Nomograms for the prediction of lateral lymph node metastasis in papillary thyroid carcinoma: Stratification by size

The clinical value of Delphian and pre-tracheal lymph nodes in predicting lateral lymph nodes metastasis of papillary thyroid carcinoma

BACKGROUND

Occult lymph node metastasis of papillary thyroid carcinoma is common. However, whether undergoing prophylactic lateral lymph node dissections is still controversial. This cross-sectional study with large cohort of patients aims to investigate the clinical value of Delphian and pre-tracheal lymph node in predicting lateral lymph node metastasis of papillary thyroid carcinoma.

MATERIALS AND METHODS

A retrospective analysis was conducted on 865 papillary thyroid carcinoma patients with Delphian and pre-tracheal lymph node data who underwent thyroidectomy plus central and lateral lymph node dissection. Data on clinicopathological characteristics were collected. Subsequently, a predictive model was established based on the results of the univariate and multivariate analyses.

RESULTS

The rates of Delphian and pre-tracheal lymph node metastasis and lateral lymph node metastasis were 54.7% and 39.1%, respectively. Having ≥ 3 or 1-2 Delphian and pre-tracheal lymph node metastasis dramatically increased the risk of lateral lymph node metastasis (OR = 8.5, 95% CI 5.3-13.4 and OR = 3.9, 95% CI 2.7-5.7, respectively). The upper tumour had a 3.7 times higher risk of lateral lymph node metastasis than other locations. Patients ≤ 42 years or tumour size >8 mm had a higher risk of lateral lymph node metastasis.

CONCLUSIONS

Delphian and pre-tracheal lymph node metastasis was associated positively with the risk of lateral lymph node metastasis. For patients without clinical lateral lymph node metastasis, the Delphian and pre-tracheal lymph node could be considered to harvest as the first step in a thyroidectomy to facilitate further conduct of the operation.

Pretreatment level of circulating tumor cells is associated with lymph node metastasis in papillary thyroid carcinoma patients with ≤ 55 years old

OBJECTIVE

To investigate the relationship of pretreatment of circulating tumor cells (CTCs) and cervical lymph node metastasis (LNM) (central LNM (CLNM) and lateral LNM (LLNM)) in papillary thyroid carcinoma (PTC) patients with ≤ 55 years old.

METHODS

Clinicopathological data (CTCs level, Hashimoto's thyroiditis, thyroid function, multifocal, tumor size, invaded capsule, clinical stage, and LNM) of 588 PTC patients with ≤ 55 years old were retrospectively collected. The relationship of CLNM, LLNM and the clinical features of patients was analyzed. Univariate and multivariate logistic regression analyses were used to evaluate the relationship between the CTCs and CLNM, LLNM.

RESULTS

There were 273(46.4%) and 89(15.1%) patients with CLNM and LLNM, respectively. Patients with CLNM had higher proportions of multifocality, tumor size > 1 cm, invaded capsule, and positive CTCs level than those without (all p < 0.05). Patients with LLNM had higher proportions of multifocality, tumor size > 1 cm, and invaded capsule than those without (all p < 0.05). Logistic regression analysis showed that multifocality (odds ratio (OR): 1.821, 95% confidence interval (CI): 1.230-2.698, p = 0.003), tumor size > 1 cm (OR: 3.444, 95% CI: 2.296-5.167, p < 0.001), invaded capsule (OR: 1.699, 95% CI: 1.167-2.473, p = 0.006), and positive CTCs level (OR: 1.469, 95% CI: 1.019-2.118, p = 0.040) were independently associated with CLNM; and multifocality (OR: 2.373, 95% CI: 1.389-4.052, p = 0.002), tumor size > 1 cm (OR: 5.344, 95% CI: 3.037-9.402, p < 0.001), and invaded capsule (OR: 2.591, 95% CI: 1.436-4.674, p = 0.002) were independently associated with LLNM.

CONCLUSIONS

Preoperative CTCs positive was associated with CLNM in PTC patients with ≤ 55 years old, but not LLNM.

Construction and validation of nomograms to predict central lymph node metastasis in clinical node-negative unilateral papillary thyroid carcinoma

The scope of neck lymph node dissection remains controversial for unilateral papillary thyroid carcinoma (UPTC) patients with no clinical evidence of lymph node metastasis (cN0). This study aims to build and validate a model for predicting central lymph node metastasis (CLNM) in UPTC patients through preoperative basic information and intraoperative rapid frozen pathology results. Retrospective analysis covered 1928 patients with PTC from the Wuhan Union Hospital database (2010-2020), randomly split into training and validation sets in a 7:3 ratio. Univariate and multivariate logistic regression analyses were performed to assess the risk factors for ipsilateral CLNM and contralateral CLNM in UPTC patients with cN0. Identified six risk factors for ipsilateral CLNM and seven risk factors for contralateral CLNM in cN0 UPTC patients. Two separate nomograms were constructed to visualize the results. The C-index for predicting ipsilateral and contralateral CLNM nomograms is 0.746 (95% CI 0.723-0.768) and 0.712 (95% CI 0.679-0.744), respectively. The calibration curves presented good agreement between prediction by nomograms and actual observation. The clinical decision curves suggest a net benefit from this model. UPTC patients can use these two nomograms to predict the probability of ipsilateral CLNM and contralateral CLNM separately, enabling risk stratification and aiding in surgical decision-making.

Neural Network and Logistic Regression Models Based on Ultrasound Radiomics and Clinical-Pathological Features to Predict Occult Level II Lymph Node Metastasis in Papillary Thyroid Carcinoma

RATIONALE AND OBJECTIVES

Papillary thyroid carcinoma (PTC) often metastasizes to lateral cervical lymph nodes, especially in level II. This study aims to develop predictive models to identify level II lymph node metastasis (LNM), guiding selective neck dissection (SND) to minimize unnecessary surgery and morbidity in low-risk patients.

METHODS

A retrospective cohort of 313 PTC patients who underwent modified radical neck dissection (MRND) between October 2020 and January 2023 was analyzed. The patients were randomly assigned to a training cohort (70%) and a validation cohort (30%). Five predictive models were developed using neural networks (NNET) and logistic regression (LR) based on ultrasound radiomic features, clinical-pathological data, or a combination of both. Each model's performance was evaluated based on accuracy, area under the receiver operating characteristic curve (AUC), sensitivity, and specificity in predicting occult level II LNM. SHapley Additive exPlanations and nomogram were used to interpret the most important features in the models.

RESULTS

The occurrence rate of level II LNM was 28% in the cohort. Among the five predictive models developed, the LR-radiomics signature model demonstrated the highest performance, achieving an accuracy of 96.8% and an AUC of 0.989 in the validation set. In comparison, the NNET-radiomic + clinical feature model achieved an AUC of 0.935, while other models exhibited moderate to low accuracy and AUCs ranging from 0.699 to 0.785. The decision curve analysis demonstrated that the LR-radiomics signature model provided the greatest clinical utility, offering the highest net benefit across a range of decision thresholds for identifying occult level II LNM.

CONCLUSION

Our study developed predictive models using ultrasound-derived radiomic features and clinical-pathological data to assess the risk of occult level II LNM in PTC. The LR-radiomics signature model demonstrated high accuracy, making it a valuable tool for guiding personalized treatment decisions, by informing MRND for high-risk patients and supporting SND for low-risk patients to minimize unnecessary surgical interventions and optimize clinical outcomes.

A lasso-based model to predict lateral lymph node metastasis in unifocal papillary thyroid carcinoma with central lymph node metastasis

OBJECTIVE

To screen the risk factors for lateral lymph node metastasis (LLNM) in unifocal papillary thyroid carcinoma (PTC) with central lymph node metastasis (CLNM) and create a corresponding model.

METHODS

A retrospective analysis of 362 patients from our hospital was performed. All patients were randomized into training and validation groups in a ratio of 7:3. Risk factors were screened using the least absolute shrinkage and selection operator (LASSO) and logistic regression analysis.

RESULTS

The analysis indicated that upper location, number of CLNM ≥ 3, rate of CLNM ≥ 0.172, prelaryngeal LNM, pretracheal LNM, and tall cell variant of papillary thyroid carcinoma (TCV-PTC) are independent risk factors. Visualizing the model with a nomogram, receiver operating characteristic (ROC) curves revealed an area under the curve (AUC) of 0.773 for the training group and 0.779 for the validation group. This confirms the stability and outstanding accuracy of the model. Also, the calibration curves and clinical descision curves reflect strong calibration,offering potential clinical benefits.

CONCLUSIONS

The risk factors for LLNM include metastasis to the prelaryngeal lymph nodes, metastasis to the pretracheal lymph nodes, location in the upper level, number of metastases ≥3 in CLNM, TCV-PTC and metastasis rate ≥0.172. A nomogram incorporating these factors exhibits excellent predictive value and stability.

Risk factors analysis of lateral cervical lymph node metastasis in papillary thyroid carcinoma: a retrospective study of 830 patients

OBJECTIVE

The aim of this study is to investigate the risk factors for lateral cervical lymph node metastasis in papillary thyroid carcinoma (PTC).

METHODS

Clinicopathological data (age, gender, Hashimoto's thyroiditis, preoperative circulating tumor cells (CTCs), multifocal, maximum lesion diameter, invaded capsule, T stage, and lymph node metastasis) of 830 PTC patients diagnosed and treated in Meizhou People's Hospital from June 2021 to April 2023 were collected. The related factors of lateral cervical lymph node metastasis were analyzed.

RESULTS

There were 334 (40.2%), and 103 (12.4%) PTC patients with central lymph node metastasis, and lateral cervical lymph node metastasis, respectively. Compared with patients without lateral cervical lymph node metastasis, PTC patients with lateral cervical lymph node metastasis had a higher proportion of multifocal, maximum lesion diameter > 1 cm, invaded capsule, T3-T4 stage. Regression logistic analysis showed that male (odds ratio (OR): 2.196, 95% confidence interval (CI): 1.279-3.769, p = 0.004), age < 55 years old (OR: 2.057, 95% CI: 1.062-3.988, p = 0.033), multifocal (OR: 2.759, 95% CI: 1.708-4.458, p < 0.001), maximum lesion diameter > 1 cm (OR: 5.408, 95% CI: 3.233-9.046, p < 0.001), T3-T4 stage (OR: 2.396, 95% CI: 1.241-4.626, p = 0.009), and invaded capsule (OR: 2.051, 95% CI: 1.208-3.480, p = 0.008) were associated with lateral cervical lymph node metastasis.

CONCLUSIONS

Male, age < 55 years old, multifocal, maximum lesion diameter > 1 cm, T3-T4 stage, and invaded capsule were independent risk factors for lateral cervical lymph node metastasis in PTC.

Accurate preoperative prediction of nodal metastasis in papillary thyroid microcarcinoma: Towards optimal management of patients

OBJECTIVE

To enhance the accuracy in predicting lymph node metastasis (LNM) preoperatively in patients with papillary thyroid microcarcinoma (PTMC), refining the "low-risk" classification for tailored treatment strategies.

METHODS

This study involves the development and validation of a predictive model using a cohort of 1004 patients with PTMC undergoing thyroidectomy along with central neck dissection. The data was divided into a training cohort (n = 702) and a validation cohort (n = 302). Multivariate logistic regression identified independent LNM predictors in PTMC, leading to the construction of a predictive nomogram model. The model's performance was assessed through ROC analysis, calibration curve analysis, and decision curve analysis.

RESULTS

Identified LNM predictors in PTMC included age, tumor maximum diameter, nodule-capsule distance, capsular contact length, bilateral suspicious lesions, absence of the lymphatic hilum, microcalcification, and sex. Especially, tumors larger than 7 mm, nodules closer to the capsule (less than 3 mm), and longer capsular contact lengths (more than 1 mm) showed higher LNM rates. The model exhibited AUCs of 0.733 and 0.771 in the training and validation cohorts respectively, alongside superior calibration and clinical utility.

CONCLUSION

This study proposes and substantiates a preoperative predictive model for LNM in patients with PTMC, honing the precision of "low-risk" categorization. This model furnishes clinicians with an invaluable tool for individualized treatment approach, ensuring better management of patients who might be proposed observation or ablative options in the absence of such predictive information.

Lateral lymph node metastasis in papillary thyroid cancer: Is there a difference between PTC and PTMC?

Papillary thyroid carcinoma (PTC) and papillary thyroid microcarcinoma (PTMC) are generally characterized as less invasive forms of thyroid cancer with favorable prognosis. However, once lateral cervical lymph node metastasis takes place, the prognosis may be significantly impacted. The purpose of this study was to evaluate whether there is a difference in the pattern of lateral lymph node metastasis between PTC and PTMC. A retrospective analysis was performed for PTC and PTMC patients that underwent central area dissection and unilateral lateral neck lymph node dissection (II-V area) between January 2020 and December 2021. Compared with PTMC group, the PTC group exhibited higher incidence of capsule invasion, extrathyroid invasion and lymphatic vessel invasion. Both the number and rate of central lymph nodes metastasis were elevated in the PTC group. While the number of lateral cervical lymph node metastasis was higher, the metastasis rate did not demonstrate significant difference. No significant differences were identified in the lymph node metastasis patterns between the 2 groups. The determination of the extent of lateral neck lymph node dissection solely based on the tumor size may be unreliable, as PTC and PTMC showed no difference in the number and pattern of lateral neck metastasis. Additional clinical data are warranted to reinforce this conclusion. For patients categorized as unilateral, bilateral, or contralateral cervical lymph node metastasis (including level I, II, III, IV, or V) or retropharyngeal lymph node metastasis who require unilateral lateral neck dissection, the size of the primary tumor may not need to be a central consideration when assessing and deciding the extent of lateral neck dissection.

Lateral lymph node metastasis in papillary thyroid microcarcinoma: a study of 5241 follow-up patients

PURPOSE

To investigate the impact of lateral lymph node metastasis in papillary thyroid microcarcinoma (PTMC).

METHODS

5241 PTMC patients with follow-up information were enrolled in the current study. These patients underwent primary surgery in our situation from January 1997 to December 2016. Additionally, a validation cohort consisting of 274 PTMC patients who underwent primary surgery between January 2020 and December 2021 was also included. Univariable and multivariate logistic analyses were conducted to identify the association between clinicopathologic features and lateral lymph node metastasis (LLNM). Kaplan-Meier survival curve analysis was used to calculate the disease-free survival (DFS) rate. The fitting curve was generated to identify the quantitative relationship between central lymph node metastases (CLNM) and LLNM.

RESULTS

Of 5241 PTMC patients, cervical lymph node metastasis was detected in 1494 (28.5%) cases, including 1364 (26.0%) with CLNM only and 130 (2.5%) with LLNM. With a median follow-up time of 60 months (interquartile range [IQR], 44-81), recurrence was detected in 114 patients (2.2%). Multivariate Cox regression analyses showed that LNM was the only independent risk factor for recurrence, with HR values of 3.03 in CLNM and 11.14 in LLNM, respectively. Tumor diameter >0.5 cm (hazard ratio [HR]:1.80), multifocality (HR:2.59), bilaterality (HR:2.13), extrathyroidal invasion (HR:2.13), and CLNM (HR:5.11) were independent risk factors for LLNM. The prevalence of LLNM escalated significantly with increasing number of lymph node involvement in CLNM when stratified by the number of metastatic lymph nodes and trend was observed similarly in the validation cohort. The fitting curve showed that the incidence of LLNM could be as high as 20.7% when the number of CLNM ≥ 5.

CONCLUSIONS

By analyzing a large database with follow-up information, our study provides evidence that LLNM is significantly correlated with tumor recurrence in patients with PTMC. Tumor size (>0.5 cm), multifocality, bilaterality, extrathyroidal extension (ETE) and CLNM are independent risk factors for LLNM.

Predicting Extrathyroidal Extension in Papillary Thyroid Carcinoma Using a Clinical-Radiomics Nomogram Based on B-Mode and Contrast-Enhanced Ultrasound

Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid cancer. PTC patients with extrathyroidal extension (ETE) are associated with poor prognoses. The preoperative accurate prediction of ETE is crucial for helping the surgeon decide on the surgical plan. This study aimed to establish a novel clinical-radiomics nomogram based on B-mode ultrasound (BMUS) and contrast-enhanced ultrasound (CEUS) for the prediction of ETE in PTC. A total of 216 patients with PTC between January 2018 and June 2020 were collected and divided into the training set (n = 152) and the validation set (n = 64). The least absolute shrinkage and selection operator (LASSO) algorithm was applied for radiomics feature selection. Univariate analysis was performed to find clinical risk factors for predicting ETE. The BMUS Radscore, CEUS Radscore, clinical model, and clinical-radiomics model were established using multivariate backward stepwise logistic regression (LR) based on BMUS radiomics features, CEUS radiomics features, clinical risk factors, and the combination of those features, respectively. The diagnostic efficacy of the models was assessed using receiver operating characteristic (ROC) curves and the DeLong test. The model with the best performance was then selected to develop a nomogram. The results show that the clinical-radiomics model, which is constructed by age, CEUS-reported ETE, BMUS Radscore, and CEUS Radscore, showed the best diagnostic efficiency in both the training set (AUC = 0.843) and validation set (AUC = 0.792). Moreover, a clinical-radiomics nomogram was established for easier clinical practices. The Hosmer-Lemeshow test and the calibration curves demonstrated satisfactory calibration. The decision curve analysis (DCA) showed that the clinical-radiomics nomogram had substantial clinical benefits. The clinical-radiomics nomogram constructed from the dual-modal ultrasound can be exploited as a promising tool for the pre-operative prediction of ETE in PTC.

Influence of Obesity Parameters on Different Regional Patterns of Lymph Node Metastasis in Papillary Thyroid Cancer

OBJECTIVE

Obesity increases risk of thyroid cancer. However, the association between obesity and the progression of papillary thyroid cancer (PTC) remains controversial. This retrospective study aimed to explore the relationship between obesity and regional patterns of lymph node metastasis (LNM) in PTC.

METHODS

We retrospectively reviewed data from 1015 patients with PTC. We calculated obese parameters, such as body mass index (BMI), body fat percentage (BFP), and body surface area (BSA). Logistic regression models were used to assess associations between obese parameters and the rate of lymph node metastasis (LNM), number of LNM, pattern of LNM, and lymph node ratio (LNR).

RESULTS

Higher BMI was not associated with different regional patterns of LNM in PTC. In men with PTC, high BFP was an independent predictor of total LNM, central lymph node metastasis (CLNM), total lateral lymph node metastasis (LLNM), multiple lateral lymph node metastasis, and simultaneous metastasis in lateral compartment. In addition, male patients with high BFP had higher central LNR and higher number of CLNM. For women, high BSA was an independent predictor of LLNM and level IV metastasis. Female patients with high BSA had higher number of CLNM.

CONCLUSION

BFP and BSA, possibly influenced by gender, were positively associated with the number and risk of LNM in different regions of PTC patients. However, BMI was not the predictor for aggressiveness of PTC in terms of LNM. Clinical decision-making for regional LNM in PTC patients should consider the factor of obesity.