Preoperative Ultrasonographic Staging of Papillary Thyroid Carcinoma With the Eighth American Joint Committee on Cancer Tumor-Node-Metastasis Staging System

Prediction of papillary thyroid metastases to the central compartment: proposal of a model taking into consideration other thyroid conditions

Objective

To construct risk prediction models for cervical lymph node metastasis (CLNM) of papillary thyroid carcinoma (PTC) under different thyroid disease backgrounds and to analyze and compare risk factors among different groups.

Methods

This retrospective study included 518 patients with PTC that was pathologically confirmed post-operatively from January 2021 to November 2021. Demographic, ultrasound and pathological data were recorded. Univariate and multivariate logistic regression analyses were performed to identify factors associated with CLNM in the whole patient cohort and in patients grouped according to diagnoses of Hashimoto's thyroiditis (HT), nodular goiter (NG), and no background disease. Prediction models were constructed for each group, and their performances were compared.

Results

Analysis of the whole PTC patient cohort identified NG as independently associated with CLNM. The independent risk factors for patients with no background disease were the maximum thyroid nodule diameter and American College of Radiology Thyroid Imaging Reporting & Data System score; those for patients with HT were the maximum thyroid nodule diameter, ACR TI-RADS score, and multifocality; and those for patients with NG were the maximum thyroid nodule diameter, ACR TI-RADS score, multifocality and gender.

Conclusion

Background thyroid disease impacts CLNM in PTC patients, and risk factors for CLNM vary among PTC patients with different background diseases. Ultrasound is useful for diagnosing background thyroid disease, which can inform treatment planning. Different prediction models are recommended for PTC cases with different thyroid diseases.

Construction and Validation of a Predictive Nomogram Based on Ultrasound for Lymph Node Metastasis of Papillary Thyroid Carcinoma in the Cervical Central Region

ABSTRACT

To establish and validate a nomogram for predicting lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) in the cervical central region. This retrospective study included 287 PTC patients with 309 nodules treated from December 2018 to May 2020 at our hospital. The cohort was divided randomly into a training set and a testing set according to a 7:3 ratio. The training set contained 216 nodules, and the testing set contained 93 nodules. The nomogram was developed using the training set, and the data of the testing set were used to validate the performance of nomogram. The predictive accuracy and discriminative ability of the nomogram were determined by concordance index (C-index) and calibration curve. The study showed multifocality, thyroid lesion size, and American College of Radiology Thyroid Imaging, Reporting and Data System (TI-RADS) score were significantly independently associated with LNM in the cervical central region. In the testing set, the calibration curve showed that the nomogram had good discrimination with a C-index of 0.775 (95% confidence interval, 0.680-0.869) and adequate calibration ( P = 0.808). By decision curve analysis and clinical impact curve analysis, the nomogram was shown to have a satisfactory net benefit between thresholds of 0.40 and 0.75. The nomogram can be used for predicting LNM of PTC in the cervical central region and may provide valuable guidance for planning the surgical treatment of PTC patients.

Radiologist versus Non-Radiologist Detection of Lymph Node Metastasis in Papillary Thyroid Carcinoma by Ultrasound: A Meta-Analysis

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer worldwide and is known to spread to adjacent neck lymphatics. Lymph node metastasis (LNM) is a known predictor of disease recurrence and is an indicator for aggressive resection. Our study aims to determine if ultrasound sonographers’ degree of training influences overall LNM detection. PubMed, Embase, and Scopus articles were searched and screened for relevant articles. Two investigators independently screened and extracted the data. Diagnostic test parameters were determined for all studies, studies reported by radiologists, and studies reported by non-radiologists. The total sample size amounted to 5768 patients and 10,030 lymph nodes. Radiologists performed ultrasounds in 18 studies, while non-radiologists performed ultrasounds in seven studies, corresponding to 4442 and 1326 patients, respectively. The overall sensitivity of LNM detection by US was 59% (95%CI = 58–60%), and the overall specificity was 85% (95%CI = 84–86%). The sensitivity and specificity of US performed by radiologists were 58% and 86%, respectively. The sensitivity and specificity of US performed by non-radiologists were 62% and 78%, respectively. Summary receiver operating curve (sROC) found radiologists and non-radiologists to detect LNM on US with similar accuracy (p = 0.517). Our work suggests that both radiologists and non-radiologists alike detect overall LNM with high accuracy on US.

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.

Total thyroidectomy versus thyroid lobectomy in the treatment of papillary carcinoma

Extent of thyroidectomy for papillary thyroid carcinoma is still matter of debate. Indeed, recently, international guidelines endorsed thyroid lobectomy as initial surgical approach for low risk, small medium-sized (T1-T2), N0 papillary thyroid carcinoma in absence of extrathyroidal extension. When dealing with a conservative surgery for oncologic disease is of utmost importance to exclude effectively more advanced disease, which could benefit from a more aggressive initial operation. However, in the setting of surgery for papillary thyroid carcinoma, despite an accurate preoperative work up could led to identify some suspicious characteristics as macroscopic evidence of multifocality or extrathyroidal extension, and/or evidence of lateral neck lymph node metastases, it is difficult to reliably assess the central neck nodal status both pre- and intra-operatively. Frozen section examination of the central neck nodes ipsilateral to the side of the tumor has been proposed in patients scheduled for thyroid lobectomy, in order to modulate the extension of both thyroidectomy and central neck dissection. Future molecular and genetic evidences are needed to establish high-risk patients with small papillary thyroid carcinoma in which thyroid lobectomy could be not and adequate surgical treatment.