Lymphatic Contrast-enhanced US to Improve the Diagnosis of Cervical Lymph Node Metastasis from Thyroid Cancer.

Background The presence of cervical lymph node (LN) metastases (LNMs) affects clinical staging and prognosis of thyroid cancer, but the role of conventional B-mode US is limited for preoperative diagnosis of LNMs. The diagnostic value of lymphatic contrast-enhanced US (LCEUS) in thyroid cancer is still being explored. Purpose To explore the diagnostic performance of LCEUS by means of thyroidal injection of contrast agent in comparison with US in detecting LNMs of suspected thyroid cancer. Materials and Methods In this single-center prospective study conducted from November 2020 to January 2021, consecutive participants with suspected thyroid cancer underwent B-mode US and LCEUS of cervical LNs before biopsy. LNMs were confirmed with fine-needle aspiration cytologic examination, thyroglobulin washout assessment, or histopathologic examination after surgery. The diagnostic performance of LCEUS for cervical LNs was compared with that of conventional B-mode US, and its association with LN size and location was evaluated. Results The final data set included 64 participants (mean age, 45 years ± 12 [SD]; 52 women) with 76 LNs. The sensitivity, specificity, and accuracy of LCEUS for LNM were 97%, 90%, and 93%, respectively, whereas they were 81%, 80%, and 80%, respectively, for LNM at conventional B-mode US. Compared with US, LCEUS had better diagnostic accuracy for the LNs smaller than 1 cm (82% vs 95%; P = .03) and for central neck LNs (level VI) (83% vs 96%; P = .04). Conclusion Lymphatic contrast-enhanced US had better diagnostic performance than conventional B-mode US for detecting cervical LN metastases in suspected thyroid cancer before surgery, especially for LNs smaller than 1 cm and central neck LNs. © RSNA, 2023 See also the editorial by Grant and Kwon in this issue.

[Comparison between Ultrasonography and CT in Diagnosis of Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma].

Objective To evaluate the efficacy of ultrasound and computed tomography (CT) in diagnosing cervical lymph node metastasis (CLNM) of papillary thyroid carcinoma (PTC). Methods The patients with PTC treated by surgery in the Chinese PLA General Hospital from January 2016 to January 2021 were selected for analysis.All the patients underwent preoperative ultrasound and CT examinations,the diagnostic values of which for CLNM were retrospectively analyzed. Results A total of 322 PTC patients were enrolled in this study,including 242 with CLNM and 80 with non-CLNM.The CLNM group and non-CLNM group had significant differences in age,tumor size,and maximum size of lateral CLNM (χ2=20.34,27.34,and 4.30,respectively,all P<0.001).For the central compartment,lateral compartment,and overall compartment,ultrasound diagnosis showed higher sensitivity (χ 2=82.26,P<0.001;χ2=114.01,P<0.001;χ2=82.26,P<0.001) and accuracy (χ2=20.27,P<0.001;χ2=15.56,P<0.001;χ2=44.00,P<0.001) than CT,and had no significant differences from ultrasound combined with CT (all P>0.05).However,ultrasound diagnosis had lower specificity than CT (χ2=17.01,P<0.001;χ2=21.29,P<0.001) in the central compartment and lateral compartment.Receiver operating characteristic curve analysis showed that in the central compartment,lateral compartment,and overall compartment,ultrasound diagnosis had larger AUC than CT (Z=2.99,P=0.003;Z=3.86,P<0.001;Z=4.47,P<0.001) and had no significant difference from ultrasound combined with CT (Z=1.87,P=0.062;Z=1.68,P=0.093;Z=1.61,P=0.107). Conclusions Ultrasound and CT have their own advantages in the diagnosis of central and lateral CLNM.In general,ultrasound has better performance than CT in the diagnosis of CLNM.

[Validated Nomogram Predicting Clinical Outcome after Radiofrequency Ablation in the Treatment of Papillary Thyroid Microcarcinoma].

Objective To establish a prediction model for the short-term efficacy of percutaneous ultrasound-guided radiofrequency ablation(RFA)in the treatment of papillary thyroid microcarcinoma(PTMC). Methods We retrospectively analyzed the preoperative and follow-up data of 159 patients with PTMC who underwent percutaneous ultrasound-guided RFA treatment in the Department of Ultrasound,the First Medical Center of Chinese PLA General Hospital from January to December in 2018.The association with 12-month tumor status(end event)was evaluated by multivariate logistic regression model.A nomogram was built to predict the risk of tumors which did not disappear completely within 12 months after RFA. Results We found that gender(P=0.017),age(P=0.047),and calcification(P=0.049)were the strongest predictors for establishing the model.The tumor maximum diameter and RFA energy were the secondary relevant factors for establishing the model.The constructed model showed good performance in both training cohort(AUC=0.762)and validation cohort(AUC=0.740). Conclusion A quantitative model was established for predicting the tumor status within one year after treatment of PTMC by RFA,which can accurately predict the short-term efficacy of RFA and provide a clinical basis for explaining the recovery results of patients.

[Value of Trans-lymphatic Contrast-enhanced Ultrasound in the Diagnosis of Cervical Lymph Node Metastasis of Thyroid Cancer].

Objective To explore the value of trans-lymphatic contrast-enhanced ultrasound(CEUS)in the diagnosis of cervical lymph node metastasis of thyroid cancer. Methods The patients with suspected thyroid cancer underwent conventional ultrasound and trans-lymphatic CEUS examinations before the biopsy.The differences in ultrasound and CEUS characteristics of cervical lymph nodes between the metastatic group and the non-metastatic group were compared,and pathological results were regarded as the golden standard. Results Twenty patients had thyroid cancer,including 12 cases with lymph node metastasis and 8 cases without metastasis.The diagnostic sensitivity(91.7% vs. 75.0%)and accuracy(90.0% vs.80.0%)of trans-lymphatic CEUS were higher than those of conventional ultrasound.The normal lymph nodes presented homogeneous enhancement,while the metastatic lymph nodes showed heterogeneous or non-enhancement during the trans-lymphatic CEUS examination.Conclusion As a new modality of ultrasound,trans-lymphatic CEUS contributes to the diagnosis of cervical lymph node metastasis of thyroid cancer and supplements the deficiencies of conventional ultrasound.

[Correlation between Contrast-enhanced Ultrasound and Risk of Tumor Recurrence in Papillary Thyroid Carcinoma].

Objective To explore the association between contrast-enhanced ultrasound and risk of tumor recurrence in papillary thyroid carcinoma(PTC). Methods A total of 287 PTCs in 287 patients who underwent surgery,conventional ultrasound,and contrast-enhanced ultrasound(CEUS)were enrolled in this study.According to 2015 American Thyroid Association(ATA)Modified Initial Risk Stratification System,the patients were categorized into three groups:low risk,intermediate risk,and high risk.The CEUS patterns of PTCs were compared between different risk stratifications. Results Hypo-enhancement was presented in 57.6% of ATA low-risk PTCs,iso-enhancement in 62.3% of ATA intermediate-risk PTCs,and hyper-enhancement in 48.2% of ATA high-risk PTCs(P<0.0001).The risk stratifications and enhanced intensity in PTC showcased a positive correlation(Spearman's rho of 0.442,P<0.0001)and a linear trend(χ 2 value of 55.921,P<0.0001).Higher enhancement intensity corresponded to higher risk stratification.Ordinal logistic regression analysis indicated that PTCs with hyper-enhancement and iso-enhancement presented higher risks than those with hypo-enhancement after age and gender were adjusted,and theOR values were 17.5(8.4-36.2)and 3.4(2.0-5.8),respectively. Conclusions CEUS patterns correlate intimately with the recurrence risk in PTC.Hyper-enhancement PTCs tend to present high risks,while hypo-enhancement PTCs tend to present low risks of recurrence.