The features of contrast enhanced ultrasound and BRAF V600E in papillary thyroid carcinoma

MRI-Based Texture Analysis for Preoperative Prediction of BRAF V600E Mutation in Papillary Thyroid Carcinoma

Purpose

BRAF V600E mutation can compensate for the low detection rate by fine-needle aspiration (FNA) and is related to aggressiveness and lymph node metastasis. This study aimed to investigate the relationship between texture analysis features based on magnetic resonance imaging (MRI) and mutations.

Methods

Retrospective analysis was performed on patients with postoperative pathology confirmed papillary thyroid carcinoma (PTC) from 2017 to 2021. One thousand one hundred and thirty-two texture features were extracted from T2-weighted imaging (T2WI) and contrast-enhanced T1-weighted imaging (CE-T1WI) separately by outlining the tumor volume of interest (VOI). Univariate, minimum redundancy maximum relevance (mRMR), and multivariate analyses were used for feature selection to construct 3 models (T2WI, CE-T1WI, and combined model) to predict mutation. The reproducibility between observers was evaluated by intraclass correlation coefficient (ICC). Receiver operating characteristic (ROC) analysis was used to assess the performance of models. The diagnostic performance of the optimal cut-off value of models were calculated and validated by 10-fold cross-validation.

Results

A total of 80 PTCs (22 BRAF V600E wild-type and 58 BRAF V600E mutant) were included in our study. Good interobserver agreement was found on texture features we selected (all ICCs >0.75). The area under the ROC curves (AUCs) for the T2WI model, CE-T1WI model, and combined model were 0.83 (95% CI: 0.75-0.91), 0.83 (95% CI: 0.73-0.90), and 0.88 (95% CI: 0.81-0.94), respectively. The accuracy, sensitivity, specificity, PPV, and NPV were 0.776, 0.679, 0.905, 0.905, and 0.679 for the T2WI model at a cut-off value of 0.674; 0.755, 0.750, 0.762, 0.808, and 0.696 for the CE-T1WI model at a cut-off value of 0.573; 0.816, 0.893, 0.714, 0.806, and 0.833 for the combined model at a cut-off value of 0.420.

Conclusion

MRI-based texture analysis could be a potential method for predicting BRAF V600E mutation in PTC preoperatively.

Differential diagnosis of diffuse sclerotic thyroid papillary carcinoma and Hashimoto's thyroiditis using fine-needle aspiration cytology, BRAFV600E , and ultrasound elastography

BACKGROUND

The diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) has ultrasound findings that are similar to Hashimoto's thyroiditis (HT), resulting in under-diagnosis. DSV-PTC combined with HT is also common, so early and accurate diagnosis of DSV-PTC using a variety of diagnostic techniques, including FNAC, BRAF^V600E mutation detection, and ultrasound elastography, is critical.

OBJECTIVE

To assess the diagnostic value of fine-needle aspiration cytology (FNAC) and BRAF^V600E detection in combination with ultrasound elastography in the diagnosis of DSV-PTC.

METHODS

We performed a retrospective analysis of 40 patients with pathologically confirmed DSV-PTC and 43 patients with HT admitted to our hospital's ultrasound department between January 2015 and December 2020. Preoperative FNAC, BRAF^V600E mutation detection, and ultrasound elastography imaging were all performed on all patients. For a definitive diagnosis, the results of these tests were compared to postoperative pathological findings. The diagnostic value of FNAC, BRAF^V600E mutation detection, ultrasound elasticity imaging, and their combination for DSV-PTC diagnosis was assessed.

RESULTS

The mean elastic strain rate ratio (E1/E2) of the 40 DSV-PTC cases was 5.75 ± 2.14, while that of the 43 HT cases was 2.81 ± 1.20. The receiver operating characteristic (ROC) curve was generated using the average value of E2/E1. The area under the ROC curve was 0.910, and the optimal E2/E1 cut-off value was 4.500. When FNAC, BRAF^V600E mutation detection, and ultrasound elasticity imaging detection were combined, the diagnostic sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of DSV-PTC diagnosis were 92.5%, 95.3%, 93.2%, 94.9%, and 94.0%, respectively, which were significantly higher than the single technique (p < 0.05).

CONCLUSIONS

The use of FNAC, BRAF^V600E mutation detection, and ultrasound elastography in combination is more helpful in establishing an accurate diagnosis of DSV-PTC than using a single diagnostic technique alone.

CircNRIP1 Exerts Oncogenic Functions in Papillary Thyroid Carcinoma by Sponging miR-653-5p and Regulating PBX3 Expression

Background

Circular RNA circ_0004771 (termed circNRIP1) was identified by RNA-Seq previously and was elevated in papillary thyroid carcinoma (PTC) tissues. A series of studies also showed that circNRIP1 was upregulated in some tumors and could promote the malignant progression of tumors. This research intended to focus on the role of circNRIP1 in PTC progression and explore the mechanisms underlying circNRIP1 functions.

Methods

RT-PCR or western blot determined circNRIP1, miR-653-5p, and pre-B-cell leukemia homeobox 3 (PBX3) expression. EdU, CCK-8, Tunel, and transwell assays determined cell proliferation, apoptosis, invasion, and migration, respectively. Luciferase reporter assay, RNA immunoprecipitation (RIP), and RNA pull down assays clarified the target relation between miR-653-5p and circNRIP1 or PBX3. Xenograft models were applied to explore the role of circNRIP1 in vivo.

Results

circNRIP1 significantly increased in PTC tissues and PTC cell lines than that in normal ones. Higher circNRIP1 expression was associated with the TNM stage and poorer overall survival. circNRIP1 knockdown attenuated the malignant progression of PTC, specifically by inhibiting proliferation and invasion/migration and promoting apoptosis. circNRIP1 was a miR-653-5p sponge; miR-653-5p knockdown reversed the suppressive role of circNRIP1 silence in PTC progression. PBX3, a target of miR-653-5p, was positively medicated through circNRIP1 via competitively sponging miR-653-5p. Knockdown of circNRIP1 attenuated the PTC tumor progression via miR-653-5p/PBX3 axis.

Conclusion

Silencing of circNRIP1 suppressed PTC development via miR-653-5p elevation and PBX3 reduction, providing a novel perspective for understanding PTC pathogenesis.

Nomogram based on radiomics analysis of ultrasound images can improve preoperative BRAF mutation diagnosis for papillary thyroid microcarcinoma

BACKGROUND

The preoperative identification of BRAF mutation could assist to make appropriate treatment strategies for patients with papillary thyroid microcarcinoma (PTMC). This study aimed to establish an ultrasound (US) radiomics nomogram for the assessment of BRAF status.

METHODS

A total of 328 PTMC patients at the China-Japan Friendship Hospital between February 2019 and November 2021 were enrolled in this study. They were randomly divided into training (n = 232) and validation (n = 96) cohorts. Radiomics features were extracted from the US images. The least absolute shrinkage and selection operator (LASSO) regression was applied to select the BRAF status-related features and calculate the radiomics score (Rad-score). Univariate and multivariate logistic regression analyses were subsequently performed to identify the independent factors among Rad-score and conventional US features. The US radiomics nomogram was established and its predictive performance was evaluated via discrimination, calibration, and clinical usefulness in the training and validation sets.

RESULTS

Multivariate analysis indicated that the Rad-score, composition, and aspect ratio were independent predictive factors of BRAF status. The US radiomics nomogram which incorporated the three variables showed good calibration. The discrimination of the US radiomics nomogram showed better discriminative ability than the conventional US model both in the training set (AUC 0.685 vs. 0.592) and validation set (AUC 0.651 vs. 0.622). Decision curve analysis indicated the superior clinical applicability of the nomogram compared to the conventional US model.

CONCLUSIONS

The US radiomics nomogram displayed better performance than the conventional US model in predicting BRAF mutation in patients with PTMC.

Thyroid Nodule Characterization: How to Assess the Malignancy Risk. Update of the Literature

Ultrasound (US) is the first imaging modality for thyroid parenchyma evaluation. In the last decades, the role of ultrasound has been improved with the introduction of new US software, such as contrast-enhanced ultrasound (CEUS) and US-elastography (USE). USE is nowadays recognized as an essential part of the multiparametric ultrasound (MPUS) examination, in particular for the indeterminate thyroid nodule with possible fine-needle aspiration cytology (FNAC) number reduction; even if further and larger studies are needed to validate it. More controversial is the role of CEUS in thyroid evaluation, due to its high variability in sensitivity and specificity. Semi-automatic US systems based on the computer-aided diagnosis (CAD) system are producing interesting results, especially as an aid to less experienced operators. New knowledge on the molecular mechanisms involved in thyroid cancer is allowing practitioners to identify new genomic thyroid markers that could reduce the number of "diagnostic" thyroidectomies. We have therefore drawn up an updated representation of the current evidence in the literature for thyroid nodule multiparametric ultrasound (MPUS) evaluation with particular regard to USE, the US CAD system and CEUS.

Higher EU-TIRADS-Score Correlated with BRAF V600E Positivity in the Early Stage of Papillary Thyroid Carcinoma

The data demonstrating a correlation between sonographic markers of malignancy of thyroid cancer (TC) and its genetic status are scarce. This study aimed to assess whether the addition of genetic analysis at the preoperative step of TC patients' stratification could aid their clinical management. The material consisted of formalin-fixed paraffin-embedded tumor fragments of 49 patients who underwent thyroidectomy during the early stages of papillary TC (PTC). Tumor DNA and RNA were subjected to next-generation sequencing (NGS) on Ion Proton using the Oncomine™ Comprehensive Assay panel. We observed a significant correlation between BRAF V600E and a higher EU-TIRADS score (p-value = 0.02) with a correlation between hypoechogenicity and taller-than-wide tumor shape in analysed patients. There were no other significant associations between the identified genetic variants and other clinicopathological features. For TC patient's stratification, a strong suspicion of BRAF V600E negativity in preoperative management of TC patients could limit the over-treatment of asymptomatic, very low-risk, indolent disease and leave room for active surveillance.

Correlation of ThyroSeq Results with Surgical Histopathology in Cytologically Indeterminate Thyroid Nodules

The ThyroSeq next-generation sequencing test refines the risk of malignancy in cytologically indeterminate thyroid nodules. Specific genetic alterations have distinct cancer probabilities and clinical phenotypes. There is limited data on the association between specific genetic alterations and histopathologic features. The aim of this study was to evaluate specific ThyroSeq alterations in prognosticating high-risk histopathologic characteristics. We performed a retrospective single-institution study of all patients diagnosed with indeterminate thyroid nodules (May 2016-December 2019) who had a mutation identified with ThyroSeq v2 or v3 and underwent surgical resection. Specific genetic alterations were correlated with surgical histopathology. The main outcomes were risk of malignancy and structural recurrence risk based on histopathologic features and the 2015 American Thyroid Association (ATA) risk stratification. Of the 78 nodules, 50 (64%) were thyroid cancer or noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) on surgical histopathology. Nodules with high-risk TERT or TP53 combination mutations (TERT/TP53) and those with BRAF-like mutations were associated with a 100% probability of cancer and higher rates of extrathyroidal extension and regional nodal involvement than nodules with RAS-like mutations. Among nodules with RAS-like mutations, there was an even distribution between benign, NIFTP, and malignant results, the latter of which were all ATA low risk for structural disease recurrence. Overall, TERT/TP53 and BRAF-like ThyroSeq mutations are associated with an increased cancer probability and risk of recurrence defined by histopathologic features, while RAS-like mutations are associated with lower cancer probability and indolent disease. Individualized management, including extent of surgery, should be considered based on specific genetic alterations found in cytologically indeterminate thyroid nodules.

Prevalence of BRAFV600E mutation in Asian series of papillary thyroid carcinoma-a contemporary systematic review

Papillary thyroid carcinoma (PTC), the most common malignancy of the endocrine system, is frequently driven by BRAFV600E mutation, which was reported in 35-60% cases in Western series. Numerous studies have recently emerged from Asian countries and regions; however sufficient summary is lacking to date. BRAF mutation serves as a diagnostic and prognostic tool in thyroid cancer, therefore establishing a rate of BRAF on the national scale could be of practical significance. We performed systematic reviews of available literature to investigate the prevalence of BRAF mutation in series of PTC from various Asian countries and regions. Out of the total 3,966 reports identified via initial screening, 138 studies encompassing over 40,000 PTCs were included for the final analysis. A vast majority (90.2%) of PTCs with known BRAF status were from East Asia, including China, South Korea, and Japan, with BRAF mutation rates of 71.2%, 75.5%, and 70.6%, respectively. Less abundant Indian and Saudi Arabian series found 45.6% and 46.3% prevalence of BRAFV600E in PTC, respectively. Much limited evidence was available from Thailand, Iran, Kazakhstan, Taiwan, Singapore, Indonesia, Hong Kong, Philippines, Vietnam, Iraq, and Myanmar. No relevant publications were found from other highly populated countries, such as Pakistan, Bangladesh, and Malaysia. After grouping by geographic region, we found that the highest rate of BRAFV600E was reported in the PTC series from East Asia (76.4%). Much lower rate (45-48%) was seen in PTC cohorts from South Asia, Central Asia, and the Middle East while the Southeast Asian series were in between (57%). Further subgroup analysis revealed that studies employing fresh frozen tissue and fine-needle aspirates showed higher rates of BRAF compared to those used formalin-fixed paraffin-embedded tissues. We found that the PTC series enrolled patients' cohorts after 2010 demonstrated a higher rate of BRAF compared to the earlier series. Finally, pediatric PTCs had lower BRAF prevalence compared to the baseline rate for the country. In conclusion, despite considerable among and within countries heterogeneity, the Asian PTC series showed a higher prevalence of BRAFV600E mutation than that in Western series. Causes of geographic heterogeneity, whether genuine (etiology, genetics) or methodology-related should be further investigated.

Is ultrasonographic evaluation sensitive enough to detect multicentric papillary thyroid carcinoma?

Background

This study aimed to investigate the preoperative ultrasonographic (US) evaluation of multicentric papillary thyroid carcinoma (PTC) and to evaluate the association of US findings with lymph node metastasis and extracapsular extension in PTC.

Methods

Preoperative US evaluations of patients with PTC who underwent total thyroidectomy were retrospectively investigated. Pathological perspectives and US features of PTC were analyzed. The sensitivity of US in detecting multicentric PTC was evaluated.

Results

The present study included 89 PTC patients who underwent total thyroidectomy. In total, 164 nodules were detected by preoperative US. Significant differences in US pattern were found between benign and malignant nodules. Of the 89 patients with PTC, 33 (37.08%) cases were confirmed as multicentric PTC by operation and pathological examination, 22 (66.67%) of which were bilateral. Before surgery, only 23 patients were suspected as multicentric PTC based on US findings. Pathological examination revealed that malignant nodules in 17 (51.51%) patients with multicentric PTC had been missed by preoperative US. The malignant nodules that went undetected by US were micronodulars (1-4 mm). Furthermore, ultrasonography was less sensitive for the diagnosis of metastatic lymph nodes in the neck. US had more than 80% sensitivity for detection of extracapsular extension of cases.

Conclusions

US evaluation is not sensitive enough to detect multicentric PTC. The minute size of some nodules in multicentric PTC, may lead to them being missed by US evaluation. Ultrasonography is an optional tool for the detection of extracapsular extension, but it is less sensitive for diagnosing lymph node metastasis.