Sonographic findings predictive of central lymph node metastasis in patients with papillary thyroid carcinoma: influence of associated chronic lymphocytic thyroiditis on the diagnostic performance of sonography

Malignancy risk of indeterminate lymph node at the central compartment in patients with thyroid cancer and concomitant sonographic thyroiditis

BACKGROUND

To evaluate the malignancy risk of sonographic (US) indeterminate lymph node (LN)s at the central compartment in thyroid cancer patients with US-thyroiditis (ST).

METHODS

Among the central compartments of suspicious, indeterminate, and probably benign LN US categories, the malignancy rates were compared between ST and non-US-thyroiditis (non-ST) groups. Those of indeterminate category were compared with suspicious and probably benign categories.

RESULTS

At 531 central compartments from 349 patients, the malignancy rate was lower in ST group (34.4% [44/128]) than non-ST group (43.4% [175/403]), although statistically not significant (p = 0.08). The malignancy rate of indeterminate category in ST group (35.7% [5/14]) was lower than non-ST group (71.9% [23/32]) (p = 0.047). Within ST group, the malignancy rate of indeterminate category (35.7% [5/14]) did not differ from probably benign category (29.1% [30/103]) (p = 0.756), but was lower than suspicious category (81.8% [9/11]) (p = 0.042).

CONCLUSIONS

The malignancy risk of US indeterminate LNs at the central compartment in thyroid cancer patients with US thyroiditis was lower than that in patients without US thyroiditis.

International Expert Consensus on US Lexicon for Thyroid Nodules

Multiple US-based systems for risk stratification of thyroid nodules are in use worldwide. Unfortunately, the malignancy probability assigned to a nodule varies, and terms and definitions are not consistent, leading to confusion and making it challenging to compare study results and craft revisions. Consistent application of these systems is further hampered by interobserver variability in identifying the sonographic features on which they are founded. In 2018, an international multidisciplinary group of 19 physicians with expertise in thyroid sonography (termed the International Thyroid Nodule Ultrasound Working Group) was convened with the goal of developing an international system, tentatively called the International Thyroid Imaging Reporting and Data System, or I-TIRADS, in two phases: (phase I) creation of a lexicon and atlas of US descriptors of thyroid nodules and (phase II) development of a system that estimates the malignancy risk of a thyroid nodule. This article presents the methods and results of phase I. The purpose herein is to show what has been accomplished thus far, as well as generate interest in and support for this effort in the global thyroid community.

Role of prophylactic central neck lymph node dissection for papillary thyroid carcinoma in the era of de-escalation

Thyroid cancer is the most common endocrine malignancy. While there has been no appreciable increase in the observed mortality of well-differentiated thyroid cancer, there has been an overall rise in its incidence worldwide over the last few decades. Patients with papillary thyroid carcinoma (PTC) and clinical evidence of central (cN1) and/or lateral lymph node metastases require total thyroidectomy plus central and/or lateral neck dissection as the initial surgical treatment. Nodal status in PTC patients plays a crucial role in the prognostic evaluation of the recurrence risk. The 2015 guidelines of the American Thyroid Association (ATA) have more accurately determined the indications for therapeutic central and lateral lymph node dissection. However, prophylactic central neck lymph node dissection (pCND) in negative lymph node (cN0) PTC patients is controversial, as the 2009 ATA guidelines recommended that CND "should be considered" routinely in patients who underwent total thyroidectomy for PTC. Although the current guidelines show clear indications for therapeutic CND, the role of pCND in cN0 patients with PTC is still debated. In small solitary papillary carcinoma (T1, T2), pCND is not recommended unless there are high-risk prediction factors for recurrence and diffuse nodal spread (extrathyroid extension, mutation in the BRAF gene). pCND can be considered in cN0 disease with advanced primary tumors (T3 or T4) or clinical lateral neck disease (cN1b) or for staging and treatment planning purposes. The role of the preoperative evaluation is fund-amental to minimizing the possible detrimental effect of overtreatment of the types of patients who are associated with low disease-related morbidity and mortality. On the other hand, it determines the choice of appropriate treatment and determines if close monitoring of patients at a higher risk is needed. Thus, pCND is currently recommended for T3 and T4 tumors but not for T1 and T2 tumors without high-risk prediction factors of recurrence.

Sonographic Diagnosis of Cervical Lymph Node Metastasis in Patients with Thyroid Cancer and Comparison of European and Korean Guidelines for Stratifying the Risk of Malignant Lymph Node

OBJECTIVE

To evaluate the ultrasonography (US) features for diagnosing metastasis in cervical lymph nodes (LNs) in patients with thyroid cancer and compare the US classification of risk of LN metastasis between European and Korean guidelines.

MATERIALS AND METHODS

From January 2014 to December 2018, US-guided fine-needle aspiration was performed on 836 LNs from 714 patients for the preoperative nodal staging of thyroid cancer. The US features of LNs were retrospectively reviewed for the following features: size, presence of hilum, margin, orientation, cystic change, punctate echogenic foci (PEF), large echogenic foci, eccentric cortical thickening, abnormal vascularity, and cortical hyperechogenicity. A multiple logistic regression analysis was performed to identify the independent US features for the diagnosis of metastatic LNs. The diagnostic performance of independent US features was subsequently evaluated. LNs were categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and European Thyroid Association (ETA) guidelines, and the correlation between the two sets of classifications was assessed.

RESULTS

Absence of the hilum, presence of cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features of metastatic LNs. Cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity showed high specificity (86.8%-99.6%). The absence of the hilum had the highest sensitivity yet low specificity (66.4%). When LNs were classified according to the ETA guidelines and K-TIRADS, they yielded similar categorizations of malignancy risks and were strongly correlated (Spearman coefficient, 0.9766 [95% confidence interval, 0.973-0.979]). According to the ETA guidelines, 9.8% (82/836) of LNs were classified as "not specified."

CONCLUSION

Absence of hilum, cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features suggestive of metastatic LNs in thyroid cancer. Both K-TIRADS and the ETA guidelines provided similar risk stratification for metastatic LNs with a high correlation; however, the ETA guidelines failed to classify 9.8% of LNs into a specific risk stratum. These results may provide a basis for revising LN classification in future guidelines.

Is total thyroidectomy with bilateral central neck dissection the only surgery for papillary thyroid carcinoma patients with clinically involved central nodes?

Background

In clinical practice, we often observed that patients who underwent total thyroidectomy due to clinically involved nodal disease (cN1a) actually had less extensive CLNM on final pathology. This study investigates whether total thyroidectomy and therapeutic bilateral CND are necessary for all PTC patients with cN1a.

Methods

This study retrospectively reviewed 899 PTC patients who underwent total thyroidectomy with bilateral CND from January 2012 to June 2017. The patients were divided into two groups according to pre-operative central lymph node (CLN) status: cN0, no suspicious CLNM; cN1a, suspicious CLNM. We compared the clinicopathological features of these two groups.

Results

There was no significant difference in recurrence between cN0 and cN1a groups after a mean follow-up time of 59.1 months. Unilateral cN1a was related to the largest central LN size ≥ 2 mm (OR = 3.67, p < 0.001) and number of CLNM > 5(OR = 2.24, p = 0.006). On the other hand, unilateral cN1a was not associated with an increased risk of contralateral lobe involvement (OR = 1.35, p = 0.364) and contralateral CLNM (OR = 1.31, p = 0.359). Among 106 unilateral cN1a patients, 33 (31.1%) were found to be pN0 or had ≤ 5 metastatic CLNs with the largest node smaller than 2 mm.

Conclusions

Most cN1a patients were in an intermediate risk group for recurrence and required total thyroidectomy. However, lobectomy with CND should have performed in approximately 30% of the cN1a patients. Pre-operative clinical examination, meticulous radiologic evaluation, and intra-operative frozen sections to check the nodal status are prerequisites for this approach.

Diagnostic Test Accuracy of Ultrasonography vs Computed Tomography for Papillary Thyroid Cancer Cervical Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

The use of ultrasonography (US) vs cross-sectional imaging for preoperative evaluation of papillary thyroid cancer is debated.

Objective

To compare thyroid US and computed tomography (CT) in the preoperative evaluation of papillary thyroid cancer for cervical lymph node metastasis (CLNM), as well as extrathyroidal disease extension.

Data Sources

MEDLINE and Embase were searched from January 1, 2000, to July 18, 2020.

Study Selection

Studies reporting on the diagnostic accuracy of US and/or CT in individuals with treatment-naive papillary thyroid cancer for CLNM and/or extrathyroidal disease extension were included. The reference standard was defined as histopathology/cytology or imaging follow-up. Independent title and abstract review (2515 studies) followed by full-text review (145 studies) was completed by multiple investigators.

Data Extraction and Synthesis

PRISMA guidelines were followed. Methodologic and diagnostic accuracy data were abstracted independently by multiple investigators. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool independently and in duplicate. Bivariate random-effects model meta-analysis and multivariable meta-regression modeling was used.

Main Outcomes and Measures

Diagnostic test accuracy of US and CT of the neck for lateral and central compartment CLNM, as well as for extrathyroidal disease extension, determined prior to study commencement.

Results

A total of 47 studies encompassing 31 942 observations for thyroid cancer (12 771 with CLNM; 1747 with extrathyroidal thyroid extension) were included; 21 and 26 studies were at low and high risk for bias, respectively. Based on comparative design studies, US and CT demonstrated no significant difference in sensitivity (73% [95% CI, 64%-80%] and 77% [95% CI, 67%-85%], respectively; P = .11) or specificity (89% [95% CI, 80%-94%] and 88% [95% CI, 79%-94%], respectively; P = .79) for lateral compartment CLNM. For central compartment metastasis, sensitivity was higher in CT (39% [95% CI, 27%-52%]) vs US (28% [95% CI, 21%-36%]; P = .004), while specificity was higher in US (95% [95% CI, 92%-98%]) vs CT (87% [95% CI, 77%-93%]; P < .001). Ultrasonography demonstrated a sensitivity of 91% (95% CI, 81%-96%) and specificity of 47% (95% CI, 35%-60%) for extrathyroidal extension.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that further study is warranted of the role of CT for papillary thyroid cancer staging, possibly as an adjunct to US.

Capsular extension at ultrasound is associated with lateral lymph node metastasis in patients with papillary thyroid carcinoma: a retrospective study

BACKGROUND

In patients with papillary thyroid cancer (PTC), cervical lymph node metastasis (LNM) must be carefully assessed to determine the extent of lymph node dissection required and patient prognosis. Few studies attempted to determine whether the ultrasound (US) appearance of the primary thyroid tumor could be used to predict cervical lymph node involvement. This study aimed to identify the US features of the tumor that could predict cervical LNM in patients with PTC.

METHODS

This was a retrospective study of patients with pathologically confirmed PTC. We evaluated the following US characteristics: lobe, isthmus, and tumor size; tumor position; parenchymal echogenicity; the number of lesions (i.e., tumor multifocality); parenchymal and lesional vascularity; tumor margins and shape; calcifications; capsular extension; tumor consistency; and the lymph nodes along the carotid vessels. The patients were grouped as no LNM (NLNM), central LNM (CLNM) alone, and lateral LNM (LLNM) with/without CLNM, according to the postoperative pathological examination.

RESULTS

Totally, 247 patients, there were 67 men and 180 women. Tumor size of > 10 mm was significantly more common in the CLNM (70.2%) and LLNM groups (89.6%) than in the NLNM group (45.4%). At US, capsular extension > 50% was most common in the LLNM group (35.4%). The multivariable analysis revealed that age (OR = 0.203, 95%CI: 0.095-0.431, P < 0.001) and tumor size (OR = 2.657, 95%CI: 1.144-6.168, P = 0.023) were independently associated with CLNM compared with NLNM. In addition, age (OR = 0.277, 95%CI: 0.127-0.603, P = 0.001), tumor size (OR = 6.069, 95%CI: 2.075-17.75, P = 0.001), and capsular extension (OR = 2.09, 95%CI: 1.326-3.294, P = 0.001) were independently associated with LLNM compared with NLNM.

CONCLUSION

Percentage of capsular extension at ultrasound is associated with LLNM. US-guided puncture cytology and eluent thyroglobulin examination could be performed as appropriate to minimize the missed diagnosis of LNM.

Prophylactic Central Neck Dissection in Well-differentiated Thyroid Cancer

Well-differentiated cancers, both papillary and follicular, account for 90% of all diagnosed thyroid cancers. They have an indolent disease course with a 20-year disease-specific survival over 90%. According to current guidelines, the therapy of choice for well-differentiated thyroid carcinoma is total thyroidectomy or lobectomy. The indication for prophylactic central neck dissection is still a controversial issue and the subject of unfinished and ongoing debate. There is no indication for prophylactic central neck dissection in follicular thyroid carcinomas, which primarily metastasize hematogenously. In small solitary papillary thyroid carcinomas (T1 and T2), prophylactic central neck dissection is not indicated as it does not bring benefits in terms of improved patient survival and at the same time significantly increases the risk of temporary and permanent postoperative complications. Prophylactic central neck dissection is indicated in advanced papillary thyroid cancers (T3 and T4) and all other high-risk well-differentiated thyroid cancer, as well as in the presence of metastatic lymph nodes in the lateral neck.

Factors Affecting Central Node Metastasis and Metastatic Lymph Node Ratio in Papillary Thyroid Cancer

OBJECTIVE

Despite the growing evidence that metastatic lymph node ratio (MLNR) is a valuable predictor for the prognosis of papillary thyroid carcinoma, it has not yet been fully determined which factors give the ratio predictive value independent of the number of metastatic lymph nodes (MLNs).

STUDY DESIGN

Retrospective cohort study.

SETTING

A comprehensive cancer center.

METHODS

Recurrence and clinicopathologic factors were analyzed in 2409 patients with papillary thyroid carcinoma who underwent total thyroidectomy and central node dissection.

RESULTS

Cutoff values of MLNs ≥2 and MLNR ≥28.2% increased the recurrence risk (hazard ratio [95% CI], 9.97 [4.73-21.0] and 11.4 [5.53-23.3], respectively). Younger age, male sex, multifocality, tumor size, lymphatic and vascular invasion, and gross extrathyroidal extension positively correlated with MLN and MLNR (all P < .05). Meanwhile, lymphocytic thyroiditis negatively correlated with MLNR in female patients (P < .001), by increasing total lymph node yields as compared with papillary thyroid carcinoma without lymphocytic thyroiditis. In multivariate analysis, younger age, tumor size, and lymphatic invasion remained significant in male and female patients for MLN and MLNR; lymphocytic thyroiditis was also significantly correlated with MLNR in female patients.

CONCLUSION

Our study demonstrates that MLN and MLNR are independently observed prognostic markers for tumor recurrence. However, lymphocytic thyroiditis in female patients seems to have lower MLNR by increasing total lymph node yields. In light of their association, a different cutoff for MLNR needs to be applied according to the presence or absence of underlying lymphocytic thyroiditis in the use of MLNR for predicting the recurrence.

LEVEL OF EVIDENCE

4.

The Association Between Chronic Lymphocytic Thyroiditis and the Progress of Papillary Thyroid Cancer

BACKGROUND

Whether chronic lymphocytic thyroiditis (CLT) influences the risk of development and the progression of papillary thyroid cancer (PTC) remains uncertain. We investigated the effects of CLT on the clinicopathologic features and prognosis of PTC.

METHODS

Two thousand nine hundred twenty-eight consecutive patients with PTC treated between 2009 and 2017 were divided into two groups: one with chronic lymphocytic thyroiditis and one without; 1174 (40%) of the patients had coincident CLT.

RESULTS

In univariate analysis, CLT correlated positively with small tumor size, frequent extrathyroidal extension, multifocal diseases, and p53 but negatively with central lymph node (LN) metastasis and BRAF mutation. In multivariate analysis, CLT was associated with extrathyroidal extension and multifocal disease; however, it was not a prognostic factor for recurrence even though it was associated with two aggressive factors. Compared with patients with PTC alone, there were more retrieved central LNs in the PTC + CLT group, and these patients also underwent more invasive diagnostic tests such as fine needle aspiration cytology and frozen biopsy of LN.

CONCLUSIONS

The CLT patients with PTC had better behavior features and prognoses than did those with PTC alone despite frequent multifocality and extrathyroidal extension. However, precaution may be necessary to avoid performing invasive diagnostic procedures for lateral LN metastasis and to manage the patients appropriately.

Shear wave elastography combined with gray-scale ultrasound for predicting central lymph node metastasis of papillary thyroid carcinoma

OBJECTIVE

To investigate the relationship between shear wave elastography (SWE) elasticity indices of papillary thyroid carcinoma (PTC) and central lymph node metastasis (CLNM) and to evaluate the value of SWE combined with gray-scale ultrasound (US) for predicting preoperative CLNM.

METHOD

This study included 172 patients with a pathology diagnosis of PTC who underwent preoperative gray-scale US and SWE evaluation. Patients were divided into CLNM-positive and CLNM-negative groups. We analyzed the association between SWE elasticity indices (Emax, Emean and Emin) and CLNM, compared the diagnostic efficacy of gray-scale US alone versus SWE combined with gray-scale US for predicting CLNM, and analyzed the influence of Hashimoto's thyroiditis (HT) on the diagnostic efficacy of CLNM.

RESULTS

SWE elasticity values Emax, Emean and Emin were significantly higher in CLNM-positive patients (P=0.000, 0.000 and 0.003, respectively). The AUC of Emax was higher than that of other SWE indices for predicting CLNM (AUC = 0.749; 95% CI = 0.676-0.822). In multivariate analysis, microcalcification (OR = 5.254; 95% CI = 2.496-11.061), extrathyroidal extension (OR = 4.210; 95% CI = 1.423-12.456), multifocality (OR = 3.084; 95% CI = 1.190-7.991) and Emax >59.0 kpa (OR = 4.934; 95% CI = 2.318-10.500) were independent risk factors for predicting CLNM. The AUC of SWE combined with gray-scale US for predicting CLNM (AUC = 0.825; 95% CI = 0.760-0.879) was significantly higher (P = 0.011) than that for gray-scale US alone (AUC = 0.774; 95% CI = 0.704-0.834). There was no significant difference in AUC between the HT and non-HT subgroups in predicting CLNM (0.798 vs. 0.833, P = 0.640).

CONCLUSIONS

SWE can be used to predict CLNM in PTC patients. SWE combined with gray-scale US can improve the prediction of CLNM.

Correlations of neck ultrasound and pathology in cervical lymph node of papillary thyroid carcinoma

Background: High-resolution sonography is becoming a method of choice for the detection and diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC). The purpose of this study is to assess the diagnostic accuracy of neck ultrasound (US) in the detection of lymph node metastases from PTC.Methods: Data for all patients with papillary thyroid cancers and preoperative neck US were reviewed retrospectively. The diagnostic accuracy of US was determined according to whether histologically confirmed cancer was present in surgical cervical lymph node specimens.Results: A total of 206 patients (149 central and 57 central and lateral lymph nodes dissection) were included. Their mean age was 56 years (14-88 years). Central and lateral lymph nodes were involved in 68% (n = 141 patients; 141/206) and 60% (n = 34 patients; 34/57) of cases, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of US in predicting papillary thyroid carcinoma (PTC) metastasis in the central neck were 69%, 71%, 84% and 51% respectively, and in the lateral neck were 85%, 65%, 78% and 75% respectively.Conclusions: Preoperative neck US is a valuable tool in the detection of cervical lymph node metastases from papillary thyroid cancer and can provide reliable information to assist in surgical management.

Diagnostic accuracy of single-source dual-energy computed tomography and ultrasonography for detection of lateral cervical lymph node metastases of papillary thyroid carcinoma

Background

Dual-energy computed tomography (DECT) imaging can generate iodine-based material decomposition (MD) images and spectral HU curve. This study aimed to investigate the diagnostic accuracy of single-source dual-energy CT (DECT) and ultrasonography (US) for detecting lateral cervical lymph node metastases of papillary thyroid carcinoma (PTC).

Methods

Thirty patients with PTC were enrolled in the study and underwent DECT and US examination before thyroidectomy and cervical lymph node dissection. The spectral parameters included iodine concentration (IC), normalized iodine concentration (NIC) and slope (λ_HU) of lymph nodes. The CT morphological parameters included maximal short diameter, shape, margin, calcification and cystic degeneration of lymph nodes. The US morphological parameters included maximal short diameter, calcification and cystic degeneration of lymph nodes. The diagnostic value of every single spectral parameter, combined gemstone spectral image (GSI) parameters, CT morphological parameters and US morphological parameters between metastatic and non-metastatic lymph nodes were statistically compared. Receiver operating characteristic (ROC) curves, sensitivity, and specificity were used to determine the diagnostic value.

Results

Ninety-nine lymph nodes from thirty patients were pathologically confirmed. Among them, 70 (70.7%) were metastatic. For single GSI parameters, ROC analysis showed that the area under the curve (AUC) for IC was the highest (AUC =0.937) but the difference was not statistically significant when compared with NIC or slope (λ_HU) (P>0.05). The optimal diagnostic threshold for IC was 2.56 mg/mL, with a sensitivity, specificity and accuracy of 87.1%, 93.1%, and 88.9%, respectively. The AUC for combined GSI parameter (AUC =0.942) was higher compared with the US morphological parameters (AUC =0.771, P<0.001), with a sensitivity, specificity, and accuracy of 92.9%, 86.2%, and 90.9%, respectively. However AUC did not differ significantly among combined GSI parameters, combined CT morphological parameters and a single application for spectral CT parameters IC (P>0.05).

Conclusions

Combined GSI parameters showed better diagnostic accuracy in lateral cervical lymph node metastasis of PTC compared with that of combined US morphological parameters. IC alone showed excellent diagnostic stability and could be performed easily.

Sonographic diagnosis in the head and neck region: from an educational lecture presented at the 56th General Assembly and Annual Scientific Congress of the Japanese Society for Oral and Maxillofacial Radiology

Sonography is a simple, inexpensive, and non-invasive diagnostic modality. Although tissues behind bony structures and deep tissues are not delineated, sonography can depict superficial soft tissues very clearly. In the head and neck region, however, it has not yet been used widely, as the anatomical structures are complicated, and considerable experience is needed both to perform an examination and to make a diagnosis. To perform examinations efficiently, operators must be familiar with the sonographic system in use, and take images at standard planes. To make a correct diagnosis, operators require knowledge of the sonographic anatomy on standard planes, representative sonographic signs and artifacts, and common diseases and their typical sonographic findings. In this paper, we have explained the sonographic anatomy on standard planes, and the sonographic findings of common diseases in the oral and maxillofacial region.

Shear wave elastography in the evaluation of level VI lymph nodes in papillary thyroid carcinoma: combined with gray-scale ultrasound ex vivo

Background

The evaluation of cervical lymph nodes is very important for patients with papillary thyroid carcinoma (PTC). Conventional ultrasound is recommended to assess the status of cervical lymph nodes but the diagnostic performance is not satisfying especially in level VI lymph nodes. Recently, shear wave elastography has shown great potential in diagnosis. Therefore, this study aimed at exploring the value of shear wave elastography in ultrasound evaluation for level VI lymph nodes in papillary thyroid carcinoma. Because Hashimoto’s thyroiditis may influence the diagnostic performance, a subgroup was also analysed that included only lymph nodes from PTC without Hashimoto’s thyroiditis.

Methods

Eighty-Seven level VI lymph nodes from 22 consecutive patients with papillary thyroid carcinoma were evaluated by gray-scale ultrasound and SWE in condition of ex vivo before rapid frozen section. Gray-scale ultrasound and shear wave elastography indexes of metastatic and non-metastatic lymph nodes were evaluated by statistical analysis separately in all patients and in patients without Hashimoto’s thyroiditis. Indexes included long diameter, short diameter, short-to-long diameter ratio (S/L ratio), E_mean, E_min, E_max and E_SD. The rapid frozen section result of each lymph node was used as gold standard to evaluate the diagnostic performance of gray-scale ultrasound and combination method which combined gray-scale ultrasound and SWE.

Results

In all patients, significant indexes included short diameter (p = 0.009), S/L ratio (p = 0.003), E_max (p = 0.016) and E_SD (p = 0.006). In patients without Hashimoto’s thyroiditis, significant indexes included short diameter (p = 0.002), S/L ratio (p = 0.003), E_mean (p = 0.030), E_max (p < 0.001) and E_SD (p = 0.001). Combining gray-scale ultrasound with SWE, combination method had higher AUC than gray-scale ultrasound both in all patients (0.887 vs 0.841) and patients without Hashimoto’s thyroiditis (0.925 vs 0.866). Gray-scale ultrasound had higher AUC in patients without Hashimoto’s thyroiditis than in all patients (0.866 vs 0.841), which was the same with combination method (0.925 vs 0.887).

Conclusion

Shear wave elastography can provide additional information for ultrasound evaluation of level VI lymph nodes in papillary thyroid carcinoma, especially in papillary thyroid carcinoma without Hashimoto’s thyroiditis.

Evaluation of diagnostic value of conventional and color Doppler ultrasound with elastography strain ratios in differentiation between benign and malignant lymph nodes

Introduction

The aim of this study was to evaluate the diagnostic value of conventional ultrasonography (USG) and color Doppler ultrasonography (CDU) with elastography strain ratios (ESR) in discrimination between benign and malignant lymphatic nodes.

Material and methods

Two hundred and forty-seven patients (252 lymph nodes) were included in this study. USG and CDU with ESR were performed. Materials were obtained by using fine-needle or vacuum-assisted aspiration methods depending on the site and condition of lymph nodes. The χ² test and Student’s t-test were used for comparisons.

Results

Ninety-two of 252 (36.5%) lymph nodes were malignant, and 160 (63.5%) were benign. Short axis, S/L ratio, presence or absence of the fatty hilum and extra-hilar vascularity were valuable, statistically significant indicators of malignancy. In contrast, long axis and ESR were not significant indicators of malignancy. The short axis cut-off value was calculated to be 12 mm and the S/L ratio cut-off value was calculated to be 1.

Conclusions

Long axis of lymph nodes and strain ratios cannot be used as malignancy criteria, and their use is controversial despite the fact that some studies have found them valuable. On the other hand, our results support common knowledge that the short axis, S/L ratio, absence of the fatty hilum, and extrahilar vascularity are significant indicators.

Fine Needle Aspiration in the Investigation of Thyroid Nodules

BACKGROUND

Thyroid nodules are a common finding in Germany. Most are benign; thyroid cancer is very rare. The challenge for the physician is to diagnose malignant tumors early. Fine needle aspiration is an important tool for this purpose.

METHODS

This review is based on pertinent articles (1980-2014) retrieved by a selective search in PubMed and on the current recommendations of guidelines issued by the specialty societies in Germany and abroad.

RESULTS

Clinical, ultrasonographic, and scintigraphic criteria are used to identify high-risk nodules, which are then further studied by fine needle aspiration. Important ultrasonographic criteria for malignancy are low echodensity (positive predictive value [PPV]: 1.85), microcalcifications (PPV: 3.65), irregular borders (PPV: 3.76), and intense vascularization. Fine needle aspiration of the thyroid gland is an inexpensive and technically straight - forward diagnostic procedure that causes little discomfort for the patient. It helps prevent unnecessary thyroid surgery and is used to determine the proper surgical strategy if malignancy is suspected. The cytological study of fine needle aspirates enables highly precise diagnosis of many tumor entities, but follicular neoplasia can only be diagnosed histologically. In the near future, molecular genetic methods will probably extend the diagnostic range of fine needle aspiration beyond what is currently achievable with classic cytology.

CONCLUSION

Fine needle aspiration biopsy of the thyroid gland in experienced hands is an easily performed diagnostic procedure with very little associated risk. It should be performed on ultrasonographically suspect nodules for treatment stratification and before any operation for an unclear nodular change in the thyroid gland.

Ultrasound features of extranodal extension in the metastatic cervical lymph nodes of papillary thyroid cancer: a case-control study

Objective:

Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer. The purpose of this study was to identify the common and characteristic preoperative ultrasonography features that are associated with the pathologic extranodal extension of metastatic papillary thyroid carcinoma.

Methods:

We retrospectively assessed and compared clinicopathologic and ultrasound features between 60 papillary thyroid cancer patients with extranodal extension and 120 control patients with papillary thyroid cancer without extranodal extension.

Results:

With respect to the pathological N stage and clinicopathologic features, N1b stage papillary thyroid carcinomas were more frequently found in patients who were extranodal extension-positive, in comparison with those who were extranodal extension-negative (78.3% vs. 63.3%, P=0.043). Extranodal extension was detected most frequently in level VI cervical lymph nodes (48.7%). In our univariate analysis of patients with papillary thyroid carcinoma, cervical lymph nodes with extranodal extension showed higher incidences of node matting, microcalcification, cystic area, aspect ratio <2, and larger diameter than those without extranodal extension (all P<0.05). Our multivariate analysis demonstrated that node matting and cystic area were independent risk factors for the presence of extranodal extension [odds ratio (OR): 4.751, 95% confidence interval (CI): 1.212~18.626, P=0.025; OR: 2.707, 95% CI: 1.127~6.502, P=0.026].

Conclusions:

Common ultrasound features may indicate the presence of extranodal extension in patients with metastatic cervical lymph nodes of papillary thyroid carcinoma.

Active Surveillance for Papillary Thyroid Microcarcinoma: Challenges and Prospects

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.

Preliminary study on the diagnostic value of single-source dual-energy CT in diagnosing cervical lymph node metastasis of thyroid carcinoma

Background

To investigate the value of single-source dual-energy spectral CT imaging in improving the accuracy of preoperative diagnosis of lymph node metastasis of thyroid carcinoma.

Methods

Thirty-four thyroid carcinoma patients were enrolled and received spectral CT scanning before thyroidectomy and cervical lymph node dissection surgery. Iodine-based material decomposition (MD) images and 101 sets of monochromatic images from 40 to 140 keV were reconstructed after CT scans. The iodine concentrations (IC) of lymph nodes were measured on the MD images and was normalized to that of common carotid artery to obtain the normalized iodine concentration (NIC). The CT number of lymph nodes as function of photon energy was measured on the 101 sets of images to generate a spectral HU curve and to calculate its slope λ_HU. The measurements between the metastatic and non-metastatic lymph nodes were statistically compared and receiver operating characteristic (ROC) curves were used to determine the optimal thresholds of these measurements for diagnosing lymph nodes metastasis.

Results

There were 136 lymph nodes that were pathologically confirmed. Among them, 102 (75%) were metastatic and 34 (25%) were non-metastatic. The IC, NIC and the slope λ_HU of the metastatic lymph nodes were 3.93±1.58 mg/mL, 0.70±0.55 and 4.63±1.91, respectively. These values were statistically higher than the respective values of 1.77±0.71 mg/mL, 0.29±0.16 and 2.19±0.91 for the non-metastatic lymph nodes (all P<0.001). ROC analysis determined the optimal diagnostic threshold for IC as 2.56 mg/mL, with the sensitivity, specificity and accuracy of 83.3%, 91.2% and 85.3%, respectively. The optimal threshold for NIC was 0.289, with the sensitivity, specificity and accuracy of 96.1%, 76.5% and 91.2%, respectively. The optimal threshold for the spectral curve slope λ_HU was 2.692, with the sensitivity, specificity and accuracy of 88.2%, 82.4% and 86.8%, respectively.

Conclusions

The measurements obtained in dual-energy spectral CT improve the sensitivity and accuracy for preoperatively diagnosing lymph node metastasis in thyroid carcinoma.

A scoring system is an effective tool for predicting central lymph node metastasis in papillary thyroid microcarcinoma: a case-control study

Background

The purpose of this study was to evaluate the clinicopathologic and ultrasonographic (US) characteristics and establish an effective scoring system for predicting central lymph node metastasis (CLNM) in papillary thyroid microcarcinoma (PTMC).

Methods

A total of 498 patients with PTMC who underwent total thyroidectomy or lobectomy with therapeutic central lymph node dissection (CLND) were enrolled. Univariate and multivariate analyses were performed to find the independent predictors for CLNM based on clinicopathological and US characteristics. Using the standardized regression coefficient, a 10-point score system was constructed in line with these independent predictors. Then, the scoring system was evaluated for the diagnostic value in predicting CLNM.

Results

Tumor location (the lower polo), tumor size (>5 mm), extrathyroidal extension, margin (no well-defined), display of enlarged lymph node, and contact of >25 % with the adjacent capsule were independent predictors for CLNM. Verifying the scoring system, a cutoff value of 5 points was found to be the best prediction for CLNM, the sensitivity and specificity were 64.7 and 80.5 %, respectively, and the positive and negative predictive values were 77.3 and 69.0 %, respectively.

Conclusions

The points ≤ 5 could be considered as a low risk for CLNM, and the points > 5 could be identified as a high risk for CLNM. More advanced diagnostic approaches and prophylactic CLND are needed for patients with the points > 5.