Efficacy of microwave ablation in the treatment of large benign thyroid nodules: a multi-center study.

OBJECTIVE: To evaluate the efficacy, safety, and improvement of symptoms by ultrasound-guided microwave ablation (MWA) for patients with large benign thyroid nodules (BTNs). METHODS: Eighty-seven patients with 87 BTNs (≥ 4 cm) treated with MWA between April 2015 and March 2021 were enrolled in this retrospective multicenter study, with clinical and ultrasound examinations performed at the 1st, 3rd, 6th, and 12th months. A multivariable linear mixed effects model was employed to explore the alterations in volume and volume reduction ratio (VRR), as well as the potential factors associated with VRR. RESULTS: The mean age of the 87 patients was 45.69 ± 14.21 years (range 18-76 years), and the ratio of men to women was 1:4.8. The mean volumes were much decreased at the 12th month after ablation compared to the initial volumes (p < .001). The mean VRR was 76.09% at the 12th month. The technique efficacy (VRR > 50%) was 90.80% at the 12th month. A multivariate analysis revealed that VRR was related to the initial volume (p = .015), annular flow (p = .010), and nodule composition (p = .024). The mean symptomatic score decreased from 4.40 ± 0.28 to 0.26 ± 0.06 at the 12th month (p < .001). At the same time, the mean cosmetic score decreased from 3.22 ± 0.10 to 1.31 ± 0.08 (p < .001). CONCLUSION: MWA could serve as a safe and effective therapy for large BTNs, significantly reducing the volume of BTNs and significantly improving compressive symptoms and appearance problems. CLINICAL RELEVANCE STATEMENT: Microwave ablation could serve as a safe and effective therapy for large benign thyroid nodules, leading to significant volume reduction and satisfied symptom and cosmetic alleviation period. KEY POINTS: • This multicenter study investigated the feasibility and safety of microwave ablation for large benign thyroid nodules. • After ablation, the nodule volume was significantly reduced, and patients' symptoms and appearance problems were significantly improved. • Microwave ablation is feasible for large benign thyroid nodules and has been a supplement treatment.

Relationship between post-ablation fever and prognosis in initial hepatocellular carcinoma: A 15-year multicenter, retrospective cohort study.

BACKGROUND: Fever is a common side effect following thermal ablation in patients with hepatocellular carcinoma (HCC), yet its impact on prognosis remains unclear. MATERIALS AND METHODS: This retrospective study included initial HCC patients who underwent US-guided percutaneous microwave ablation at 13 hospitals between January 2006 and February 2021. All patients were categorized into afebrile, transient low-grade fever (TLF), and prolonged or high-grade fever (PHF) groups. Primary outcomes included very early recurrence (VER) and early recurrence (ER), secondary outcomes were disease-free survival (DFS) and overall survival (OS). Fever cut-offs for VER/ER were established using restrictive cubic splines and adjusted Cox model. Survival analyses used the Kaplan-Meier method. RESULTS: A total of 1458 initial HCC patients (mean age, 59±11[SD]; 1146 men). Compared to afebrile individuals, patients with TLF (temperatures ranging 37.0-38.8°C for 1-2 d), showed independent protective effects against VER (HR, 0.73; 95% CI: 0.57,0.95; P=0.02) and ER (HR, 0.66; 95% CI: 0.54,0.81; P<0.001), however, PHF showed no differences in VER (HR, 0.99; 95% CI: 0.76,1.30; P=0.96) and ER (HR, 0.86; 95% CI: 0.69,1.07; P=0.17). With a median follow-up of 47 months (IQR:26-79), the median DFS for TLF patients was 40 months, superior to afebrile (30 mo, P=0.019) and PHF patients (33 mo, P=0.049). The 5-year OS rate for TLF patients was 73.2%, higher than afebrile (69.3%, P=0.02) and PHF patients (66.7%, P=0.03). No significant difference was found in DFS and OS between afebrile and PHF patients (P=0.90 and 0.71). Notably, TLF patients exhibited the highest lymphocyte counts increasing median 7 days after ablation (P<0.001 vs. afebrile and P=0.01 vs. PHF). CONCLUSION: Transient low-grade fever following percutaneous microwave ablation in hepatocellular carcinoma patients demonstrated protection against early recurrence, possibly attributed to the short-term activation of lymphocytes.

Contrast-enhanced ultrasound features predict the prognosis of percutaneous microwave ablation of intrahepatic cholangiocarcinoma.

OBJECTIVE: To evaluate the prognostic effect of pre-operative contrast-enhanced ultrasound (CEUS) features on intrahepatic cholangiocarcinoma (ICC) after percutaneous microwave ablation (MWA). METHODS: A total of ICC 29 patients (average age 56.34 ± 9.78 years old, 33~75 years old) underwent MWA from March 2012 to December 2020, with a total of 58 lesions (0.5-8.1 cm, mean diameter, 2.68 ± 1.59 cm), and their pre-operative CEUS images and clinical data were collected and reviewed. Survival rate, local progression rate, intra- and extrahepatic metastasis rate were evaluated. Uni- and multivariate analysis were used to analyze the prognostic factors affecting the survival of ICC patients with pre-operative CEUS features. RESULTS: The median follow-up time after MWA was 18.43 months (4.17-93.13 months). 1-, 2-, and 3-year OS rates were 64.4%, 48.1% and 48.1%; 6-, 12-, 18-, 24-, 36-, 48-, and 60-month local progress and extrahepatic metastasis rates were 0.0%, 4.0%, 17.7%, 17.7%, 17.7%, 17.7%, 17.7% and 3.4%, 21.5%, 32.7%, 45.6%, 55.2%, 55.2% and 77.6%, respectively. Uni- and multivariate analysis showed that post-operative extrahepatic metastasis was an important factor for long-term survival of ICC patients after MWA (p = 0.006, 0.01), and Rim-enhancement feature of pre-operative CEUS was identified as an independent predictor of post-operative extrahepatic metastasis and long-term survival (p = 0.02, 0.02). CONCLUSION: Rim-enhancement feature of pre-operative CEUS is a predictor high post-operative extrahepatic metastasis and poor prognosis through distant microvascular metastasis after MWA of ICC patients. ADVANCES IN KNOWLEDGE: This study determined the important CEUS features of ICC and analyzed their impact on the prognosis of ICC patients after MWA, providing scientific guidance for better clinical treatment in the future.