancer: surgical technique

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.

Lymph Node Posterior to the Right Recurrent Laryngeal Nerve Metastasis in Right Lobe T1a Papillary Thyroid Carcinoma: A Retrospective Cohort Study

INTRODUCTION AND OBJECTIVES

This study analyzed the incidence and predictors of lymph node posterior to the right recurrent laryngeal nerve metastasis in T1a papillary thyroid carcinoma of the right lobe.

METHODS

This was a retrospective cohort study. Patients were selected from those who had received surgical treatment for primary papillary thyroid carcinoma between January 2019 and December 2020. The association between clinicopathologic variables and lymph node posterior to the right recurrent laryngeal nerve metastasis was assessed using univariate and multivariate analyses. Postoperative complications were also described.

RESULTS

Lymph node posterior to the right recurrent laryngeal nerve metastasis was present in 6.0% of the 402 study patients. It was the most likely to occur when there were other lymph node metastases, particularly in the lymph node anterior to the recurrent laryngeal nerve. Independent predictors for lymph node posterior to the right recurrent laryngeal nerve metastasis were a tumor size of ≥5.0 mm, a lower pole location, and lymph node anterior to the right recurrent laryngeal nerve metastasis. The rate of persistent vocal cord paralysis was .5%, and no patient developed permanent hypoparathyroidism.

CONCLUSIONS

Although lymph node posterior to the right recurrent laryngeal nerve metastases of the right lobe T1a papillary thyroid carcinoma is uncommon, the possibility of metastasis should be investigated when there is a positive lymph node anterior to the right recurrent laryngeal nerve in a tumor >5.0 mm in size located in the lower pole. Lymph node posterior to the right recurrent laryngeal nerve dissection is recommended for such tumors.

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.

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.

The localization of thyroid cancers on the thyroid gland is a new risk factor for metastases of perithyroidal, peritracheal and central lymph nodes

OBJECTIVE

Lymph node metastasis is frequently detected in differentiated thyroid cancers. Central dissection is performed to the lymph nodes in patients with microscopic metastases in the intraoperative evaluation. Other indications for central dissections are tumor size and cervical lateral lymph node metastasis. We consider that the localization of thyroid cancer in the thyroid lodge may be another risk factor for central lymph node metastasis. For this reason, the purpose of the present study was to investigate the relations between thyroid cancer localization and lymph node metastasis in differentiated thyroid cancer patients who had no preoperative cervical metastases and who underwent total thyroidectomy, and peritracheal, perithyroidal, and central lymph node dissection.

METHOD

A total of 213 differentiated thyroid cancer cases followed in our general surgery and endocrinology clinic between September 2016 and May 2020 were evaluated retrospectively. Based on the data in the files, the patients who underwent total thyroidectomy, and central, perithyroidal, and peritracheal lymph node dissection were included in the study. The patients were divided into four Groups according to tumor localizations, those with tumors adjacent to the trachea (Group 1), upper thyroid pole (Group 2), thyroid middle part (Group 3), thyroid inferior (Group 4). The demographic characteristics, laboratory parameters, cancer types, and lymph node metastasis rates of the Groups were evaluated.

RESULTS

A total of 84% (179) of the cases had thyroid papillary cancer, 11.73% (25) had thyroid follicular cancer, and 4.2% (9) had poorly differentiated thyroid cancer. The mean age of all patients was found to be 49 ± 8.3 years, and the female/male ratio was 2.4. It was found that the differentiated thyroid cancers metastasized to the perithyroidal, peritracheal, and central lymph nodes at a rate of 57.74%. The distribution of these metastases according to the Groups was; 62.85% in Group 1, 11.53% in Group 2, 43.9% in Group 3, and 88.57% in Group 4. It was also found that 80.32% of the papillary cancer cases and 57.14% of the follicular cancer cases metastasized to central (level VI) lymph nodes in Group 4.

CONCLUSION

The localization of differentiated thyroid cancers is a new risk factor for perithyroidal metastases.

Clinical advantages and neuroprotective effects of monitor guided fang's capillary fascia preservation right RLN dissection technique

OBJECTIVE

To investigate the feasibility and advantages of Fang's capillary fascia preservation right recurrent laryngeal nerve (RLN) dissection technique (F-R-RLN dissection) with preservation of the capillary network and fascia between the RLN and common carotid artery for greater neuroprotective efficiency compared with traditional techniques.

METHODS

We retrospectively analyzed 102 patients with papillary thyroid carcinoma undergoing right level VI lymph node dissection in our department from March 2021 to January 2022. Sixty patients underwent F-R-RLN dissection (the experimental group) and 42 patients underwent standard dissection (the control group). The intraoperative electrical signal amplitude ratios of the RLN, the number of dissected lymph nodes, and the preservation rates of the parathyroid glands were recorded and compared between the two groups.

RESULTS

The electrical signal amplitude ratio of the lower neck part point of the RLN to the upper laryngeal inlet point in the experimental group was significantly lower than the ratio in the control group (p = 0.006, Z-score = -2.726). One patient suffered transient RLN paralysis in both groups, but this resolved within 1 month after operation. There were no significant differences between the two groups in terms of the number of level VIa or level VIb lymph nodes dissected, nor in the rate of preservation of the parathyroid glands.

CONCLUSIONS

F-R-RLN dissection is a thorough dissection technique that is effective at preventing an electrical signal amplitude decrease in the RLN, and at preventing RLN paralysis by preserving its blood supply.

Unnecessity of Routine Dissection of Right Central Lymph Nodes in cN0 Papillary Thyroid Carcinoma Located at the Left Thyroid Lobe

Objective

The lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) is an important part of the central lymph nodes (LNs). We aimed to explore the rate and predictors of LN-prRLN metastasis in cN0 papillary thyroid carcinoma (PTC) located at the left thyroid lobe.

Methods

Patients with surgically treated primary left lobe PTC were retrospectively enrolled. The metastatic distribution of LN-prRLN and postoperative complications were assessed. The association between LN-prRLN metastasis and clinicopathological variables was evaluated by univariate and multivariate analyses.

Results

A total of 857 patients were included for the analysis. Central LN metastasis was noted in 310 (35.3%) cases. The most (27.6%) and least (1.7%) commonly involved LNs were the left paratracheal LN and the LN-prRLN. In the univariate analysis, the tumor size, multifocality, the extent of extrathyroidal extension (none vs. macroscopic vs. macroscopic maximal), and perineural invasion were associated with positive LN-prRLN. In the multivariate analysis, tumor size of >40.0 mm and macroscopic maximal invasion were found as the only two independent predictors. Transient and permanent hypoparathyroidism were noted in 90 (10.2%) and 13 (1.5%) patients, respectively. Voice change was noted in 40 (4.6%) patients, and 20 patients recovered.

Conclusions

In cN0 PTC located at the left lobe, LN-prRLN metastasis was very uncommon. We found that LN-prRLN dissection is not required routinely, but should be performed if the tumor size is >40.0 mm and macroscopic maximal extrathyroidal extension is present.

Application of lateral supraclavicular incision in unilateral thyroid papillary carcinoma surgery

INTRODUCTION

The standard approach to thyroidectomy is a collar incision via the anterior neck, and the neck scar has always been a source of worry for patients. Acceptable wound cosmetology has become a focus for thyroid surgeons.

OBJECTIVE

To verify the effectiveness and cosmetic results of thyroidectomy through a lateral supraclavicular incision.

METHODS

180 patients were randomly divided into two groups: a lateral supraclavicular approach and a conventional transcervical approach. The main outcomes included incision length, intraoperative blood loss, operative time, total drainage volume, hospitalization expense, early postoperative pain measured by visual analog scale, infection, and perceived cosmetic outcome.

RESULTS

There were no statistical significances between the two groups in terms of age, gender, nodule size, intraoperative blood loss, operative time, total drainage volume, hospital expense and postoperative complications, whereas there were significant differences in terms of incision length (5.2±1.04cm vs. 6.9±1.14cm, p<0.05).

CONCLUSIONS

The lateral supraclavicular incision is a safe and feasible approach for thyroidectomy. Compared with conventional approach, it provides a better cosmetic result.

Clinical Analysis of Cervical Lymph Node Metastasis Risk Factors and the Feasibility of Prophylactic Central Lymph Node Dissection in Papillary Thyroid Carcinoma

OBJECTIVE

To identify the risk factors for cervical lymph node metastasis (CLNM) and the feasibility of prophylactic central lymph node dissection.

METHODS

The characteristics of 1107 patients were extracted and analyzed. Univariate and multivariate analyses were used to identify risk factors associated with lymph node metastasis. The relationship between the central lymph node dissection (CLND) and lateral lymph node metastasis (LLNM) was analyzed using the correlation analysis.

RESULTS

The probability of CLNM was closely related to the male gender, age <55, and the increase of tumor size. Those patients with an increase in tumor size and CLNM were extremely prone to LLNM. Also, LLNM was more likely to happen in those with the more positive central lymph nodes. Routine prophylactic central lymph node dissection (P-CLND) did not increase the risk of complications.

CONCLUSION

P-CLND should be considered as a reasonable surgical treatment for PTC.

Metastasis of cN0 Papillary Thyroid Carcinoma of the Isthmus to the Lymph Node Posterior to the Right Recurrent Laryngeal Nerve

OBJECTIVE

The association between metastasis to the lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) and cN0 papillary thyroid carcinoma (PTC) located in the thyroid isthmus remains unknown; therefore, our goal was to analyze the characteristics of LN-prRLN metastasis of cN0 PTCs of the thyroid isthmus and determine its potential predictors.

PATIENTS AND METHODS

This retrospective study included patients who underwent bilateral central neck dissection between January 2018 and January 2021. The specimen was divided into five groups of prelaryngeal lymph node (LN), pretracheal LN, left paratracheal LN, lymph node anterior to the right recurrent laryngeal nerve (LN-arRLN), and LN-prRLN. Univariate and multivariate analyses were used to assess the association between the clinical pathologic variables and LN-prRLN metastases. Surgical complications were presented descriptively.

RESULTS

A total of 357 patients were included, LN-prRLN metastasis occurred in 23 (6.4%) patients, and LN-prRLN was positive only when there were other LN metastases, especially LN-arRLN metastases. Other independent risk factors for LN-prRLN included foci numbers ≥2, tumor size ≥5.0 mm, and extrathyroidal extensions. The rates of permanent hypoparathyroidism and vocal cord paralysis were 1.1% and 2.0%, respectively.

CONCLUSION

LN-prRLN metastases should not be ignored in cN0 PTC located in the thyroid isthmus; however, its dissection is a safe procedure, and the status of LN-arRLN can be a reliable predictor for LN-prRLN metastases.

Para-tracheal neck dissection - is dissection of the upper part of level Ⅵ necessary?

Papillary thyroid carcinoma (PTC) has a high propensity for regional metastases, however, the impact of such metastases on the outcome of the patients is minimal. The central compartment of the neck is considered the first and the most common echelon of metastases from thyroid carcinoma. Physical examination along with ultrasonography are the gold standard pre-operative evaluation of patients with PTC. Ultrasonography is highly sensitive in evaluating lateral neck nodes, however, its value in evaluating the central compartment is limited, resulting in a relatively high rate of occult metastases in this compartment. The main potential complications of para-tracheal neck dissection (PTND) are recurrent laryngeal nerve paralysis and hypocalcemia and these may be higher in patients undergoing PTND compared to thyroidectomy alone. New histological data is available showing no evidence of lymph nodes in the central compartment above a level parallel to the inferior border of the cricoid cartilage. These findings support withholding dissection of the upper para-tracheal region routinely as a part of PTND in patients with well-differentiated thyroid cancer. By doing that, the complications may be lower and identical to thyroidectomy alone, thus may abolish arguments against more common use of elective PTND in patients with thyroid carcinoma.

Prevalence, Risk Factors And Location Of Skip Metastasis In Papillary Thyroid Carcinoma: A Systematic Review And Meta-Analysis

Background

Skip metastasis is a special type in cervical lymph node metastasis (LNM) of patients diagnosed with papillary thyroid carcinoma (PTC) which induced poor prognosis. There are few studies about skip metastasis and conclusions remained uncertain. Therefore, this study aims to explore the frequency and to investigate risk factors of skip metastasis in PTC.

Methods

Through searching the keyword by PubMed and Embase databases which articles published up to 1^st August 2018 about skip metastasis in papillary thyroid carcinoma, we extract data in order to assure whether those materials meet the criteria.

Results

The prevalence of skip metastasis is 12.02% in light of our meta-analysis of 18 studies with 2165 patients. The upper pole location (RR = 3.35, 95% CI =1.65-6.79, P = 0.0008) and tumors size ≤1 cm (RR = 2.65, 95% CI =1.50-4.70, P = 0.0008) are significantly associated with skip metastasis, whereas lymphovascular invasion (RR = 0.33, 95% CI =0.15-0.75, P = 0.0083) exists lower rate of skip metastasis. Multifocality, gender, age, bilaterality, thyroiditis and Extrathyroidal extension (ETE) are insignificantly associated with skip metastasis. Level II and level III are the most frequently affected areas.

Conclusion

The lateral compartment should be carefully examined especially for those PTC patients who present primary tumors in the upper lobe with a primary tumor size ≤10 mm which could be detected with skip metastasis.

Right posterior paratracheal lymph nodes metastasis is one of the predictive factors in right-sided papillary thyroid carcinoma

BACKGROUND

Lymph nodes in the right paratracheal region are separated as anterior and posterior on the basis with right recurrent laryngeal nerve. Dissection of the right posterior paratracheal lymph nodes is sometimes overlooked during a central neck dissection. Therefore, this study was designed to assess the clinicopathologic risk factors and prognostic implication for recurrence related to the presence of right posterior paratracheal lymph nodes metastasis in patient with right-sided papillary thyroid carcinoma.

METHODS

Records from 763 patients with papillary thyroid carcinoma who underwent total thyroidectomy with central neck dissection, including the right posterior paratracheal lymph nodes, between January 2007 and March 2015 were reviewed retrospectively.

RESULTS

Among 763 patients (120 men and 643 women; mean age 49.04 years) with right-sided papillary thyroid carcinoma, 127 exhibited right posterior paratracheal lymph nodes metastases. In multivariate analysis, central-compartment lymph nodes metastases (odds ratio 5.203; 95% confidence interval, 2.864-9.453) and lateral cervical lymph nodes metastases (odds ratio 3.668; 95% confidence interval, 2.375-5.667) were independently correlated with right posterior paratracheal lymph nodes metastases. Twenty-three patients (3.0%) showed loco-regional recurrence. The loco-regional recurrence rate was greater in the groups for males (P = .012), larger tumor size (>10 mm; P = .044), extrathyroidal extention (P = .002), and right posterior paratracheal lymph nodes metastasis (P < .001).

CONCLUSION

Right posterior paratracheal lymph nodes metastases are predictive factors of loco-regional recurrence, and these lymph nodes should be removed completely during a right central neck dissection in patients with right-sided papillary thyroid carcinoma with central or lateral cervical lymph node metastasis.

Risk factors for contralateral central lymph node metastasis in unilateral cN0 papillary thyroid carcinoma: A meta-analysis

BACKGROUND

Central lymph node metastasis(CLNM) is common in papillary thyroid carcinoma(PTC). LNM is related to local recurrence and adverse prognosis. The extent of prophylactic central lymph node dissection(pCLND) is not well defined. We aim to investigate the prevalence and risk factors for contralateral central lymph node metastasis (CCLNM) in unilateral clinical node-negative (cN0) PTC patients to determine the appropriate extent of pCLND.

METHODS

A systematic literature search was performed using PubMed and Embase databases until May 2018. Published studies that estimated the association between clinicopathologic factors and CCLNM were included.

RESULTS

A total of 6 studies involving 1399 patients were included. The prevalence of CCLNM was 10.9% in all patients. The pooled analysis revealed that male gender (pooled OR = 1.67, 95%CI = 1.11-2.53, p = 0.015), age<45years (pooled OR = 1.97, 95%CI = 1.37-2.85, p < 0.001), lymphovasular invasion (pooled OR = 4.23, 95%CI = 2.25-7.98, p < 0.001), extrathyroid invasion (pooled OR = 1.75, 95%CI = 1.08-2.83, p = 0.023), and ipsilateral CLNM (pooled OR = 12.26, 95%CI = 7.27-20.67, p < 0.001) were significant risk factors for CCLNM. While tumor size>1 cm (pooled OR = 3.39, 95%CI = 0.83-13.88, P = 0.090), capsular invasion (pooled OR = 1.28, 95%CI = 0.79-2.06, p = 0.313), extrathyroid extension (pooled OR = 1.49, 95%CI = 0.86-2.56, p = 0.152), and MACIS≥6 (pooled OR = 1.08, 95%CI = 0.51-2.26, p = 0.844) were not significantly associated with CCLNM.

CONCLUSIONS

Our meta-analysis identified that male gender, age<45years, lymphovasular invasion, extrathyroid invasion and ipsilateral CLNM were significant risk factors for CCLNM. These findings may guide the extent of pCLND in unilateral cN0 PTC patients.

Independent predictors and lymph node metastasis characteristics of multifocal papillary thyroid cancer

The multifocal papillary thyroid cancer (PTC), with more aggressive and poorer prognosis, is not rare in papillary histotype. Few studies evaluated risk factors and lymph node metastasis in multifocal PTC. The aim of this present study focusing on risk factors and lymph node metastasis characteristics in multifocal PTC was excepted to assist clinical decisions regarding surgery.It was a retrospective study. The 1249 consecutive patients with PTC were reviewed. Of these, 570 patients who met the criteria were selected: 285 with solitary papillary thyroid cancer and 285 with multifocal PTC. The risk factors and lymph node metastasis in multifocal PTC were investigated by univariate and multivariate analysis.Multifocal PTC showed a higher positive rate of capsular invasion, extrathyroidal extension, tumor size >10 mm, pathological T classification, N+ stage, local recurrence, and radioactive iodine ablation (RAI). Capsular invasion (hazard ratio [HR], 1.589; 95% confidence interval [CI],1.352-1.984), advanced pathological T classification (HR, 3.582; 95% CI, 2.184-5.870), and pathological N+ stage (HR, 1.872; 95% CI, 1.278-2.742) were related to increased risk of multifocality and there was a significant increased HR for central neck compartment involvement in male sex (HR, 2.694; 95% CI, 1.740-4.169), advanced pathological T classification (HR, 2.403; 95% CI, 1.479-3.907) and multifocality (HR, 1.988; 95% CI, 1.361-2.906).There is a significant association between capsular invasion, advanced pathological T classification, N+ stage, and multifocal PTC. Total thyroidectomy plus prophylactic bilateral central lymph node dissection should be recommended during surgery due to a stronger predilection for level VI lymph node metastasis in multifocal PTC.

Skip metastasis in papillary thyroid carcinoma is difficult to predict in clinical practice

BACKGROUND

Cervical lymph node metastases are very common in papillary thyroid cancer (PTC), and typically spread in a predictable stepwise fashion in clinical practice. However, lateral lymph node metastasis (LLNM) without central lymph node metastasis (CLNM) as skip metastasis is not rare in PTC. The aim of this study was to investigate the incidence, risk factors and pattern of skip metastasis in PTC.

METHODS

A total of 271 patients with PTC and suspicious LLN diagnosed by pre-operation examinations who underwent total thyroidectomy and central lymph node dissection plus lateral lymph node dissection between January 2008 and December 2011 were enrolled in this study. Clinicopathological features were collected, and the pattern of cervical lymph node metastasis and skip metastasis were analyzed.

RESULTS

The LLNM rate was 74.9% (203/271, diagnosed by postoperative pathology examination) and significantly associated with extrathyroid extension (ETE), primary tumor located at the upper pole, and CLNM (p < 0.05). The skip metastasis rate was 14.8% (30/203) and was more frequently found in microcarcinoma patients, especially when the primary tumor size was ≤0.5 cm (p = 0.001 OR = 12.9). However, skip metastasis was unrelated to the remaining factors examined.

CONCLUSION

Small cancers with a pre-operation diagnosis of LLNM are more likely to have skip metastases, especially when the primary tumor size is less than 0.5 cm in diameter; however, this type of metastasis appears to develop in a random fashion. Thus, additional research is needed to identify potential predictive factors, such as a primary tumor located at the upper pole.

Predictors of lymph nodes posterior to the right recurrent laryngeal nerve metastasis in patients with papillary thyroid carcinoma: A retrospective study

The aim of this study was to identify the risk factors associated with lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) metastasis in patients with papillary thyroid carcinoma (PTC).A total of 81 PTC patients who underwent total/near-total thyroidectomy with LN-prRLN dissection in the Department of General Surgery at Guangdong General Hospital between June 2015 and August 2016 were assessed retrospectively. The relations of LN-prRLN metastasis with clinicopathologic characteristics of PTC were analyzed by univariate and multivariate logistic regression.The incidence of LN-prRLN metastasis in patients with PTC was 51.9% (42 of 81 cases). Univariate analysis showed that lateral LN metastasis (P = .005), VIa central LN metastasis (P = .000), pathologic tumor size (P = .000), capsular invasion (P = .002), and extrathyroidal invasion (P = .018) (P < .05) were significantly associated with the increased incidence of LN-prRLN metastasis in PTC. No significant correlations were found between LN-prRLN metastasis and other variables such as gender (P = .056), age (P = .448), clinical N stage (cN) (P = .063), tumor location (P = .336), tumor site (P = .909), right tumor existence (P = .793), and multifocality (P = .381). Multivariate logistic regression analysis revealed that VIa central LN metastasis (OR: 4.490, P = .027) was independent risk factors of LN-prRLN metastasis in patients with PTC.LN-prRLN metastasis is often indentified in patients with PTC. VIa central LN metastasis is an independent predictors of LN-prRLN metastasis, which allow for selective LN-prRLN dissection in patients with PTC.

Early prediction of hypocalcemia following thyroid surgery. A prospective randomized clinical trial

PURPOSE

The aim of this randomized-controlled trial was to validate the results of a previous prospective single-cohort observational study conducted in the same surgical unit regarding the use of concomitant intact parathyroid hormone (iPTH) and serum calcium measurement in predicting hypocalcemia after total thyroidectomy.

METHODS

From January 2014 to January 2015, 150 patients underwent total thyroidectomy in our department and were randomized into two groups. The experimental group was submitted to iPTH assay 6 h after surgery while the control group was submitted to a daily assay of serum calcium and phosphorus. Sensitivity and specificity of different serum measurements have been calculated using the receiver-operator characteristics (ROC) curve.

RESULTS

The prevalence of hypocalcemia was 14.25% in both groups. The assay of iPTH 6 h after surgery combined with the serum calcium assay 24 h after surgery yielded the highest diagnostic accuracy in predicting hypocalcemia using ROC curves, with 100% sensitivity and 100% specificity.

CONCLUSIONS

According to our previous study, the combined measurement of iPTH 6 h after surgery and of serum calcium 24 h after surgery are highly predictive of early postoperative hypocalcemia. These results are important in selecting the patients eligible for early discharge and those who need calcium and vitamin D supplementation.

Incidence and Risk Factors for Occult Level 3 Lymph Node Metastases in Papillary Thyroid Cancer

BACKGROUND

Papillary thyroid cancer (PTC) frequently disseminates into cervical lymph nodes. Lateral node involvement is described in up to 50 % patients undergoing prophylactic lateral neck dissection. This study aimed to assess this finding and identify which factors predict for occult lateral node disease.

METHODS

Patients with fine needle aspiration-confirmed PTC (Bethesda V or VI), without evidence of cervical lymph node metastases, underwent a total thyroidectomy with prophylactic ipsilateral central and level 3 dissection. Level 3 nodes were removed by compartmental dissection or by sampling the sentinel nodes overlying the jugular vein, according to surgeon preference. Data were collected prospectively from January 2011 to August 2014. Statistical analysis was performed by SPSS software.

RESULTS

A total of 137 patients underwent total thyroidectomy with prophylactic ipsilateral central and level 3 dissection for PTC. The incidence of occult level 3 disease was 30 % (41/137 patients). A total of 48 % of patients (66/137) harbored occult central neck disease. A total of 80.5 % of patients with pN1b disease had macrometastases (≥2 mm), and 15 % exhibited skip metastases with central compartment sparing. In patients with pN1b disease, a median of 6 level 3 nodes were retrieved, with an average involved nodal ratio of 0.29. Multivariate regression demonstrated risk factors for occult lateral neck metastasis include tumor size (odds ratio 1.1), upper pole tumors (odds ratio 6.6), and vascular invasion (odds ratio 3.2) (p < 0.05).

CONCLUSIONS

PTC is associated with a significant incidence of occult central and lateral nodal metastases. In patients undergoing prophylactic central neck dissection, inclusion of level 3 dissection should be considered in patients with large upper lobe cancers.

Predictive Value of Estimated Tumor Volume Measured by Ultrasonography for Occult Central Lymph Node Metastasis in Papillary Thyroid Carcinoma

The clinical and prognostic value of tumor volume in various solid tumors has been investigated. However, there have been few studies on the clinical impact of tumor volume in papillary thyroid carcinoma (PTC). This study was performed to investigate the predictive value of estimated tumor volume measured by ultrasonography for occult central neck metastasis (OCNM) of PTC. A total of 264 patients with clinically node-negative PTC on ultrasonography and computed tomography who underwent total thyroidectomy in conjunction with at least ipsilateral prophylactic central neck dissection were enrolled in this study. Tumor volume was derived with the formula used to calculate ellipsoids from two orthogonal scans during 2-D ultrasonography at initial aspiration biopsy. We retrospectively evaluated demographic characteristics, pre-operative ultrasonographic features (tumor size, volume and multifocality) and pathologic results. The OCNM rate was 35.6%; estimated tumor volume was used to predict OCNM (p = 0.035). At 0.385 mL, sensitivity and specificity were 51.1% and 66.5%, and the area under the curve for OCNM detection was 0.610. In multivariate analysis, tumor volume, but not size, was an independent predictive factor for OCNM (odds ratio = 1.83, p = 0.029). The other factors were extrathyroidal extension (odds ratio = 2.39, p = 0.004) and male gender (odds ratio = 3.90, p < 0.001). The estimated tumor volume of PTC measured by ultrasonography could be a pre-operative predictor of OCNM.

The Clinical Significance of the Right Para-Oesophageal Lymph Nodes in Papillary Thyroid Cancer

PURPOSE

Although guidelines indicate that routine dissection of the central lymph nodes in patients with thyroid carcinoma should include the right para-oesophageal lymph nodes (RPELNs), located between the right recurrent laryngeal nerve and the cervical oesophagus and posterior to the former, RPELN dissection is often omitted due to high risk of injuries to the recurrent laryngeal nerve and the right inferior parathyroid gland.

MATERIALS AND METHODS

We retrospectively identified all patients diagnosed with papillary thyroid carcinoma who underwent total thyroidectomy with central lymph node dissection, including the RPELNs, between January 1, 2009 and December 31, 2013 at the Thyroid Cancer Center of Yonsei University College of Medicine, Seoul, Korea.

RESULTS

Of 5556 patients, 148 were positive for RPELN metastasis; of the latter, 91 had primary tumours greater than 1 cm (p<0.001). Extrathyroidal extension by the primary tumour (81.8%; p<0.001), bilaterality, and multifocality were more common in patients with than without RPELN metastasis; however, there were no significant differences in age and sex between groups. A total of 95.9% of patients with RPELN metastasis had central node (except right para-oesophageal lymph node) metastasis, and the incidence of lateral neck node metastasis was significantly higher in patients with than without RPELN metastasis (63.5% vs. 14.3%, p<0.001). Forty-one patients underwent mediastinal dissection, with 11 patients confirmed as having mediastinal lymph node metastasis with RPELN metastasis on pathological examination.

CONCLUSION

RPELN metastasis is significantly associated with lateral neck and mediastinal lymph node metastasis.

Multifocal Papillary Thyroid Cancer Increases the Risk of Central Lymph Node Metastasis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common thyroid malignancy, with a strong predilection for lymph node metastasis, most commonly to the central neck compartment (level VI). Few studies have evaluated lymph node metastasis in multifocal PTC, and the role of level VI dissection in the management of PTC remains controversial. This retrospective analysis evaluated the rate of level VI lymph node positivity in multifocal PTC, as compared with unifocal disease, in order to inform surgical decision making better.

METHODS

Patients with PTC who underwent total or hemi-thyroidectomy plus level VI lymph node dissection at the authors' institution between January 2008 and June 2014 were included (N=227). The number and laterality of PTC foci, lymphovascular invasion (LVI), extrathyroidal extension (ETE), and positive/total number of level VI lymph nodes were recorded. Fisher's exact test was used to determine univariate associations, and multivariate analysis was done by logistical regression.

RESULTS

There was an association between the number of PTC foci and level VI node positivity (p<0.001), with an odds ratio (OR) of 2.355 in patients with three or more tumor foci (p=0.026). The OR for central neck metastasis was 1.088 with each additional focus of PTC (p=0.018). The risk of level VI node positivity in the presence of one or two foci was only 19%, with no appreciable difference between one and two foci. This risk increased in the presence of between three and nine foci (38%), and 10 or more foci (88%). Level VI node positivity was associated with ETE (p<0.001), LVI (p<0.001), and size of the largest focus (p<0.001). There was no association between level VI lymph node positivity and male sex (p=0.089), bilaterality (p=0.276), or age (p=0.076).

CONCLUSIONS

There is a significant association between multifocal PTC and level VI lymph node positivity, increasing proportionally with the number of foci. These findings recognize multifocality as a sign of tumor aggressiveness, as evidenced by a higher propensity for lymph node metastasis.

Patterns of structural recurrence in papillary thyroid cancer

BACKGROUND

Papillary thyroid carcinoma (PTC) is uncommonly associated with tumor-related mortality, although local recurrence can be a frequent and difficult problem. This study was conducted to clarify the pattern of structural locoregional recurrence in PTC.

MATERIAL AND METHOD

A retrospective cohort study of patients undergoing surgical intervention for PTC was undertaken. Data were collected from a comprehensive thyroid cancer database maintained within a single tertiary referral center. The primary outcome measure was cancer recurrence requiring surgical intervention. Secondary outcome measures were site of recurrence, time to recurrence, and risk factors for recurrence.

RESULTS

In the period 1980-2013, 1,183 patients with PTC were included in the study. The overall rate of structural recurrence requiring reoperative surgery was 7.9 %. The median time to reoperation was 31 months. Younger age, male gender, large primary tumor diameter, and number of positive lymph nodes at initial presentation were all significantly associated with disease recurrence. The lateral compartments (levels I, II, III, IV, V) were involved almost twice as frequently as the central compartment (level VI) (67 vs 32 %, P < 0.01). The distribution of recurrences was level I (1 %), level II (12 %), level III (18 %), level IV (18 %), level V (17 %), level VI (32 %), level VII (2 %).

CONCLUSIONS

In a center with a liberal approach to central compartment lymph node dissection for PTC, the lateral neck compartment is the most common site of structural recurrence requiring reoperative surgery.

The pros and cons of prophylactic central neck dissection in papillary thyroid carcinoma

Prophylactic central neck dissection (pCND) for management of papillary thyroid carcinoma (PTC) is controversial. Compared to many malignancies, PTC has a high overall survival but local recurrence due to lymph node metastases continue to present management challenges. Unlike lateral cervical nodal metastasis metastasis, central neck nodal metastasis are unable to be reliably detected clinically or radiologically at pre-operative assessment. Residual disease (recurrent or persistent) typically requires re-operative surgery in the central compartment, which carries a heightened risk of significant morbidity. These nodal groups can be accessed during the index thyroidectomy for PTC. Thus, pCND offers potential to reduce the rates of recurrence and the need for re-operative surgery in the central neck. This benefit needs to be balanced with the potential morbidity risk from pCND itself at the index resection. This review will discuss the advantages and disadvantages of pCND with regard to long-term outcomes and potential morbidity. The rationale of pCND will be discussed, along with the indications for ipsilateral and contralateral pCND, the role of re-operative surgery for recurrence and the use of selective versus routine pCND. Strategies to select higher risk patients for pCND with the use of molecular markers will be addressed, along with a discussion of quality of life (QoL) research in PTC.

A preoperative nomogram for the prediction of ipsilateral central compartment lymph node metastases in papillary thyroid cancer

BACKGROUND

Central compartment lymph node metastases in papillary thyroid carcinoma (PTC) are difficult to detect preoperatively, and the role of routine or prophylactic central compartment lymph node dissection (CLND) in managing PTC remains controversial. The aim of this project was to create a nomogram able to predict the occurrence of central compartment lymph node metastasis using readily available preoperative clinical characteristics.

METHODS

Records from patients undergoing total thyroidectomy and lymph node dissection for PTC in the period 1968-2012 were analyzed. Nodal status was based on results of serial hematoxylin and eosin (H&E) examination. Age, sex, tumor size, tumor site, and multifocality were included in a multivariable logistic regression model to predict lymph node metastasis. A coefficient-based nomogram was developed and validated using an external patient cohort.

RESULTS

The study population included 914 patients (80% females) with an average central compartment nodal yield of eight per patient. Central compartment lymph node metastases were present in 390 patients (42.7%). The variables with the strongest predictive value were age (p<0.001), male sex (p<0.001), increasing tumor size (p<0.001), and tumor multifocality (p<0.05). The nomogram had good discrimination with a concordance index of 76.4% [95% confidence interval 73.3-79.4], supported by an external validation point estimate of 61.5% [95% confidence interval 49.5-73.6]. An online calculator and smartphone application were developed for point of care use.

CONCLUSIONS

A validated nomogram utilizing readily available preoperative variables has been developed to give a predicted probability of central lymph node metastases in patients presenting with PTC. This nomogram may help guide surgical decision making in PTC.

Nodal recurrence in the lateral neck after total thyroidectomy with prophylactic central neck dissection for papillary thyroid cancer

PURPOSE

The aim of this study was to examine risk factors for nodal recurrence in the lateral neck (NRLN) in patients with papillary thyroid cancer (PTC) who underwent total thyroidectomy with prophylactic central neck dissection (TT + pCND).

METHODS

This was a retrospective cohort study of patients with PTC who underwent TT + pCND. Data of all patients treated over a 10-year period (between 1998 and 2007) were analysed. The primary outcome was prevalence of NRLN within the 5-year follow-up after initial surgery. Predictors of NRLN were determined in the univariable and multivariable analysis.

RESULTS

Of 760 patients with PTC included in this study, 44 (6.0 %) developed NRLN. In the univariable analysis, the following factors were identified to be associated with an increased risk of NRLN: positive/negative lymph node ratio ≥0.3 (odds ratio (OR) 14.50, 95 % confidence interval (CI) 7.21 to 29.13; p < 0.001), central lymph node metastases (OR 7.47, 95 % CI 3.63 to 15.38; p < 0.001), number of level VI lymph nodes <6 in the specimen (OR 2.88, 95 % CI 1.21 to 6.83; p = 0.016), extension through the thyroid capsule (OR 2.55, 95 % CI 1.21 to 5.37; p = 0.013), localization of the tumour within the upper third of the thyroid lobe (OR 2.35, 95 % CI 1.27 to 4.34; p = 0.006) and multifocal lesions (OR 1.85, 95 % CI 1.01 to 3.41; p = 0.048).

CONCLUSIONS

Central lymph node metastases together with positive to negative lymph node ratio ≥0.3 represent the strongest independent prognostic factors for the PTC recurrence in the lateral neck.

Complication rates of central compartment dissection in papillary thyroid cancer

BACKGROUND

The benefits of central compartment dissection (CCD) in papillary thyroid carcinoma (PTC) are still debatable and should be weighed against its potential risks. We aim to compare the complication rates in total thyroidectomy with and without CCD for patients with PTC.

METHODS

This is a retrospective study on prospectively collected data from our cancer registry over a 15-year period. Patients with pathologically proven PTC treated with total thyroidectomy alone or with CCD were included. CCD was performed at the operating surgeon's discretion. A total of 105 patients were included and divided into two groups for analysis: group A - total thyroidectomy alone (51 patients, 49%) and group B - total thyroidectomy with CCD (54 patients, 51%). The operative complications between the two groups were then evaluated.

RESULTS

Overall, 6.9% and 0.98% patients had transient and permanent recurrent laryngeal nerve palsies, respectively. About 19.0% and 2.9% patients had transient and permanent hypoparathyroidism, respectively and 27.6% patients had parathyroid glands found to be included in the resected specimen. Complication rates in terms of transient or permanent recurrent laryngeal nerve palsy or hypoparathyroidism did not differ significantly between groups A and B. Within group B, 41 patients had unilateral CCD and 12 had bilateral CCD. Transient hypoparathyroidism was more frequent in bilateral CCD (50% versus 12.2%, P = 0.01).

CONCLUSIONS

Total thyroidectomy with prophylactic unilateral CCD is a safe procedure for PTC without added complication rates compared with total thyroidectomy alone. It is recommended for patients with PTC and clinically negative neck lymph nodes.

Prophylactic central neck dissection for papillary thyroid cancer

BACKGROUND

Prophylactic central neck dissection (CND) for papillary thyroid cancer (PTC) remains controversial. The aim of this study was to examine whether prophylactic CND for PTC affected long-term survival and locoregional control.

METHODS

This was a retrospective cohort study of patients who underwent total thyroidectomy (TT) with bilateral prophylactic CND. They were compared with patients who had TT without CND. Personalized adjuvant radioiodine treatment was used in both groups. Primary outcomes were overall and disease-specific survival, and locoregional control. Secondary outcomes were number of patients with negative serum thyroglobulin levels, and morbidity.

RESULTS

Of 640 patients with PTC included in this study, 282 (treated in 1993-1997) had TT without CND and 358 (treated in 1998-2002) underwent TT with CND. The 10-year disease-specific survival rate for patients who had TT without CND was 92·5 per cent compared with 98·0 per cent in patients with CND (P = 0·034), and the locoregional control rate was 87·6 and 94·5 per cent respectively (P = 0·003). In multivariable analysis, extrathyroidal extension was an independent predictive factor for locoregional recurrence (odds ratio 12·47, 95 per cent confidence interval 6·74 to 23·06; P < 0·001), whereas CND was an independent predictive factor for improved locoregional control at 10 years after surgery (odds ratio 0·21, 0·11 to 0·41; P < 0·001). No differences were seen in the rates of permanent hypoparathyroidism or recurrent laryngeal nerve injury between the groups.

CONCLUSION

Bilateral prophylactic CND for staging of the neck in PTC, followed by personalized adjuvant radioiodine treatment, improved both 10-year disease-specific survival and locoregional control, without increasing the risk of permanent morbidity.

REGISTRATION NUMBER

NCT01510002 (http://www.clinicaltrials.gov).

Optimal surgical extent of lateral and central neck dissection for papillary thyroid carcinoma located in one lobe with clinical lateral lymph node metastasis

BACKGROUND

The indications and extent of cervical lymph node dissection in papillary thyroid carcinoma (PTC) are still being debated. The aim of this study was to analyze the patterns of cervical lymph node metastasis in the lateral and central compartment and related factors and suggest the optimal extent of lateral and central neck dissection for PTC patients with clinical lateral lymph node metastasis.

METHODS

We retrospectively analyzed 72 patients with unilateral PTC who underwent therapeutic lateral neck dissections with concomitant total thyroidectomy and central neck dissection between January 2001 and December 2009.

RESULTS

The 72 patients underwent 79 sides of therapeutic lateral neck dissection. The most frequent metastatic level in the ipsilateral lateral compartment was level IV (75.0%), followed by level III (69.4%), level II (56.9%) and level V (20.8%). Multiple level metastases were common (77.8%) and were correlated with tumor size (≥ 10 mm). The central compartment lymph node metastasis rate was 87.5%, including 26.4% of contralateral central compartment metastases.

CONCLUSION

In PTC patients with clinical lateral lymph node metastasis, the optimal extent of lateral and central neck dissection should include levels II, III, IV and V as well as the bilateral central compartment.

Management of well-differentiated thyroid cancer

This review provides an overview of current guideline recommendations for the clinical evaluation and surgical management of well-differentiated thyroid cancer, and further examines the evidence for controversial topics such as the minimum degree of primary resection, the role of elective central neck dissection, and the extent of lateral neck dissection. Well-differentiated thyroid cancer comprises the majority of thyroid cancers, about 90%, and includes both papillary and follicular carcinomas. Despite convergence of the medical community in establishing treatment guidelines under the American Thyroid Association, there still remain many areas of disagreement.

Role of prophylactic ipsilateral central compartment lymph node dissection in papillary thyroid microcarcinoma

Central compartment lymph node (CCLN) management in patients without clinical or radiologic evidence of CCLN metastasis is debatable. The aim of the present study was to evaluate outcomes of surgery for papillary thyroid microcarcinoma (PTMC) with prophylactic ipsilateral CCLN dissection (PI-CCND) in a large cohort of patients treated at one single institution in a 5-year follow-up. Between January 2000 and December 2005, 2192 patients with papillary thyroid carcinoma underwent thyroid surgery. Inclusion criteria were patients with PTMC, absence of clinical or radiologic evidence of CCLN metastasis, and a follow-up for a period ≥60 months. Data from 842 patients were retrieved in the current retrospective cohort study. PI-CCND was routinely performed in addition to thyroid surgery in all cases. Ipsilateral CCLN metastasis was found in 218 patients (25.9%). Postoperative complications included 76 cases of transient hypoparathyroidism (9%), 11 cases of permanent hypoparathyroidism (2.6%), four cases of vocal cord palsy (0.5%), and one case of bleeding (0.1%). Univariate analysis and multivariate logistic regression analysis revealed that CCLN metastasis was statistically significantly correlated with tumor size and extracapsular invasion. Recurrence has been observed to date in 19 patients (2.26%). No CCLN site recurrence occured in patients who underwent PI-CCND. This study demonstrates the technical feasibility and safety of PI- CCND, which is a better way to determine lymph node status for a more accurate staging of disease and risk stratification. PI-CCND should be considered even if clinical or radiological exams are negative for CCLN metastasis.

Central compartment dissection for well differentiated thyroid cancer … and the band plays on

PURPOSE OF REVIEW

The role of central compartment dissection in the surgical management of well differentiated thyroid cancer is controversial. Lack of high-quality prospective studies results in management decisions being based on expert opinions and weaker levels of evidence. The American Thyroid Association has recently revised its management guidelines with particular emphasis on this topic, and a separate working group has set out to define the surgical anatomy that encompasses this procedure.

RECENT FINDINGS

Central compartment dissection comprises the removal of nodal tissue from the prelaryngeal, pretracheal and paratracheal compartments, with no role for berry-picking procedures. There is universal agreement that therapeutic nodal dissection should be performed in patients with metastatic disease detected either through preoperative imaging or during intraoperative evaluation of the central compartment, with either visual inspection or frozen-section pathology. In contrast, there may be limited benefit from routine prophylactic central compartment dissection, for either disease recurrence or survival outcomes. As such, it should be performed only in patients deemed high risk: larger tumors, extra-thyroidal extension or aggressive histologic subtypes.

SUMMARY

Future studies should focus on identifying the subpopulation of patients who would most benefit from these procedures and spare low-risk patients from the unwanted complications.

Performing contralateral central lymph node dissection in papillary thyroid carcinoma: a decision approach

BACKGROUND

Substantial controversy exists over the role of prophylactic neck dissection for patients with papillary thyroid carcinoma (PTC). We hypothesized that a therapeutic strategy of performing a routine intraoperative frozen section of the ipsilateral central lymph node (CLN) after elective ipsilateral CLN dissection (CLND) for all unilateral PTC and then performing a contralateral CLND if the frozen section is positive for malignancy would reduce morbidity compared to a therapeutic strategy of routine bilateral CLND.

METHODS

In a group of 419 patients with PTC undergoing thyroidectomy during study the period, the 203 patients who had unilateral PTC and no evidence of adenopathy on ultrasonography were prospectively enrolled in our nonrandomized study that was performed between March 2009 and February 2010. Patients underwent a total thyroidectomy if tumor size was over 1 cm or extrathyroidal was detected on ultrasonography. Patients underwent a subtotal or near-total thyroidectomy if tumor size was <1 cm and additional benign tumor existed on contralateral lobe. There were 25 patients who had a unilateral CLND with a subtotal or near-total thyroidectomy, and 178 patients who underwent a unilateral or bilateral CLND with a total thyroidectomy.

RESULTS

There was no difference in the rate of major complications between unilateral CLND group and bilateral CLND group. The rate of transient hypocalcemia was 31.8% in the unilateral CLND group and 45.7% in the bilateral CLND group (p = 0.084). The rate of voice change was 7.6% in the unilateral CLND group 4.3% in the bilateral CLND group (p = 0.438). The ratio of malignant to all nodes retrieved was 0.5/7.88 in the unilateral CLND group and 5.13/17.20 in the bilateral CLND group. There was 78.3% sensitivity and 100% specificity for frozen biopsy of ipsilateral CLN to predict contralateral CLN metastasis. A positive ipsilateral CLN frozen biopsy was significantly associated with contralateral CLN metastasis (p < 0.001), as was younger age (p = 0.002) and existence of extrathyroidal extension (p = 0.031), each on univariate analysis.

CONCLUSIONS

In patients with unilateral PTC, routine ipsilateral CLND with intraoperative reading of the frozen section can be employed to assess the risk of contralateral CLN metastasis. This information should be of value in deciding whether to perform contralateral CLND or not.

Predictive value of the Delphian and level VI nodes in papillary thyroid cancer

BACKGROUND

Recent published data has shown that metastatic involvement of the prelaryngeal or Delphian lymph node (DLN), the highest of the central (level VI) cervical lymph nodes, is highly predictive of advanced nodal disease in papillary thyroid cancer (PTC). The aims of this study were to determine the diagnostic accuracy of all the level VI cervical nodes in PTC and to determine which node group, if any, is the most accurate in predicting lateral node (N1b) disease.

METHODS

This was a retrospective cohort study. Data were obtained from the University of Sydney Endocrine Surgical Unit Database and through a review of the histopathology records. The study cohort was composed of 177 consecutive patients with a final diagnosis of PTC who underwent total thyroidectomy and lymph node dissection, spanning the period from May 2001 to December 2006.

RESULTS

Of the 177 patients with PTC, 86 had the DLN removed, 51 had a pretracheal node removed and 76 had the paratracheal group removed. DLN, paratracheal and pretracheal node disease was present in 21%, 39% and 46%, respectively. Lateral node (N1b) disease was present in 35%. Paratracheal node involvement was mildly predictive of further disease with patients 1.7 times more likely to have lateral node involvement (sensitivity=55%, specificity=68%). Pretracheal node involvement was moderately predictive of further disease with patients three times more likely to have lateral node involvement (sensitivity=72%, specificity=74%). DLN involvement was highly predictive of further node involvement with patients nine times more likely to have lateral node disease (sensitivity=53%, specificity=94%) and 40 times more likely to have any nodal disease (sensitivity=41%, specificity=100%).

CONCLUSION

This is the first study to examine the diagnostic accuracy of all level VI lymph nodes in PTC. While, metastatic involvement of all central nodal groups is indicative of further disease, the DLN is the most accurate predictor.

Surgical management of cervical lymph nodes in differentiated thyroid cancer

Well-differentiated thyroid cancer (DTC) carries an excellent prognosis. Although long-term survival rates are high, regional lymph node metastases are common. Surgical management of cervical lymph nodes is integral to the comprehensive treatment of DTC, but data from large randomized trials do not exist to define optimal treatment. Therapy is thus guided by observational data, and founded on an understanding of the behavior of lymphatic metastases in DTC. This article focuses on the significance of lymph node metastases in thyroid cancer, and the strategy for surgical management.

Indeterminate thyroid nodules: a challenge for the surgical strategy

BACKGROUND

Because no clinical parameter can establish the final status of a cytologically indeterminate thyroid nodule (ITN) or nodal-metastases in case of malignancy, the initial surgical strategy should define an oncologically adequate procedure with low morbidity.

METHODS

The prognostic relevance of sex, age, tumor sizes, multifocality, thyroid function, and recurrence was analyzed in 156 consecutive patients according to the presence of malignancy and nodal metastases. The accuracy of frozen sections to reveal malignancy was determined. Clinical parameters were compared with regard to their ability to identify malignancy and nodal metastases in an ITN to determine an appropriate initial operative strategy.

RESULTS

One hundred and eighteen (75.6%) patients underwent (total) thyroidectomy, 37 (23.7%) patients underwent hemithyroidectomy, and 1 patient underwent isthmus resection. Fifty-five (35.3%) patients showed malignancy. First step lymphadenectomy (lymph node dissection along the recurrent laryngeal nerve before removing the thyroid lobe) was performed in 142 patients documenting 10 nodal metastases. Comparing benign and malignant ITN, no association was found for sex (P = .17), age (P = 1.0), tumor sizes (P = .33, P = .12, P = .19 for < or =30 mm, < or =40 mm, and < or =50 mm, respectively), or thyroid function (P = .26). The determination of malignancy by frozen section showed a sensitivity of 30.9% and a specificity of 100%. No permanent hypoparathyroidism or recurrent laryngeal nerve palsy was observed postoperatively.

CONCLUSION

Because of the failure of available clinical parameters to predict malignancy in cytologically ITN, hemithyroidectomy in unilateral goiter and thyroidectomy in bilateral goiter is recommended. Ipsilateral "first step central neck dissection" on the side of ITN offers the advantages of oncologically adequate resection and staging with a low morbidity, as well as avoids reoperation.

Does failure to perform prophylactic level VI node dissection leave persistent disease detectable by ultrasonography in patients with low-risk papillary carcinoma of the thyroid?

BACKGROUND

There is controversy regarding the need for prophylactic level VI central node dissection in patients with low-risk papillary thyroid carcinoma (PTC). This study focuses on the incidence of persistent level VI nodal disease in low-risk PTC without prophylactic central node dissection.

METHODS

PTC was known at the time of thyroidectomy in 304 of the 761 patients who had initial thyroid surgery from 2001 to 2007. Therapeutic level VI node dissection was performed for suspicious or positive nodes. A prophylactic central node dissection was not done if suspicious nodes were not identified. All patients had a high-resolution ultrasonography, and almost all patients had a suppressed serum thyroglobulin level 4-6 months after thyroidectomy.

RESULTS

A total of 112 of 304 patients (37%) had a therapeutic level VI node dissection. A prophylactic central node dissection was not performed in the remaining 192 patients. One hundred and sixty-one of the 192 patients (84%) were low risk. Biopsy-proven persistent disease was identified at the 4-6-month postoperative ultrasonography in only 3 of the 161 low-risk patients (1.8%). The suppressed serum thyroglobulin level was increased in these 3 patients and 2 additional patients.

CONCLUSION

Failure to perform a prophylactic central node dissection in low-risk PTC resulted in both a very low incidence of persistent level VI nodal disease and elevated suppressed thyroglobulin 4-6 months after thyroidectomy.