THERAPY OF ENDOCRINE DISEASE: Central neck dissection: a step forward in the treatment of papillary thyroid cancer

Diagnosis of Metastatic Lymph Nodes in Patients With Papillary Thyroid Cancer: A Comparative Multi-Center Study of Semantic Features and Deep Learning-Based Models

OBJECTIVES

Deep learning algorithms have shown potential in streamlining difficult clinical decisions. In the present study, we report the diagnostic profile of a deep learning model in differentiating malignant and benign lymph nodes in patients with papillary thyroid cancer.

METHODS

An in-house deep learning-based model called "ClymphNet" was developed and tested using two datasets containing ultrasound images of 195 malignant and 178 benign lymph nodes. An expert radiologist also viewed these ultrasound images and extracted qualitative imaging features used in routine clinical practice. These signs were used to train three different machine learning algorithms. Then the deep learning model was compared with the machine learning models on internal and external validation datasets containing 22 and 82 malignant and 20 and 76 benign lymph nodes, respectively.

RESULTS

Among the three machine learning algorithms, the support vector machine model (SVM) outperformed the best, reaching a sensitivity of 91.35%, specificity of 88.54%, accuracy of 90.00%, and an area under the curve (AUC) of 0.925 in all cohorts. The ClymphNet performed better than the SVM protocol in internal and external validation, achieving a sensitivity of 93.27%, specificity of 92.71%, and an accuracy of 93.00%, and an AUC of 0.948 in all cohorts.

CONCLUSION

A deep learning model trained with ultrasound images outperformed three conventional machine learning algorithms fed with qualitative imaging features interpreted by radiologists. Our study provides evidence regarding the utility of ClymphNet in the early and accurate differentiation of benign and malignant lymphadenopathy.

Bilateral and Ipsilateral Central Neck Dissection in Total Thyroidectomy: a Long Term Comparison of Complications

The role of prophylactic central compartment neck dissection (CCND) in total thyroidectomy (TT) is controversial in patients without clinically evident lymph nodes metastasis (cN0) because of association with transient and permanent hypoparathyroidism (HPT) as well as transient and permanent recurrent laryngeal nerve (RLN) injury. Instead of bilateral central neck dissection (bCCND), ipsilateral central compartment neck dissection (iCCND) has recently been proposed as a safer, alternative treatment for selected patients. The aim of this study is to characterize the morbidity that CCND (ipsilateral and bilateral) adds to TT. We enrolled 453 patients: Group A (316 patients) underwent TT alone, Group B (86 patients) underwent TT + iCCND, Group C (51 patients) underwent TT + bCCND. We compared the rates of RLN injury and HPT in three groups and data analysis showed that iCCND was associated with increased rate of transient HPT but not permanent HPT and bCCND was associated with increased rate of transient and permanent HPT, when compared with TT alone. Further studies are needed to evaluate the clear advantages of CCND (both ipsilateral and bilateral), but this should be considered in the context of an higher risk of surgical complications (especially transient and permanent hypoparathyroidism), in comparison with TT alone.

Incidental Parathyroidectomy Among Pediatric Patients Undergoing Thyroid Surgery

OBJECTIVE

To evaluate rates of incidental parathyroidectomy(IP) and to determine risk factors among children undergoing thyroid surgery.

STUDY DESIGN

Retrospective case-control study.

METHODS

Pediatric patients undergoing thyroidectomy with or without neck dissection were included in this retrospective cohort study over a 20 year period. Demographics, clinical features, and surgical outcomes were evaluated. The primary outcome was the presence of parathyroid tissue in the surgical specimen.

RESULTS

Two hundred and eighty-six patients were included (100 cases with ≥1 parathyroid gland found in the pathology specimen and 186 controls). The most common surgical indication was cancer (49%), followed by benign nodule (25%). Hemithyroidectomy was performed in 119 (42%) patients, total thyroidectomy in 138 (48%), and completion in 29 (10%). Central neck dissection (CND) and lateral neck dissection were performed in 41% and 13%, respectively. 27 (9%) patients had parathyroid reimplantation. On univariable analysis, diagnosis, adenopathy on preoperative ultrasound, extent of thyroidectomy, neck dissection, and parathyroid reimplantation were significant predictors of IP. On multivariate analysis, CND > 5 nodes were the sole predictor of IP. Patients with IP were more likely to require postoperative calcium/vitamin D supplementation compared to those without (44% vs. 16%; P < .001).

CONCLUSIONS

Incidental parathyroidectomy during pediatric thyroidectomy is relatively common. CND was independently predictive of IP. There were increased rates of postoperative hypocalcemia when 1 or more parathyroid gland was identified in the specimen. Reimplantation of 1 parathyroid gland was predictive of another gland in the specimen. Anticipating outcomes may help optimize patient care by allowing for early supplementation, frequent monitoring, and consideration of ancillary monitoring modalities in high-risk procedures.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 132:2262-2269, 2022.

Total Laryngectomy: A Review of Surgical Techniques

Since the first total laryngectomy was performed in the late 18th century, several improvements and variations in surgical techniques have been proposed for this procedure. The surgical techniques employed in total laryngectomy have not been comprehensively discussed to date. Thus, the main objective of this article was to address controversial aspects related to this procedure and compare different surgical techniques used for a total laryngectomy procedure from the beginning to the end.

Although the management paradigms in laryngeal and hypopharyngeal squamous cell carcinomas have shifted to organ-preserving chemoradiotherapy protocols, total laryngectomy still plays a prominent role in the treatment of advanced and recurrent tumors. The increased incidence of complications associated with salvage total laryngectomy has driven efforts to improve the surgical techniques in various aspects of the operation. Loss of voice and impaired swallowing are the most difficult challenges to be overcome in laryngectomies, and the introduction of tracheoesophageal voice prostheses has made an enormous difference in postoperative rehabilitation and quality of life. Advancements in reconstruction techniques, tumor control, and metastatic management, such as prophylactic neck treatments and paratracheal nodal dissection (PTND), as well as the use of thyroid gland-preserving total laryngectomy in selected patients have all led to the increasing success of modern total laryngectomy. Several conclusions regarding the benchmarking of surgical techniques cannot be drawn. Issues regarding total laryngectomy are still open for discussion, and the technique will continue to require improvement in the near future.

Atypical Histiocytoid Cells and Multinucleated Giant Cells in Fine-Needle Aspiration Cytology of the Thyroid Predict Lymph Node Metastasis of Papillary Thyroid Carcinoma

Preoperative detection of cervical lymph node metastasis in papillary thyroid carcinoma (PTC) is crucial for determining the surgical strategy to prevent locoregional recurrence of the disease. We identified the cytological predictors of lymph node metastasis in 222 consecutive patients with PTC using fine-needle aspiration cytology (FNAC) of the thyroid. Cervical lymph node metastases occurred in 99 (44.6%) of 222 PTC patients. Lymph node metastasis was significantly associated with tumor multifocality (p = 0.003), and high cellularity (p = 0.021), atypical histiocytoid cells (p < 0.001), and multinucleated giant cells (p < 0.001) in thyroid FNAC. The BRAF V600E mutation was marginally associated with lymph node metastasis (p = 0.054). Multivariate analysis revealed that atypical histiocytoid cells (odds ratio = 2.717; p = 0.001) and multinucleated giant cells (odds ratio = 3.070; p = 0.031) were independent predictors of lymph node metastasis in patients with PTC. In a subgroup analysis of 164 patients with microcarcinomas, atypical histiocytoid cells (odds ratio = 2.761; p = 0.005) was an independent predictor of lymph node metastasis. Cytological detection of atypical histiocytoid cells and multinucleated giant cells on thyroid FNAC can be used to preoperatively predict cervical lymph node metastasis in patients with PTC.

Patterns of Lymph Node Metastasis in Differentiated Thyroid Cancer; Clinical Implications with Particular Emphasis on the Emerging Role of Compartment-Oriented Lymph Node Dissection

Recent advances in modern imaging allow an accurate identification of involved or suspicious lymph nodes within the nodal compartments of the neck. Careful ultrasonographic lymphatic mapping of the neck by an experienced radiologist allows a targeted, compartment-oriented (or selective) lymph node dissection to be performed instead of the more extensive modified radical lymph node dissection. Compartment-oriented lymph node dissection necessitates the close cooperation of an experienced radiologist with a particular interest in thyroid and neck ultrasonography. There is emerging evidence that this more conservative strategy allows local control of the disease while at the same time morbidity is minimized and a better cosmetic result is achieved. Further investigation is needed to establish the precise role of this interesting surgical approach.

Parathyroid autotransplantation at a novel site for better evaluation of the grafted gland function: study protocol for a prospective, randomized controlled trial

Background

Hypoparathyroidism is one of the most common complications encountered in thyroidectomy. In addition to parathyroid in-situ preservation, parathyroid autotransplantation (PA) is another important remedial method for patients whose parathyroid glands have been removed. However, an accurate evaluation method for the function of a transplanted parathyroid is lacking. Our preliminary study indicated that patients with PA at novel sites near antecubital veins had higher serum concentrations of parathyroid hormone (PTH). Therefore, the main hypothesis is that a grafted site closer to the cephalic vein is more useful for better evaluation of transplanted parathyroid function. This study aims to confirm the more efficient and accurate evaluation system through a prospective, randomized controlled trial.

Methods

In total, 280 patients will be enrolled in this study and randomly divided into two groups: 140 patients with transplanted parathyroid glands in the traditional sites (group A) and the other 140 transplanted in the novel sites (group B), close to the antecubital veins. The serum concentration of PTH and calcium ion from both forearms will be measured and monitored regularly for 12 months. The primary outcome of this trial will be the survival of grafted glands, defined as the ratio of PTH between the grafted vs. the non-grafted forearms being no less than 1.5. The secondary outcome is hypoparathyroidism, defined as the PTH level from the non-grafted forearms being less than 15 pg/ml (normal range 15–65 pg/ml).

Discussion

Our results from this study should provide a more accurate method to evaluate the function of transplanted parathyroid glands by comparing PTH concentrations in both the grafted and non-grafted forearms following PA at novel sites. A better PTH measurement is helpful not only for the management of postoperative patients, but also for further identification of factors affecting PA success.

Trial registration

ClinicalTrials.gov, ID: NCT02906748. Registered on 16 March 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3195-9) contains supplementary material, which is available to authorized users.

High-Dose RAI Therapy Justified by Pathological N1a Disease Revealed by Prophylactic Central Neck Dissection for cN0 Papillary Thyroid Cancer Patients: Is it Superior to Low-Dose RAI Therapy?

OBJECTIVE

One of the presumed advantages of prophylactic central neck dissection (pCND) is offering staging basis for more aggressive radioactive iodine (RAI) therapy, which postulates the necessity of high dose for treatment efficacy. The present study aims to compare the effectiveness between low-dose and high-dose RAI in a select cohort of cN0 papillary thyroid cancer (PTC) patients with pathological N1a (pN1a) disease revealed by pCND in terms of ablation rate and response to therapy. The frequency of short-term adverse effects between the two groups was also compared.

PATIENTS AND METHODS

From January 2014 to April 2016, cN0 PTC patients with pN1a disease revealed by pCND in our hospital were retrospectively reviewed. Patients with other indications for high-dose RAI, such as the presence of extrathyroidal extension, vascular invasion or suspicions of distant metastasis, were excluded. For the included patients, high dose (3700 MBq) was administered between January 2014 and August 2015 and low dose (1110 MBq) between August 2015 and April 2016. Ablation assessment was performed 6 months after RAI therapy. Response evaluation after RAI therapy was performed after 46.3 ± 9.5 months for high-dose group and 29.1 ± 2.6 months for low-dose group. All patients were also evaluated for short-term adverse effects 24 and 72 hours after RAI administration.

RESULTS

A total of 84 patients were enrolled. Among them, 42 were in the high-dose group and the other 42 in the low-dose group. There was no significant difference in ablation rate (P = 0.7707) and response to RAI therapy (P = 0.6454) between the two groups. Twenty-four hours after RAI administration, neck pain and swelling (33.3% VS. 11.9%; P = 0.0372) and gastrointestinal discomfort (45.2% vs. 21.4%; P = 0.0373) were significantly more frequent in the high-dose group.

CONCLUSION

High-dose RAI therapy, with higher frequency of short-term adverse effects, appears to be not superior to low-dose RAI therapy for cN0 PTC patients with pN1a disease revealed by pCND to achieve better response to therapy. Further randomized studies with larger series of patients and longer follow-up duration, especially with the low-dose group, are needed to validate our results.

The Relationship of Clinicopathological Factors of the Tumor with Preoperative TSH Level in Papillary Thyroid Cancers

Objective

Thyroid-stimulating hormone/thyrotropin (TSH) is known to induce malignancies and tissue growth of the thyroid gland. While the relationship of higher levels of TSH with advanced stages of cancer had been published in previous studies, the relationship of the tumor with the clinicopathological factors had not been completely evaluated. The aim of the present study was to evaluate the relationship between highly risky clinicopathological factors with preoperative high levels of TSH.

Materials and Methods

The records of 89 patients (67 females and 22 males) who underwent surgery for differentiated thyroid cancer between 2011 and 2013 were reviewed. The relationship of preoperative TSH between tumor size, multicentricity, lymphovascular invasion, extrathyroidal extension, central neck metastasis, and lateral neck metastasis was evaluated.

Results

The preoperative TSH levels were high in patients with multicentricity (p=0.022), lymphovascular invasion (p=0.018), and central neck metastasis (p=0.002). The prevalence of extrathyroidal extension (p=0.41), lymphovascular invasion (p=0.020), and central metastasis (p=0.009) was significantly high in patients with a TSH level ≥2.5 mIU/L. The preoperative TSH levels were determined as an independent predictive risk factor for central neck metastases (p=0.012) and extrathyroidal extension (p=0.041) in multinomial logistical regression analysis.

Conclusion

The power of radiological imaging for the identification of central neck metastases in preoperative evaluation is limited. The preoperative high level of TSH is an independent predictive factor for central metastases and extrathyroidal extension. It can help to predict tumor staging. Furthermore, related with multicentricity and lymphovascular invasion, it can affect the high risk characteristics of the tumor except the stage. The preoperative TSH level can be considered for the probability of preoperative metastases and can contribute to plan the extent of surgery.

European Thyroid Association Guidelines regarding Thyroid Nodule Molecular Fine-Needle Aspiration Cytology Diagnostics

Molecular fine-needle aspiration (FNA) cytology diagnostics has the potential to address the inherent limitation of FNA cytology which is an indeterminate (atypia of undetermined significance/follicular lesion of undetermined significance follicular neoplasm) cytology. Because of the emerging role of molecular FNA cytology diagnostics, the European Thyroid Association convened a panel of international experts to review methodological aspects, indications, results, and limitations of molecular FNA cytology diagnostics. The panel reviewed the evidence for the diagnostic value of mutation panel assessment (including at least BRAF, NRAS, HRAS, KRAS, PAX8/PPARG, RET/PTC) of targeted next generation sequencing and of a microarray gene expression classifier (GEC) test in the diagnostic assessment of an indeterminate cytology thyroid nodule. Moreover, possible surgical consequences of molecular FNA diagnostic results of thyroid nodules and the evidence that analysis of a molecular FNA diagnostic panel of somatic mutations or a microarray GEC test can alter the follow-up were reviewed. Molecular tests may help clinicians to drive patient care and the surgical decision if the analysis is performed in specialized laboratories. These molecular tests require standardization of performance characteristics and appropriate calibration as well as analytic validation before clinical interpretation.

Identification of risk factors of central lymph node metastasis and evaluation of the effect of prophylactic central neck dissection on migration of staging and risk stratification in patients with clinically node-negative papillary thyroid microcarcinoma

OBJECTIVE

The first aim of this study was to explore the risk factors that were associated with central lymph node metastasis (CLNM) in patients with clinically node-negative papillary thyroid microcarcinoma (cN₀ PTMC) after prophylactic central neck dissection (PCND). The second aim was to evaluate the influence of PCND on migration of TNM staging and risk stratification (RS) in patients with cN₀ PTMC.

METHODS

A total of 295 cN₀ PTMC patients who underwent thyroidectomy with PCND in the Department of General Surgery at Guangdong General Hospital between March 2014 to December 2015 were assessed retrospectively. The relations of CLNM with clinicopathologic characteristics of cN₀ PTMC were analyzed by univariate and multivariate logistic regression. The effect of PCND on migration of TNM staging and RS was also observed.

RESULTS

The incidence of CLNM was 42.4% (125 of 295 cases) in patients with cN₀ PTMC. Univariate analysis showed that age (P=0.000), ultrasonographic tumor size (P=0.009), pathologic tumor size (P=0.005), and multifocality (P=0.031) were significantly associated with the incidence of CLNM. No significant correlations were found between the presence of CLNM and other variables such as gender (P=0.399), bilaterality (P=0.118), capsular invasion (P=0.111), lymphovascular invasion (P=0.184), extent of thyroidectomy (P=0.319) and lymphadenectomy (P=0.458). Multivariate logistic regression analysis revealed that age <45 years (P=0.000) and multifocality (P=0.033) were independent predictors of CLNM in patients with cN₀ PTMC. Because of the identification of CLNM in the implementation of PCND, 42 (14.2%) patients were upstaged, and 118 (40.0%) patients upgraded in RS.

CONCLUSIONS

CLNM is highly prevalent in cN₀ PTMC. Age <45 years and multifocality are independent risk factors of CLNM in cN₀ PTMC patients. PCND can identify CLNM, which allows more accurate TNM staging/RS and may have an important impact on postoperative treatment in cN₀ PTMC patients.

Role of prophylactic central neck dissection in clinically node-negative differentiated thyroid cancer: assessment of the risk of regional recurrence

Prophylactic central neck dissection in clinically node-negative patients remains controversial. The aim of this multicenter retrospective study was to determine the rate of metastases in the central neck in clinically node-negative differentiated thyroid cancer patients, to examine the morbidity, and to assess the risk of regional recurrence in patients treated with total thyroidectomy with concomitant bilateral or ipsilateral central neck dissection compared with those undergoing total thyroidectomy alone. 258 consecutive clinically node-negative patients were divided into three groups according to the procedures performed: total thyroidectomy only (group A), total thyroidectomy with concomitant ipsilateral central neck dissection (group B), and total thyroidectomy combined with bilateral central neck dissection (group C). Mean operative time and postoperative stay were shorter in Group A (p < 0.01). The incidence of postoperative transient hypoparathyroidism was lower in Group A (p = 0.03), whereas no differences in the incidence of permanent hypoparathyroidism and nerve palsy were present. Postoperative radioactive iodine administration was higher in group B and particularly C (p = 0.03) compared with group A. There were no statistically significant differences in terms of regional recurrence. Differentiated thyroid cancer has a high rate of central lymph node metastasis even in clinically node-negative patients; in the present study there was no statistically significant difference in the rates of locoregional recurrence between the three modalities of treatment. Total thyroidectomy appears to be an adequate treatment for clinically node-negative differentiated thyroid cancer. Prophylactic central neck dissection might be considered for differentiated thyroid cancer patients with large tumor size or extrathyroidal extension.

Inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid carcinoma

BACKGROUND

The main drawback of central neck lymph node dissection is postoperative parathyroid failure. Little information is available concerning inadvertent resection of the parathyroid glands in this setting and its relationship to postoperative hypoparathyroidism. Our aim was to determine the prevalence of inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid cancer and its impact on short-and long-term parathyroid function.

METHODS

This was a prospective observational study of consecutive patients undergoing first-time total thyroidectomy with a central neck dissection for papillary carcinoma >10 mm. Prevalence and risk factors for inadvertent parathyroidectomy were recorded. Serum calcium and intact parathyroid hormone concentrations were determined 24 hours after operation and then periodically in patients developing postoperative hypocalcemia. All patients were followed for a minimum of one year.

RESULTS

Whole gland (n = 33) or microscopic parathyroid fragments (n = 14) were identified in 47/170 (28%) operative specimens. The lower parathyroid glands were involved more often. Variables influencing inadvertent parathyroidectomy were extrathyroidal extension of the tumor and therapeutic lymphadenectomy. Neither lateral neck dissection nor the number of lymph nodes retrieved affected the rate of inadvertent parathyroid resection. Postoperative hypocalcemia and permanent hypoparathyroidism were more frequent after inadvertent parathyroidectomy (64% vs 46% and 15% vs 4%; P ≤ .03 each).

CONCLUSION

Inadvertent parathyroidectomy during total thyroidectomy with central neck dissection for papillary thyroid carcinoma is common and involves the inferior glands more frequently in patients with extended resections and clinical N1a disease. Inadvertent resection of parathyroid glands is associated with greater rates of postoperative hypocalcemia and permanent hypoparathyroidism.

Evaluating the influence of prophylactic central neck dissection on TNM staging and the recurrence risk stratification of cN0 differentiated thyroid carcinoma

OBJECTIVE

The purpose of this study was to explore the risk factors that were associated with central lymph node metastasis (CLNM) in patients with clinical nodal negative differentiated thyroid carcinoma (cN0 DTC) after prophylactic central neck dissection (pCND). The influence of pCND on TNM staging and recurrence risk stratification (RRS) in patients with cN0 DTC was also evaluated in our study.

METHODS

A total of 153 cN0 DTC patients in Guangdong general hospital who underwent thyroidectomy with pCND from March 2014 to October 2014 were enrolled in this study. The relations of CLNM with clinicopathologic characteristics of cN0 DTC were analyzed by univariate and multivariate logistic regression. The influence of pCND on migration of TNM staging and RRS in cN0 DTC was observed.

RESULTS

In the present study, CLNM was found in 42.5% (65 of 153 cases) of patients with cN0 DTC. On univariate analysis, the age less than 45 years old, tumor size more than 2cm, pT staging, and a total number of central lymph nodes dissected more than 3 were significantly associated with CLNM (P<0.05); however, gender, tumors affecting both lobes, multifocality, capsular invasion, and Hashimoto's thyroiditis were not related with CLNM (P>0.05). On multivariate logistic regression, age<45 years (P=0.001) and a total number of central lymph nodes dissected >3 (P=0.002) were significantly associated with CLNM. Because of the identification of CLNM in the implementation of pCND, 15 (9.8%) of 153 cN0 DTC patients were upgraded in TNM staging; all these patients were older than 45 years. Fifty-six patients (36.6%) developed higher RRS (from low to intermediate) after pCND.

CONCLUSIONS

For younger patients (age<45 years), careful preoperative assessment of the lymph node status must be done; surgeons should consider this risk factor when deciding whether to perform pCND. Thorough lymphadenectomy in the implementation of pCND can avoid residual lymph node metastasis and help to increase the incidence of CLNM. pCND can indentify occult CLNM which allows more precise TNM staging (for patients with age≥45 years) and RRS.