Ultrasound thyroid nodule measurements: the "gold standard" and its limitations in clinical decision making

Diagnostic Accuracy of Preoperative Radiologic Findings in Papillary Thyroid Microcarcinoma: Discrepancies with the Postoperative Pathologic Diagnosis and Implications for Clinical Outcomes

BACKGRUOUND

The diagnostic accuracy of preoperative radiologic findings in predicting the tumor characteristics and clinical outcomes of papillary thyroid microcarcinoma (PTMC) was evaluated across all risk groups.

METHODS

In total, 939 PTMC patients, comprising both low-risk and non-low-risk groups, who underwent surgery were enrolled. The preoperative tumor size and lymph node metastasis (LNM) were evaluated by ultrasonography within 6 months before surgery and compared with the postoperative pathologic findings. Discrepancies between the preoperative and postoperative tumor sizes were analyzed, and clinical outcomes were assessed.

RESULTS

The agreement rate between radiological and pathological tumor size was approximately 60%. Significant discrepancies were noted, including an increase in tumor size in 24.3% of cases. Notably, in 10.8% of patients, the postoperative tumor size exceeded 1 cm, despite being initially classified as 0.5 to 1.0 cm based on preoperative imaging. A postoperative tumor size >1 cm was associated with aggressive pathologic factors such as multiplicity, microscopic extrathyroidal extension, and LNM, as well as a higher risk of distant metastasis. In 30.1% of patients, LNM was diagnosed after surgery despite not being suspected before the procedure. This group was characterized by smaller metastatic foci and lower risks of distant metastasis or recurrence than patients with LNM detected both before and after surgery.

CONCLUSION

Among all risk groups of PTMCs, a subset showed an increase in tumor size, reaching 1 cm after surgery. These cases require special consideration due to their association with adverse clinical outcomes, including an elevated risk of distant metastasis.

Exploring the research landscape of the past, present, and future of thyroid nodules

Introduction

The purpose of this study was to assess the landscape of thyroid nodules research during the last 22 years using machine learning and text analysis.

Methods

In November 2021, we obtained from PubMed all works indexed under the Medical Subject Headings (MeSH) subject line "thyroid nodules." The entire set of search results was retrieved in XML format, and metadata such as title, abstract, keywords, MeSH words, and year of publication were extracted for bibliometric evaluation from the original XML files. To increase the specificity of the investigation, the Latent Dirichlet allocation (LDA) topic modeling method was applied.

Results

Our study included 5,770 research papers. By using frequency analysis of MeSH terms, research on thyroid nodules was divided into two categories: clinical and basic. The proportion of clinical research is nearing 89% and is dominated by the differential diagnosis of thyroid nodules. In contrast, the proportion of MeSH terms relating to basic research was just 11%, with DNA mutation analysis being the most common topic. Following this, LDA analysis revealed the thyroid nodule study had three clusters: Imaging Studies, Biopsy and Diagnosis, and Epidemiology and Screening of Thyroid Cancer. The result suggests that current thyroid nodule research appears to have focused on ultrasonography and histological diagnosis, which are tightly correlated. Molecular biomarker research has increased, therefore enhancing the diagnostic precision of thyroid nodules. However, inflammation, anxiety, and mental health disorders related to thyroid nodules have received little attention.

Conclusion

Basic research on thyroid nodules has unmet research requirements. Future research could focus on developing strategies to more efficiently identify malignant nodules, exploring the mechanism of thyroid nodule development, and enhancing the quality of life of thyroid patients.

Prevalence and characterization of asymptomatic thyroid nodules in Assin North District, Ghana

Background

Ultrasound is now the initial imaging modality of choice for detection and characterization of lesions of the thyroid gland. Ultrasound imaging studies of the thyroid gland report varied prevalence of asymptomatic thyroid nodules (ATN), ranging from 20 to 67%. This study estimated the prevalence, characterized and determined factors associated with ATN in selected communities in the Assin North Municipality, Central Region, Ghana.

Methods

The study was a cross-sectional design, involving 320 participants from six (6) communities in the Assin North District of the Central Region of Ghana. Socio-demographic data and data from ultrasound examination of the thyroid gland were analyzed using descriptive and inferential statistical techniques.

Results

The prevalence of ATN was 11.3% among 320 participants with the mean age of 56.53(±16.5) years. ATNs were common in the left lobe (69%) and predominantly solitary (64%). ATNs increased with age and body mass index (BMI). Those aged 60 years and above had significantly higher odds (OR = 24.40, 95% CI = 2.59–229.86) of having ATNs, likewise overweigh (OR = 5.32, 95% CI = 1.12–25.20) and obese (OR = 12.51, 95% CI = 1.47–106.58) individuals.

Conclusion

The prevalence of ATN in our study population was relatively low, and more predictable among those 60 years or older, those in unhealthy BMI categories. There is the need for the reinforcement and intensification of educational campaigns on the consumption of iodized dietary salt as well as the consumption of foods rich in iodine content, particularly among older individuals.

Thyroid function disorders and secondary cancer following haematopoietic stem cell transplantation in pediatrics: State of the art and practical recommendations for a risk-based follow-up

Thyroid disorders (TD) represent a remarkable share of all the late morbidities experienced following pediatric haematopoietic stem cell transplantation (HSCT), with long-term reported occurrence often exceeding 70%. In addition, the data collected on wide cohorts of survivors assessed longitudinally outlined a progressive increase in the cumulative incidence of TD as far as 30 years following transplantation. Accordingly, a life-long monitoring of thyroid health is warranted among patients exposed to HSCT in childhood, in order to early detect TD and undertake a prompt dedicated treatment. Although several national and international consortia have provided recommendations for the early detection of thyroid disorders among childhood cancer survivors exposed to radiotherapy and alkylating agents, no guidelines specifically and thoroughly focused on HSCT-related TD have been published to date. As stem cell transplantation has become the standard-of-care in a growing body of non-oncological conditions, this urge has become pivotal. To highlight the challenging issues specifically involving this cohort of patients and to provide clinicians with the proposal of a practical follow-up protocol, we reviewed published literature in the light of the shared experience of a multidisciplinary team of pediatric oncologists, transplantologists, pathologists and endocrinologists involved in the long-term care of HSCT survivors. As a final result, we hereby present the proposals of a practical and customized risk-based approach to tailor thyroid health follow-up based on HSCT-related detrimental factors.

Identification of circulating biomarkers for differentiating patients with papillary thyroid cancers from benign thyroid tumors

BACKGROUND

This study aimed to identify the potential circulating biomarkers of protein, mRNAs, and long non-coding RNAs (lncRNAs) to differentiate the papillary thyroid cancers from benign thyroid tumors.

METHODS

The study population of 100 patients was classified into identification (10 patients with papillary thyroid cancers and 10 patients with benign thyroid tumors) and validation groups (45 patients with papillary thyroid cancers and 35 patients with benign thyroid tumors). The Sengenics Immunome Protein Array-combined data mining approach using the Open Targets Platform was used to identify the putative protein biomarkers, and their expression validated using the enzyme-linked immunosorbent assay. Next-generation sequencing by Illumina HiSeq was used for the detection of dysregulated mRNAs and lncRNAs. The website Timer v2.0 helped identify the putative mRNA biomarkers, which were significantly over-expressed in papillary thyroid cancers than in adjacent normal thyroid tissue. The mRNA and lncRNA biomarker expression was validated by a real-time polymerase chain reaction.

RESULTS

Although putative protein and mRNA biomarkers have been identified, their serum expression could not be confirmed in the validation cohorts. In addition, seven lncRNAs (TCONS_00516490, TCONS_00336559, TCONS_00311568, TCONS_00321917, TCONS_00336522, TCONS_00282483, and TCONS_00494326) were identified and validated as significantly downregulated in patients with papillary thyroid cancers compared to those with benign thyroid tumors. These seven lncRNAs showed moderate accuracy based on the area under the curve (AUC = 0.736) of receiver operating characteristic in predicting the occurrence of papillary thyroid cancers.

CONCLUSIONS

We identified seven downregulated circulating lncRNAs with the potential for predicting the occurrence of papillary thyroid cancers.

Thyroid disorders in elderly: A comprehensive review

The approach to management of thyroid disorders in the elderly differs from that for younger individuals: it considers frailty of the population, coexisting medical illness and medications, clearance rate of medications and drug-drug interactions along with target organ sensitivity to the treatment. We present a comprehensive review of literature for the clinical presentation, pathophysiology, diagnostic evaluation, and management of thyroid disorders in the elderly.

Ultrasound is superior to palpation for thyroid cancer detection in high-risk childhood cancer and BMT survivors

PURPOSE

Thyroid cancer is a common subsequent malignant neoplasm in childhood cancer survivors (CCS). Patients who received radiotherapy (RT) to the head, neck, upper thorax, or total body irradiation (TBI) are considered to be at risk for subsequent thyroid cancer. Current Children's Oncology Group screening guidelines recommend annual neck palpation. Our objective was to determine if ultrasound (US) is more sensitive and specific than palpation to detect thyroid cancer in high-risk CCS and bone marrow transplant (BMT) survivors.

METHODS

Electronic medical records of patients followed in a longitudinal survivorship clinic from January 1, 2010 to December 31, 2017 were reviewed. Inclusion criteria included history of RT to the head, neck, upper thorax, or TBI for primary therapy or preparation for BMT prior to the age of 20 years.

RESULTS

Two hundred and twenty-five patients had documented palpation and 144 (64%) also had US evaluation. Mean radiation dose was 28.6 Gy. Sixteen of 225 patients (7.1%) developed a subsequent thyroid cancer at a mean of 9.7 years from the completion of RT. Sensitivity of US was 100% compared with 12.5% for palpation. US demonstrated higher accuracy, with a receiver operating characteristic (ROC) area under the curve (AUC) of 0.87 versus 0.56 for palpation (P < 0.0001).

CONCLUSION

Routine screening with US was more sensitive than palpation for detection of subsequent thyroid cancer after high-risk RT in CCS and BMT survivors. Screening US may lead to earlier detection of thyroid cancer in this population. Earlier diagnosis has the potential to decrease operative complexity, and earlier definitive therapy reduces the likelihood of metastatic disease.

The effect of suppressive thyroxine therapy in nodular goiter in postmenopausal women and 2 year's bone mineral density change

The efficacy of thyroxine suppressive therapy in reducing nodular growth and its effect to bone mineral density (BMD) in postmenopausal women is still debated. This study aimed to evaluate the therapeutic effect of thyroxine and its influence on BMD. Postmenopausal women with nodular or multinodular goiter during 2013-2015 at Chang Gung Memorial Hospital were enrolled and retrospectively traced back to the first date of visit or treatment. Ninety-four eligible patients were enrolled, of whom 45 were thyroxine-treated (LT-4 group) and 49 were treatment-naïve (control group). Data, including volume of nodules, were analyzed retrospectively. BMD was measured in each LT-4 group patient since the year of enrollment. Nodular volumes were reduced in both LT-4 (from 4.89 ± 4.46 to 4.10 ± 4.57 mL, p = 0.033) and control group (3.48 ± 4.36 to 3.09 ± 2.88 mL, p = 0.239) at initial 2-year follow-up. Nodular volume in LT-4 group increased insignificantly (from 4.89 ± 4.46 to 4.91 ± 5.40 mL, p = 0.711) at the end of 7-year follow-up. The best cut-off predictive nodular volume that may have responded to thyroxine is 2.6 mL (AUC, 0.740; sensitivity, 0.750; specificity, 0.733) during first 2 year. Lumbar spine, total hip and femoral neck BMD were not significantly changed during 2 year's thyroxine suppression therapy. In conclusion, thyroxine suppressive therapy in postmenopausal women had significant reduction in nodule volume at initial 2 years of treatment, especially in volume larger than 2.6 mL. Prolonged thyroxine treatment did not benefit nodular size reduction and may affect BMD minimally in postmenopausal women.

Comparison of Strain Elastography, Shear Wave Elastography, and Conventional Ultrasound in Diagnosing Thyroid Nodules

Objective:

The purpose of this study is to compare the diagnostic performances of strain elastography (SE), shear wave elastography (SWE), and traditional ultrasound (US) features in diagnosing thyroid nodules.

Subjects and Methods:

This study included 185 adult patients with thyroid nodules who underwent conventional gray-scale US, SE, and SWE. SE was scored using a four-pattern elastographic scoring (ES) system. SWE values were presented as mean SWE values and standard derivation using Young's modules. The optimal cutoff values of the mean SWE values for predicting malignancy were determined using receiver operating characteristic (ROC) curve analysis. We used logistic regression models to test elastography as a novel significant predictor for the diagnosis of malignant nodules. The diagnostic performance of elastography parameters was compared with a traditional trained model.

Results:

Malignant thyroid nodules were stiffer for SE (ES patterns 1 and 2/3 and 4) and mean SWE values (4/17; 51.0 ± 24.4 kPa) than for benign nodules (114/50; 33.1 ± 25.2 kPa) (P < 0.01). In ROC curve analyses, a mean SWE value of 32 kPa was the optimal cutoff point, with diagnostic performance measures of 81% sensitivity, 65% specificity, a 23% positive predictive value (PPV), and 96% negative predictive value (NPV). In multivariate logistic regression, the mean SWE value (≥32 kPa) was an independent predictor for malignancy (odds ratio: 16.8; 95% confidence interval [CI]: 3.6–78.3). However, after the addition of SE and SWE to traditional US features, the C-statistic was not significantly increased compared to the traditional model (0.88, 95% CI: 0.81–0.94 vs. 0.91, 0.85–0.97, P = 0.4).

Conclusion:

In this study, we confirmed SWE as an independent predictor for malignant thyroid nodules. However, in comparing the new extended elastography model to our previous prediction model, the new extended model showed no significant difference in the diagnostic performance.

Systematic differences between ultrasound and pathological evaluation of thyroid nodules: a method comparison study

BACKGROUND

The size of thyroid nodules as measured by ultrasound (ultrasound size, USS) is routinely used in clinical decision-making. Reports of discrepancy between USS and pathological size (PS) evaluation have not analysed their systematic differences. The objective of this study was to uncover the lack of agreement (bias) between USS and PS measurements.

METHODS

A retrospective study was performed on 121 patients who had a total or hemi-thyroidectomy for a solitary nodule. Ordinary least product regression was used to detect and distinguish constant and proportional bias in unidimensional size measurements between USS and PS evaluation. Three-dimensional volume measurements were compared in a subgroup of 31 patients. Pre-specified acceptable limits of interchange were defined as 20% difference.

RESULTS

Ordinary least product regression demonstrated no constant or proportional bias between the two methods; regression equation: USS = (0.863) + (1.040) × PS. When nodules were grouped by size, discrepancies between the two methods were observed in nodules <10 mm (P = 0.004). However, potential overtreatment of patients with USS >10 mm but PS <10 mm only accounted for 4.1% of total patients. Subgroup analysis of volume measurements showed no bias between USS and PS evaluation.

CONCLUSIONS

USS and PS measurements were interchangeable, as there was no evidence of constant or proportional bias between the two measurements. However, USS may misclassify the size for smaller nodules and potentially lead to unnecessary workup and treatment. Discrepancy in size measurements between USS and PS should be taken into account in clinical practice, particularly in smaller nodules.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ASSOCIAZIONE MEDICI ENDOCRINOLOGI MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE DIAGNOSIS AND MANAGEMENT OF THYROID NODULES--2016 UPDATE

Thyroid nodules are detected in up to 50 to 60% of healthy subjects. Most nodules do not cause clinically significant symptoms, and as a result, the main challenge in their management is to rule out malignancy, with ultrasonography (US) and fine-needle aspiration (FNA) biopsy serving as diagnostic cornerstones. The key issues discussed in these guidelines are as follows: (1) US-based categorization of the malignancy risk and indications for US-guided FNA (henceforth, FNA), (2) cytologic classification of FNA samples, (3) the roles of immunocytochemistry and molecular testing applied to thyroid FNA, (4) therapeutic options, and (5) follow-up strategy. Thyroid nodule management during pregnancy and in children are also addressed. On the basis of US features, thyroid nodules may be categorized into 3 groups: low-, intermediate-and high-malignancy risk. FNA should be considered for nodules ≤10 mm diameter only when suspicious US signs are present, while nodules ≤5 mm should be monitored rather than biopsied. A classification scheme of 5 categories (nondiagnostic, benign, indeterminate, suspicious for malignancy, or malignant) is recommended for the cytologic report. Indeterminate lesions are further subdivided into 2 subclasses to more accurately stratify the risk of malignancy. At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data, US signs, elastographic pattern, or results of other imaging techniques to improve the management of these lesions. Most thyroid nodules do not require any treatment, and levothyroxine (LT4) suppressive therapy is not recommended. Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while US-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules. Surgery remains the treatment of choice for malignant or suspicious nodules. The present document updates previous guidelines released in 2006 and 2010 by the American Association of Clinical Endocrinologists (AACE), American College of Endocrinology (ACE) and Associazione Medici Endocrinologi (AME).

Development of a control algorithm for the ultrasound scanning robot (NCCUSR) using ultrasound image and force feedback

BACKGROUND

Clinicians who frequently perform ultrasound scanning procedures often suffer from musculoskeletal disorders, arthritis, and myalgias. To minimize their occurrence and to assist clinicians, ultrasound scanning robots have been developed worldwide. Although, to date, there is still no commercially available ultrasound scanning robot, many control methods have been suggested and researched. These control algorithms are either image based or force based. If the ultrasound scanning robot control algorithm was a combination of the two algorithms, it could benefit from the advantage of each one. However, there are no existing control methods for ultrasound scanning robots that combine force control and image analysis. Therefore, in this work, a control algorithm is developed for an ultrasound scanning robot using force feedback and ultrasound image analysis.

METHODS

A manipulator-type ultrasound scanning robot named 'NCCUSR' is developed and a control algorithm for this robot is suggested and verified. First, conventional hybrid position-force control is implemented for the robot and the hybrid position-force control algorithm is combined with ultrasound image analysis to fully control the robot. The control method is verified using a thyroid phantom.

RESULTS

It was found that the proposed algorithm can be applied to control the ultrasound scanning robot and experimental outcomes suggest that the images acquired using the proposed control method can yield a rating score that is equivalent to images acquired directly by the clinicians.

CONCLUSIONS

The proposed control method can be applied to control the ultrasound scanning robot. However, more work must be completed to verify the proposed control method in order to become clinically feasible. Copyright © 2016 John Wiley & Sons, Ltd.

Discrepancies between the ultrasonographic and gross pathological size of papillary thyroid carcinomas

Purpose:

The goal of this study was to investigate the level of agreement between tumor sizes measured on ultrasonography (US) and in pathological specimens of papillary thyroid carcinomas (PTCs) and to identify the US characteristics contributing to discrepancies in these measurements.

Methods:

We retrospectively reviewed the US findings and pathological reports of 490 tumors in 431 patients who underwent surgery for PTC. Agreement was defined as a difference of <20% between the US and pathological tumor size measurements. Tumors were divided by size into groups of 0.5-1 cm, 1-2 cm, 2-3 cm, and ≥3 cm. We compared tumors in which the US and pathological tumor size measurements agreed and those in which they disagreed with regard to the following parameters: taller-than-wide shape, infiltrative margin, echogenicity, microcalcifications, cystic changes in tumors, and the US diagnosis.

Results:

The rate of agreement between US and the pathological tumor size measurements was 64.1% (314/490). Statistical analysis indicated that the US and pathological measurements significantly differed in tumors <1.0 cm in size (P=0.033), with US significantly overestimating the tumor size by 0.2 cm in such tumors (P<0.001). Cystic changes were significantly more frequent in the tumors where US and pathological tumor size measurements disagreed (P<0.001).

Conclusion:

Thyroid US may overestimate the size of PTCs, particularly for tumors <1.0 cm in size. This information may be helpful in guiding decision making regarding surgical extent.

Hashimoto's Thyroiditis Does Not Affect Ultrasonographical, Cytological, and Histopathological Features in Patients with Papillary Thyroid Carcinoma

The association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) is controversial. In this study, we aimed to compare preoperative thyroid functions, ultrasonography (US) features, fine-needle aspiration biopsy (FNAB) results, and histopathological characteristics of PTC in patients with and without HT. Data of 919 PTC patients were reviewed retrospectively. The diagnosis of HT was based on histopathological examination and patients were grouped as HT and non-HT. There were 1321 PTC lesions in 919 patients among which 317 (34.5 %) had coexistent HT. There were no significant differences in nodule volume, longitudinal diameter, texture, echogenicity, marginal regularity, presence of microcalcification and hypoechoic halo, and peripheral vascularization in patients with and without HT (p > 0.05, for all parameters). Macrocalcification was observed more frequently in the non-HT group (p = 0.021). FNAB results were similar in the two groups (p = 0.105). Distribution of variants, capsule invasion, vascular invasion, and extrathyroidal extension were observed with similar rates in the HT and non-HT groups. Lymph node metastasis was significantly higher in patients without HT (p = 0.012). Of the carcinomas, 66.1 % (n = 874) were papillary thyroid microcarcinoma (PTMC). Tumor size was lower in PTMC lesions coexistent with HT (p = 0.026). We observed lower rates of capsule invasion, extrathyroidal extension, and lymph node metastases in PTMC with HT compared to without HT (p = 0.007, p = 0.003, and p = 0.015, respectively). This study showed that US features, FNAB results, and histopathological findings of PTC lesions are not influenced by the presence of HT. However, PTMC seems to be related with less aggressive histopathological behavior in HT.

Tumor size measured by preoperative ultrasonography and postoperative pathologic examination in papillary thyroid carcinoma: relative differences according to size, calcification and coexisting thyroiditis

Ultrasonography (US) is a useful diagnostic modality for evaluation of the size and features of thyroid nodules. Tumor size is a key indicator of the surgical extent of thyroid cancer. We evaluated the difference in tumor sizes measured by preoperative US and postoperative pathologic examination in papillary thyroid carcinoma (PTC). We reviewed the medical records of 172 consecutive patients, who underwent thyroidectomy for PTC treatment. We compared tumor size, as measured by preoperative US, with that in postoperative specimens. And we analyzed a number of factors potentially influencing the size measurement, including cancer size, calcification and coexisting thyroiditis. The mean size of the tumor measured by preoperative US was 11.4, and 10.2 mm by postoperative pathologic examination. The mean percentage difference (US-pathology/US) of tumor sizes measured by preoperative US and postoperative pathologic examination was 9.9 ± 19.3%, which was statistically significant (p < 0.001). When the effect of tumor size (≤10.0 vs. 10.1-20.0 vs. >20.0 mm) and the presence of calcification or coexisting thyroiditis on the tumor size discrepancy between the two measurements was analyzed, the mean percentage differences according to tumor size (9.1 vs. 11.2% vs. 9.8%, p = 0.842), calcification (9.2 vs. 10.2%, p = 0.756) and coexisting thyroiditis (17.6 vs. 9.5%, p = 0.223) did not show statistical significance. Tumor sizes measured in postoperative pathology were ~90% of those measured by preoperative US in PTC; this was not affected by tumor size, the presence of calcification or coexisting thyroiditis. When the surgical extent of PTC treatment according to tumor size measured by US is determined, the relative difference between tumor sizes measured by preoperative US and postoperative pathologic examination should be considered.

Evaluation and development of a real-time predictive model for ultrasound investigation of malignant thyroid nodules

Ultrasound investigations and correct identification of malignant thyroid nodules depend on the experience and qualifications of the investigators; thus, a model that provides better evaluation before needle aspiration is desired. Data from 687 patients with 726 thyroid nodules comprising 65 malignant nodules (61 papillary and 4 follicular carcinoma) and 661 benign nodules were used to construct a predictive model. Presence of micro-calcification, taller-than-wide shape, predominant solid echostructure, and irregular margins were shown to be good independent predictive parameters. A thyroid nodule was predicted as malignant with a score ≥3.3. Internal validation of this predictive tool by the bootstrapping method showed excellent overall model performance.

Advantages and disadvantages of 3D ultrasound of thyroid nodules including thin slice volume rendering

BACKGROUND

The purpose of this study was to assess the advantages and disadvantages of 3D gray-scale and power Doppler ultrasound, including thin slice volume rendering (TSVR), applied for evaluation of thyroid nodules.

METHODS

The retrospective evaluation by two observers of volumes of 71 thyroid nodules (55 benign, 16 cancers) was performed using a new TSVR technique. Dedicated 4D ultrasound scanner with an automatic 6-12 MHz 4D probe was used. Statistical analysis was performed with Stata v. 8.2.

RESULTS

Multiple logistic regression analysis demonstrated that independent risk factors of thyroid cancers identified by 3D ultrasound include: (a) ill-defined borders of the nodule on MPR presentation, (b) a lobulated shape of the nodule in the c-plane and (c) a density of central vessels in the nodule within the minimal or maximal ranges. Combination of features provided sensitivity 100% and specificity 60-69% for thyroid cancer.Calcification/microcalcification-like echogenic foci on 3D ultrasound proved not to be a risk factor of thyroid cancer.Storage of the 3D data of the whole nodules enabled subsequent evaluation of new parameters and with new rendering algorithms.

CONCLUSIONS

Our results indicate that 3D ultrasound is a practical and reproducible method for the evaluation of thyroid nodules. 3D ultrasound stores volumes comprising the whole lesion or organ. Future detailed evaluations of the data are possible, looking for features that were not fully appreciated at the time of collection or applying new algorithms for volume rendering in order to gain important information. Three-dimensional ultrasound data could be included in thyroid cancer databases. Further multicenter large scale studies are warranted.

A simple method to predict pretracheal tissue thickness to prevent accidental decannulation in the obese

OBJECTIVE

Accidental decannulation is the most common and serious complication associated with tracheostomy in obese patients. We lack a simple way to choose appropriate-size tracheostomy tubes in this patient subset. Our purpose was to 1) establish the range of trachea-to-skin soft tissue thickness (TTSSTT) in obese patients and 2) determine which easily obtained anthropometric measurements are most predictive of TTSSTT.

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Forty consenting patients with body mass index ranging from 30 to 70 were evaluated. These patients, from a bariatric clinic, underwent ultrasound (US) of the neck in predetermined sitting, supine, and neck-extended positions (as for tracheostomy). US was performed by a qualified radiologist. Standard anthropometric measurements of weight, height, arm, hip, waist, and neck sizes were performed. Multiple regression analysis was used to determine which anthropometric measurements best correlated with TTSSTT.

RESULTS

The TTSSTT, as measured by US in the supine position, ranged from 0.65 to 3.53 cm. Although the anthropometric measurement most predictive of TTSSTT was waist circumference, a combination of the more practical arm and neck circumferences resulted in an equivalent correlation (r = 0.82). The average root mean squared error was 0.4 cm. From the fitted regression equation, a table predicting TTSSTT from neck and arm circumference was prepared.

CONCLUSION

TTSSTT can be closely predicted using simple anthropometric tape measures. The predicted TTSSTT can be used to select appropriate tracheostomy tube size in obese patients. Use of this simple tool is expected to significantly reduce the incidence of accidental decannulation in obese patients.

Concordance between thyroid nodule sizes measured by ultrasound and gross pathology examination: Effect on patient management

Ultrasound examination (US) is an essential tool in the evaluation of thyroid nodules. The size determined by US is used to distinguish between clinical vs. nonclinical thyroid nodules i.e. greater than or equal to or less than 1 cm. In this study, we evaluated the concordance between the sizes of thyroid nodules measured by US and by gross examination after thyroidectomy. This study included 664 nodules that underwent fine-needle aspiration (FNA) and subsequent excision in 621 patients; 580 had single and 41 patients had multiple (39 with 2, and 2 with 3 nodules) nodules. Both US and gross pathology measurements were taken in three dimensions. The nodule sizes as measured by US were stratified into five groups: A: <or=1.0 cm, B: 1.1-2.0 cm, C: 2.1-3.0 cm, D: 3.1-5.0 cm, and E: >or=5.1 cm. FNA diagnoses were categorized into: Benign (n = 59), Neoplastic / Indeterminate (n = 342), Suspicious (n = 123), Malignant (n = 106), and nondiagnostic (n = 34). Upon excision 278 (42%) nodules were classified as malignant and 386 (58%) as benign. In group A the concordance between US and excisional size was 78.5%, group B 56%, group C 34.5%, group D 40% and group E 52.5%. Only 14 (14/664 2%) nodules measured <or=1.0 cm by US, however, after thyroidectomy 105 (105/664 15.5%) measured <or=1.0 cm in size. Histological diagnoses of this group were benign 62 (58%), papillary microcarcinoma 39 (37%), medullary microcarcinoma 3 (3%) and follicular/Hurthle cell carcinoma 2 (2%) cases. In this study the concordance in benign or malignant nodules measured by US and surgical pathology examination is <or=50%, except in the <or=1.0 cm size range (78.5%). This may lead to an increase in the number of patients undergoing FNA and subsequent surgical excision.

Thyroid nodule: A potentially malignant lesion; optimal management from a surgical perspective

Thyroid nodules are very common lesions, frequently detected by modern imaging methods (mainly ultrasonography). Despite that most thyroid nodules represent benign lesions, a small but significant percentage of them are malignant. Surgery is indicated when there is underlying malignancy (or suspicion for), pressure symptoms, or for cosmetic reasons. Total/near total thyroidectomy is the most radical procedure, which achieves cure, avoids the possibility of reoperation in the future (completion thyroidectomy), and facilitates postoperative management of the patient with underlying malignancy. Simple observation and thyroid hormone suppressive therapy are acceptable management options for patients with presumably benign thyroid nodules. Radioiodine therapy may be used for the management of patients with hyperfunctioning ("hot") thyroid nodules. Ablation of thyroid nodules (sclerosing therapy [alcohol injection] and laser photocoagulation) have been used for the in situ destruction of thyroid nodules; ablation therapy is currently viewed as experimental therapeutic method. Careful evaluation is required in order to avoid both overtreatment (mainly unnecessary surgery) as well as undertreatment of these potentially malignant, but highly curable lesions.

A novel thyroid phantom for ultrasound volumetry: determination of intraobserver and interobserver variability

A novel thyroid ultrasound phantom with tissue-equivalent characteristics was designed consisting of two lobes with three lesions each. One set of lesions is manufactured with a -5 dB echo difference to the surrounding tissue, the other with -10 dB. This phantom was used as a standardized measuring object for reproducibility of two-dimensional and three-dimensional ultrasound volumetry and for an interobserver and intraobserver variability study. For the variability study, nine experienced physicians scanned all specimen three times. Each time the volumes were calculated using the ellipsoid method. A three-dimensional ultrasound scan of each specimen was performed to evaluate all volumes by multiplanar volume approximation. The results of these volume data were compared to the known true volumes. The interobserver variability ranged from -13.4% to 11.9% (median, 0.7%); the intraobserver variability from -9.1% to 16.4% (median, 3.6%). The systematic error as calculated from the total mean of all specimens is 0.5% for the interobserver variability and 4.1% for the intraobserver variability. The phantom can be used for training purposes, to improve the skills of the examining physicians by simulating real thyroid morphology, to provide a standardized reference object for long-term quality control of conventional ultrasound scanners, and the determination of the accuracy and reproducibility of volumetry using three-dimensional ultrasound systems.