Locally advanced thyroid cancer: can CT help in prediction of extrathyroidal invasion to adjacent structures?

Role of CT imaging in addressing resectability issues in differentiated thyroid cancer: imaging-based Mahajan grading system for TI and ETE

Background and objective

Extrathyroidal extension (ETE) is the term used to describe the growth of the primary thyroid tumor beyond the thyroid capsule. ETE is a critical prognostic marker for thyroid tumors, necessitating accurate preoperative assessment. This study aims to evaluate the diagnostic performance of computed tomography (CT)-based grading for ETE and tracheal invasion (TI) for preoperative prediction in patients with differentiated papillary thyroid carcinoma (PTC) and compare the diagnostic accuracy with ultrasound (US).

Materials and methods

This retrospective study was approved by our institutional review board. Preoperative US and CT were performed for 83 patients who underwent surgery for PTC between 1 January 2010 and 31 December 2020. The US and CT features of ETE and TI of each case were retrospectively and independently investigated by two radiologists. The diagnostic performances of US and CT, including their specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) for ETE, and their accuracy in predicting ETE and TI were analyzed. As per the grading for ETE on USG and CT, lesions were graded into three grades and Mahajan grading was also devised on CT to predict the TI and graded into four grades.

Results

The accuracy and specificity of CT are relatively good for identifying tumor infiltration into the adjacent structures and range from 82% to 87% and 95% to 98%, respectively. It, however, has a low sensitivity, between 14.3% and 77.78%, when compared to US, which suggests that in case of any doubt regarding CT evidence of tumor infiltration into surrounding structures, additional clinical examination must be performed. CT showed better sensitivity (78%) and specificity (75%) in detecting TI compared to previous studies. The diagnostic accuracy of CT Mahajan grading was 91.5% with p <0.005 in the prediction of TI.

Conclusion

Preoperative US should be regarded as a first-line imaging modality for predicting minimal ETE, and CT should be additionally performed for the evaluation of maximal ETE. The specificity and PPV of CT are higher than those of US in detecting overall ETE and TI of PTC. The US- and CT-based grading systems have the potential to optimize preoperative surgical planning.

Comprehensive Review of the Imaging Recommendations for Diagnosis, Staging, and Management of Thyroid Carcinoma

Thyroid cancer is the most common head and neck cancer (HNC) in the world. In this article, we comprehensively cover baseline, posttreatment, and follow-up imaging recommendations for thyroid carcinomas along with the eighth edition of the tumor, node, metastasis (TNM) staging system proposed by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). We include characterization and risk stratification of thyroid nodules on ultrasound (US) proposed by various international bodies. Management guidelines (depending upon the type of thyroid carcinoma) based on the international consensus recommendations (mainly by the American Thyroid Association) are also extensively covered in this article, including the role of a radioiodine scan. The management of recurrent disease is also briefly elucidated in this article. In addition, we cover the risk factors and etiopathogenesis of thyroid carcinoma along with the non-imaging diagnostic workup essential for thyroid carcinoma management, including the significance of genetic mutations. US is the diagnostic imaging modality of choice, with US-guided fine needle aspiration (FNA) being the procedure of choice for tissue diagnosis. The roles of computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) in thyroid carcinoma staging are also specified. Through this article, we aim to provide a comprehensive reference guide for the radiologists and the clinicians in the pursuit of optimal care for patients with thyroid carcinoma.

CT-based quantification of trachea shape to detect invasion by thyroid cancer

OBJECTIVE

This study aims to develop a CT-based method for quantifying tracheal shape and evaluating its ability to distinguish between cases with or without tracheal invasion in patients with thyroid carcinoma.

METHODS

A total of 116 quantitative shape features, including 56 geometric moments and 60 bounding shape features, were defined. The tracheal lumen was semi-automatically defined with a CT threshold of less than - 500 HU. Three contiguous slices with the 1st, 2nd, and 3rd smallest trachea lumen areas were contiguously selected, and the appropriate number of slices to be included was determined. Fifty-six patients with differentiated thyroid carcinoma (DTC) invading the trachea and 22 patients with DTC but without invasion were retrospectively included. A receiver operating characteristic (ROC) curve was applied to select the representative shape features and determine the optimal threshold.

RESULTS

23.3%, 25.9%, and 24.1% of the features displayed an area under the ROC curve (AUC) ≥ 0.800 when derived from 1, 2, and 3 slices, respectively. Calculating feature values from two slices with the 1st and 2nd smallest tracheal lumen area were considered appropriate. Six final features, including 3 geometric moments and 3 bounding shape features, were selected to determine the tracheal invasion status of DTC and displayed AUCs of 0.875-0.918, accuracies of 0.821-0.891, sensitivities of 0.813-0.893, and specificities of 0.818-0.932, outperforming the visual evaluation results.

CONCLUSIONS

Geometric moments and bounding shape features can quantify the tracheal shape and are reliable for identifying DTC tracheal invasion. The selected features quantified the extent of tracheal deformity in DTC patients with and without tracheal invasion.

CLINICAL RELEVANCE STATEMENT

Six geometric features provide a non-invasive, semi-automated evaluation of the tracheal invasion status of thyroid cancer.

KEY POINTS

• A novel method for quantifying tracheal shape using 56 geometric moments and 60 bounding shape features was developed. • Six features identify tracheal invasion by thyroid carcinoma. • The selected features quantified the extent of tracheal deformity in differentiated thyroid carcinoma patients with and without tracheal invasion.

Analysis of preoperative computed tomography radiomics and clinical factors for predicting postsurgical recurrence of papillary thyroid carcinoma

BACKGROUND

Postsurgical recurrence is of great concern for papillary thyroid carcinoma (PTC). We aim to investigate the value of computed tomography (CT)-based radiomics features and conventional clinical factors in predicting the recurrence of PTC.

METHODS

Two-hundred and eighty patients with PTC were retrospectively enrolled and divided into training and validation cohorts at a 6:4 ratio. Recurrence was defined as cytology/pathology-proven disease or morphological evidence of lesions on imaging examinations within 5 years after surgery. Radiomics features were extracted from manually segmented tumor on CT images and were then selected using four different feature selection methods sequentially. Multivariate logistic regression analysis was conducted to identify clinical features associated with recurrence. Radiomics, clinical, and combined models were constructed separately using logistic regression (LR), support vector machine (SVM), k-nearest neighbor (KNN), and neural network (NN), respectively. Receiver operating characteristic analysis was performed to evaluate the model performance in predicting recurrence. A nomogram was established based on all relevant features, with its reliability and reproducibility verified using calibration curves and decision curve analysis (DCA).

RESULTS

Eighty-nine patients with PTC experienced recurrence. A total of 1218 radiomics features were extracted from each segmentation. Five radiomics and six clinical features were related to recurrence. Among the 4 radiomics models, the LR-based and SVM-based radiomics models outperformed the NN-based radiomics model (P = 0.032 and 0.026, respectively). Among the 4 clinical models, only the difference between the area under the curve (AUC) of the LR-based and NN-based clinical model was statistically significant (P = 0.035). The combined models had higher AUCs than the corresponding radiomics and clinical models based on the same classifier, although most differences were not statistically significant. In the validation cohort, the combined models based on the LR, SVM, KNN, and NN classifiers had AUCs of 0.746, 0.754, 0.669, and 0.711, respectively. However, the AUCs of these combined models had no significant differences (all P > 0.05). Calibration curves and DCA indicated that the nomogram have potential clinical utility.

CONCLUSIONS

The combined model may have potential for better prediction of PTC recurrence than radiomics and clinical models alone. Further testing with larger cohort may help reach statistical significance.

Using a CT-based scale to evaluate disease extension and the resectability of locally advanced thyroid cancer

OBJECTIVES

To establish a computed tomography (CT)-based scale to evaluate the resectability of locally advanced thyroid cancer.

METHODS

This twin-centre retrospective study included 95 locally advanced thyroid cancer patients from the 1st centre as the training cohort and 31 patients from the 2nd centre as the testing cohort, who were categorised into the resectable and unresectable groups. Three radiologists scored the CT scans of each patient by evaluating the extension to the recurrent laryngeal nerve (RLN), trachea, oesophagus, artery, vein, soft tissue, and larynx. A 14-score scale (including all comprised structures) and a 12-score scale (excluding larynx) were developed. Receiver-operating characteristic (ROC) analysis was used to evaluate the performance of the scales. Stratified fivefold cross-validation and external verification were used to validate the scale.

RESULTS

In the training cohort, compromised RLN (p < 0.001), trachea (p = 0.001), oesophagus (p = 0.002), artery (p < 0.001), vein (p = 0.005), and soft tissue (p < 0.001) were predictors for unresectability, while compromised larynx (p = 0.283) was not. The 12-score scale (AUC = 0.882, 95%CI: 0.812-0.952) was not inferior to the 14-score scale (AUC = 0.891, 95%CI: 0.823-0.960). In subgroup analysis, the AUCs of the 12-score scale were 0.826 for treatment-naïve patients and 0.976 for patients with prior surgery. The 12-score scale was further validated with a fivefold cross-validation analysis, with an overall accuracy of 78.9-89.4%. Finally, external validation using the testing cohort showed an AUC of 0.875.

CONCLUSIONS

The researchers built a CT-based 12-score scale to evaluate the resectability of locally advanced thyroid cancer. Validation with a larger sample size is required to confirm the efficacy of the scale.

CLINICAL RELEVANCE STATEMENT

This 12-score CT scale would help clinicians evaluate the resectability of locally advanced thyroid cancer.

KEY POINTS

• The researchers built a 12-score CT scale (including recurrent laryngeal nerve, trachea, oesophagus, artery, vein, and soft tissue) to evaluate the resectability of locally advanced thyroid cancer. • This scale has the potential to help clinicians make treatment plans for locally advanced thyroid cancer.

Artificial Intelligence in Thyroidology: A Narrative Review of the Current Applications, Associated Challenges, and Future Directions

Background: The use of artificial intelligence (AI) in health care has grown exponentially with the promise of facilitating biomedical research and enhancing diagnosis, treatment, monitoring, disease prevention, and health care delivery. We aim to examine the current state, limitations, and future directions of AI in thyroidology. Summary: AI has been explored in thyroidology since the 1990s, and currently, there is an increasing interest in applying AI to improve the care of patients with thyroid nodules (TNODs), thyroid cancer, and functional or autoimmune thyroid disease. These applications aim to automate processes, improve the accuracy and consistency of diagnosis, personalize treatment, decrease the burden for health care professionals, improve access to specialized care in areas lacking expertise, deepen the understanding of subtle pathophysiologic patterns, and accelerate the learning curve of less experienced clinicians. There are promising results for many of these applications. Yet, most are in the validation or early clinical evaluation stages. Only a few are currently adopted for risk stratification of TNODs by ultrasound and determination of the malignant nature of indeterminate TNODs by molecular testing. Challenges of the currently available AI applications include the lack of prospective and multicenter validations and utility studies, small and low diversity of training data sets, differences in data sources, lack of explainability, unclear clinical impact, inadequate stakeholder engagement, and inability to use outside of the research setting, which might limit the value of their future adoption. Conclusions: AI has the potential to improve many aspects of thyroidology; however, addressing the limitations affecting the suitability of AI interventions in thyroidology is a prerequisite to ensure that AI provides added value for patients with thyroid disease.

Cervical exenteration and its variants for locally advanced thyroid cancer: when, why, and how?

PURPOSE OF REVIEW

To describe the modern surgical approach for management of advanced thyroid cancers infiltrating the cervicovisceral axis with special attention to well differentiated tumors not amenable to organ-sparing techniques. In particular, cervical exenteration, herein defined as the sum of total thyroidectomy, central compartment and lateral neck dissections, variously associated with total laryngectomy and possible partial or total pharyngoesophagectomy, represents an extreme surgical procedure that, in properly selected cases, allows for reasonable palliation of central compartment life-threatening signs/symptoms if not cure for an advanced oncologic condition.

RECENT FINDINGS

Cervical exenteration is not contraindicated by the presence of limited distant metastases at presentation. Even though it requires that the patient is in general good health as it can be associated with a number of complications and long in-hospital stay, when appropriately planned and performed according to the most recent reconstructive nuances, it allows good oncologic outcomes that are not inferior to those described for similarly advanced primaries of the upper aerodigestive tract. In addition, quality of life and functional results are not significantly different from those described after total laryngectomy for primary laryngeal squamous cell carcinomas.

SUMMARY

Cervical exenteration requires a tertiary, expert, multidisciplinary effort in terms of diagnosis, surgical performance, and postoperative care. A patient-centered decision process is strongly warranted taking into consideration alternative therapeutic and symptom-based palliative strategies.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Combined Conventional Ultrasound and Contrast-Enhanced Computed Tomography for Cervical Lymph Node Metastasis Prediction in Papillary Thyroid Carcinoma

OBJECTIVES

This study aimed to evaluate conventional ultrasound (US) combined with contrast-enhanced computed tomography (CT) of the neck to predict central lymph node metastasis (CLNM) in clinical lymph-negative patients with papillary thyroid carcinoma (PTC), establish a simple preoperative risk-scoring model, and validate its effectiveness in a two-center dataset.

METHODS

A total of 423 patients with PTC preoperatively evaluated by US and contrast-enhanced CT were included in the modeling group, and 102 patients from two hospitals were enrolled in the validation group. Independent predictive factors were determined using multivariate logistic regression analysis. Diagnostic performance was evaluated using receiver operating characteristic curve analysis.

RESULTS

The independent predictive factors for CLNM were age ≤45 years (odds ratio [OR] = 3.950), nodule presence in the non-upper pole (OR = 2.385), nodule size >12.5 mm (OR = 2.130), Thyroid Imaging Reporting and Data System score ≥9 (OR = 2.857), normalized enhancement CT value ≥0.75 (OR = 3.132), central enhancement (OR = 0.222), and capsular invasion (OR = 3.478). The area under the curve (AUC) of the model was 0.790 (95% confidence interval [CI]: 0.747-0.834), and the sensitivity and specificity were 70.4% and 73.9%, respectively. The AUC in the validation group was 0.827 (95% CI: 0.747-0.907), and the sensitivity and specificity were 88.9% and 63.2%, respectively.

CONCLUSIONS

We found conventional US combined with contrast-enhanced CT of the neck to be useful in predicting CLNM preoperatively and established a simple risk-scoring model that might help surgeons with appropriate surgical plans and prognostic evaluation.

Dual-modal radiomics for predicting cervical lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

Preoperative prediction of cervical lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC) is significant for surgical decision-making.

OBJECTIVE

This study aims to develop a dual-modal radiomics (DMR) model based on grayscale ultrasound (GSUS) and dual-energy computed tomography (DECT) for non-invasive CLNM in PTC.

METHODS

In this study, 348 patients with pathologically confirmed PTC at Jiangsu University Affiliated People's Hospital who completed preoperative ultrasound (US) and DECT examinations were enrolled and randomly assigned to training (n = 261) and test (n = 87) cohorts. The enrolled patients were divided into two groups based on pathology findings namely, CLNM (n = 179) and CLNM-Free (n = 169). Radiomics features were extracted from GSUS images (464 features) and DECT images (960 features), respectively. Pearson correlation coefficient (PCC) and the least absolute shrinkage and selection operator (LASSO) regression with 10-fold cross-validation were then used to select CLNM-related features. Based on the selected features, GSUS, DECT, and GSUS combined DECT radiomics models were constructed by using a Support Vector Machine (SVM) classifier.

RESULTS

Three predictive models based on GSUS, DECT, and a combination of GSUS and DECT, yielded performance of areas under the curve (AUC) = 0.700 [95% confidence interval (CI), 0.662-0.706], 0.721 [95% CI, 0.683-0.727], and 0.760 [95% CI, 0.728-0.762] in the training dataset, and AUC = 0.643 [95% CI, 0.582-0.734], 0.680 [95% CI, 0.623-0.772], and 0.744 [95% CI, 0.686-0.784] in the test dataset, respectively. It shows that the predictive model combined GSUS and DECT outperforms both models using GSUS and DECT only.

CONCLUSIONS

The newly developed combined radiomics model could more accurately predict CLNM in PTC patients and aid in better surgical planning.

Circumferential Laryngotracheal Resection in Thyroid Cancer: Experience and Outcome in a Single Center

There is limited experience of laryngotracheal resection in patients with differentiated thyroid carcinoma (DTC). The aim of this study was to report our experience of circumferential laryngotracheal resection in DTC and its long-term outcome. In this retrospective study, 10 patients of locally invasive DTC who underwent circumferential laryngotracheal resection between January 2000 and December 2015 were included. Clinicopathologic profile and follow up was noted. Mean age of the cohort was 50.1 ± 7.8 years (M:F = 1: 2.3). Papillary carcinoma was the commonest pathology (60%) followed by follicular carcinoma (20%), 10% each had Hurthle cell and poorly differentiated thyroid carcinoma. Sixty percent patients presented with recurrent or persistent disease and 20% with distant metastases. Vocal cord palsy was observed in 30%. Fifty percent patients underwent tracheal resection with end to end anastomosis and remaining laryngotracheal resection. Carotid artery resection and anastomosis was performed in one patient. Shin stage IV invasion was observed in 80% and stage III in remaining. There was no perioperative mortality. All patients received adjuvant radioiodine therapy and 40% external beam radiotherapy. Median follow up was 48 months. One patient who earlier had tracheal resection underwent total laryngectomy due to recurrent disease after 24 months. Forty percent patients developed distant metastases during follow-up. Mean survival was 77.8 months (CI = 63.0-92.5). Five-year overall survival was 60% and was significantly high in those without distant metastases (p = 0.006). The outcome of circumferential larygotracheal resections for DTC is excellent in terms of local disease control and long term survival.

Iodine Maps from Dual-Energy CT to Predict Extrathyroidal Extension and Recurrence in Papillary Thyroid Cancer Based on a Radiomics Approach

BACKGROUND AND PURPOSE

Accurate prediction of extrathyroidal extension and subsequent recurrence is crucial in papillary thyroid cancer clinical management. Our aim was to conduct iodine map-based radiomics to predict extrathyroidal extension and to explore its prognostic value for recurrence-free survival in papillary thyroid cancer.

MATERIALS AND METHODS

A total of 452 patients with papillary thyroid cancer were retrospectively recruited between June 2017 and June 2020. Radiomics features were extracted from noncontrast images, dual-phase mixed images, and iodine maps, respectively. Random forest and least absolute shrinkage and selection operator (LASSO) were applied to build 6 radiomics scores (noncontrast radiomics score_random forest; noncontrast rad-score_LASSO; mixed rad-score_random forest; mixed rad-score_LASSO; iodine radiomics score_random forest; iodine radiomics score_LASSO) respectively. Logistic regression was used to construct 6 radiomics models incorporating 6 radiomics scores with clinical risk factors and to compare them with the clinical model. A radiomics model that achieved the highest performance was presented as a nomogram and assessed by discrimination, calibration, clinical usefulness, and prognosis evaluation.

RESULTS

Iodine radiomics scores performed significantly better than mixed radiomics scores. Both of them outperformed noncontrast radiomics scores. Iodine map-based radiomics models significantly surpassed the clinical model. A radiomics nomogram incorporating size, capsule contact, and iodine radiomics score_random forest was built with the highest performance (training set, area under the curve = 0.78; validation set, area under the curve  = 0.84). Stratified analysis confirmed the nomogram stability, especially in group negative for CT-reported extrathyroidal extension (area under the curve  = 0.69). Nomogram-predicted extrathyroidal extension risk was an independent predictor of recurrence-free survival. A high risk for extrathyroidal extension portended significantly lower recurrence-free survival than low risk (P < .001).

CONCLUSIONS

Iodine map-based radiomics might be a supporting tool for predicting extrathyroidal extension and subsequent recurrence risk in patients with papillary thyroid cancer, thus facilitating clinical decision-making.

Radiomics from Primary Tumor on Dual-Energy CT Derived Iodine Maps can Predict Cervical Lymph Node Metastasis in Papillary Thyroid Cancer

RATIONALE AND OBJECTIVES

To develop and validate 2 iodine maps based radiomics nomograms for preoperatively predicting cervical lymph node metastasis (LNM) and central lymph node metastasis (CLNM) in papillary thyroid cancer (PTC).

MATERIALS AND METHODS

A total of 346 patients with PTC were enrolled and allocated to training (242) and validation (104) sets. Radiomics features were extracted from arterial and venous phase iodine maps, respectively. Aggregated machine-learning strategy was applied for features selection and construction of 2 radiomics scores (LN rad-score; CLN rad-score). Logistic regression model was employed to establish two radiomics nomograms (nomogram 1: predicting LNM; nomogram 2: predicting CLNM) after incorporating LN or CLN rad-score with clinical predictors. Nomograms performance was determined by discrimination, calibration and clinical usefulness.

RESULTS

Nomogram 1 incorporated LN rad-score, age (categorized by 55) and CT reported LN status; Nomogram 2 incorporated CLN rad-score, capsule contact >25% and CT reported CLN status. 2 nomograms both showed good discrimination and calibration in the training (AUC = 0.847; AUC = 0.837) and validation cohorts (AUC = 0.807; AUC = 0.795). Significant improved AUC, net reclassification index (NRI) and integrated discriminatory improvement (IDI) confirmed additional great predictive value of 2 rad-scores, compared with clinical models without radiomics. Decision curve analysis indicated clinical utility of nomograms. 2 nomograms both demonstrated favorable predictive efficacy in CT reported LN or CLN negative subgroup (AUC = 0.766; AUC = 0.744).

CONCLUSION

The presented 2 radiomics nomograms are useful tools for preoperative prediction of LNM and CLNM in PTC.

Extrathyroidal Extension Prediction of Papillary Thyroid Cancer With Computed Tomography Based Radiomics Nomogram: A Multicenter Study

OBJECTIVES

To develop and validate a Computed Tomography (CT) based radiomics nomogram for preoperative predicting of extrathyroidal extension (ETE) in papillary thyroid cancer (PTC) patients.

METHODS

A total of 153 patients were randomly assigned to training and internal test sets (7:3). 46 patients were recruited to serve as an external test set. A radiologist with 8 years of experience segmented the images. Radiomics features were extracted from each image and Delta-radiomics features were calculated. Features were selected by using one way analysis of variance and the least absolute shrinkage and selection operator in the training set. K-nearest neighbor, logistic regression, decision tree, linear-support vector machine (linear -SVM), gaussian-SVM, and polynomial-SVM were used to build 6 radiomics models. Next, a radiomics signature score (Rad-score) was constructed by using the linear combination of selected features weighted by their corresponding coefficients. Finally, a nomogram was constructed combining the clinical risk factors with Rad-scores. Receiver operating characteristic (ROC) curve, decision curve analysis (DCA), and calibration curve were performed on the three sets to evaluate the nomogram's performance.

RESULTS

4 radiomics features were selected. The six models showed the certain value of radiomics, with area under the curves (AUCs) from 0.642 to 0.701. The nomogram combining the Rad-score and clinical risk factors (radiologists' interpretation) showed good performance (internal test set: AUC 0.750; external test set: AUC 0.797). Calibration curve and DCA demonstrated good performance of the nomogram.

CONCLUSION

Our radiomics nomogram incorporating the radiomics and radiologists' interpretation has utility in the identification of ETE in PTC patients.

Tracheal and Cricotracheal Resection With End-to-End Anastomosis for Locally Advanced Thyroid Cancer: A Systematic Review of the Literature on 656 Patients

Airway involvement by advanced thyroid carcinoma (TC) constitutes a negative prognosticator, besides being a critical clinical issue since it represents one of the most frequent causes of death in locally advanced disease. It is generally agreed that, for appropriate laryngo-tracheal patterns of invasion, (crico-)tracheal resection and primary anastomosis [(C)TRA] is the preferred surgical technique in this clinical scenario. However, the results of long-term outcomes of (C)TRA are scarce in the literature, due to the rarity of such cases. The relative paucity of data prompts careful review of the available relevant series in order to critically evaluate this surgical technique from the oncologic and functional points of view. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement on the PubMed, Scopus, and Web of Science databases. English-language surgical series published between January 1985 and August 2021, reporting data on ≥5 patients treated for TC infiltrating the airway by (C)TRA were included. Oncologic outcomes, mortality, complications, and tracheotomy-dependency rates were assessed. Pooled proportion estimates were elaborated for each end-point. Thirty-seven studies were included, encompassing a total of 656 patients. Pooled risk of perioperative mortality was 2.0%. Surgical complications were reported in 27.0% of patients, with uni- or bilateral recurrent laryngeal nerve palsy being the most common. Permanent tracheotomy was required in 4.0% of patients. Oncologic outcomes varied among different series with 5- and 10-year overall survival rates ranging from 61% to 100% and 42.1% to 78.1%, respectively. Five- and 10-year disease specific survival rates ranged from 75.8% to 90% and 54.5% to 62.9%, respectively. Therefore, locally advanced TC with airway invasion treated with (C)TRA provides acceptable oncologic outcomes associated with a low permanent tracheotomy rate. The reported incidence of complications, however, indicates the need for judicious patient selection, meticulous surgical technique, and careful postoperative management.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Ultrasound in active surveillance for low-risk papillary thyroid cancer: imaging considerations in case selection and disease surveillance

Active surveillance (AS) of small, low-risk papillary thyroid cancers (PTCs) is increasingly studied in prospective observational studies. Ultrasound is the primary imaging modality for case selection. While researchers have put forward selection criteria for PTCs based on size, absence of suspicious lymph nodes and tumor location, there are limited reported data highlighting inherent ultrasound limitations and guidelines for case selection and follow-up. We report our experience including imaging limitations encountered in the ongoing AS prospective observational study for PTCs measuring < 2 cm at our institute. We define disease progression as an increase in size of > 3 mm in the largest dimension of nodule or evidence of metastatic disease or extrathyroidal extension. Accurate, consistent and reproducible measurements of PTCs are essential in risk stratifying patients for the option of AS or disease progression. Interobserver discrepancy, shadowing from coarse calcification and background parenchyma heterogeneity or thyroiditis can limit accurate PTC size assessment and therefore hinder patient eligibility evaluation or AS follow-up. Following the ACR Thyroid Imaging, Reporting and Data System (TI-RADS) protocol of three-axes technique to measure a thyroid nodule enables reproducibility of measurements. In patients with multi-nodular goiter, accurate identification and labeling of the PTC is important to avoid mistaking with adjacent benign nodules at follow-up. Ultrasound assessment for extrathyroid extension of PTC, and relationship of PTC to trachea and the anatomic course of the recurrent laryngeal nerve are important considerations in evaluation for AS eligibility.

Imaging of the Thyroid: Practical Approach

Imaging evaluation of the thyroid gland spans a plethora of modalities, including ultrasound imaging, cross-sectional studies, and nuclear medicine techniques. The overlapping of clinical and imaging findings of benign and malignant thyroid disease can make interpretation a complex undertaking. We aim to review and simplify the vast current literature and provide a practical approach to the imaging of thyroid disease for application in daily practice. Our approach highlights the keys to differentiating and diagnosing common benign and malignant disease affecting the thyroid gland.

2020 Imaging Guidelines for Thyroid Nodules and Differentiated Thyroid Cancer: Korean Society of Thyroid Radiology

Imaging plays a key role in the diagnosis and characterization of thyroid diseases, and the information provided by imaging studies is essential for management planning. A referral guideline for imaging studies may help physicians make reasonable decisions and minimize the number of unnecessary examinations. The Korean Society of Thyroid Radiology (KSThR) developed imaging guidelines for thyroid nodules and differentiated thyroid cancer using an adaptation process through a collaboration between the National Evidence-based Healthcare Collaborating Agency and the working group of KSThR, which is composed of radiologists specializing in thyroid imaging. When evidence is either insufficient or equivocal, expert opinion may supplement the available evidence for recommending imaging. Therefore, we suggest rating the appropriateness of imaging for specific clinical situations in this guideline.

A Radiomic Nomogram for the Ultrasound-Based Evaluation of Extrathyroidal Extension in Papillary Thyroid Carcinoma

Purpose

To construct a sequence diagram based on radiological and clinical factors for the evaluation of extrathyroidal extension (ETE) in patients with papillary thyroid carcinoma (PTC).

Materials and Methods

Between January 2016 and January 2020, 161 patients with PTC who underwent preoperative ultrasound examination in the Affiliated People’s Hospital of Jiangsu University were enrolled in this retrospective study. According to the pathology results, the enrolled patients were divided into a non-ETE group and an ETE group. All patients were randomly divided into a training cohort (n = 97) and a validation cohort (n = 64). A total of 479 image features of lesion areas in ultrasonic images were extracted. The radiomic signature was developed using least absolute shrinkage and selection operator algorithms after feature selection using the minimum redundancy maximum relevance method. The radiomic nomogram model was established by multivariable logistic regression analysis based on the radiomic signature and clinical risk factors. The discrimination, calibration, and clinical usefulness of the nomogram model were evaluated in the training and validation cohorts.

Results

The radiomic signature consisted of six radiomic features determined in ultrasound images. The radiomic nomogram included the parameters tumor location, radiological ETE diagnosis, and the radiomic signature. Area under the curve (AUC) values confirmed good discrimination of this nomogram in the training cohort [AUC, 0.837; 95% confidence interval (CI), 0.756–0.919] and the validation cohort (AUC, 0.824; 95% CI, 0.723–0.925). The decision curve analysis showed that the radiomic nomogram has good clinical application value.

Conclusion

The newly developed radiomic nomogram model is a noninvasive and reliable tool with high accuracy to predict ETE in patients with PTC.

Surgical Management of Tracheal Invasion by Well-Differentiated Thyroid Cancer

Simple Summary

Tracheal invasion is a poor prognostic factor in well-differentiated thyroid cancer. Appropriate resection can improve the prognosis and maintain the patient’s quality of life. Shaving resection for superficial tracheal invasion is minimally invasive because it does not involve the tracheal lumen, despite the problematic risk of local recurrence. Window resection for tracheal mucosal and luminal invasion provides good tumor control and does not cause postoperative airway obstruction; however, the need for surgical closure of the tracheocutaneous fistula is a disadvantage of this method. Circumferential (sleeve) resection and end-to-end anastomosis are highly curative, but the risk of fatal complications, such as anastomosis dehiscence, is a concern.

Abstract

Well-differentiated thyroid carcinoma (WDTC) is a slow-growing cancer with a good prognosis, but may show extraglandular progression involving the invasion of tumor-adjacent tissues, such as the trachea, esophagus, and recurrent laryngeal nerve. Tracheal invasion by WDTC is infrequent. Since this condition is rare, relevant high-level evidence about it is lacking. Tracheal invasion by a WDTC has a negative impact on survival, with intraluminal tumor development constituting a worse prognostic factor than superficial tracheal invasion. In WDTC, curative resection is often feasible with a small safety margin, and complete resection can ensure a good prognosis. Despite its resectability, accurate knowledge of the tracheal and peritracheal anatomy and proper selection of surgical techniques are essential for complete resection. However, there is no standard guideline on surgical indications and the recommended procedure in trachea-invading WDTC. This review discusses the indications for radical resection and the three currently available major resection methods: shaving, window resection, and sleeve resection with end-to-end anastomosis. The review shows that the decision for radical resection should be based on the patient’s general condition, tumor status, expected survival duration, and the treating facility’s strengths and weaknesses.

Surgical Treatment of Advanced Thyroid Cancer with Tracheal Invasion

Introduction

Tracheal invasion in thyroid cancer occurs in one-third of locally advanced cases and is the third most common site of infiltration following strap muscles and recurrent laryngeal nerves. Surgical resection plays an important role in the management strategy followed by either radioactive iodine or external beam radiotherapy. Nonetheless, there has been still controversy about the optimal extension of the surgery. Case Presentation. Total thyroidectomy, airway resection and bilateral neck dissection were performed in two cases diagnosed as advanced thyroid cancer with tracheal invasion (stage IV according to McCaffrey). The first case underwent partial tracheal resection and direct anastomosis by the V-shape technique, while the latter one required tracheal resection and permanent tracheotomy. After one-year follow-up, no evidence of tumor recurrence or any postoperative complications were found.

Conclusion

Surgical resection still remains the mainstay of management for advanced thyroid cancer in general and for tracheal invasion cases in particular. The decision of surgical resection and tracheal reconstruction methods mostly depends on the extent of tracheal invasion.

Surgical treatment of locally advanced thyroid cancer

Operations in this area are demanding and require special experience in endocrine, thoracic and vascular surgery, an experienced anaesthesiologist, as well as the interdisciplinary cooperation with other medical specialists (nuclear medicine, oncology, radiology, otolaryngology). A reliable system of surgical guidelines has been developed from a few individual publications with special impact.

Case for staged thyroidectomy

Recent modifications in the management of well-differentiated thyroid cancer have resulted in significant alterations in clinical approach. Utilizing a series of preoperative and postoperative risk factors involving both the patient and the disease pathology, we offer the term "staged thyroidectomy" to help organize these risk factors for patients and the endocrine team to optimize management. This approach is intended to incorporate our latest nuanced understanding of certain endocrine pathology and may serve to optimize patient outcomes.

The Impact of Arterial Phase on the Detection of Cervical Lymph Node Metastasis From Papillary Thyroid Carcinoma: A Quantitative Evaluation on Multiphasic Computed Tomography

OBJECTIVE

The purpose of this study was to assess the diagnostic performance of multiphasic computed tomography (CT) in the discrimination of metastatic lymph nodes (LNs) of papillary thyroid cancer by using quantitative parameters.

METHODS

This study enrolled 272 pathologically proven metastatic and benign LNs. Multiphasic CT was utilized by using nonenhanced, arterial (25-second delay), and venous (80-second delay) phases. Mean tissue attenuation values (MAVs) of metastatic and benign LNs were measured, and normalized MAV (common carotid artery and paraspinal muscle) and wash-in and wash-out percentages were also calculated.

RESULTS

The arterial phase showed the highest diagnostic performance in differentiation (area under the curve ± standard error, 0.97 ± 0.02; 95% confidence interval, 0.94-1.0; P < 0.001). Cutoff values for MAVs, normalized MAVs, and wash-in and wash-out percentages to predict metastatic LNs were calculated as 109 HU, 0.33, 1.93, 122.5, and -5.6 (sensitivity: 93.4%, 93.3%, 90.4%, 94.1%, and 97.8%, and specificity: 99.3%, 90.4%, 98.5%, 92.6%, and 99.3%, respectively).

CONCLUSIONS

Early-phase enhanced CT and the use of quantitative parameters derived from multiphasic CT improve the detection of cervical lymph node metastasis from papillary thyroid cancer.

Diagnostic Capabilities of MRI Versus 18F FDG PET-CT in Postoperative Patients with Thyroglobulin Positive, 131I-negative Local Recurrent or Metastatic Thyroid Cancer

BACKGROUND

The detection of recurrence or metastasis might be challenging in patients, who underwent total thyroidectomy and radioactive iodine therapy for Differentiated Thyroid Carcinoma (DTC), with increased serum Thyroglobulin (Tg) levels and negative 131I whole body scan (131I-WBS) results.

AIMS

The purpose of this study was to compare the ability of Magnetic Resonance Imaging (MRI) and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET-CT) to detect recurrence or cervical and upper mediastinal metastases in postoperative DTC patients who had negative 131I-WBS despite elevated serum Tg levels.

STUDY DESIGN

This study has a retrospective study design.

METHODS

We evaluated cervical and upper mediastinal MRI and 18F FDG PET-CT of 32 postoperative patients with DTC (26 patients with papillary thyroid carcinoma and 6 patients with follicular thyroid carcinoma).

RESULTS

We evaluated 44 lesions in 32 patients. For all lesions, the Positive Predictive Value, (PPV) Negative Predictive Value (NPV), sensitivity, specificity, and accuracy of MRI were 81.4%, 76.4%, 84.6%, 72.2%, and 79.5% respectively. The PPV, NPV, sensitivity, specificity, and accuracy of 18F FDG PET-CT were 100.0%, 85.7%, 88.4%, 100.0%, and 93.1%, respectively.

CONCLUSION

Although we could not replace 18F FDG PET-CT, MRI might be used as an adjunct to 18F FDG PET-CT for the evaluation of recurrent or cervical and upper mediastinal metastatic thyroid cancers; however, MRI is inadequate for the detection of metastases in small lymph nodes.

Computed Tomography Radiomic Nomogram for Preoperative Prediction of Extrathyroidal Extension in Papillary Thyroid Carcinoma

Objectives: Determining the presence of extrathyroidal extension (ETE) is important for patients with papillary thyroid carcinoma (PTC) in selecting the proper surgical approaches. This study aimed to explore a radiomic model for preoperative prediction of ETE in patients with PTC. Methods: The study included 624 PTC patients (without ETE, n = 448; with minimal ETE, n = 52; with gross ETE, n = 124) whom were divided randomly into training (n = 437) and validation (n = 187) cohorts; all data were gathered between January 2016 and November 2017. Radiomic features were extracted from computed tomography (CT) images of PTCs. Key radiomic features were identified and incorporated into a radiomic signature. Combining the radiomic signature with clinical risk factors, a radiomic nomogram was constructed using multivariable logistic regression. Delong test was used to compare different receiver operating characteristic curves. Results: Five key radiomic features were incorporated into the radiomic signature, which were significantly associated with ETE (p < 0.001 for both cohorts) and slightly better than clinical model integrating significant clinical risk factors in the training cohort (area under the receiver operating characteristic curve (AUC), 0.791 vs. 0.778; F₁ score, 0.729 vs. 0.714) and validation cohort (AUC, 0.772 vs. 0.756; F₁ score, 0.710 vs. 0.692). The radiomic nomogram significantly improved predictive value in the training cohort (AUC, 0.837, p < 0.001; F₁ score, 0.766) and validation cohort (AUC, 0.812, p = 0.024; F₁ score, 0.732). Conclusions: The radiomic nomogram significantly improved the preoperative prediction of ETE in PTC patients. It indicated that radiomics could be a valuable method in PTC research.

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

OBJECTIVE

The purpose of this study was to evaluate the performance of preoperative ultrasonography (US) in the staging of papillary thyroid carcinoma (PTC) according to the eighth AJCC TNM classification system, to determine the effect of the preoperative US staging in the management of PTC.

PATIENTS AND METHODS

Preoperative US was performed by 2 highly trained sonographers in 665 consecutive patients with PTC, and the T and N categories were determined preoperatively. The accuracy of preoperative US in clinical staging was evaluated based on the histopathological specimens according to the eighth AJCC TNM classification. Further analysis was performed to identify the high-risk factors of N1b stage.

RESULTS

Overall accuracy of preoperative US for T stage was 92.5% (615/665). The accuracy of sonographic evaluation for T was high except for the T4a. Overall accuracy of preoperative US for N stage was 59% (426/655). The accuracies of sonographic evaluation for N0, N1a, and N1b were 81.8% (274/335), 33.3% (70/250), and 87.5% (70/80), respectively. Of 250 N1a patients, 164 (65.6%) were underestimated by US. Univariate and multivariate analyses showed that larger tumor diameter, multifocality, and higher T stage significantly increase the risk of N1b stage (P < 0.01).

CONCLUSIONS

Preoperative US was useful for the evaluation in staging of PTC, but some limitations still existed. For higher-risk patients of N1b (larger tumor size, multifocality, and higher T stage), preoperative US examination for lateral neck region should be further emphasized, and prophylactic lateral nodal dissection should be determined based on both preoperative imaging results and intraoperative evaluation.

Papillary thyroid carcinoma with tracheal invasion: A case report

RATIONALE

Compared with most malignant tumors, papillary thyroid carcinoma (PTC) is usually associated with favorable survival and low recurrence rate. The prognostic factors of PTC include age, sex, tumor size, enlarged lymph nodes, and extrathyroidal extension. Among the extrathyroidal extension, upper aerodigestive tract (ADT) invasion by PTC is a marker of more aggressive tumor behavior, defining a subpopulation of patients at a greater risk of recurrence and death.

PATIENT CONCERNS

A 61-year-old woman had a cervical mass that was slowly growing for three years. Additionally, she had haemoptysis of 1-year duration. During the month prior to her visit, she had difficulty breathing.

DIAGNOSIS

Neck ultrasonography (US) and thyroid computed tomography (CT) images both showed a well-defined calcified mass on the left lobe of the thyroid gland. Additionally, the thyroid CT revealed that part of the mass protruded into the lumen which resulted in the thickening on the left side of the trachea. Accordingly, her diagnoses were as follows: firstly, a solid mass on the left lobe of the thyroid gland with tracheal compression; and finally, the space-occupying airway lesion.

INTERVENTIONS

She underwent a bronchoscopic examination, which revealed a mass blocking most of the upper endoluminal trachea. Thus, the mass was resected at the upper tracheal segment, followed by electrotome and argon plasma coagulation treatment. She was then transferred to the Thyroid Surgery Department. Thyroid surgeons took the surgical type of bilateral subtotal thyroidectomy + exploration of bilateral recurrent laryngeal nerve + dissection of the lymph node in neck central area + circumferential sleeve resection + end-to-end anastomosis + tracheotomy in the patient.

OUTCOMES

After surgery, she recovered well without any local recurrence or distant metastasis.

LESSONS

When patients with PTC have haemoptysis, hoarseness, dyspnea, or any other symptoms, and the imaging examinations reveal a space-occupying lesion in the thyroid and airway, clinicians should focus on PTC with tracheal invasion, a bronchoscopic examination must be immediately performed because the subsequent surgical management depends on the degree of tracheal invasion.

Can Thyroid Ultrasonography Predict Substernal Extension or Tracheal Compression in Goiters?

PURPOSE

To determine whether an ultrasonography (US)-defined thyroid volume can accurately predict substernal extension or tracheal narrowing.

METHODS

After research ethics approval, we identified patients with thyroid nodules investigated with both US and computed tomography (CT). Reviewers assigned scores for both substernal extension and tracheal compression on CT using pre-established classification systems. Statistical analysis with receiver operating characteristic curve analysis was performed to find the US-determined thyroid volume thresholds that correlated with each substernal extension and tracheal compression.

RESULTS

This study included 120 patients (mean age 63.4 years; SD ± 15.9; 67% female). Thirty-five patients (29%) had substernal extension. The mean US total thyroid gland volume in patients with and without substernal extension were 92.4 and 37.6 cm³, respectively (P < .001). 86% of patients with substernal extension had tracheal narrowing vs. 27% of patients without substernal extension (P < .0001). A cutoff dominant gland volume of ≥37.5 cm³ showed 83% sensitivity and 79% specificity for substernal extension (area under the curve [AUC] = 0.84). A total thyroid gland volume threshold of ≥37.8 cm³ showed 89% sensitivity and 87% specificity for any degree of tracheal narrowing (AUC = 0.90).

CONCLUSIONS

This study suggests that US volumes may be used as a predictor to identify those patients with thyroid enlargement who are most at risk of substernal extension and tracheal compression and who may benefit from preoperative CT imaging for optimal surgical and anesthetic planning.

Chapter 4 Thyroid Malignancy: Staging and Restaging

Determining the extent of disease is necessary for guiding the management of thyroid carcinomas. Diagnostic imaging, including ultrasound, computed tomography, magnetic resonance imaging, and nuclear medicine scans, plays an essential role in staging and restaging of thyroid carcinomas. This article reviews the approaches and imaging findings for evaluating the primary tumor, regional lymph node metastases, and distant metastases. In addition, potential pitfalls are discussed and depicted.

Thyroid cancer with tracheal invasion: a pathological estimation

We review the clinical and pathologic features of seven cases of papillary carcinoma of the thyroid that invaded the trachea and were treated by thyroidectomy, airway resection with reconstructive surgery over an interval of 15 years. We depicted the peculiarity of invasion of well differentiated papillary thyroid carcinoma (PTC) cells is perpendicularly oriented to the tracheal lumen, in between cartilaginous rings, along blood vessels and collagen fibers. Tracheal rings appear non-infiltrated in all histological sections of well differentiated PTC infiltrating the trachea. Similar description of inter-cartilage PTC infiltration into the trachea was first provided by Shin et al. in 1993. Interestingly, our pathological revision support the estimation by Shin et al., though that cartilage rings infiltration did occur in poorly differentiated thyroid cancers with exiguous prognosis.

Feasibility Study of a Contrast-Enhanced Multi-Detector CT (64 Channels) Protocol for Papillary Thyroid Carcinoma: The Influence of Different Scan Delays on Tumor Conspicuity

BACKGROUND

Recently, a number of studies have advocated the diagnostic benefit of contrast-enhanced computed tomography (CECT) in the current ultrasound (US)-based preoperative evaluation of thyroid cancer. However, no study has been conducted to optimize a CECT protocol focusing on tumor conspicuity using a multi-detector CT scanner. This study aimed at determining the optimal scan delay for increased CT attenuation differences between thyroid cancer and parenchymal background using a biphasic CECT examination.

METHODS

This study retrospectively enrolled 84 patients (M:F = 7:77; Mage = 44.8 ± 10.9 years) with 87 papillary thyroid carcinomas (Msize = 14.1 mm) who consecutively underwent US and CECT examination prior to surgery. In each patient, CT scanning was taken twice-once with a 40-second delay and once with a 70-second delay-using a 64-channel multi-detector scanner. After obtaining the mean attenuation value (MAV) of the thyroid cancer and the ipsilateral parenchyma by drawing regions of interest on the CECT images based on their cytopathologic results and US findings, the parenchyma-cancer differences (PCD) between the early and delayed scans were simply compared using a paired t-test. Then, the mean differences in the MAVs of the thyroid cancer and ipsilateral parenchyma (hereafter abbreviated as Group) between the early and delayed scans (abbreviated as Time) were compared after adjusting for the other factors that significantly affected MAVs, such as concentration of iodinated contrast medium (abbreviated as CCM) and size of thyroid cancer (abbreviated as Size) using a repeated-measures general linear model.

RESULTS

Because the ipsilateral parenchyma exhibited significantly higher attenuation on the early scan and further decline on the delayed scan compared with thyroid cancer (p < 0.001), the PCD for thyroid cancer was significantly better with a 40-second scan delay than a 70-second delay (58.8 ± 36.6 Hounsfield units [HU] vs. 40.4 ± 25.6 HU; p < 0.001). Similar results were obtained from the repeated-measures general linear model that considered the effects of CCM, Size, Group, and Time, and the interaction of Group and Time.

CONCLUSION

Based on this CECT study that adjusted for the effects of CCM and size on MAV, early scans (e.g., 40-second scan delay) are helpful for improving the tumor conspicuity of thyroid cancer on CECT images.

Protection and Dissection of Recurrent Laryngeal Nerve in Salvage Thyroid Cancer Surgery to Patients with Insufficient Primary Operation Extent and Suspicious Residual Tumor

Some thyroid cancer patients undergone insufficient tumor removal in the primary surgery in China . our aim is to evaluate the impact of dissection of the recurrent laryngeal nerve during a salvage thyroid cancer operation in these patients to prevent nerve injury. Clinical data of 49 enrolled patients who received a salvage thyroid operation were retrospectively reviewed. Primary pathology was thyroid papillary cancer. The initial procedure performed included nodulectomy (20 patients), partial thyroidectomy (19 patients) and subtotal thyroidectomy (10 patients). The effect of dissection and protection of the recurrent laryngeal nerve and the mechanism of nerve injury were studied. The cervical courses of the recurrent laryngeal nerves were successfully dissected in all cases. Nerves were adherent to or involved by scars in 22 cases. Three were ligated near the place where the nerve entered the larynx, while another three were cut near the intersection of inferior thyroid artery with the recurrent laryngeal nerve. Light hoarseness occurred to four patients without a preoperative voice change. In conclusion, accurate primary diagnosis allows for a sufficient primary operation to be performed, avoiding insufficient tumor removal that requires a secondary surgery. The most important cause of nerve damage resulted from not identifying the recurrent laryngeal nerve during first surgery , and meticulous dissection during salvage surgery was the most efficient method to avoid nerve damage.

A cross-specialty survey to assess the application of risk stratified surgery for differentiated thyroid cancer in the UK

INTRODUCTION

This study describes variability of treatment for differentiated thyroid cancer among thyroid surgeons, in the context of changing patterns of thyroid surgery in the UK.

METHODS

Hospital Episodes Statistics on thyroid operations between 1997 and 2012 were obtained for England. A survey comprising six scenarios of varying 'risk' was developed. Patient/tumour information was provided, with five risk stratified or non-risk stratified treatment options. The survey was distributed to UK surgical associations. Respondent demographics were categorised and responses analysed by assigned risk stratified preference.

RESULTS

From 1997 to 2012, the Hospital Episode Statistics data indicated there was a 55% increase in the annual number of thyroidectomies with a fivefold increase in otolaryngology procedures and a tripling of cancer operations. Of the surgical association members surveyed, 264 respondents reported a thyroid surgery practice. Management varied across and within the six scenarios, and was not related consistently to the level of risk. Associations were demonstrated between overall risk stratified preference and higher volume practice (>25 thyroidectomies per year) (p=0.011), fewer years of consultant practice (p=0.017) and multidisciplinary team participation (p=0.037). Logistic regression revealed fewer years of consultant practice (odds ratio [OR]: 0.96/year in practice, 95% confidence interval [CI]: 0.922-0.997, p=0.036) and caseload of >25/year (OR 1.92, 95% CI: 1.044-3.522, p=0.036) as independent predictors of risk stratified preference.

CONCLUSIONS

There is a substantial contribution to thyroid surgery in the UK by otolaryngology surgeons. Adjusting management according to established case-based risk stratification is not widely applied. Higher caseload was associated with a preference for management tailored to individual risk.

Management of invasive well-differentiated thyroid cancer: an American Head and Neck Society consensus statement. AHNS consensus statement

BACKGROUND

Invasive differentiated thyroid cancer (DTC) is relatively frequent, yet there is a paucity of specific guidelines devoted to its management. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to provide clinical consensus statements based on review of the literature, synthesized with the expert opinion of the group.

METHODS

An expert panel, selected from membership of the AHNS, constructed the manuscript and recommendations for management of DTC with invasion of recurrent laryngeal nerve, trachea, esophagus, larynx, and major vessels based on current best evidence. A Modified Delphi survey was then constructed by another expert panelist utilizing 9 anchor points, 1 = strongly disagree to 9 = strongly agree. Results of the survey were utilized to determine which statements achieved consensus, near-consensus, or non-consensus.

RESULTS

After endorsement by the AHNS Endocrine Committee and Quality of Care Committee, it received final approval from the AHNS Council.

Peering through the glare: using dual-energy CT to overcome the problem of metal artefacts in bone radiology

OBJECTIVE

Imaging of patients with large metal implants remains one of the most difficult endeavours for radiologists. This article reviews the theory of dual-energy CT (DECT) and its ability to reduce metal artefact, thus enhancing the diagnostic value of musculoskeletal imaging. The strengths, weaknesses, and alternative applications of DECT, as well as areas requiring further research, will also be reviewed.

CONCLUSION

Currently, DECT stands as the frontier for metal artefact reduction in musculoskeletal imaging. DECT requires no additional radiation and provides significantly enhanced image acquisition. When considered along with its other capabilities, DECT is a promising new tool for musculoskeletal and trauma radiologists.

Imaging of thyroid carcinoma with CT and MRI: approaches to common scenarios

Computed tomography (CT) and magnetic resonance imaging (MRI) can play an important role in preoperative and post-treatment assessment of thyroid malignancy. The radiologist should be aware of the pathological behavior of thyroid carcinoma, and the characteristic imaging appearance of the primary tumor and metastases. This review describes the approach to imaging thyroid cancer on CT and MRI for four common scenarios: detection of the incidental thyroid nodule, evaluation of thyroid metastases, presurgical imaging for invasive disease, and evaluation for recurrence in the post-treatment neck.

American Thyroid Association guidelines for management of patients with anaplastic thyroid cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare but highly lethal form of thyroid cancer. Rapid evaluation and establishment of treatment goals are imperative for optimum patient management and require a multidisciplinary team approach. Here we present guidelines for the management of ATC. The development of these guidelines was supported by the American Thyroid Association (ATA), which requested the authors, members the ATA Taskforce for ATC, to independently develop guidelines for ATC.

METHODS

Relevant literature was reviewed, including serial PubMed searches supplemented with additional articles. The quality and strength of recommendations were adapted from the Clinical Guidelines Committee of the American College of Physicians, which in turn was developed by the Grading of Recommendations Assessment, Development and Evaluation workshop.

RESULTS

The guidelines include the diagnosis, initial evaluation, establishment of treatment goals, approaches to locoregional disease (surgery, radiotherapy, systemic therapy, supportive care during active therapy), approaches to advanced/metastatic disease, palliative care options, surveillance and long-term monitoring, and ethical issues including end of life. The guidelines include 65 recommendations.

CONCLUSIONS

These are the first comprehensive guidelines for ATC and provide recommendations for management of this extremely aggressive malignancy. Patients with stage IVA/IVB resectable disease have the best prognosis, particularly if a multimodal approach (surgery, radiation, systemic therapy) is used, and some stage IVB unresectable patients may respond to aggressive therapy. Patients with stage IVC disease should be considered for a clinical trial or hospice/palliative care, depending upon their preference.

[Extrathyroidal thyroid cancer : results of tracheal shaving and tracheal resection]

Extrathyroidal thyroid cancer invading the laryngotracheal system (UICC stage pT4a) represents a progressive process of infiltration of the tracheal wall layers from the outer to the inner parts of the trachea. These tumors usually present with high proliferation activity correlating with a reduced long-term prognosis. In contrast to intraluminal manifestation requiring complete wall resection, in cases of non-transmural invasion, complete tumor removal can be sometimes achieved by extraluminal tangential resection (shaving). Tangential resections, however, are associated with a higher frequency of microscopically invaded resection margins (R1 resection rate >40%). The available comparative studies (all retrospective, maximum EBM level 3) analyzing oncological outcome show inconsistent results. In more recently published studies, however, complete wall resection in well-differentiated thyroid cancer with tracheal invasion only was found to be associated with longer recurrence-free and tumor-specific survival when compared to shaving. Deep larynx invasion is associated with reduced long-term prognosis when compared to invasion of the trachea. Salvage resections should therefore be performed in selected cases only.