Cervical lymph node metastasis prediction from papillary thyroid carcinoma US videos: a prospective multicenter study.

BACKGROUND: Prediction of lymph node metastasis (LNM) is critical for individualized management of papillary thyroid carcinoma (PTC) patients to avoid unnecessary overtreatment as well as undesired under-treatment. Artificial intelligence (AI) trained by thyroid ultrasound (US) may improve prediction performance. METHODS: From September 2017 to December 2018, patients with suspicious PTC from the first medical center of the Chinese PLA general hospital were retrospectively enrolled to pre-train the multi-scale, multi-frame, and dual-direction deep learning (MMD-DL) model. From January 2019 to July 2021, PTC patients from four different centers were prospectively enrolled to fine-tune and independently validate MMD-DL. Its diagnostic performance and auxiliary effect on radiologists were analyzed in terms of receiver operating characteristic (ROC) curves, areas under the ROC curve (AUC), accuracy, sensitivity, and specificity. RESULTS: In total, 488 PTC patients were enrolled in the pre-training cohort, and 218 PTC patients were included for model fine-tuning (n = 109), internal test (n = 39), and external validation (n = 70). Diagnostic performances of MMD-DL achieved AUCs of 0.85 (95% CI: 0.73, 0.97) and 0.81 (95% CI: 0.73, 0.89) in the test and validation cohorts, respectively, and US radiologists significantly improved their average diagnostic accuracy (57% vs. 60%, P = 0.001) and sensitivity (62% vs. 65%, P < 0.001) by using the AI model for assistance. CONCLUSIONS: The AI model using US videos can provide accurate and reproducible prediction of cervical lymph node metastasis in papillary thyroid carcinoma patients preoperatively, and it can be used as an effective assisting tool to improve diagnostic performance of US radiologists. TRIAL REGISTRATION: We registered on the Chinese Clinical Trial Registry website with the number ChiCTR1900025592.

Follow-up strategy of radiofrequency ablation for papillary thyroid microcarcinoma: defining a response-to-ablation system.

OBJECTIVE: To define a response-to-ablation system based on dynamic risk stratification proposed by the 2015 American Thyroid Association guidelines for predicting clinical outcomes and guiding follow-up strategies for patients with low-risk papillary thyroid microcarcinoma (PTMC) who underwent radiofrequency ablation (RFA). METHODS: This retrospective study reviewed patients with low-risk PTMC who underwent RFA between 2014 and 2018. We classified patients into three groups based on their response to therapy at the 1-year follow-up: complete, indeterminate, and incomplete. The primary endpoints were local tumor progression (LTP) and disease-free survival (DFS). RESULTS: Among the 748 patients (mean age, 43.7 years ± 9.8; 586 women), 4.0% (30/748) had LTP during a median follow-up of 5 years. The response was complete in 80.2% (600/748) of the patients, indeterminate in 18.1% (135/748), and incomplete in 1.7% (13/748). The LTP rate in the final follow-up was 1% (6/600), 8.1% (11/135), and 100% (13/13), respectively. The risk of LTP was significantly different in the incomplete response group (HR, 1825.82; 95% CI: 458.27, 7274.36; p < 0.001) and indeterminate response group (HR, 8.12; 95% CI: 2.99, 22.09; p < 0.001) than in the complete response group. There were significant differences in DFS among groups (p < 0.001). The proportion of variation explained and C-index of the system was high (27.66% and 0.79, respectively). CONCLUSIONS: We defined a response-to-ablation system that provides a new paradigm for the management of patients with PTMC who underwent RFA. Our data confirm that the system can effectively predict the risk of LTP and guide ongoing follow-up recommendations. KEY POINTS: • The response-to-ablation system can classify patients with low-risk PTMC who underwent RFA into complete, indeterminate, or incomplete response categories. • Results suggest that, in this population, this system can identify three separate cohorts of patients who have significantly different clinical outcomes. • The response-to-ablation system will help better tailor the ongoing follow-up recommendations.

Radiofrequency ablation for capsular-located versus noncapsular-located papillary thyroid microcarcinoma: a propensity score matching study of 1095 patients.

OBJECTIVES: To assess the safety and efficacy of radiofrequency ablation (RFA) for capsular-located papillary thyroid microcarcinoma (PTMC) in a large cohort and to compare its outcomes with those of noncapsular-located PTMC. METHODS: We retrospectively reviewed patients who underwent RFA for solitary capsular-located and noncapsular-located low-risk PTMC (n = 1095) from June 2014 to October 2020. To balance confounding variables between capsular and noncapsular groups, we employed the 1:1 propensity score matching approach. We evaluated and compared tumor changes, disease progression, and complications in both groups. Furthermore, we analyzed the association between capsular location and disease progression using multivariable Cox regression. RESULTS: During a mean follow-up time of 29.86 ± 16.14 months and 29.73 ± 15.69 months, no substantial difference was observed between capsular and noncapsular groups in the latest volume (0.83 ± 3.66 mm3 vs. 0.85 ± 3.67 mm3, p = 0.44) and volume reduction ratio (99.29 ± 4.04% vs. 99.43 ± 3.03%, p = 0.43), and cumulative disappearance rate (87.87% vs. 86.07%, p = 0.31). In addition, no significant differences were observed in complication incidence (1.35% vs. 1.12%, p = 0.76) and progression-free survival (p = 0.53). Based on adjusted multivariate Cox proportional hazard analysis, the association between capsular location and disease progression was nonsignificant (all p > 0.05). CONCLUSION: This study demonstrates that the short-term outcomes of RFA for capsular-located PTMCs are comparable to those of noncapsular-located PTMCs. These findings indicate that RFA may be a viable and effective alternative for eligible patients with solitary capsular-located PTMC. CLINICAL RELEVANCE STATEMENT: Radiofrequency ablation may serve as a safe and effective alternative treatment method for eligible patients with capsular-located and noncapsular-located papillary thyroid microcarcinoma. KEY POINTS: • The safety and efficacy of radiofrequency ablation for capsular-located and noncapsular-located papillary thyroid microcarcinomas were comparable. • Disease progression did not differ significantly between capsular-located and noncapsular-located papillary thyroid microcarcinomas. • The incidence of complications for capsular-located papillary thyroid microcarcinoma was low.

Radiofrequency ablation for papillary thyroid microcarcinoma with a trachea-adjacent versus trachea-distant location.

OBJECTIVE: To evaluate the outcomes of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) adjacent to the trachea and compare them with those of PTMC distant from the trachea. METHODS: Patients who received RFA for solitary low-risk PTMC between June 2014 and July 2020 were reviewed and classified into adjacent and distant groups. To balance between-group confounders, the propensity score matching approach was employed. Volume, volume reduction ratio (VRR), tumor disappearance, complications, and disease progression were assessed and compared between the groups. Furthermore, factors affecting disease progression were evaluated. RESULTS: A total of 122 and 470 patients were included in the adjacent and distant groups, respectively. Overall VRR was 99.5% ± 3.1 and cumulative tumor disappearance rate was 99.4% after a mean follow-up time of 40.1 months ± 16.2. Overall disease progression and complications incidence were 3.7% and 1.0%, respectively. No substantial differences were observed between the two groups in the latest volume (0.8 mm3 ± 4.1 vs. 0.9 mm3 ± 4.2, p = .77), VRR (99.7% ± 1.6 vs. 99.5% ± 2.7, p = .75), cumulative tumor disappearance rate (92.6% vs. 94.2%, p = .58), and incidence of disease progression (4.1% vs. 4.5%, p = .70) and complication (1.7% vs. 0.8%, p = .86) after 1:2 matching. Additionally, tracheal adjacency exhibited no association with disease progression in multivariate Cox regression analysis (p = .73). CONCLUSION: For eligible patients with PTMC located adjacent to or distant from the trachea, RFA may offer a safe and effective alternative treatment method.

Clinical outcomes of ultrasound-guided radiofrequency ablation for solitary T1N0M0 papillary thyroid carcinoma: A retrospective study with more than 5 years of follow-up.

BACKGROUND: Ultrasound-guided radiofrequency ablation (RFA) has been used in patients with papillary thyroid carcinoma (PTC) who refuse surgery or active surveillance. However, the long-term outcomes are still limited. This study aimed to evaluate the clinical outcomes of RFA for solitary T1N0M0 PTC in a large cohort over a more than 5-year follow-up period. METHODS: This retrospective study included 358 patients with solitary T1N0M0 PTC who were treated with RFA and followed for at least 5 years. The bipolar RFA procedure was performed using hydrodissection technique, transisthmic approach, and moving-shot technique. The primary outcomes were disease progression, including lymph node metastasis (LNM), recurrent tumor, persistent tumor, and distant metastasis. The secondary outcomes were volume reduction rate, complete disappearance rate, complications, and delayed surgery. RESULTS: During a mean follow-up period of 75.5 ± 9.7 months, the overall disease progression was 5.0%. The incidence of LNM, recurrent tumor, and persistent tumor was 1.4%, 3.1%, and 0.6%, respectively. There were no significant differences in the disease progression (5.0% vs. 5.5%, p = 1.000), LNM (1.3% vs. 1.8%, p = .568), recurrent tumor (3.3% vs. 1.8%, p = .872), persistent tumors (0.3% vs. 1.8%, p = .284), and 5-year recurrence-free survival rates (95.4% vs. 96.4%, p = .785) in the T1a and T1b groups. Volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. No complications occurred. No patients underwent delayed surgery because of anxiety. CONCLUSIONS: RFA is an effective and safe alternative for patients with T1N0M0 PTC and can offer a minimally invasive curative option for patients who refuse surgery or active surveillance. PLAIN LANGUAGE SUMMARY: During a mean follow-up period of 75.5 ± 9.7 months, the overall papillary thyroid carcinoma disease progression was 5.0%. The volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. The T1a and T1b groups had similar incidence of disease progression and 5-year recurrence-free survival rates. No patients experienced complications or underwent delayed surgery because of anxiety.

Long-term Outcomes of Ultrasound-guided Thermal Ablation for the Treatment of Solitary Low-risk Papillary Thyroid Microcarcinoma: A Multicenter Retrospective Study.

OBJECTIVE: To report more than 5-year outcomes of ultrasound-guided thermal ablation (TA) for patients with solitary low-risk papillary thyroid microcarcinoma (PTMC) in a large multicenter cohort. BACKGROUND: TA, including radiofrequency ablation (RFA) and microwave ablation (MWA) have been used in patients with low-risk PTMC who refuse surgery or active surveillance. However, its clinical value remains controversial. MATERIALS AND METHODS: This retrospective multicenter study included 474 patients with solitary low-risk PTMC treated with TA (357 for RFA; 117 for MWA) from 4 centers and followed up for at least 5 years. Disease progression including lymph node metastasis and recurrent tumors, volume reduction rate (VRR), tumor disappearance rate, complications, and delayed surgery were assessed. RFA and MWA outcomes were compared using propensity score matching. RESULTS: During the median follow-up period of 77.2 months, disease progression incidence, lymph node metastasis, and recurrent tumors rates were 3.6%, 1.1%, and 2.5%, respectively. Age below 40 years old, male sex, Hashimoto thyroiditis, and tumor size were not independent factors associated with disease progression by Cox analysis. The median VRR was 100% and 471 tumors disappeared radiographically. Eight patients experienced transient voice change (1.7%) which recovered within 3 months. None of the patients underwent delayed surgery because of anxiety. After 1:1 matching, no significant differences were found in the disease progression, VRR, tumor disappearance rate, or complications between RFA and MWA subgroups. CONCLUSION: This multicenter study revealed that TA was an effective and safe treatment for patients with solitary low-risk PTMC, which could be offered as a treatment option for the management for low-risk PTMC.

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 of ultrasound-guided radiofrequency ablation versus thyroid lobectomy for T1bN0M0 papillary thyroid carcinoma.

OBJECTIVE: To investigate and compare the clinical outcomes between radiofrequency ablation (RFA) and thyroid lobectomy (TL) for T1bN0M0 papillary thyroid carcinoma (PTC). METHODS: This retrospective study evaluated 283 patients with solitary T1bN0M0 PTC treated with RFA (RFA group, 91 patients) or TL (TL group, 192 patients) from May 2014 to November 2018. The patients were regularly followed up after treatment. Local tumor progression, lymph node metastasis (LNM), recurrent tumor, persistent tumor, recurrence-free survival (RFS), treatment variables (hospitalization, procedure time, estimated blood loss, and cost), complication, and delayed surgery were compared. RESULTS: During the follow-up (median [interquartile ranges], 50.4 [18.0] months), no significant differences were found in the local tumor progression (4.4% vs 3.6%, p = 1.000), LNM (1.1% vs 2.1%, p = 0.917), recurrent tumor (2.2% vs 1.6%, p = 1.000), persistent tumor (1.1% vs 0%, p = 0.146), and RFS rate (95.6% vs 96.4%, p = 0.816) in the RFA and TL groups. Distant metastasis was not detected. Patients in the RFA group had a shorter hospitalization (0 vs 7.0 [3.0] days, p < 0.001), shorter procedure time (5.6 [2.9] vs 90.0 [38.5] min, p < 0.001), lower estimated blood loss (0 vs 20 [20] mL, p < 0.001), lower cost ($1972.5 [0.1] vs $2362.4 [1009.3], p < 0.001), and lower complication rate (0 vs 12/192 [6.3%], p = 0.015) than those in the TL group. No patients in the RFA group underwent delayed surgery. CONCLUSIONS: This study revealed comparable 4-year clinical outcomes between RFA and TL for T1bN0M0 PTC in terms of local tumor progression and RFS. As a minimally invasive modality, RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation. KEY POINTS: • No significant difference in local tumor progression and RFS was found between RFA and TL for T1bN0M0 PTC during a median follow-up period of 50.4 months. • Compared with TL, RFA led to a shorter hospitalization, lower estimated blood loss, lower cost, and lower complication rate. • RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

Analysis and prediction of regrowth in benign thyroid nodules undergoing radiofrequency ablation: a retrospective study with a 5-year follow-up.

OBJECTIVES: To evaluate the 5-year follow-up results of radiofrequency ablation (RFA) for benign thyroid nodules (BTNs), and construct pre- and postablation nomogram models to predict regrowth in BTNs undergoing RFA. METHODS: According to the occurrence of regrowth, BTNs were divided into two subgroups, the regrowth group and the nonregrowth group, and the variables were compared between these two subgroups. Then, univariate and multivariate Cox regression analyzes were utilized to filter the independent prognostic factors of regrowth, which then were introduced into the pre- and postablation prognostic nomograms, respectively. The discrimination powers and prediction performances of the nomograms were appraised by receiver operating characteristic (ROC) curves and calibration charts. RESULTS: The 5-year mean volume reduction rate was 88.80%, with a complication rate of 0.35% (7/200). Within 5 years of follow-up, the regrowth rate was 19% (38/200). Pre- and postablation prognostic nomograms were established to predict the probability of nonregrowth at 1, 3, and 5 years after RFA. The preablation nomogram included initial volume, perinodular vascularity, and high enhancement ring. The postablation nomogram incorporated total volume, perinodular vascularity, and energy applied per volume. The area under the ROC curves and concordance index values of these models were all above 0.7, indicating that the prognostic nomograms achieved satisfactory discrimination powers and prediction performances. CONCLUSION: RFA for BTNs has long-term efficacy and safety under the influence of key techniques. The pre- and postablation nomograms constructed in the present study might facilitate clinical decision-making before RFA and for the follow-up management after RFA. KEY POINTS: • Perinodular vascularity, rather than intranodular vascularity was an independent predictor of regrowth, both before and after the RFA procedure. • A high enhancement ring on preablation contrast-enhanced ultrasound was an independent predictor of regrowth. • Pre- and postablation nomograms might facilitate clinical decision-making before RFA and follow-up management after RFA.

Comparative diagnostic performance of contrast-enhanced ultrasound and dynamic contrast-enhanced magnetic resonance imaging for differentiating clear cell and non-clear cell renal cell carcinoma.

OBJECTIVE: To compare the diagnostic efficiency of contrast-enhanced ultrasound (CEUS) with that of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the differential diagnosis of clear and non-clear cell renal cell carcinoma, as confirmed by subsequent pathology. METHODS: A total of 181 patients with 184 renal lesions diagnosed by both CEUS and DCE-MRI were enrolled in the study, including 136 clear cell renal cell carcinoma (ccRCC) and 48 non-clear cell renal cell carcinoma (non-ccRCC) tumors. All lesions were confirmed by histopathologic diagnosis after surgical resection. Interobserver agreement was estimated using a weighted kappa statistic. Diagnostic efficiency in evaluating ccRCC and non-ccRCC was compared between CEUS and DCE-MRI. RESULTS: The weighted kappa value for interobserver agreement was 0.746 to 0.884 for CEUS diagnosis and 0.764 to 0.895 for DCE-MRI diagnosis. Good diagnostic performance in differential diagnosis of ccRCC and non-ccRCC was displayed by both CEUS and DCE-MRI: sensitivity was 89.7% and 91.9%, respectively; specificity was 77.1% and 68.8%, respectively; and area under the receiver operating curve was 0.834 and 0.803, respectively. No statistically significant differences were present between the two methods (p = 0.54). CONCLUSIONS: Both CEUS and DCE-MRI imaging are effective for the differential diagnosis of ccRCC and non-ccRCC. Thus, CEUS could be an alternative to DCE-MRI as a first test for patients at risk of renal cancer, particularly where DCE-MRI cannot be carried out. KEY POINTS: • CEUS and DCE-MRI features can help differentiate ccRCC and non-ccRCC. • The differential diagnosis of ccRCC and non-ccRCC by CEUS is comparable to that of DCE-MRI. • Interobserver agreement is generally high using CEUS and DCE-MRI.

Clinical value of artificial intelligence in thyroid ultrasound: a prospective study from the real world.

OBJECTIVE: To evaluate the diagnostic performance of a commercial artificial intelligence (AI)-assisted ultrasonography (US) for thyroid nodules and to validate its value in real-world medical practice. MATERIALS AND METHODS: From March 2021 to July 2021, 236 consecutive patients with 312 suspicious thyroid nodules were prospectively enrolled in this study. One experienced radiologist performed US examinations with a real-time AI system (S-Detect). US images and AI reports of the nodules were recorded. Nine residents and three senior radiologists were invited to make a "benign" or "malignant" diagnosis based on recorded US images without knowing the AI reports. After referring to AI reports, the diagnosis was made again. The diagnostic performance of AI, residents, and senior radiologists with and without AI reports were analyzed. RESULTS: The sensitivity, accuracy, and AUC of the AI system were 0.95, 0.84, and 0.753, respectively, and were not statistically different from those of the experienced radiologists, but were superior to those of the residents (all p < 0.01). The AI-assisted resident strategy significantly improved the accuracy and sensitivity for nodules ≤ 1.5 cm (all p < 0.01), while reducing the unnecessary biopsy rate by up to 27.7% for nodules > 1.5 cm (p = 0.034). CONCLUSIONS: The AI system achieved performance, for cancer diagnosis, comparable to that of an average senior thyroid radiologist. The AI-assisted strategy can significantly improve the overall diagnostic performance for less-experienced radiologists, while increasing the discovery of thyroid cancer ≤ 1.5 cm and reducing unnecessary biopsies for nodules > 1.5 cm in real-world medical practice. KEY POINTS: • The AI system reached a senior radiologist-like level in the evaluation of thyroid cancer and could significantly improve the overall diagnostic performance of residents. • The AI-assisted strategy significantly improved ≤ 1.5 cm thyroid cancer screening AUC, accuracy, and sensitivity of the residents, leading to an increased detection of thyroid cancer while maintaining a comparable specificity to that of radiologists alone. • The AI-assisted strategy significantly reduced the unnecessary biopsy rate for thyroid nodules > 1.5 cm by the residents, while maintaining a comparable sensitivity to that of radiologists alone.

Rigorous radiofrequency ablation can completely treat low-risk small papillary thyroid carcinoma without affecting subsequent surgical management.

OBJECTIVE: Minimally invasive therapies are gaining interest because of the indolence and excellent prognosis of low-risk papillary thyroid carcinoma (PTC). This study aimed to evaluate the outcomes of radiofrequency ablation (RFA) for low-risk PTC and to determine the effects of ablation on subsequent surgical management. METHODS: A medical record review was conducted including patients with low-risk PTC who underwent surgery after RFA from July 2015 to July 2021. Demographic characteristics, tumor characteristics, ablation procedures, surgical findings, and pathological changes were reviewed for all patients. The primary outcomes were surgical and pathological changes in post-ablation patients. RESULTS: Of the 10 patients with 11 PTCs, 9 (90%) were women; the median (SD) patient age was 41.5 (8.2) years. The maximum diameter range of PTCs was 3.0-12.0 mm. All 10 patients underwent rigorous RFA procedure involving a four-step approach, and had received surgical management. Intraoperatively, no patients had muscle and nerve injuries, and mild adhesion of the post-ablation lesions with the anterior cervical muscle was observed in two cases. Histopathologically, no residual PTCs were observed in the ablated areas in all patients. Central lymph node metastasis (LNM) was found in three (30.0%, pN1a). Occult PTCs were observed in three cases (30.0%). CONCLUSIONS: Our findings suggest that low-risk small PTCs can be completely treated with rigorous RFA, which does not affect subsequent surgical management, if necessary. RFA may be a treatment option, but occult PTCs and clinically negative LNMs may be overlooked. Long-term follow-up data are necessary to further identify its efficacy. KEY POINTS: • RFA can completely treat low-risk small PTC. • RFA does not affect the subsequent surgical management if necessary. • Because occult PTCs and clinically negative LNMs may be overlooked by RFA, long-term follow-up data are necessary to further identify its efficacy.

Ultrasound-guided microwave ablation combined with ethanol injection for the treatment of solitary nodular retrosternal goiter: a prospective study of 72 patients.

OBJECTIVES: We prospectively evaluated the efficacy and safety of microwave ablation (MWA) combined with ethanol injection (EI) in solitary nodular retrosternal goiters (RSGs). METHODS: From November 2018 to November 2020, 72 patients diagnosed with solitary nodular RSG were treated by ultrasound-guided MWA with EI. Patients were followed up at 1, 3, 6, and 12 months and every 6-12 months thereafter by ultrasound and contrast-enhanced ultrasound (CEUS). The nodule volume, volume reduction ratio (VRR), neck circumference, symptom score, and cosmetic grading score were recorded to evaluate the treatment efficacy. RESULTS: All patients successfully underwent treatment. The mean initial nodule volume was 71.25 mL ± 61.61 mL, which decreased significantly to 7.47 mL ± 9.19 mL at a mean follow-up time of 23.89 months ± 7.66 months (range 15-39 months) with a mean VRR of 90.99% ± 7.52%. The neck circumference, symptom score, and cosmetic grading score significantly decreased from 36.94 cm ± 3.04 cm to 35.06 cm ± 2.84 cm, from 3.78 ± 1.19 to 0.36 ± 0.63, and from 3.42 ± 0.76 to 1.13 ± 0.37, at the 12 months after treatment, respectively (all 7 p < 0.001). Of all the nodules, eight (11.1%) received a second ablation. No major complications occurred. CONCLUSION: Ultrasound-guided MWA combined with EI is an effective and safe treatment for solitary nodular RSG and may be a potential alternative to surgery in selected patients, especially for those who are ineligible or unwilling to receive surgical treatment. KEY POINTS: • MWA combined with EI is an effective and safe approach for the treatment of solitary nodular RSG. • This treatment should be conducted by experienced physicians. • It provides a potential alternative to surgery for solitary nodular RSG in patients who are ineligible or unwilling to receive surgical treatment.

Safety findings after intravenous administration of sulfur hexafluoride microbubbles to 463,434 examinations at 24 centers.

OBJECTIVES: We aimed to evaluate the safety of the ultrasound contrast agent sulfur hexafluoride microbubbles in a large group of patients referred for routine contrast-enhanced ultrasound (CEUS). METHODS: A retrospective assessment was made of all patients that received sulfur hexafluoride microbubbles intravenously for CEUS at 24 centers between January 2006 and April 2019. Patient demographic details, examination type, and the dose of sulfur hexafluoride microbubbles administered were recorded with specific adverse events (AEs) documentation tools at each center. All AEs were recorded as serious or non-serious. Non-serious AEs were classified by intensity as mild, moderate, or severe according to ACR criteria. The frequencies of AEs across patient subgroups were compared using the chi-square test. RESULTS: A total of 463,434 examinations were evaluated. Overall, 157 AEs (153 [0.033%] non-serious; 4 [0.001%] serious) were reported after sulfur hexafluoride microbubbles administration, giving an AE frequency of 0.034% (157/463,434). Among the non-serious AEs, 66 (0.014%) were mild, 70 (0.015%) moderate, and 17 (0.004%) severe in intensity. The liver was the most common examination site, presenting an AE frequency of 0.026%. The highest AE frequency (0.092%) was for patients undergoing CEUS for vascular disease. There were no significant gender differences in either the total number or the severity of non-serious AEs (chi-square = 2.497, p = 0.287). The onset of AEs occurred within 30 min of sulfur hexafluoride microbubbles administration in 91% of cases. CONCLUSION: The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare, confirming that sulfur hexafluoride microbubbles are appropriate for routine CEUS applications. KEY POINT: • The frequency of AEs to sulfur hexafluoride microbubbles is very low and severe reactions are rare.

Single-plane versus real-time biplane approaches for ultrasound-guided central venous catheterization in critical care patients: a randomized controlled trial.

BACKGROUND: Critical care patients often require central venous cannulation (CVC). We hypothesized that real-time biplane ultrasound-guided CVC would improve first-puncture success rate and reduce mechanical complications. The purpose of this study was to compare the success rate and safety of single-plane and real-time biplane approaches for ultrasound-guided CVC. METHODS: From October 2022 to March 2023, 256 participants with critical illness requiring CVC were randomized to either the single-plane (n = 128) or biplane (n = 128) ultrasound-guided cannulation groups. The success rate, number of punctures, procedure duration, incidence of catheterization-related complications, and confidence score of operators were documented. RESULTS: The central vein was successfully cannulated in all 256 participants (163 [64%] man and 93 [36%] women; mean age 69 ± 19 [range 13-104 years]), including 182 and 74 who underwent internal jugular vein cannulation (IJVC) and femoral vein cannulation (FVC), respectively. The incidence of successful puncture on the first attempt was higher in the biplane group than that in the single-plane group (91.6% vs. 74.7%; relative risk (RR), 1.226; 95% confidence interval (CI), 1.069-1.405; P = 0.002 for the IJVC and 90.9% vs. 68.3%; RR, 1.331; 95% CI, 1.053-1.684; P = 0.019 for the FVC). The biplane group was also associated with a higher first-puncture single-pass catheterization success rate (87.4% vs. 69.0% and 90.9% vs. 68.3%), fewer undesired punctures (1[1-1(1-2)] vs. 1[1-2(1-4)] and 1[1-1(1-3)] vs. 1[1-2(1-4)]), shorter cannulation time (205 s [162-283 (66-1,526)] vs. 311 s [243-401 (136-1,223)] and 228 s [193-306 (66-1,669)] vs. 340 s [246-499 (130-944)]), and fewer immediate complications (10.5% vs. 28.7% and 9.1% vs. 34.1%) for both IJVC and FVC (all P < 0.05). CONCLUSION: Real-time biplane imaging of ultrasound-guided CVCs offers advantages over the single-plane approach for critically ill patients. TRIAL REGISTRATION: This prospective RCT was registered at Chinese Clinical Trial Registry (ChiCTR2200064843). Registered 19 October 2022.

Gabexate Mesylate-Poloxamer 407 Conjugate Alleviates Sodium Taurocholate-Induced Severe Acute Pancreatitis in an Optimized Rat Model.

BACKGROUND AND AIMS: We have previously shown that gabexate mesylate-poloxamer 407 conjugate (GMTI) alleviates traumatic pancreatitis in rats. In this study, we evaluated the therapeutic effect of GMTI on sodium taurocholate-induced severe acute pancreatitis (SAP) in an optimized rat model. METHODS: An SAP rat model was established via microinjection of 3.5% sodium taurocholate and retention in the bile duct for 1 min. SAP rats were administered GMTI via tail vein injection (i.v.) or tail vein injection + intraperitoneal injection (i.v. + i.p.). All rats were sacrificed at 12 h after treatment. Biochemical approach and enzyme-linked immunosorbent assay were performed to measure the serum levels of amylase (AMY), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Hematoxylin and eosin staining and TUNEL assay were conducted to examine histopathology and acinar cell apoptosis in the rat pancreas. RESULTS: SAP was successfully induced in all model rats, as evidenced by progressively aggravating SAP symptoms and signs, pancreatic histopathological abnormalities, as well as elevated serum levels of TNF-α, IL-6, and AMY. The mortality rates at 1 h, 6 h, and 12 h were 0%, 0%, and 25%, respectively. GMTI therapy via i.v. or i.v. + i.p. significantly reduced pancreatic wet weights, ascites amounts, pathological scores, and circulating levels of TNF-α and IL-6 while promoting acinar cell apoptosis in SAP rats. GMTI therapy via i.v. + i.p. outperformed i.v. in improving pancreatic histology and reducing TNF-α and IL-6 serum levels in SAP rats. CONCLUSIONS: Our optimized SAP rat model is reliable and reproducible. GMTI therapy is a promising approach against SAP.

Predictors of metastasis in cervical indeterminate lymph nodes after thyroid cancer ablation by long-term ultrasound follow-up.

OBJECTIVES: To investigate the pattern of change over time and predictors for metastasis in indeterminate lymph nodes (LNs) among patients with thyroid cancer post-ablation. METHODS: We enrolled patients who developed new cervical LNs after papillary thyroid carcinoma (PTC) ablation. Changes in the ultrasound characteristics of the indeterminate LN were recorded at months 1, 3, 6 and 12 after ablation. LN puncture pathology and long-term follow-up were standard of diagnosis. The indeterminate LNs were divided into benign and malignant groups, the differences between the two groups were compared, and the risk characteristics of malignant LNs were screened using generalized estimating equations (GEE). RESULTS: In total, we included 138 LNs from 99 patients, of which 48 were indeterminate LNs. When following up indeterminate LNs, non-cervical lymph node metastasis (non-CLNM) lesions demonstrated a statistically significant gradual decrease in volume (p = 0.012), though there was no significant change in the volume of CLNM lesions (p = 0.779). Compared to non-CLNM lesions, the diagnostic efficiency was the highest for CLNM lesions at 1-3 months after ablation, when the LN volume changed by -0.08 to 0.12 mL (p = 0.048). The third month after ablation became an important time point for review. Moreover, GEE analysis showed that microcalcifications, cystic changes, and vascularity were strongly associated with CLNMs (p = 0.004, p = 0.002, and p = 0.010, respectively). CONCLUSIONS: There is a pattern of volume change of indeterminate LNs after PTC ablation, which, together with microcalcifications, cystic changes, and vascularity, can be used as criteria for differentiating the benignity and malignancy of indeterminate LNs.

Optimal thyrotropin level for low-risk papillary thyroid carcinoma after ultrasound-guided radiofrequency ablation.

PURPOSE: Maintaining an optimal thyroid stimulating hormone (TSH) level is important in the postoperative management of papillary thyroid carcinoma (PTC). However, there is little evidence for TSH target levels in patients undergoing radiofrequency ablation (RFA). This study aimed to determine the optimal TSH level for management in low-risk patients who underwent RFA. METHODS: This retrospective propensity score-matched cohort study included patients with low-risk PTC who underwent RFA from January 2014 to December 2018. The patients were categorized into two groups based on the range of TSH levels: low (≤2 mU/L) and high (>2 mU/L) TSH levels. Local tumor progression and disease-free survival (DFS) were compared between the low TSH and high TSH groups, using propensity score analyses based on patient- and tumor-level characteristics. Univariate analyses were performed to select risk factors for tumor progression. RESULTS: Overall, our study included 516 patients with low-risk PTC who underwent RFA with a long-term follow-up of 5-years. During follow-up, the overall incidence rate of local tumor progression was 4.8% (25/516), with no significant difference between the matched groups (7/106 [6.6%] vs. 5/53 [9.4%], p = 0.524). DFS did not differ between the two groups (p = 0.5). Moreover, TSH level was not regarded as a significant predictor of tumor progression after Cox analysis; primary tumor size was the only relevant risk factor. CONCLUSION: This large propensity-matched study revealed no association between TSH levels and tumor progression. Thus, for patients with low-risk PTC who underwent RFA, the optimalTSH level is recommended at the euthyroid range.

Long-term results of radiofrequency ablation for locally recurrent papillary thyroid carcinoma.

OBJECTIVE: To evaluate the long-term efficacy and safety of ultrasound-guided radiofrequency ablation (RFA) for treating locally recurrent papillary thyroid cancer (PTC). METHODS: This retrospective study involved 32 patients with pathologically confirmed locally recurrent PTC. The ablation zone was assessed by contrast-enhanced ultrasound (CEUS) after RFA. At baseline, 6 and 12 months and every 6 months or 12 months thereafter, the following results were recorded: recurrence rate, largest diameter, volume, volume reduction rate (VRR) of recurrent lesions, serum thyroglobulin (Tg) level and complications. RESULTS: 58 recurrent lesions in 32 patients were successfully ablated with RFA. The mean follow-up time was 73.19 ± 12.68 months (range, 60 to 98 months). At the last follow-up, almost all ablated lesions disappeared completely, and only one lesion showed scar-like changes. Nine (28.13%) patients developed new locally recurrent tumors; they were successfully treated with repeat RFA sessions. No new recurrent lesions were found during the follow-up. The largest diameter and volume of recurrent lesions decreased from 13.71 ± 6.48 mm and 520.43 ± 627.85 mm3 to 0 each at the end of observation period (p < .001). The average VRRs at 6, 12, 24, 36, 48, 60 months and last follow-up after RFA were 54.17%, 72.90%, 82.28%, 89.30%, 92.57%, 96.60%, 96.88%, 98.14% and 100% respectively. The median of serum Tg level was decreased from 1.48 ng/mL to 0.00 ng/mL (p < .05). No complications were reported during the follow-up. CONCLUSIONS: US-guided RFA is an effective and safe option for treating locally recurrent PTC in selected patients, with favorable long-term outcomes.

Radiofrequency ablation for papillary thyroid cancer located in isthmus: comparison with that originated in thyroid lobe.

PURPOSE: To analyze the outcomes of radiofrequency ablation (RFA) for isthmus papillary thyroid cancer (PTC) versus PTC originating from the lobes. METHODS: Patients with solitary low-risk PTC treated with RFA between July 2014 and December 2019 were retrospectively reviewed. This study was approved by our institutional review board. Of the 562 patients, 104 and 458 had PTCs located in the thyroid isthmus and thyroid lobes, respectively. Local tumor progression (LTP), LTP-free survival (LTPFS), changes in tumor volume, and complications were compared between the two groups using propensity-score matching (PSM). RESULTS: The isthmic and lobar groups showed no significant differences in LTP (2.9% vs. 3.8%), new PTC (2.9% vs. 2.9%), persistent lesions (0.0% vs. 0.2%), or LTPFS after PSM. Before PSM, the two groups showed significant differences in the volume reduction ratio (VRR) of the ablated tumors at 1, 3, 24, 30, and 48 months after RFA, but no differences between the two groups were observed in tumor volume, VRR, or disappearance rate after PSM (p > .05). One patient in the isthmic group presented with coughing, while another complained of hoarseness. Complications did not differ significantly between the two groups (p > .05). CONCLUSIONS: The outcomes of RFA for patients with low-risk PTC in the thyroid isthmus and thyroid lobes were similar. Therefore, RFA may serve as an alternative treatment option for patients with low-risk isthmic PTC.