Color Doppler sonography in cold thyroid nodules for malignancy prediction

The value of color Doppler ultrasound in the diagnosis of thyroid nodules: a systematic review and meta-analysis

BACKGROUND

This study aimed to analyze the value of color Doppler ultrasound in the diagnosis of thyroid nodules.

METHODS

We searched the PubMed, Web of Science, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) on using color Doppler ultrasound, thyroid nodules, thyroid tumors, and Doppler ultrasound to diagnose the thyroid nodules. The outcome indicators in the articles had to include the numbers of true positives (TP), false positives (FP), false negatives (FN), and true negatives (TN). Subsequently, the Jadad tool was adopted to evaluate the quality of the included articles, and Review Manager 5.3 software was used to conduct a meta-analysis of the experimental data.

RESULTS

A total of eight suitable articles were selected. The results showed that the estimated sensitivity and specificity of color Doppler ultrasound for the diagnostic of thyroid nodules were 0.46-0.89 and 0.00-1.00, respectively. The pooled estimate of sensitivity for the different articles was 0.71 [95% confidence interval (CI): 0.46-0.89], and the pooled estimate of specificity was 0.77 (95% CI: 0.00-1.00). The area under the summary receiver operating characteristic (SROC) curve (AUC) was 0.917, which was larger than 0.9, signifying high diagnostic accuracy. This suggests that color doppler ultrasound can realize the clinical diagnosis of thyroid nodules.

DISCUSSION

In summary, the results of this study could provide a clinical data for the promotion and application of color Doppler ultrasound in the clinical diagnosis of thyroid nodules, as well as further reliable data for follow-up clinical research on the diagnosis and treatment of thyroid nodules.

Color Doppler ultrasonography diagnostic value in detection of malignant nodules in cysts with pathologically proven thyroid malignancy: a systematic review and meta-analysis

AIMS

Today, the color Doppler ultrasonography is used to further evaluate suspected malignant tumors. This study investigates the malignant thyroid nodules using color Doppler.

METHODS

After extracting true positive, false positive, false negative, and true negative among included studies, a quality was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (with 95% confidence interval) were found using a random effect model. Summary receiver operating characteristic curves (SROC) were used to assess relationship between sensitivity and specificity. The area under the curve of the SROC was calculated to estimate the performance of color Doppler ultrasound to distinguish malignant thyroid nodules. Our registration code in PROSPERO is CRD42018111198.

RESULTS

Of 1125 articles, 288 articles were selected for the further investigation. After excluding irrelevant and poor articles, 20 studies were included for the meta-analysis. According to a random effect model, the pooled sensitivity and specificity of color Doppler ultrasound to distinguish malignant thyroid nodules were estimated as 0.74 (95% CI 0.62-0.83; [Formula: see text]) and 0.70 (95% CI 0.56-0.81; [Formula: see text]), respectively. The SROC curve consists of representing the paired results for sensitivity and specificity. According to SROC, AUC = 0.78 (95% CI 0.74-0.81) is between 0.75 and 0.92, so that color Doppler ultrasound has a good accuracy.

CONCLUSION

Color Doppler is a valuable non-invasive method for evaluating thyroid nodules, and it is a high-sensitivity diagnostic tool for assessing thyroid nodules. Resistive index > 0.75 and a pattern III or more in color Doppler predicts malignant with the confidence. Due to its precision, cost-efficiency, easy access, and non-invasive nature, color Doppler should be included in the standard clinical protocol for the decision-making period and the treatment evaluation.

The Place of Elastography in Evaluating the Efficacy of Radiofrequency Ablation of Thyroid Nodules

The usage of radiofrequency ablation (RFA) therapy and elastography to treat thyroid nodules has been increasing recently. Elastography specifically measures the stiffness of tissue using ultra-sonography (US). The aim of the present study was to evaluate the relationship between the elastography values of thyroid nodules and the efficacy of RFA therapy. Ultrasonography was performed on 49 patients who had a thyroid nodule with a diameter of 1 cm or greater before RFA therapy. The RFA was performed under local anesthesia, and elastography was used to measure the stiffness of the normal thyroid tissue, sternocleidomastoid muscle (SCM) and thyroid nodules three months after RFA. The nodule diameter significantly decreased three months after RFA (P < 0.05). According to a cross-evaluation of the mean elastography rates, the thyroid/SCM and nodule/thyroid elastography rates had an inverse relationship (P: 0.009). However, the thyroid/ SCM elastography rates and nodule/SCM elastography rates (P: 0.022) and the thyroid/SCM elastography rates and the rates of reduction (%) of the nodule diameter before and three months after RFA (P: 0.016) had positive relationships. In conclusion, RFA therapy is more effective in patients with thyroid nodules if there are high thyroid tissue/SCM rates in elastography.

Thyroid ultrasound features and risk of carcinoma: a systematic review and meta-analysis of observational studies

BACKGROUND

Thyroid nodules are a common finding in the general population, and their detection is increasing with the widespread use of ultrasound (US). Thyroid cancer is found in 5-15% of cases depending on sex, age, and exposure to other risk factors. Some US parameters have been associated with increased risk of malignancy. However, no characteristic seems sufficiently reliable in isolation to diagnose malignancy. The objective of this meta-analysis was to evaluate the diagnostic performance of US features for thyroid malignancy in patients with unselected thyroid nodules and nodules with indeterminate fine-needle aspiration (FNA) cytology.

METHODS

Electronic databases were reviewed for studies published prior to July 2012 that evaluated US features of thyroid nodules and reported postoperative histopathologic diagnosis. A manual search of references of review and key articles, and previous meta-analyses was also performed. A separate meta-analysis was performed including only nodules with indeterminate cytology. Analyzed features were solid structure, hypoechogenicity, irregular margins, absence of halo, microcalcifications, central vascularization, solitary nodule, heterogeneity, taller than wide shape, and absence of elasticity.

RESULTS

Fifty-two observational studies (12,786 nodules) were included. Nine studies included nodules with indeterminate cytology as a separate category, comprising 1851 nodules. In unselected nodules, all US features were significantly associated with malignancy with an odds ratio varying from 1.78 to 35.7, and microcalcifications, irregular margins, and a taller than wide shape had high specificities (Sp; 87.8%, 83.1%, 96.6%) and positive likelihood ratios (LHR; 3.26, 2.99, 8.07). Absence of elasticity was the single feature with the best diagnostic performance (sensitivity 87.9%, Sp 86.2%, and positive LHR 6.39). The presence of central vascularization was the most specific US feature in nodules with indeterminate cytology (Sp 96% and positive LHR 2.13).

CONCLUSIONS

US features in isolation do not provide reliable information to select nodules that should have a FNA performed. A combination of US characteristics with higher likelihood ratios and consequently with higher post-test probabilities of malignancy-microcalcifications, or a taller than wide shape, or irregular margins, or absence of elasticity-will probably identify nodules with an increased risk for malignancy. Further studies are required to standardize elastography techniques and evaluate outcomes, especially in nodules with an indeterminate cytology.

[Colour-coded duplex-sonography versus scintigraphy. Can scintigraphy be replaced by sonography for diagnosis of functional thyroid autonomy?]

Since the development of colour coded duplex-sonography (ccds), several attempts have been made to implement this technique for diagnosis of focal lesions in the thyroid. There are controversial discussions on whether ccds might replace thyroid scintigraphy in diagnosis of hyperfunctional thyroid nodules. Aim of this study was the comparison of ccds and thyroid scintigraphy in diagnosis of functional thyroid autonomy.

PATIENTS, MATERIAL AND METHODS

192 patients with thyroid nodules > 10mm detected by conventional sonography underwent thyroid scintigraphy. Additionally, these patients were subjected to ccds of the thyroid. In total, 286 thyroid nodules were examined by scintigraphy, ccds and blood tests.

RESULTS

Thyroid scintigraphy showed 67% of thyroid nodules as hyperfunctional, 19% indifferent and 14% as hypofunctional. Mean 99mTc uptake of hyperfunctional nodules was 2.19%, of indifferent nodules 1.12% and of hypofunctional nodules 1.06% respectively. The ccds allowed perinodular measurement of flow speed (hyperfunctional: 0.23 ± 0.1 m/s; hypofunctional: 0.22 ± 0.1; indifferent: 0.21 ± 0.09), resistance index (hyperfunctional: 1.21 ± 1.16; hypofunctional: 0.62 ± 0.48; indifferent: 0.93 ± 1.02) and pulsatility index (hyperfunctional: 0.97 ± 0.45; hypofunctional: 0.84 ± 0.4; indifferent: 1.04 ± 0.6) in all nodules as well as intranodular measurement in some of the nodules (24% in hyperfunctional, 2% in indifferent and 15% in hypofunctional nodules). Statistic analysis of the obtained ccds data did not show any practically relevant correlations (p>0.05) with 99mTc uptake, basal TSH, fT3 or fT4.

CONCLUSION

Thyroid scintigraphy cannot be replaced by ccds for diagnosis of functional thyroid autonomy. Reliable diagnostics still require a combination of thyroid scintigraphy, sonography and blood tests.

Characterization of single thyroid nodules by contrast-enhanced 3-D ultrasound

High-resolution ultrasonography (HRUS) has potentialities in differential diagnosis between malignant and benign thyroid lesions, but interpretative pitfalls remain and accuracy is still poor. We developed an image processing technique for characterizing the intra-nodular vascularization of thyroid lesions. Twenty nodules (10 malignant) were analyzed by three-dimensional (3-D) contrast-enhanced ultrasound imaging. The 3-D volumes were preprocessed and skeletonized. Seven vascular parameters were computed on the skeletons: number of vascular trees (NT); vascular density (VD); number of branching nodes (or branching points) (NB); mean vessel radius (MR); 2-D (DM) and 3-D (SOAM) tortuosity; and inflection count metric (ICM). Results showed that the malignant nodules had higher values of NT (83.1 vs. 18.1), VD (00.4 vs. 0.01), NB (1453 vs. 552), DM (51 vs. 18), ICM (19.9 vs. 8.7) and SOAM (26 vs. 11). Quantification of nodular vascularization based on 3-D contrast-enhanced ultrasound and skeletonization could help differential diagnosis of thyroid lesions.

Is there a role for fluorodeoxyglucose positron emission tomography/computed tomography in cytologically indeterminate thyroid nodules?

OBJECTIVE

The aim of this study was to determine the accuracy of the fluorine 18 ((18)F)-labeled fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scan in the evaluation of thyroid nodules in which the cytopathology of fine-needle aspiration (FNA) biopsies are classified as "indeterminate," ie, either follicular or Hürthle cell lesion.

METHODS

At an academic medical center, we conducted a prospective pilot study of 15 patients with thyroid nodules in whom adequate FNA was diagnosed as indeterminate. All patients underwent a whole-body FDG-PET/CT scan followed by thyroidectomy. Preoperative FDG-PET/CT results and the histopathology of the surgical specimen were compared and statistically analyzed.

RESULTS

The FNA demonstrated follicular cells in 11 (73%) patients, Hürthle cells in 3 (20%) patients, and both types of cells in 1 (7%) patient. The histopathology of the surgical specimen revealed thyroid cancer in 7 (47%) patients. The FDG-PET/CT scan was positive in 8 patients; 4 (50%) patients were found to have cancer. The FDG-PET/CT scan was negative in 7 patients. Four of these patients had benign lesions and 3 had thyroid carcinoma. Thus, 4 (27%) patients had false-positive FDG-PET/CT scans and 3 (20%) patients had false-negative studies. The sensitivity of FDG-PET/CT to detect a malignant focus was 57% with a specificity of 50%. The positive predictive value was 50% and the negative predictive value was 57%.

CONCLUSIONS

In this pilot study of patients with cytologically indeterminate thyroid nodules, FDG-PET/CT was not a predictable indicator of benign or malignant disease. Although a larger series may elucidate a role for FDG-PET/CT, the relatively low predictability shown in this study should caution clinicians about using FDG-PET/CT to consider foregoing thyroidectomy for cytologically indeterminate nodules.

[Diagnosis of thyroid nodule. Application of evidence-based medicine]

OBJECTIVE

The frequency of thyroid nodules requires an appropriate and consistent undertaking of such pathology by the entire medical profession. Over the past few years, the ANAES (National Agency of Health Accreditation and Evaluation - 1995 - 1997) had formulated medical recommendations. Our work aimed at updating such recommendations considering recent literature developments and their level of evidence.

MATERIAL AND METHODS

We have selected high-level of evidence's articles published since 1997 dealing with the diagnostic undertaking of thyroid nodule. Such analysis was conducted using the search engine "Medline" and the level of evidence of the selected articles was evaluated by taking into account the professional recommendations of the "literature analysis and gradation of recommendations' guide" of ANAES.

RESULT

At present, two diagnostic tests are necessary in the diagnostic evaluation of a thyroid nodule (ultrasonography and fine-needle aspiration).

CONCLUSION

The medical recommendation will hence result in the synthesis of these two different diagnostic tests, nevertheless fine-needle aspiration being essential and having priority in evaluating the risk of cancer.