Node-negative Papillary Thyroid Carcinoma Research Articles

The Impact of Intraoperative Neural Monitoring During Papillary Thyroid Cancer Surgery on Completeness of Thyroidectomy and Thyroglobulin Response: A Propensity-Score Matched Study

ABSTRACT Background Intraoperative neural monitoring (IONM) has been utilized for a variety of thyroid pathologies, including papillary thyroid carcinoma (PTC). Remnant thyroid tissue following total thyroidectomy (TT) in patients with PTC is associated with increased recurrence. The aim of this study is to investigate whether the use of IONM in PTC surgery has an impact on the completeness of thyroidectomy. Methods Retrospectively, patients with preoperative diagnosis of PTC, who underwent TT in a tertiary center were reviewed. They were grouped based on the IONM usage, and 1:1 propensity-score match was performed. Primary outcome was the completeness of thyroidectomy, determined by measuring postoperative stimulated thyroglobulin levels (sTg). Results Among 274 clinically node-negative PTC patients who underwent TT and ipsilateral prophylactic central lymph-node dissection, a total of 170 patients (85:85) were matched. Postoperative sTg levels were significantly lower in the IONM group (1ng/dL vs. 0.4ng/dL;p < 0.01) with higher percentage of the patients with sTg levels <1ng/ml (50.6% vs. 69.4%;p = 0.01). More patients in the no-IONM group received RAI ablation with significantly higher doses (mean mci:120 vs. 102;p = 0.02). Conclusion The use of IONM during thyroidectomy provides improvement in the completeness of thyroidectomy and reduction in postoperative sTg levels which can be used as a guide by clinicians to avoid RAI ablation in selected PTC patients and to adjust low ablative doses in patients who are scheduled for remnant ablation.

Deep learning predicts cervical lymph node metastasis in clinically node-negative papillary thyroid carcinoma

ObjectivesPrecise determination of cervical lymph node metastasis (CLNM) involvement in patients with early-stage thyroid cancer is fairly significant for identifying appropriate cervical treatment options. However, it is almost impossible to directly judge lymph node metastasis based on the imaging information of early-stage thyroid cancer patients with clinically negative lymph nodes.MethodsPreoperative US images (BMUS and CDFI) of 1031 clinically node negative PTC patients definitively diagnosed on pathology from two independent hospitals were divided into training set, validation set, internal test set, and external test set. An ensemble deep learning model based on ResNet-50 was built integrating clinical variables, BMUS, and CDFI images using a bagging classifier to predict metastasis of CLN. The final ensemble model performance was compared with expert interpretation.ResultsThe ensemble deep convolutional neural network (DCNN) achieved high performance in predicting CLNM in the test sets examined, with area under the curve values of 0.86 (95% CI 0.78–0.94) for the internal test set and 0.77 (95% CI 0.68–0.87) for the external test set. Compared to all radiologists averaged, the ensemble DCNN model also exhibited improved performance in making predictions. For the external validation set, accuracy was 0.72 versus 0.59 (p = 0.074), sensitivity was 0.75 versus 0.58 (p = 0.039), and specificity was 0.69 versus 0.60 (p = 0.078).ConclusionsDeep learning can non-invasive predict CLNM for clinically node-negative PTC using conventional US imaging of thyroid cancer nodules and clinical variables in a multi-institutional dataset with superior accuracy, sensitivity, and specificity comparable to experts.Critical relevance statementDeep learning efficiently predicts CLNM for clinically node-negative PTC based on US images and clinical variables in an advantageous manner.Key points• A deep learning-based ensemble algorithm for predicting CLNM in PTC was developed.• Ultrasound AI analysis combined with clinical data has advantages in predicting CLNM.• Compared to all experts averaged, the DCNN model achieved higher test performance.Graphical

Age and Post-Lobectomy Recurrence after Endoscopic or Robotic Thyroid Surgery: A Retrospective Cohort Study of 2348 Papillary Thyroid Carcinoma Patients

The biology of papillary thyroid carcinoma (PTC) in young patients is poorly understood, and there are conflicting data regarding the recurrence for younger patients compared to older patients. We retrospectively analyzed 2348 clinically node-negative (cN0) PTC patients who underwent a thyroid lobectomy between 2008 and 2017. Young age was defined as less than 35 years old. The clinicopathological characteristics and oncologic outcomes of the young age group were compared to those of the older age group. The number of young age cN0 PTC patients accounted for 20.7% of the enrolled patients, and 24.2% were upstaged into pathologic N1a. The young age group had a significantly larger proportion of females, endoscopic/robotic thyroid lobectomies, stage N1a, and larger tumor sizes. Post-lobectomy recurrences were significantly higher in the young age group. In the Cox analysis, young age, large tumor size, and stage N1a were significant risk factors. The multivariate analysis reveals that young age and stage N1a are significant risk factors. Conversely, minimally invasive or robot-endoscopic thyroidectomies were not risk factors for post-lobectomy recurrence compared to conventional thyroidectomies. While young patients with a stage N1a had a significant risk factor for post-lobectomy recurrence, endoscopic/robotic thyroidectomy was as feasible and safe as conventional thyroidectomies in the median seven-year oncologic follow-up. Further high-quality studies are needed to elucidate the relationship between age and the risk of post-lobectomy recurrence.

Development and Validation of a Dual-Energy CT-Based Model for Predicting the Number of Central Lymph Node Metastases in Clinically Node-Negative Papillary Thyroid Carcinoma

This study aimed to develop and validate a dual-energy CT (DECT)-based model for preoperative prediction of the number of central lymph node metastases (CLNMs) in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) patients. Between January 2016 and January 2021, 490 patients who underwent lobectomy or thyroidectomy, CLN dissection, and preoperative DECT examinations were enrolled and randomly allocated into the training (N=345) and validation cohorts (N=145). The patients' clinical characteristics and quantitative DECT parameters obtained on primary tumors were collected. Independent predictors of>5 CLNMs were identified and integrated to construct a DECT-based prediction model, for which the area under the curve (AUC), calibration, and clinical usefulness were assessed. Risk group stratification was performed to distinguish patients with different recurrence risks. More than 5 CLNMs were found in 75 (15.3%) cN0 PTC patients. Age, tumor size, normalized iodine concentration (NIC), normalized effective atomic number (nZeff) and the slope of the spectral Hounsfield unit curve (λHu) in the arterial phase were independently associated with>5 CLNMs. The DECT-based nomogram that incorporated predictors demonstrated favorable performance in both cohorts (AUC: 0.842 and 0.848) and significantly outperformed the clinical model (AUC: 0.688 and 0.694). The nomogram showed good calibration and added clinical benefit for predicting>5 CLNMs. The KaplanMeier curves for recurrence-free survival showed that the high- and low-risk groups stratified by the nomogram were significantly different. The nomogram based on DECT parameters and clinical factors could facilitate preoperative prediction of the number of CLNMs in cN0 PTC patients.

Effect of prophylactic central neck dissection following total thyroidectomy on surgical site wound infection, hematoma, and haemorrhage in subjects with clinically node-negative papillary thyroid carcinoma: A meta-analysis.

We performed a meta-analysis to evaluate the effect of prophylactic central neck dissection following total thyroidectomy on surgical site wound infection, hematoma, and haemorrhage in subjects with clinically node-negative papillary thyroid carcinoma. A systematic literature search up to April 2022 was performed and 3517 subjects with clinically node-negative papillary thyroid carcinoma at the baseline of the studies; 1503 of them were treated with prophylactic central neck dissection following total thyroidectomy, and 2014 were using total thyroidectomy. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of prophylactic central neck dissection following total thyroidectomy on surgical site wound infection, hematoma, and haemorrhage in subjects with clinically node-negative papillary thyroid carcinoma using the dichotomous method with a random or fixed-effect model. The prophylactic central neck dissection following total thyroidectomy subjects had a significantly lower surgical site wound infection (OR, 0.40; 95% CI, 0.20-0.78, P=.007) in subjects with clinically node-negative papillary thyroid carcinoma compared with total thyroidectomy. However, prophylactic central neck dissection following total thyroidectomy did not show any significant difference in hematoma (OR, 0.08; 95% CI, 0.43-2.71, P=.87), and haemorrhage (OR, 0.72; 95% CI, 0.26-1.97, P=.52) compared with total thyroidectomy in subjects with clinically node-negative papillary thyroid carcinoma. The prophylactic central neck dissection following total thyroidectomy subjects had a significantly higher surgical site wound infection, and no significant difference in hematoma, and haemorrhage compared with total thyroidectomy in subjects with clinically node-negative papillary thyroid carcinoma. The analysis of outcomes should be with caution because of the low number of studies in certain comparisons.

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

BACKGROUNDLymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) has a certain regularity and occurs first to the central lymph node and then to the lateral lymph node. The pathway of PTC LNM can guide surgical prophylactic lymph node dissection (LND) for clinical surgeons.AIMTo investigate the relationship between subgroups of central LNM and lateral LNM in unilateral clinically node-negative PTC (cN0-PTC).METHODSData were collected for 1089 PTC patients who underwent surgical treatment at the Department of Endocrine and Breast Surgery of the First Hospital of Chongqing Medical University from January 2016 to December 2017. A total of 388 unilateral cN0-PTC patients met the inclusion criteria and were enrolled in this study. The clinical and pathological data for these 388 patients who underwent total thyroidectomy + central LND + lateral LND were retrospectively analyzed. The relationship between the central LNM and lateral LNM subgroups was investigated.RESULTSThe coincidence rate of cN0-PTC was only 30.0%.Optimal scaling regression analysis showed that sex (57.1% vs 42.9%, P = 0.026), primary tumor size (68.8% vs 31.2%, P = 0.008), tumor location (59.7% vs 40.3%, P = 0.007), extrathyroid extension (ETE) (50.6% vs 49.9%, P = 0.046), and prelaryngeal LNM (57.1% vs 42.9%, P = 0.004) were significantly associated with ipsilateral level-II LNM. Their importance levels were 0.122, 0.213, 0.172, 0.110, and 0.227, respectively. Primary tumor size (74.6% vs 30.2%, P = 0.016), pretracheal LNM (67.5% vs 32.5%, P < 0.001), and paratracheal LNM (71.4% vs 28.6%, P < 0.001) were significantly associated with ipsilateral level-III LNM. Their importance levels were 0.120, 0.408, and 0.351, respectively. Primary tumor size (72.1% vs 27.9%, P = 0.003), ETE (70.4% vs 29.6%, P = 0.016), pretracheal LNM (68.3% vs 31.7%, P=0.001), and paratracheal LNM (80.8% vs 19.2%, P < 0.001) were significantly associated with ipsilateral level-IV LNM. Their importance levels were 0.164, 0.146, 0.216, and 0.472, respectively. CONCLUSIONThe LNM pathway of thyroid cancer has a certain regularity. For unilateral cN0-PTC patients with a tumor diameter > 2 cm and pretracheal or ipsilateral paratracheal LNM, LND at ipsilateral level III and level IV must be considered. When there is a tumor in the upper third of the thyroid with prelaryngeal LNM, LND at level II, level III and level IV must be considered.

Prophylactic central lymph node dissection performed selectively with cN0 papillary thyroid carcinoma according to a risk-scoring model.

This study aimed to explore the risk factors of central lymph node metastasis (CLNM) in patients with clinical central lymph node-negative papillary thyroid carcinoma (PTC), and emphasize the guidance of the risk scoring model for prophylactic central lymph node dissection (pCLND) in patients with clinical lymph node-negative (cN0) PTC. A total of 582 patients with cN0 PTC who underwent unilateral/bilateral thyroidectomy and prophylactic central lymph node dissection (pCLND) in the Affiliated Hospital of Nantong University from January 2020 to February 2021 were retrospectively analyzed. Univariate and multivariate analyses were performed to determine the risk factors of cN0 PTC. According to the independent risk factors of patients with cN0 PTC, a risk-scoring model was established. Then, the rationality of this risk scoring model was verified by additional clinical data of 112 patients with cN0 PTC in the Affiliated Hospital of Nantong University from March 2021 to April 2021. Among 582 cases of cN0 PTC, 53.6% of the patients with cN0 had CLNM. The independent risk factors for CLNM in patients with cN0 PTC included male gender, <45 years of age, tumor with a maximum diameter of ≥1.0 cm, tumor location: middle/lower poles of the thyroid gland, multifocality, and extrathyroidal extension (ETE), and some ultrasound features, such as intra-nodular vascularity, microcalcification, irregular shape, and infiltrative margin. According to independent risk factors, a 24-point risk scoring model was established to predict CLNM in patients with cN0 PTC. Currently, prophylactic central neck lymph node dissection is a controversial operation, which should be selectively performed only for high-risk patients with cN0 PTC. For cN0 PTC patients with scores ≥14 and high-risk patients, even if no CLNM is found before surgery, routine prophylactic CLND is recommended. In addition, for cN0 PTC patients with a score of fewer than 14 points, it is recommended to perform fine-needle aspiration (FNA) before surgery, carefully assess the condition of the central lymph nodes, and then select the best surgical plan based on the results of the assessment.

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

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) that scrutinized the oncological benefits and postsurgical complications of total thyroidectomy (TT) plus prophylactic central neck dissection (pCND) versus TT alone among clinically node-negative (cN0) papillary thyroid cancer (PTC) patients. We screened five databases from inception to September 4, 2021 and evaluated the risk of bias of the eligible studies. We pooled dichotomous outcomes using the risk ratio (RR) with 95% confidence interval (CI). Overall, we included 5 RCTs with low risk of bias comprising 795 patients (TT plus pCND=410 and TT alone=385). With regard to efficacy endpoint, the rate of structural loco-regional recurrence did not significantly differ between both groups (n= 4 RCTs, RR=0.49, 95% CI [0.19, 1.27], P= .14). With regard to safety endpoints, the rates of hypoparathyroidism (n= 5 RCTs, RR=1.48, 95% CI [0.73, 2.97], P= .27), recurrent laryngeal nerve injury (n= 5 RCTs, RR=1.34, 95% CI [0.59, 3.03], P= .48), and bleeding (n= 3 RCTs, RR=1.75, 95% CI [0.42, 7.26], P= .44) did not significantly differ between both groups. For cN0 PTC patients, there was no significant difference between TT plus pCND and TT alone with regard to the rate of structural loco-regional recurrence or frequency of postsurgical complications. Adaptation of pCND in cN0 PTC patients should be contemplated by taking into consideration the clinical oncological benefits and rate of postsurgical adverse events. 1 Laryngoscope, 132:1320-1328, 2022.

Application of Carbon Nanoparticles in Neck Dissection of Clinically Node-Negative Papillary Thyroid Carcinoma.

Purpose The purpose of this retrospective study was to evaluate the advantages of carbon nanoparticles in neck dissection and to conclude its application in the treatment of clinically node-negative papillary thyroid carcinoma (CN0PTC). Methods As a retrospective cohort study, we divided the enrolled patients into two groups, the carbon nanoparticle (CN) group and the control group according to the usage of CN. In the CN group, CN was applied to reveal drainage lymph nodes and the picked LNs were sent for fast frozen testing. If metastasis exits, modified radical lateral lymph node dissection (LLND) was performed. For both groups, prophylactic central lymph node dissection was routinely done. Finally, the demographic information, tumor characteristics, postoperative pathological results, and laboratory data were collected for analysis. Results A total of 61 CN0PTC were enrolled in this study, 33 in the CN group and 28 in the control group. The black-stained rate for CN was 29/40 (72.5%) with a positive prediction rate of 34.5%. The mainly black-stained region in the lateral neck was level III and possesses the highest lymph node ratio (17.5%). The metastasis that occurred in level VI was 30% and 11.8% in the CN and control groups, respectively (p = 0.058). During the available follow-up, no one showed recurrence. Statistical analysis showed that the CN suspension can significantly reduce the risk of damage to the parathyroid gland (p = 0.001 for hypocalcemia, <0.05; p = 0.047 for hypoparathyroidism, <0.05). Conclusion The lateral neck metastasis in patients with papillary thyroid microcarcinoma in clinical stage cT1aN0 is not rare. CN can help surgeons to distinguish the real person who actually needs LLND. In prophylactic CLND, CN acts as a tracer which makes the parathyroid gland more identifiable and avoids risks of injuries to nerves and glands.

Value of Combining Clinical Factors, Conventional Ultrasound, and Contrast-Enhanced Ultrasound Features in Preoperative Prediction of Central Lymph Node Metastases of Different Sized Papillary Thyroid Carcinomas.

PurposeEarly and accurate preoperative diagnosis of central lymph node metastasis (CLNM) is crucial to improve surgical management of patients with clinical lymph node-negative papillary thyroid carcinoma (PTC). Towards improving diagnosis of CLNM, we assessed the value of combining preoperative clinical characteristics, conventional ultrasound, and contrast-enhanced ultrasound (CEUS) in preoperative prediction of CLNM of different sized PTCs.Patients and MethodsPatients were divided according to tumor size: a PTC group (>10 mm) and a papillary thyroid microcarcinoma (PTMC) group (≤10 mm). We retrospectively analyzed the clinical and ultrasonographic features of 120 PTC patients and 165 PTMC patients. Multivariate logistic regression analysis was used to screen independent risk factors and establish prediction models. Receiver operating characteristic curves were used to determine the best cut-off values for continuous variables and assess the performance of prediction models.ResultsIndependent risk predictors of CLNM for the PTC group were extrathyroidal extension in CEUS (OR=7.923), tumor size >14 mm (OR=5.491), and multifocality (OR=3.235). For the PTMC group, the independent risk factors were the distance from the thyroid capsule =0 mm (OR=4.629), male (OR=3.315), tumor size >5 mm (OR=3.304), and microcalcification (OR=2.560). The predictive model of combined method had better performance in predicting CLNM of PTC compared with models based on CEUS and conventional ultrasound alone (area under the curve: 0.832 vs 0.739, P=0.0011; 0.832 vs 0.678, P=0.0012). For PTMC, comparing with CEUS, the combined method and conventional ultrasound performed better than CEUS alone in predicting CLNM (area under the curve: 0.783 vs 0.636, P=0.0016; 0.738 vs 0.636, P=0.0196).ConclusionThe predictive models of combined method obtained from significant preoperative clinical and ultrasonographic features can potentially improve the preoperative diagnosis and individual treatment of CLNM in patients with PTC and PTMC. CEUS may be helpful in predicting CLNM of PTC, but CEUS would be ineffective in predicting CLNM of PTMC.

Application of Machine Learning Algorithms to Predict Central Lymph Node Metastasis in T1-T2, Non-invasive, and Clinically Node Negative Papillary Thyroid Carcinoma.

Purpose: While there are no clear indications of whether central lymph node dissection is necessary in patients with T1-T2, non-invasive, clinically uninvolved central neck lymph nodes papillary thyroid carcinoma (PTC), this study seeks to develop and validate models for predicting the risk of central lymph node metastasis (CLNM) in these patients based on machine learning algorithms.Methods: This is a retrospective study comprising 1,271 patients with T1-T2 stage, non-invasive, and clinically node negative (cN0) PTC who underwent surgery at the Department of Endocrine and Breast Surgery of The First Affiliated Hospital of Chongqing Medical University from February 1, 2016, to December 31, 2018. We applied six machine learning (ML) algorithms, including Logistic Regression (LR), Gradient Boosting Machine (GBM), Extreme Gradient Boosting (XGBoost), Random Forest (RF), Decision Tree (DT), and Neural Network (NNET), coupled with preoperative clinical characteristics and intraoperative information to develop prediction models for CLNM. Among all the samples, 70% were randomly selected to train the models while the remaining 30% were used for validation. Indices like the area under the receiver operating characteristic (AUROC), sensitivity, specificity, and accuracy were calculated to test the models' performance.Results: The results showed that ~51.3% (652 out of 1,271) of the patients had pN1 disease. In multivariate logistic regression analyses, gender, tumor size and location, multifocality, age, and Delphian lymph node status were all independent predictors of CLNM. In predicting CLNM, six ML algorithms posted AUROC of 0.70–0.75, with the extreme gradient boosting (XGBoost) model standing out, registering 0.75. Thus, we employed the best-performing ML algorithm model and uploaded the results to a self-made online risk calculator to estimate an individual's probability of CLNM (https://jin63.shinyapps.io/ML_CLNM/).Conclusions: With the incorporation of preoperative and intraoperative risk factors, ML algorithms can achieve acceptable prediction of CLNM with Xgboost model performing the best. Our online risk calculator based on ML algorithm may help determine the optimal extent of initial surgical treatment for patients with T1-T2 stage, non-invasive, and clinically node negative PTC.

Extent of thyroid surgery for clinically node-negative papillary thyroid carcinoma with confirmed nodal metastases after prophylactic central neck dissection: a 15-year experience in a single center.

PurposeThe use of prophylactic central neck dissection (PCND) and the extent of thyroid surgery in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) are controversial. This study aimed to investigate whether the extent of thyroid surgery influences the prognosis of patients with PTC with central lymph node metastasis (N1a), which was cN0 but pathologically confirmed after PCND.MethodsThis was a single-center retrospective study using medical records. Patients who underwent thyroid surgery with PCND for the treatment of PTC between 2004 and 2019 were included. Predictive factors and local recurrence rates were analyzed.ResultsOf 2,274 patients with cN0 PTC, 436 were confirmed to have pathologic N1a disease after PCND. Among them, 340 patients (78.0%) underwent total thyroidectomy (TT) and 96 patients (22.0%) underwent less than TT. Of the 374 patients who were followed up for >6 months, 5 (1.3%) experienced recurrence. The 15-year recurrence-free survival (RFS) rate was 98.2%. No clinicopathologic factor was predictive of tumor recurrence. RFS tended to be lower in patients who underwent less than TT than in those who underwent TT; however, the difference was not statistically significant.ConclusionOur study showed low recurrence rates in patients with cN0 PTC pathologically confirmed as N1a after PCND. The RFS did not differ according to the extent of thyroid surgery. Considering the low recurrence rate and the surgical morbidity associated with thyroid surgery, less than TT with PCND may be considered for patients with cN0 unilateral PTC even with a pathologic staging of N1a after PCND.

Efficacy of prophylactic central neck dissection in hemithyroidectomy for papillary thyroid carcinoma.

To evaluate the efficacy of prophylactic central neck dissection (pCND) in hemithyroidectomy for clinically node-negative papillary thyroid carcinoma (PTC). We retrospectively analyzed 299 patients who underwent thyroid lobectomy with or without pCND for unilateral PTC. Of the 299 patients, 245 (81.9%) underwent unilateral pCND along with lobectomy, and 54 (18.1%) patients underwent lobectomy without pCND. Propensity score matching was performed for five covariates to reduce selection bias. In the baseline cohort of 299 patients, mean age, extrathyroidal extension, T classification and stage were higher in the cases undergoing pCND than in those not undergoing pCND. After propensity score matching, the significant differences between the two groups seen in the baseline cohort disappeared. Recurrence rates and recurrence-free survival curves did not differ between the 2 matched groups each of 54 patients. The value of pCND in hemithyroidectomy for PTC is limited.

Identifying risk factors of recurrence for clinically node negative papillary thyroid carcinoma with pathologic N1a

BackgroundWhether or not to perform prophylactic central lymph node dissection (CLND) in the case of clinically node-negative papillary thyroid cancer (PTC) is controversial. The purpose of this study was to investigate the risk factors for recurrence in clinically node-negative PTC patients who underwent total thyroidectomy plus bilateral central neck dissection and was verified pathologic N1a.MethodsWe retrospectively reviewed the medical records of 1082 PTC patients who underwent total thyroidectomy and prophylactic bilateral CLND between January 2004 and December 2012. We used Cox-proportional hazard regression analyses in order to explore potential predictive factors for recurrence.ResultsDuring a median follow-up (range) of 78 (12–158) months, recurrence occurred in 62 (5.7%) patients. Main tumor size more than 1 cm, gross extrathyroidal extension (ETE), positive lymph node (LN) more than 3, and LN ratio > 0.5 were all significantly associated with recurrence according to univariate analysis. In model I multivariate analysis (tumor size, gross ETE, LN ratio), LN ratio > 5 (hazards ratio [HR], 4.794; 95% confidence interval [CI], 2.674–8.595; p < 0.001) was found to be predictive of recurrence. Gross ETE (HR, 1.794; 95% CI, 1.024–3.143; p = 0.041) and positive LN more than 3 (HR, 2.505; 95% CI, 1.513–4.146; p < 0.001) were predictors for recurrence in model II multivariate analysis (tumor size, gross ETE, the number of positive LN).ConclusionsWe recommend that surgeons try to focus completely on performing prophylactic CLND for patients with suspicious gross ETE during preoperative evaluation. Close monitoring and thorough management are needed for clinically node-negative PTC patients with LN ratio of more than 0.5 and more than 3 positive LN in the central compartment.

Magnetic Resonance Imaging Characteristics of Papillary Thyroid Carcinoma for the Prediction of Cervical Central Compartment Lymph Node Metastasis.

Cervical lymph node metastasis (LNM) is associated with local recurrence and distant metastasis in papillary thyroid carcinoma (PTC). This study was to assess magnetic resonance imaging (MRI) characteristics for predicting cervical LNM in PTC. A total of 119 patients with 154 PTC examined by MRI were assessed. According to inclusion and exclusion criteria, 78 subjects (78 tumors) were included in the final analysis. Conventional MRI findings and apparent diffusion coefficient were recorded. Descriptive statistics for LNM, sensitivity, specificity, and accuracy of various features were obtained. Multivariate logistic regression was performed for identifying independent variables for predicting LNM. Receiver operating characteristic curves were used to assess the diagnostic performance of the independent variables and model. There were 31 node-positive and 47 node-negative PTCs in this study. Node-positive patients significantly differed from the node-negative group in age (P = 0.039), long/short diameter of lymph nodes (both P < 0.001), lymph nodes cystic change (P = 0.005), tumor size (P < 0.001), poorly defined tumor margin in contrast-enhanced imaging (P < 0.001), and thyroid contour protrusion sign (P < 0.001). Satisfactory interobserver agreement was obtained between the 2 examiners (Cohen κ of 0.871 and 0.872). Thyroid contour protrusion sign and poorly defined tumor margin were identified as independent predictive factors of LNM in PTC (both P < 0.05), with area under the curves of 0.813 and 0.851, and accuracies of 0.810 and 0.838. When the independent factors were combined, the diagnostic performance was improved with an area under the curve of 0.944 and an accuracy of 0.884. Thyroid contour protrusion sign and poorly defined tumor margin in contrast-enhanced imaging could be 2 important predicted findings for cervical LNM in PTC.

Efficacy of Central Neck Dissection for Clinically Node-Negative Papillary Thyroid Carcinoma: Propensity Scoring Matching.

Objectives: The utility of prophylactic central neck dissection (pCND) for papillary thyroid carcinoma (PTC) is still controversial. Although the procedure may reduce locoregional recurrence, it is associated with a high rate of postoperative complications. The aim of this study was to evaluate the role of pCND in patients with PTC.Materials and Methods: From January 1995 to April 2011, the records of 477 patients who underwent total thyroidectomy with or without pCND for clinically node-negative PTC measuring < 4 cm were retrospectively reviewed. Of these, 341 patients had undergone pCND with total thyroidectomy and 136 patients did not undergo pCND. The clinicopathologic characteristics, surgical outcomes, complications, recurrence, and survival were analyzed using propensity score matching, using age, sex, tumor size, extrathyroidal extension, and radioactive iodine ablation as covariates to minimize selection bias.Results: At baseline, there was no significant difference in sex, age, and multiplicity and bilaterality of the cancer between the two groups. However, extrathyroidal extension was more common and tumor size larger in patients who underwent pCND. For the propensity score-matched analysis, two matched groups, each comprising 135 patients, were generated. After propensity score matching, the significant differences observed at baseline between the two groups disappeared. The postoperative complication rate did not differ between the two groups. Recurrence occurred in 4 patients (2.96%) who had undergone pCND and in 2 patients (1.48%) who did not undergo pCND (P = 0.684). The recurrence-free survival curves did not differ between the two groups.Conclusion: The efficacy of pCND in total thyroidectomy for clinically node-negative PTC is limited, and pCND is not recommended for these patients.

Significance of distance between tumor and thyroid capsule as an indicator for central lymph node metastasis in clinically node negative papillary thyroid carcinoma patients.

The aim of this study was to evaluate preoperatively identifiable clinical and ultrasonographic characteristics associated with central lymph node metastasis (CLNM) in clinically node negative papillary thyroid carcinoma (PTC) patients. Records of the patients who underwent thyroidectomy with prophylactic central lymph node dissection due to clinically node negative PTC (size, 1.0–3.0 cm) were reviewed. Of a total of 174 patients, 71 (40.8%) had CLNMs. CLNM was more associated with capsule invasion than capsule non-invasion on ultrasonography (68.4% vs. 37.4%, p = 0.009). In the 155 patients without capsule invasion, a distance from the capsule < 1.9 mm was associated with CLNM in univariable (p = 0.002) and multivariable analysis (p < 0.001). Any PTC patient with a distance from the capsule ≥ 1.9 mm did not have CLNM whereas 40.8% (58/142) of PTC patients with a distance from the capsule < 1.9 mm had CLNM. CLNM was not associated with age, gender, or tumor size on ultrasonography. Distance from capsule ≥ 1.9 mm on preoperative ultrasonography was a significant indicator for not having CLNM in clinically node negative PTC patients. Measuring distance from the capsule on preoperative ultrasonography images could help select patients with PTC who could benefit from prophylactic central lymph node dissection.

Risk factors of lateral lymph node metastasis in cN0 papillary thyroid carcinoma

BackgroundCervical lymph node metastasis of papillary thyroid carcinoma (PTC) is common. However, whether undergoing prophylactic central lymph node (CLN) dissection or lateral lymph node (LLN) dissections to prevent metastasis is still controversial. This study aimed to retrospectively investigate the risk factors of LLN metastasis in clinical lymph node-negative (cN0) PTC patients.MethodsWe retrospectively studied 783 lymph node-negative (cN0) PTC patients who underwent total thyroidectomy plus CLN dissection and LLN dissection.ResultsThe rates of CLN and LLN metastases were 68.2 and 47.4%, respectively. Large tumor size (> 20 mm) had a fourfold higher risk of LLN metastasis compared with small tumor size (≤ 20 mm; OR = 4.082, 95% CI 2.646–6.289; P = 0.001). Patients with tumor in the upper lobe had ~ 3-fold higher risk of LLN metastasis compared with patients with tumor in other locations (OR = 2.874, 95% CI 1.916–4.310; P = 0.001). Multifocality and extrathyroidal extension indicated a twofold higher risk of LLN metastasis. Having ≥ 2 CLN metastases dramatically increased the risk of LLN metastasis, compared with those with < 2 CLN metastases (OR = 6.536, 95% CI 4.630–9.259; P = 0.001).ConclusionsLarge tumor size (> 20 mm), tumor located in the upper lobe, multifocality, extrathyroidal extension, and ≥ 2 CLN metastases may increase the risk of LLN metastasis in cN0 PTC patients.

Number of Metastatic Lymph Nodes and Ratio of Metastatic Lymph Nodes to Total Number of Retrieved Lymph Nodes Are Risk Factors for Recurrence in Patients With Clinically Node Negative Papillary Thyroid Carcinoma

Objectives The number of metastatic lymph nodes (LNs) and the ratio between the number of metastatic LNs and the total number of retrieved LNs (the LN ratio [LNR]) have been proposed as risk factors for recurrence of papillary thyroid carcinoma (PTC). However, the significance of the number of LNs and the LNR in patients with clinically node negative PTC has not been clearly determined. The purpose of this study is to evaluate their significance.Methods We retrospectively analyzed 382 patients with PTC who had undergone total thyroidectomy with prophylactic central neck dissection (CND) between January 2000 and December 2010. We excluded patients with lobectomy, concurrent lateral compartment neck dissection, a follow-up period less than at least 2 years, number of harvested central LNs less than or equal to one, clinically positive LN, distant metastasis, recurrent cancer or other types of malignancy. The correlations between recurrence and various clinicopathologic characteristics including tumor size, extrathyroidal extension (ETE), stage, number of metastatic central LNs, and the LNR were investigated.Results After a mean follow-up period of 82.2±26.4 months, recurrence occurred in 14 patients (3.7%). Tumor size ≥20 mm, maximal ETE, presence of central LN metastasis, number of metastatic LNs ≥2, and LNR ≥0.31 correlated with recurrence in the univariate analysis. However, tumor size ≥20 mm, maximal ETE, number of metastatic LNs ≥2, and LNR ≥0.31 were significantly associated with recurrence in the multivariate analysis (hazard ratio=6.61, 7.17, 3.43, and 11.23, respectively).Conclusion The LNR and the number of metastatic LNs are independent prognostic risk factors for recurrence in patients with clinically node negative PTC, and these factors can be used to guide postoperative adjuvant therapy and follow-up strategy after prophylactic CND.

Concerns in patients undergoing neck dissection surgery

SummaryLymph node involvement is common in patients with papillary thyroid carcinoma. The knowledge of surgical techniques and classifications of the lymph node levels and of the surgical procedures is essential. Some concerns still exist regarding the indications and the extension of lymph node dissection both for central and lateral neck dissection. Central neck dissection is mandatory in case of macroscopic central neck nodal involvement. In patients with clinically node negative papillary thyroid carcinoma the role of prophylactic central neck dissection remains matter of debate. Regarding the lateral neck dissection the majority of guidelines recommend that it should be performed only with therapeutic intent. In spite of this consensus regarding the indications, the extension of therapeutic lateral neck dissection is still debated. In case of reoperation surgical strategy should be adequately planned in order to reduce the risk of potential complications achieving an optimal locoregional control of t...