Cross-Sectional Imaging of the Thyroid Gland

Diagnostic value of multiple diagnostic methods for lymph node metastases of papillary thyroid carcinoma: A systematic review and meta-analysis

OBJECTIVE

This study compared the diagnostic value of various diagnostic methods for lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) through network meta-analysis.

METHODS

In this experiment, databases such as CNKI, Wanfang, PubMed, and Web of Science were retrieved according to the Cochrane database, Prisma, and NMAP command manual. A meta-analysis was performed using STATA 15.0, and the value of the surface under the cumulative ranking curve (SUCRA) was used to determine the most effective diagnostic method. Quality assessments were performed using the Cochrane Collaboration's risk of bias tool, and publication bias was assessed using Deeks' funnel plot.

RESULTS

A total of 38 articles with a total of 6285 patients were included. A total of 12 diagnostic methods were used to study patients with LNM of PTC. The results showed that 12 studies were direct comparisons and 8 studies were indirect comparisons. According to the comprehensive analysis of the area of SUCRA, US+CT(86.8) had the highest sensitivity, FNAC had the highest specificity (92.4) and true positive predictive value (89.4), and FNAC+FNA-Tg had higher negative predictive value (99.4) and accuracy (86.8). In the non-invasive method, US+CT had the highest sensitivity, and the sensitivity (SEN) was [OR=0.59, 95% confidence interval (CI): (0.30, 0.89]. Among the invasive methods, the combined application of FNAC+FNA-Tg had higher diagnostic performance. The sensitivity was [OR=0.62, 95% CI: (0.26, 0.98)], the specificity (SPE) was [OR=1.12, 95% CI: (0.59, 1.64)], the positive predictive value was [OR=0.98, 95% CI: (0.59, 1.37)], the negative predictive value was [OR=0.64, 95% CI (0.38, 0.90)], and the accuracy was [OR=0.71, 95% CI: (0.31, 1.12)].

CONCLUSION

In the non-invasive method, the combined application of US+CT had good diagnostic performance, and in the invasive method, the combined application of FNAC+FNA-Tg had high diagnostic performance, and the above two methods were recommended.

Assessment of qualitative and quantitative parameters of healthy thyroid gland in adult horses by magnetic resonance imaging

In humans and pets, magnetic resonance imaging (MRI) provides important adjunctive anatomic information about the thyroid and its adjacent structures. To the best of our knowledge, however, no studies have been reported regarding the use of MRI for thyroid evaluation in horses. The aim of this study was to obtain qualitative and quantitative parameters of healthy thyroid gland in adult horses by MRI. Eleven horses were submitted to thyroid MRI evaluation. The healthy thyroid of these animals was ensured by normal examinations performed before (free thyroxine and ultrasound) and after (cytology) to MRI. It was concluded that the dorsal spin-echo T1-weighted, fast spin-echo T2-weighted, sagittal STIR and a three-dimensional T1-weighted gradient echo were the sequences that best characterized the thyroid lobes. Qualitatively, there was a significant variation in the elliptical format of some lobes considering the sagittal plane, which oscillated between rounded and flattened conformation. Excellent reproducibility of the quantitative thyroid parameters obtained was verified. The thyroid gland total volume mean of observers was 14.31 cm³ (±0.69). In relation with comparisons between quantitative parameters of left and right lobes, only differences regarding their respective lengths were observed. Thus, we can infer that the difference in some thyroid lobes format can be explained by the significant variation identified between left and right lobes lengths.

2021 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. Since the guidelines for the management of ATC by the American Thyroid Association were first published in 2012, significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, and researchers on published evidence relating to the diagnosis and management of ATC. Methods: The specific clinical questions and topics addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of the Task Force members (authors of the guideline). Relevant literature was reviewed, including serial PubMed searches supplemented with additional articles. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. Results: The guidelines include the diagnosis, initial evaluation, establishment of treatment goals, approaches to locoregional disease (surgery, radiotherapy, targeted/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 31 recommendations and 16 good practice statements. Conclusions: We have developed evidence-based recommendations to inform clinical decision-making in the management of ATC. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with ATC.

Diagnostic values of F-18 FDG PET or PET/CT, CT, and US for Preoperative Lymph Node Staging in Thyroid Cancer: A Network Meta-Analysis

OBJECTIVE

This study compared the diagnostic performance of three different imaging modalities for preoperative lymph node (LN) staging in thyroid cancer patients, using a network meta-analysis (NMA).

METHODS

PubMed and Embase were searched to identify studies evaluating the performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET or PET/CT), computed tomography (CT), and ultrasonography (US) for preoperative LN staging in thyroid cancer patients. The NMA included both patient- and lesion-based analyses. The surface under the cumulative ranking curve (SUCRA) values was used to decide on the most effective diagnostic method.

RESULTS

A total of 3,571 patients from 19 direct comparison studies using three different imaging modalities for preoperative LN staging in thyroid cancer patients were included. US showed the highest SUCRA values for positive predictive values (PPV), negative predictive values (NPV), and accuracy in detection of all cervical LN metastasis. F-18 FDG PET or PET/CT and US showed the highest SUCRA values for PPV and sensitivity, respectively, for central LN, and the highest SUCRA value of specificity and sensitivity, respectively, for lateral LN.

CONCLUSION

The results from this NMA indicate that F-18 FDG PET or PET/CT, CT, and US have complementary diagnostic roles for preoperative staging in thyroid cancer patients.

ADVANCES IN KNOWLEDGE

Using NMA, we comprehensively compared the different diagnostic values and limitations of F-18 FDG PET or PET/CT, CT, and US for the preoperative LN staging in thyroid cancer patients.

Computed Tomography for Detecting Cervical Lymph Node Metastasis in Patients Who Have Papillary Thyroid Microcarcinoma with Tumor Characteristics Appropriate for Active Surveillance

Background: Active surveillance (AS) has been considered one of the management options in patients with low-risk papillary thyroid microcarcinoma (PTMC). It is important to evaluate clinical lymph node (LN) metastasis to select appropriate candidates with low-risk disease. We investigated the predictive accuracy of computed tomography (CT) for cervical LN metastasis in patients who have PTMC with tumor characteristics appropriate for AS. Methods: This was a retrospective study. Medical records from December 2014 to the end of 2016 were reviewed. Patients who underwent thyroidectomy and who had pathologically confirmed PTMC were included. A total of 464 patients who had tumors with ultrasound (US) characteristics appropriate for AS and who underwent preoperative CT were included in the analysis. Results: CT showed higher diagnostic values especially in positive predictive value (PPV) than US. In patient-based analyses, CT showed low sensitivity and negative predictive value (NPV) (16.0% and 58.5%, respectively), but high specificity and PPV (99.6% and 97.1%, respectively) for detecting cervical LN metastasis. Similar trends were observed for the results of the central neck-level by CT (sensitivity, 14.9%; specificity, 97.4%; PPV, 82.9%; and NPV, 57.4%) in level-by-level analyses. When restricted to lateral neck levels, CT showed high diagnostic accuracy of 95.4% for detecting LN metastasis. In all analyses, CT showed better diagnostic values for cervical LN metastasis than US. Combining US and CT did not improve the diagnostic accuracy compared with CT. Conclusions: In patients with PTMC whose tumor has characteristics suitable for AS, CT had additional benefit after cervical LN assessment by US. Further studies are needed to evaluate routine initial CT scanning for patients who are candidates for AS.

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.

Extranodal lymphoma of the head and neck: a pictorial essay

Primary extranodal lymphoma is defined as a lymphoma at a solitary extranodal site, with or without involvement of the lymph nodes. The clinical and radiological features of extranodal lymphoma have been documented in recent studies. In this pictorial essay, we reviewed imaging findings of extranodal lymphoma in the head and neck region.

Surveillance for Differentiated Thyroid Cancer Recurrence

Serum thyroglobulin monitoring along with anatomic and functional imaging play key roles in the surveillance of patients with differentiated thyroid cancer after initial treatment. Among patients with a disease stage justifying thyroid remnant ablation or with suspected metastatic disease, radioiodine whole-body scans are essential in the months after surgery. For patients with low to moderate-risk cancers, ultrasonography of the neck (with measurement of serum thyroglobulin on thyroid hormone replacement) are the best initial diagnostic modalities, and are often the only tests required. In individuals suspected of having distant metastases, CT, MRI, and 18F-FDG PET can make important contributions in localizing residual disease and monitoring its progression and responses to therapy, provided they are used in the appropriate setting.

Ectopic thyroids have lower computed tomography attenuation values than orthotopic thyroids

PURPOSE

To determine whether ectopic thyroid had the same computed tomography (CT) value as orthotopic thyroid.

METHODS

Twenty-one patients with 23 ectopic thyroids and 23 controls with orthotopic thyroids underwent CT scans and were included in this retrospective study. The CT images were reviewed in a blinded fashion by two radiologists. Independent-Samples T-test was used for comparison of CT attenuation values between two groups.

RESULTS

Ectopic thyroids had significantly lower non-enhanced attenuation (91.04 ± 5.97 Hounsfield Units vs. 106.56 ± 4.06 Hounsfield Units, P = 0.038) and contrast-enhanced attenuation (141.32 ± 6.42 Hounsfield Units vs. 169.82 ± 4.30 Hounsfield Units, P = 0.001) values than orthotopic thyroids.

CONCLUSIONS

Ectopic thyroids have lower CT attenuation values than orthotopic thyroids probably due to the structural or functional abnormalities. The dysgenesis and pathological changes of the ectopic thyroids may contribute to functional deficiency which finally leads to decrease of the CT attenuation values.

Imaging Evaluation of the Head and Neck Oncology Patient

Imaging plays a multifaceted role in the diagnosis and characterization of head and neck oncological patients and is integral to their care. Given the complexity of treatment, a multimodality approach is often necessary. With the advent of new technologies, imaging can also be used to predict tumor behavior and treatment response. In this chapter, with selected case examples, we describe the various imaging modalities available and offer suggestions on their utilization.

Imaging and Screening of Thyroid Cancer

Ultrasound is the first-line diagnostic tool for diagnosis of thyroid diseases. The low aggressiveness of many thyroid cancers coupled with high sensitivity of sonography can lead to cancer diagnosis and treatment with no effect on outcomes. Ultrasound is recognized as the most important driver of thyroid cancer overdiagnosis. Ultrasound should not be used as a general screening tool and should be reserved for patients at high risk of thyroid cancer and in the diagnostic management of incidentally discovered thyroid nodules. With prescreening risk stratification and application of consensus criteria for nodule biopsy, the value of the diagnostic ultrasound can be maximized.

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.

Updated guidelines on the preoperative staging of thyroid cancer

Recent studies have provided prognostic information and recommendations for staging thyroid cancers that have changed the staging and management guidelines for the disease. Consequently, minimal extrathyroidal extension (ETE) was removed from the T3 stage classification in the eighth edition of the TNM staging system by the American Joint Committee on Cancer. New T categories have been subsequently added, including T3a, defined as a tumor >4 cm in its greatest dimension, limited to the thyroid gland, and T3b, defined as a tumor of any size with gross ETE invading only the strap muscles. In this article, the author reviews the changes in the TNM staging system for thyroid cancer, with an emphasis on ultrasonography in preoperative staging.

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.

Resection of Unresectable Stage IVB Thyroid Cancer Encasing the Carotid Artery

Stage IVB thyroid cancer includes carotid encasement or infiltration of the prevertebral fascia and mediastinal vessels. Stage IVB disease is considered unresectable due to grave consequences of attempting resection. We report a rare case of carotid artery engulfment being resected uneventfully without carotid resection.

Total thyroidectomy as primary surgical management for thyroid disease: surgical therapy experience from 5559 thyroidectomies in a less-developed region

Background

The objective of this study was to evaluate the safety of total thyroidectomy for thyroid disorders and summarise the treatment experience in a less-developed region.

Methods

This was a retrospective observational cohort study using the computerised database of the First Affiliated Hospital of Harbin Medical University. All consecutive thyroidectomy patients from 2003 to 2014 were included in this study. Demographics, surgical procedure, diagnoses, morbidity and mortality were retrospectively reviewed.

Results

There were a total of 714 men and 4845 women in this study, with a mean age of 55 (range 9–87) years. A total of 4632 patients underwent total thyroidectomy for primary surgical treatment, and 189 patients previously underwent partial thyroidectomy. A total of 56.2 % of the patients had multinodular goitre, including 12.23 % who were thyrotoxic. Graves’ disease and Hashimoto’s disease were diagnosed in 2.82 and 7.23 % of the patients, respectively. Papillary thyroid cancer was identified in 1336 patients, 44.99 % of whom had papillary microcarcinoma. The total prevalence of permanent complications of first-time and secondary surgeries was 0.35 and 7.41 %, respectively. During thyroid surgery, 945 patients underwent parathyroid autotransplantation.

Conclusions

Initial total thyroidectomy can be safely performed for both benign and malignant thyroid diseases in a less-developed region. The morbidity of a secondary surgical procedure after subtotal thyroidectomy is significantly high compared to first-time surgery.

Sonographic appearance of thyroid glands in patients treated with intensity-modulated radiotherapy or conventional radiotherapy for nasopharyngeal carcinoma

BACKGROUND

This study aimed to investigate the sonographic appearances of the thyroid glands in nasopharyngeal carcinoma (NPC) patients whose cervical lymph nodes were treated with conventional radiotherapy (RT) or intensity-modulated radiotherapy (IMRT). The post-RT sonographic appearances of the thyroid glands in NPC patients were also correlated with the thyroid function.

METHODS

One hundred and three NPC patients who had completed RT of cervical lymph nodes using the anterior cervical field, 30 NPC patients who had completed RT of cervical lymph nodes using IMRT, and 61 healthy subjects were included in the study. Thyroid glands were sonographically assessed for their size, echogenicity, vascularity, and internal architecture. Thyroid function tests were also performed on each subject.

RESULTS

In comparison with the patients with abnormal thyroid function, the thyroid glands of the patients with normal thyroid function tended to be homogeneous and to have greater volume and echogenicity index (p < 0.05). Compared with those of the healthy subjects, the thyroid glands of patients previously treated with IMRT and those treated with the anterior cervical field showed significantly lower thyroid volume, lower incidence and number of nodules, and higher vascularity index (p < 0.05).

CONCLUSIONS

The patient's history of previous RT should be taken into consideration in the sonographic examination of the thyroid gland post-RT. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:210-223, 2015.

A mathematical model using computed tomography for the diagnosis of metastatic central compartment lymph nodes in papillary thyroid carcinoma

OBJECTIVES

The purpose of this study was to establish a potential mathematical model for the diagnosis of the central compartment lymph node (LN) metastases of papillary thyroid carcinoma (PTC) using CT imaging.

METHODS

303 patients with PTC were enrolled. We determined the optimal cut-off points of LN size and nodal grouping by calculating the diagnostic value of each cut-off point. Then, calcification, cystic or necrotic change, abnormal enhancement, size, and nodal grouping were analysed by univariate and multivariate statistical methods. The mathematical model was obtained using binary logistic regression analysis, and a scoring system was developed for convenient use in clinical practice.

RESULTS

30 mm(2) for LNs area (size) and two LNs as the nodal grouping criterion had the best diagnostic value. The mathematical model was: p = e (y) /(1+ e (y) ), y = -0.670-0.087 × size + 1.010 × cystic or necrotic change + 1.371 × abnormal enhancement + 0.828 × nodal grouping + 0.909 × area. We assigned the value for cystic or necrotic change, abnormal enhancement, size and nodal grouping value as 25, 33, 20, and 22, respectively, yielding a scoring system.

CONCLUSIONS

This mathematical model has a high diagnostic value and is a convenient clinical tool.

KEY POINTS

• Papillary thyroid carcinoma has a relatively high rate of metastasis. • CT has unique advantages in evaluating the central compartment. • The mathematical model can improve the diagnosis of CT imaging. • Corresponding scoring system is a convenient clinical tool.

PET/CT in the management of thyroid cancers

OBJECTIVE

Thyroid cancer is the most common endocrine cancer. This review evaluates the established use of (18)F-FDG PET/CT in papillary, follicular, Hürthle cell, anaplastic, and medullary thyroid cancers. The significance of incidental diffuse and focal thyroid FDG uptake is discussed. The evolving value of non-FDG radiotracers, including (124)I, (18)F-dihydroxyphenylalanine, and (68)Ga somatostatin analogs, is summarized.

CONCLUSION

PET/CT is a valuable imaging test, in the appropriate clinical context, for the management of thyroid cancers.

Thyroid lymphoma: recent advances in diagnosis and optimal management strategies

Primary thyroid lymphoma is rare, composing approximately 5% of all thyroid malignancies and less than 3% of all extranodal lymphomas. It typically presents as a rapidly enlarging goiter with associated compressive symptoms. Thyroid ultrasound and fine needle aspiration cytology, using flow cytometry and immunohistochemistry, remain the main modalities used to confirm the presence of lymphoma. The increasing use of an ultrasound-guided core biopsy to achieve an accurate diagnosis has further limited the role of surgery. An open surgical biopsy may still be required not only for definitive diagnosis but also to confirm the subtype of lymphoma. There are limited numbers of randomized or prospective trials to guide management, and controversy remains over optimal treatment. Treatment and prognosis of this disease can be dichotomized into two separate groups: pure mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBCL) or mixed subtypes. Early stage (stage IE) intrathyroidal MALT lymphomas typically have an indolent course and may be treated with single-modality surgery, radiotherapy, or a combination of both. DLBCLs are more aggressive, and survival outcomes are highest with multimodal therapy incorporating monoclonal antibodies, chemotherapy, and radiotherapy. The prognosis is generally excellent but can be varied because of the heterogeneous nature of thyroid lymphomas. The aim of this paper is to discuss the changes in diagnostic modalities and to focus on the recent alterations in the management of this rare disease, including targeted therapies as well as the more limited role of the endocrine surgeon.

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.

Staging of papillary thyroid carcinoma with ultrasonography: performance in a large series

BACKGROUND

This study was designed to evaluate the performance of ultrasonography (US) for the preoperative staging of papillary thyroid carcinoma (PTC) in a large series according to the TNM classification.

METHODS

Preoperative US was performed for the evaluation of primary tumors and lymph node metastasis in 722 consecutive patients with cytologically proven PTC. Three experienced radiologists prospectively determined T and N categories of PTC. N categorization was based on compartments, including left and right lateral compartments (levels II-V) and central compartment (level VI). All patients underwent surgery and central compartment dissection. Lateral compartment dissection was selectively performed. We assessed the diagnostic performance of preoperative US for staging of PTC on the basis of pathologic findings of surgical specimens. Subgroup analysis according to suspicion of diffuse thyroid disease (DTD) on US was performed to compare US accuracies for N categorization.

RESULTS

US predicted 61.7% (142/230) of patients with multifocal PTC and 67.1% (100/149) of patients with bilateral malignancy. Overall accuracy of US for T categorization was 69.7% (503/722) and that of US for N categorization was 59% (426/722). Accuracies of sonographic categorization for N0, N1a, and N1b were 66% (276/418), 33.3% (70/210), and 85.1% (80/94), respectively. Overall US accuracy for prediction of an N category was significantly lower in patients with US-indicated DTD (51.1%, 67/131) than it was in patients without DTD (60.7%, 359/591; P = 0.043).

CONCLUSIONS

Preoperative US is a feasible technique for the preoperative staging of PTC and is helpful for the detection of lateral compartment metastasis. Presence of DTD can affect the staging of lymph node metastasis.

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

OBJECTIVE

The purpose of this study was to determine the diagnostic accuracy of CT for detecting extrathyroidal invasion of thyroid cancer to adjacent structures.

MATERIALS AND METHODS

Eighty-four patients (19 men, 65 women; age range, 19-84 years; mean, 54.2 +/- 15.4 years) with 86 malignant tumors of the thyroid with extracapsular extension (37 T3, 49 T4) were retrospectively enrolled in this study. Two radiologists independently evaluated the CT findings of invasion of thyroid cancer into the trachea, esophagus, common carotid artery, internal jugular vein, and recurrent laryngeal nerve. These results were compared with the surgical and histopathologic findings.

RESULTS

The mean sensitivity, specificity, and accuracy of CT were as follows: 59.1%, 91.4%, and 83.2% for tracheal invasion; 28.6%, 96.2%, and 90.7% for esophageal invasion; 75.0%, 99.4%, and 98.8% for invasion of the common carotid artery; 33.3%, 98.8%, and 97.1% for invasion of the internal jugular vein; and 78.2%, 89.8%, and 85.5% for invasion to the recurrent laryngeal nerve. Interobserver agreement was moderate to good in the five categories of extrathyroidal invasion with a mean kappa value of 0.65 (range, 0.49-0.77).

CONCLUSION

Although the effectiveness is limited by low sensitivity, CT may be a valuable tool for evaluation of extrathyroidal invasion of thyroid cancer to adjacent structures.

Preoperative staging of papillary thyroid carcinoma: comparison of ultrasound imaging and CT

OBJECTIVE

The purpose of this study was to compare the diagnostic accuracy of ultrasound imaging with that of CT in the preoperative evaluation of primary tumors and cervical lymph nodes in patients with papillary thyroid carcinoma and to determine whether CT has greater diagnostic value than ultrasound alone in the care of these patients.

MATERIALS AND METHODS

The study population consisted of 299 consecutively registered patients with pathologically proven papillary thyroid carcinoma. The diagnostic accuracies of ultrasound, CT, and the combination of ultrasound and CT in the evaluation of primary tumors and lymph node metastasis were compared. We performed subgroup analysis to compare the findings on papillary thyroid microcarcinoma (10 mm in maximum diameter or smaller) with the findings on papillary thyroid carcinoma larger than 1 cm in maximum diameter.

RESULTS

Ultrasound was more accurate than CT in prediction of the presence of extrathyroidal tumor extension and of malignant disease in both thyroid lobes (p < 0.05) for overall lesions and for the two subgroups. In prediction of central node (neck level VI) metastasis, CT had greater sensitivity than ultrasound alone (p = 0.04) for overall lesions. Although the combination of ultrasound and CT had greater sensitivity than ultrasound alone in prediction of the presence of central node metastasis in the two subgroups, the sensitivity of the combination of ultrasound and CT did not reach statistical significance for papillary thyroid microcarcinoma. Ultrasound alone and ultrasound with CT had greater sensitivity than CT in prediction of lateral node (levels II-V) metastasis, but there was no significant difference in diagnostic value between ultrasound and the combination of ultrasound and CT for overall lesions or for the two subgroups (p > 0.05).

CONCLUSION

High-resolution ultrasound can be accurate in preoperative evaluation for extrathyroidal tumor extension and lateral lymph node metastasis. CT had greater sensitivity than ultrasound alone in the detection of central lymph node metastasis for all lesions. For papillary thyroid microcarcinoma, however, there was no significant difference in the diagnostic accuracy rates of ultrasound, CT, and the combination of ultrasound and CT.