Comparison of the effect of ethanol infusion into the vein of Marshall between with and without collateral veins.

BACKGROUND: Despite the potential benefits of ethanol infusion into the vein of Marshall (EIVOM) for atrial fibrillation (AF) ablation, concerns about its reversible and unpredictable effects persist. OBJECTIVE: To assess the effectiveness of EIVOM in the vein of Marshall (VOM) with collateral veins (CVs) during mitral isthmus and AF ablation. METHODS: We included 142 AF patients. EIVOM was performed before radiofrequency ablation, and low-voltage areas (<0.5 mV) were measured before, immediately after, and 1 h after EIVOM. RESULTS: Among the 142 patients, 93 (65%) underwent EIVOM, and among these, 35 (37%) were found to have CVs. In the VOM with CVs group, areas with low voltage measured 0 (0-1.85) cm2 before EIVOM, 6.9 (4.1-11.2) cm2 immediately after EIVOM, and 5.7 (3.5-10.6) cm2 1 h after EIVOM. Conversely, in the group designated as VOM without CVs-from which the nine leakage cases were excluded-the areas measured 0 (0-1.35) cm2 , 5.5 (2.6-11.8) cm2 , and 4.7 (1.8-13.5) cm2 at the respective time points. MI line block was fully achieved in 89% (31/35) of cases in the VOM with CVs group and 88% (44/49) in the VOM without CVs groups (p = .94). There was no significant difference in the outcome of AF ablation between these groups (log-rank p = .73). Additionally, no significant difference was observed between EIVOM (+) and EIVOM (-) groups (log-rank p = .59). CONCLUSION: EIVOM effectively creates MI line block, and its beneficial effects are sustained for at least 1 h after the procedure despite the low-voltage areas showing a slight reduction in size.

Slow conduction velocity predicts atrial fibrillation recurrence after radiofrequency ablation.

OBJECTIVE: To evaluate the progression of electrophysiological phenomena in atrial fibrillation (AF) and elucidate the association between the left atrial conduction velocity (LACV) and AF recurrence after pulmonary vein isolation. METHODS: A total of 188 AF patients (121 paroxysmal AF and 67 persistent AF) who underwent PVI for the first time were enrolled in this prospective study. The left atrium was mapped using a 20-pole electrode catheter combined with the CARTO3 system. The conduction distances and conduction times of the left atrium from the Bachmann bundle area to the mitral isthmus were calculated. Anterior, posterior, and septal LACV were calculated as conduction distance divided by conduction time. RESULTS: The anterior, posterior, and septal LACVs in the AF recurrence group were slower than those in the nonrecurrence group (anterior: 0.807 [0.766, 0.848] and 1.048 [1.000, 1.093] m/s, p < .05; posterior: 1.037 [0.991, 1.084] vs. 1.315 [1.249, 1.380] m/s, p < .05; septal: 0.904 [0.862, 0.946] vs. 1.163 [1.107, 1.219] m/s, p < .05). The best cut-off value of anterior LACV for predicting AF recurrence was 0.887 m/s (sensitivity 73.9% and specificity 76.5%). Multivariate analysis showed slow anterior LACV <0.887 m/s was an independent predictor of AF recurrence with an adjusted odds ratio of 1.42 (1.04, 1.94). CONCLUSIONS: Slowing conduction velocity is a predictor of AF recurrence after pulmonary vein isolation.

Laparoscopic liver resection versus radiofrequency ablation for small hepatocellular carcinoma: randomized clinical trial.

BACKGROUND: The aim of this study was to compare the efficacy of laparoscopic liver resection versus radiofrequency ablation for treatment of small hepatocellular carcinoma. METHODS: This single-centre RCT was conducted at a tertiary referral centre in China. Patients with small hepatocellular carcinoma who had a single nodule no larger than 5 cm, or up to three nodules of 3 cm or smaller, were eligible. Patients were assigned randomly in a 1 : 1 ratio to either laparoscopic liver resection or radiofrequency ablation. Blinding was not attempted. Sample size calculations led to 75 patients per group. The primary outcome was overall survival, and the secondary outcome was recurrence-free survival. RESULTS: Seventy-five patients were included in each group. Overall survival (HR 1.26, 95% c.i. 0.69 to 2.30; P = 0.451) and recurrence-free survival (HR 1.34, 0.86 to 2.08; P = 0.189) did not differ between the resection and ablation groups. The 1-, 3- and 5-year overall survival rates were 94.7, 80.0, and 74.7% respectively after laparoscopic liver resection versus 93.3, 78.7, and 67.9% after radiofrequency ablation. Corresponding recurrence-free survival rates were 78.7, 61.3, and 51.6%, and 69.3, 53.3, and 41.0%, respectively. CONCLUSION: For small hepatocellular carcinoma, percutaneous radiofrequency ablation provides therapeutic effects similar to those of laparoscopic liver resection. REGISTRATION NUMBER: NCT02243384 (http://www.clinicaltrials.gov).

Percutaneous radiofrequency ablation may provide similar therapeutic effects to laparoscopic liver resection for patients with small hepatocellular carcinoma. This study compared the two treatments. Survival was similar after the two treatments. The choice of treatment may depend on the patient's preference and local availability.

Radioiodine versus radiofrequency ablation to treat autonomously functioning thyroid nodules: a systematic review and comparative meta-analysis.

PURPOSE: Radioiodine (RAI) is a well-established first-line therapy for autonomously functioning thyroid nodules (AFTN). Radiofrequency ablation (RFA) is a minimally invasive procedure that has been proposed as an alternative treatment option for hyperthyroidism caused by AFTN. Although RFA has been shown to be useful for reducing nodule volume and improving TSH levels in AFTN, no comprehensive comparative clinical studies have been proposed to evaluate the overall response to RFA treatment. The aim of this comparative systematic review and meta-analysis was to evaluate the response of RAI and RFA treatments in AFTN. METHODS: A systematic search strategy was applied in PubMed, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov until July 2023 without time or language restrictions. Studies investigating the response to RAI and/or RFA treatment in AFTN patients 6 and/or 12 months after treatment were included. The risk of bias was assessed based on the study design. Random-effect models were used for the meta-analysis. RESULTS: Twenty-three articles (28 reports) met the inclusion criteria and were included in the study. Overall, RAI therapy was found to have a significantly higher treatment response (94%) than RFA (59%), although the volume of AFTNs was reduced to a similar extent. In the direct comparison (n = 3 studies), RFA showed a higher risk of non-response than RAI (RR, 1.24; 95% CI, 0.94-1.63; z = 1.55; p = 0.12). CONCLUSIONS: Our results demonstrate the superiority of RAI over RFA in terms of success rates and safety profile and confirm RAI as the first choice for the treatment of AFTNs.

Adjuvant holmium-166 radioembolization after radiofrequency ablation in early-stage hepatocellular carcinoma patients: a dose-finding study (HORA EST HCC trial).

PURPOSE: The aim of this study was to investigate the biodistribution of (super-)selective trans-arterial radioembolization (TARE) with holmium-166 microspheres (166Ho-MS), when administered as adjuvant therapy after RFA of HCC 2-5 cm. The objective was to establish a treatment volume absorbed dose that results in an absorbed dose of ≥ 120 Gy on the hyperemic zone around the ablation necrosis (i.e., target volume). METHODS: In this multicenter, prospective dose-escalation study in BCLC early stage HCC patients with lesions 2-5 cm, RFA was followed by (super-)selective infusion of 166Ho-MS on day 5-10 after RFA. Dose distribution within the treatment volume was based on SPECT-CT. Cohorts of up to 10 patients were treated with an incremental dose (60 Gy, 90 Gy, 120 Gy) of 166Ho-MS to the treatment volume. The primary endpoint was to obtain a target volume dose of ≥ 120 Gy in 9/10 patients within a cohort. RESULTS: Twelve patients were treated (male 10; median age, 66.5 years (IQR, [64.3-71.7])) with a median tumor diameter of 2.7 cm (IQR, [2.1-4.0]). At a treatment volume absorbed dose of 90 Gy, the primary endpoint was met with a median absorbed target volume dose of 138 Gy (IQR, [127-145]). No local recurrences were found within 1-year follow-up. CONCLUSION: Adjuvant (super-)selective infusion of 166Ho-MS after RFA for the treatment of HCC can be administered safely at a dose of 90 Gy to the treatment volume while reaching a dose of ≥ 120 Gy to the target volume and may be a favorable adjuvant therapy for HCC lesions 2-5 cm. TRIAL REGISTRATION: Clinicaltrials.gov NCT03437382 . (registered: 19-02-2018).

Combined image-guided radiofrequency and iodine-125 seeds implantation in the treatment of recurrent hepatocellular carcinoma after hepatectomy.

BACKGROUND: Currently, there is no consensus on the treatment of recurrent hepatocellular carcinoma (HCC) after hepatectomy. It is necessary to assess the efficacy and safety of radiofrequency ablation (RFA) combined with iodine-125 seeds implantation (RFA-125I) in the treatment of recurrent HCC. METHODS: This study retrospectively analyzed the clinical data of patients with postoperative recurrence of HCC receiving RFA-125I or RFA treatment from January 2013 to January 2023. Both RFA and 125I seeds implantation were performed under dual guidance of ultrasound and CT. Overall survival (OS), progression-free survival (PFS), recurrence, and complications were compared between the two groups. RESULTS: A total of 210 patients with recurrent HCC were enrolled in this study, including 125 patients in the RFA-125I group and 85 patients in the RFA group. The RFA-125I group showed a significantly better survival benefit than RFA group (median OS: 37 months vs. 16 months, P < 0.001; median PFS: 15 months vs. 10 months, P = 0.001). The uni- and multivariate analysis showed that RFA-125I was a protective factor for OS and PFS. There were no procedure-related deaths and no grade 3 or higher adverse events in both groups. CONCLUSIONS: RFA combined with 125I seeds implantation under dual guidance of ultrasound and CT is effective and safe for the treatment of HCC patients with recurrence after hepatectomy.

Protect the recurrent laryngeal nerves in US-guided microwave ablation of thyroid nodules at Zuckerkandl tubercle: a pilot study.

BACKGROUND: To evaluate the safety and efficacy of US-guided microwave ablation in patients with thyroid nodules at Zuckerkandl tubercle. METHODS: 103 consecutive patients with thyroid nodules at Zuckerkandl tubercle (ZTTN) were enrolled in this study from November 2017 to August 2021. Prior to the surgery or US-guided microwave ablation (MWA), preoperative ultrasound visualization of the recurrent laryngeal nerve (RLN) and ZTTN was performed, the size and the position relationship between them were observed. Patients were followed up at 1, 3, 6, and 12 months after MWA and the volume reduction rates (VRR) of the thyroid nodules were analyzed. RESULTS: All patients successfully had the RLN and ZTTN detected using ultrasound before surgery or ablation with a detection rate of 100%. For the 103 patients, the majority of ZTTN grades were categorized as grade 2, with the distance from the farthest outside of ZTTN to the outer edge of thyroid ranging between 6.0 and 10.0 mm. The position relationship between ZTTN and RLN was predominantly type A in 98 cases, with type D observed in 5 cases. After MWA, the median nodule volume had significantly decreased from 4.61 (2.34, 8.70) ml to 0.42 (0.15, 1.41) ml and the VRR achieved 84.36 ± 13.87% at 12 months. No nodules regrew throughout the 12-month follow-up period. Of the 11 patients experienced hoarseness due to RLN entrapment before ablation, 7 recovered immediately after separation of the RLN and ZTTN during MWA, 2 recovered after one week, and the other 2 recovered after two months. CONCLUSIONS: The RLN is closely related to ZTTN and mainly located at the back of ZTTN. The RLN can be separated from ZTTN by hydrodissection during MWA. US-guided MWA is a safe and effective treatment for ZTTN.

The role of adjuvant transcatheter arterial chemoembolization following repeated curative resection/ablation for hepatocellular carcinoma with early recurrence: a propensity score matching analysis.

BACKGROUND: The role of adjuvant transcatheter arterial chemoembolization (TACE) following repeated resection/ablation for recurrent hepatocellular carcinoma (HCC) remains uncertain. The aim of this study was to assess the effectiveness of adjuvant TACE following repeated resection or ablation in patients with early recurrent HCC. METHODS: Information for patients who underwent repeated surgery or radiofrequency ablation (RFA) for early recurrent HCCs (< 2 years) at our institution from January 2017 to December 2020 were collected. Patients were divided into adjuvant TACE and observation groups according to whether they received adjuvant TACE or not. The recurrence-free survival (RFS) and overall survival (OS) were compared between the two groups before and after propensity score matching (PSM). RESULTS: Of the 225 patients enrolled, the median time of HCC recurrence was 11 months (IQR, 6-16 months). After repeated surgery or radiofrequency ablation (RFA) for recurrent tumors, 45 patients (20%) received adjuvant TACE while the remaining 180 (80%) didn't. There were no significant differences in RFS (P = 0.325) and OS (P = 0.072) between adjuvant TACE and observation groups before PSM. There were also no significant differences in RFS (P = 0.897) and OS (P = 0.090) between the two groups after PSM. Multivariable analysis suggested that multiple tumors, liver cirrhosis, and RFA were independent risk factors for the re-recurrence of HCC. CONCLUSION: Adjuvant TACE after repeated resection or ablation for early recurrent HCCs was not associated with a long-term survival benefit in this single-center cohort.

Feasibility of esophageal endoscopic submucosal dissection after radiofrequency ablation treatment in patients with Barrett's esophagus.

BACKGROUND AND AIMS: Radiofrequency ablation (RFA) is a well-established treatment for Barrett's esophagus (BE) in the United States. Similarly, endoscopic submucosal dissection (ESD) has been widely performed for early esophageal carcinoma. However, conducting ESD after RFA can be technically challenging. The aim of this study was to assess the feasibility and safety of ESD in patients with prior RFA. METHODS: This study was a single-center retrospective analysis of patients who underwent esophageal ESD after undergoing prior RFA treatment for BE. RESULTS: Of 44 esophageal ESD cases, 7 underwent prior RFA. In those 7 cases, the en bloc resection rate was 100%, and the R0 resection rate was 86%. No acute or delayed adverse events or rehospitalizations occurred in any patient. CONCLUSIONS: ESD may be a feasible and safe option for patients with a history of RFA. It could be considered for esophageal neoplasms in patients previously treated with RFA for BE.

A Transformer-Based microvascular invasion classifier enhances prognostic stratification in HCC following radiofrequency ablation.

BACKGROUND & AIMS: We aimed to develop a Transformer-based deep learning (DL) network for prognostic stratification in hepatocellular carcinoma (HCC) patients undergoing RFA. METHODS: A Swin Transformer DL network was trained to establish associations between magnetic resonance imaging (MRI) datasets and the ground truth of microvascular invasion (MVI) based on 696 surgical resection (SR) patients with solitary HCC ≤3 cm, and was validated in an external cohort (n = 180). The multiphase MRI-based DL risk outputs using an optimal threshold of .5 was employed as a MVI classifier for prognosis stratification in the RFA cohort (n = 180). RESULTS: Over 90% of all enrolled patients exhibited hepatitis B virus infection. Liver cirrhosis was significantly more prevalent in the RFA cohort compared to the SR cohort (72.2% vs. 44.1%, p < .001). The MVI risk outputs exhibited good performance (area under the curve values = .938 and .883) for predicting MVI in the training and validation cohort, respectively. The RFA patients at high risk of MVI classified by the MVI classifier demonstrated significantly lower recurrence-free survival (RFS) and overall survival rates at 1, 3 and 5 years compared to those classified as low risk (p < .001). Multivariate cox regression modelling of a-fetoprotein > 20 ng/mL [hazard ratio (HR) = 1.53; 95% confidence interval (95% CI): 1.02-2.33, p = .047], high risk of MVI (HR = 3.76; 95% CI: 2.40-5.88, p < .001) and unfavourable tumour location (HR = 2.15; 95% CI: 1.40-3.29, p = .001) yielded a c-index of .731 (bootstrapped 95% CI: .667-.778) for evaluating RFS after RFA. Among the three risk factors, MVI was the most powerful predictor for intrahepatic distance recurrence. CONCLUSIONS: The proposed MVI classifier can serve as a valuable imaging biomarker for prognostic stratification in early-stage HCC patients undergoing RFA.

Upfront multi-bipolar radiofrequency ablation for HCC in transplant-eligible cirrhotic patients with salvage transplantation in case of recurrence.

INTRODUCTION: We aim to assess the long-term outcomes of percutaneous multi-bipolar radiofrequency (mbpRFA) as the first treatment for hepatocellular carcinoma (HCC) in transplant-eligible cirrhotic patients, followed by salvage transplantation for intrahepatic distant tumour recurrence or liver failure. MATERIALS AND METHODS: We included transplant-eligible patients with cirrhosis and a first diagnosis of HCC within Milan criteria treated by upfront mbp RFA. Transplantability was defined by age <70 years, social support, absence of significant comorbidities, no active alcohol use and no recent extrahepatic cancer. Baseline variables were correlated with outcomes using the Kaplan-Meier and Cox models. RESULTS: Among 435 patients with HCC, 172 were considered as transplantable with HCCs >2 cm (53%), uninodular (87%) and AFP >100 ng/mL (13%). Median overall survival was 87 months, with 75% of patients alive at 3 years, 61% at 5 years and 43% at 10 years. Age (p = .003) and MELD>10 (p = .01) were associated with the risk of death. Recurrence occurred in 118 patients within Milan criteria in 81% of cases. Local recurrence was observed in 24.5% of cases at 10 years and distant recurrence rates were observed in 69% at 10 years. After local recurrence, 69% of patients were still alive at 10 years. At the first tumour recurrence, 75 patients (65%) were considered transplantable. Forty-one patients underwent transplantation, mainly for distant intrahepatic tumour recurrence. The overall 5-year survival post-transplantation was 72%, with a tumour recurrence of 2.4%. CONCLUSION: Upfront multi-bipolar RFA for a first diagnosis of early HCC on cirrhosis coupled with salvage liver transplantation had a favourable intention-to-treat long-term prognosis, allowing for spare grafts.

Long-term oncological results of percutaneous radiofrequency ablation for intrahepatic cholangiocarcinoma.

INTRODUCTION: The effectiveness of percutaneous radiofrequency ablation (RFA) in intrahepatic cholangiocarcinomas (iCCA) remains insufficiently studied. METHODS: We conducted a retrospective study including patients with histologically proven iCCA within Milan criteria treated by percutaneous RFA from 2000 to 2022. The primary outcome was overall survival in treatment-naive patients and secondary outcomes included ablation completeness, adverse events, local and distant recurrence. A total of 494 patients with hepatocellular carcinoma (HCC) on cirrhosis treated by RFA were included as a comparison group. Oncological events were analysed using Kaplan-Meier, log-rank and univariate/multivariate Cox models. RESULTS: The main population included 71 patients, mostly cirrhotic (80%) with solitary tumours (66%) of a median size of 24 mm. Local recurrence was 45% at 5 years, lower in multibipolar versus monopolar RFA (22% vs. 55%, p = .007). In treatment-naive patients (n = 45), median overall and recurrence-free survivals were 26 and 11 months, respectively. Tumour size (p = .01) and Child-Pugh B (p = .001) were associated with death. The rate of distant recurrence was 59% at 5 years significantly lower for single tumours of less than 2 (p = .002) or 3 cm (p = .02). In cirrhotic patients naïve of previous treatment (n = 40), overall survival was shorter than in HCC (26 vs 68 months, p < .0001), with more local recurrences (p < .0001). Among distant recurrences, 50% were extrahepatic metastases compared to 12% in HCC (p < .001). CONCLUSION: Multibipolar RFA provides better results in terms of tumour recurrence than monopolar RFA and could be used to treat small iCCA (<3 cm). Adjuvant chemotherapy should be discussed due to the frequent extra-hepatic metastasis at recurrence.

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.

Volume reduction rate of radiofrequency ablation in ≤ 2 cm Bethesda IV thyroid nodules.

OBJECTIVE: This prospective observational study aimed to evaluate the efficacy of radiofrequency ablation (RFA) in treating ≤ 2 cm thyroid nodules with Bethesda IV cytology and C-TIRADS 4A categorization. Additionally, the factors influencing the completed absorption of ablation (CAA) were examined. METHODS: A total of 62 cases with 62 nodules underwent ultrasound-guided RFA and were included in the study. The volume reduction rate (VRR), CAA, and incomplete absorption of ablation (IAA) were assessed at the 1st, 3rd, 6th, and subsequent 6-month follow-ups. Clinical and ultrasound features were compared between the CAA and IAA groups at the 12th month follow-up. RESULTS: The average VRR at the 1st, 3rd, 6th, 12th month, and last follow-up were -88.6%, 16.0%, 59.7%, 82.0%, and 98.2%, respectively. More than half of the nodules achieved a 90% VRR after 1 year of RFA, with 88.7% demonstrating CAA at the end of the study (follow-up duration of 14 to 63 months). Nodules with grade 3 vascularity and those associated with chronic thyroiditis showed delayed CAA at the 12th month follow-up (p = 0.036 and 0.003, respectively). CONCLUSION: RFA is an effective technique for treating ≤ 2 cm thyroid nodules with Bethesda IV cytology and C-TIRADS 4A categorization. Nodules with grade 3 blood supply and patients with chronic thyroiditis exhibited an impact on the completed absorption following RFA. CLINICAL RELEVANCE STATEMENT: Our study has shown that radiofrequency ablation is an effective treatment for ≤ 2 cm thyroid nodules classified as Bethesda IV cytology. However, we identified that high vascularity of the nodule and chronic thyroiditis are adverse factors affecting the completed absorption of the ablation. KEY POINTS: •Radiofrequency ablation (RFA) is an effective technique for treatment of ≤ 2 cm Bethesda IV category thyroid nodules. •Higher blood supply and chronic thyroiditis influence the completed absorption after RFA.

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.

LI-RADS category is associated with treatment outcomes of small single HCC: surgical resection vs. radiofrequency ablation.

OBJECTIVES: To assess whether the Liver Imaging Reporting and Data System (LI-RADS) category is associated with the treatment outcomes of small single hepatocellular carcinoma (HCC) after surgical resection (SR) and radiofrequency ablation (RFA). METHODS: This retrospective study included 357 patients who underwent SR (n = 209) or RFA (n = 148) for a single HCC of ≤ 3 cm between 2014 and 2016. LI-RADS categories were assigned. Overall survival (OS), recurrence-free survival (RFS), and local tumor progression (LTP) rates after treatment were compared according to the LI-RADS category (LR-4/5 vs. LR-M) before and after propensity score matching (PSM). Prognostic factors for treatment outcomes were assessed. RESULTS: In total, 357 patients (mean age, 59 years; men, 272) with 357 HCCs (294 LR-4/5 and 63 LR-M) were included. After PSM (n = 78 in each treatment group), there were 10 and 11 LR-M HCCs in the SR and RFA group, respectively. There were no significant differences in OS or RFS. However, SR provided a lower 5-year LTP rate than RFA (1.4% vs. 14.9%, p = 0.001). SR provided a lower 5-year LTP rate than RFA for LR-M HCCs (0% vs. 34.4%, p = 0.062) and LR-4/5 HCCs (1.5% vs. 12.0%, p = 0.008). The LI-RADS category was the sole risk factor associated with poor OS (hazard ratio [HR] 3.79, p = 0.004), RFS (HR 2.12; p = 0.001), and LTP (HR 2.89; p = 0.032). CONCLUSION: LI-RADS classification is associated with the treatment outcome of HCC, supporting favorable outcomes of SR over RFA for LTP, especially for HCCs categorized as LR-M. CLINICAL RELEVANCE STATEMENT: Liver Imaging Reporting and Data System category has a potential prognostic role, supporting favorable outcomes of surgical resection over radiofrequency ablation for local tumor progression, especially for hepatocellular carcinoma categorized as LR-M. KEY POINTS: • SR provided a lower 5-year LTP rate than RFA for HCCs categorized as LR-M (0% vs. 34.4%, p = 0.062) and HCCs categorized as LR-4/5 (1.5% vs. 12.0%, p = 0.008). • There is a steeply increased risk of LTP within 1 year after RFA for LR-M HCCs, compared to SR. • The LI-RADS category was the sole risk factor associated with poor OS (HR 3.79, p = 0.004), RFS (HR 2.12; p = 0.001), and LTP (HR 2.89; p = 0.032) in patients with HCC of ≤ 3 cm treated with SR or RFA.

3D fusion is superior to 2D point-to-point contrast-enhanced US to evaluate the ablative margin after RFA for hepatocellular carcinoma.

PURPOSE: To compare the efficiency of three-dimensional (3D) and two-dimensional (2D) contrast-enhanced ultrasound (CEUS)-derived techniques in evaluating the ablative margin (AM) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: In total, 98 patients with 98 HCCs were enrolled. The 2D CEUS point-to-point imaging (2D CEUS-PI) was conducted by comparing the pre- and post-RFA 2D CEUS images manually, and the 3D CEUS fusion imaging (3D CEUS-FI) was conducted by fusing the pre- and post-RFA 3D CEUS images automatically. These two techniques were compared in distinguishing an adequate AM ≥ 5 mm. Risk factors for local tumor progression (LTP) after RFA were analyzed by the Kaplan-Meier method with log-rank test. RESULTS: The mean registration time of 3D CEUS-FI and 2D CEUS-PI was 5.0 and 9.3 min, respectively (p < 0.0001). The kappa coefficient was 0.680 for agreement between 2D CEUS-PI and 3D CEUS-FI in the evaluation of AM (p < 0.0001). Tumors with AM < 5 mm by 2D CEUS-PI were all identified as AM < 5 mm by 3D CEUS-FI. Nonetheless, 16 (26%) tumors identified as AM ≥ 5 mm by 2D CEUS-PI were re-classified as AM < 5 mm by 3D CEUS-FI. During a median follow-up time of 31.2 months (range, 3.2-66.0 months), LTP was identified in 8 tumors. The estimated 1-/2-/3-year cumulative incidence of LTP was 4.4%, 8.1%, and 10.3%, respectively. Higher estimated cumulative incidence of LTP was identified in tumors with AM < 5 mm by 2D CEUS-PI (at 3-year, 27.2% vs 0%; p < 0.001), and by 3D CEUS-FI (at 3-year, 20.7% vs 0%; p = 0.004). CONCLUSION: 3D CEUS-FI excelled in the evaluation of AM when compared with 2D CEUS-PI. With equivalent efficacy in the prediction of LTP, 3D CEUS-FI was superior to 2D CEUS-PI for its automatic and time-saving procedure. CLINICAL RELEVANCE STATEMENT: 3D CEUS fusion imaging may serve as an effective tool in evaluating ablative margin and predicting local tumor progression after RFA in HCC. KEY POINTS: • Both 2D and 3D CEUS-derived techniques could evaluate ablative margin (AM) after RFA for hepatocellular carcinoma. • 3D CEUS fusion imaging was more precise in the evaluation of AM compared to 2D CEUS point-to-point imaging, with advantages of its automatic and time-saving procedure. • An inadequate AM < 5 mm evaluated by CEUS-derived techniques was the only risk factor of LTP after RFA for hepatocellular carcinoma (p < 0.001 for 2D CEUS point-to-point imaging, and p = 0.004 for 3D CEUS fusion imaging).

Radiofrequency ablation of subcapsular versus nonsubcapsular hepatocellular carcinomas ≤ 3 cm: analysis of long-term outcomes from two large-volume liver centers.

OBJECTIVES: To compare the safety and efficacy of RFA for single HCCs ≤ 3 cm in subcapsular versus nonsubcapsular locations using a propensity score matched analysis. MATERIALS AND METHODS: This retrospective study included patients with solitary HCCs ≤ 3 cm in size who underwent percutaneous RFA from 2005 to 2015 as initial treatment at two large-volume liver centers. Patients were divided into two groups, consisting of those with subcapsular and nonsubcapsular tumor locations. Complications, local tumor progression (LTP), and overall survival (OS) were compared in these two groups before and after propensity score matching (PSM). RESULTS: The study population consisted of 964 patients (712 men [74%]) of mean age 58.3 years. Of these 964 patients, 561 (58%) had nonsubcapsular and 403 (42%) had subcapsular HCCs. PSM generated 402 pairs of patients. Major complication rate was low, but significantly higher in the subcapscular group (p = 0.047). Rates of technical effectiveness in these two groups were 99% and 98%, respectively (p = 0.315). However, during follow-up, cumulative 1-, 3-, 5-, and 10-year LTP and OS rates did significantly differ in both entire and PSM cohorts, resulting in the latter 8%, 15%, 20%, and 26% in the nonsubcapsular group vs. 13%, 24%, 30%, and 31% in the subcapsular group (p = 0.015), and 99%, 91%, 80%, and 59% vs. 98%, 85%, 73%, and 50% in the two groups (p = 0.004), respectively. CONCLUSION: Rates of major complications, LTP, and OS differed significantly following first-line RFA treatment of single HCCs ≤ 3 cm in favor of the nonsubcapsular locations. CLINICAL RELEVANCE STATEMENT: This large-scale study provides evidence that radiofrequency ablation for small (≤ 3 cm) hepatocellular carcinomas is safer and more effective in nonsubcapsular location than in subcapsular location. KEY POINTS: • There exist conflicting outcomes on the effectiveness of RFA for early HCC depending on tumor location. • Rate of local tumor progression was significantly higher in the subcapsular hepatocellular carcinomas. • Overall survival rate was significantly poorer in the subcapsular hepatocellular carcinomas.

Synergizing Thermal Ablation Modalities with Immunotherapy: Enough to Induce Systemic Antitumoral Immunity?

Thermal ablation modalities (cryoablation, radiofrequency ablation, and microwave ablation) have long been noted to occasionally induce a systemic antitumoral response. With the widespread use of checkpoint inhibitors, there is a significant interest in whether thermal ablation can promote immune system tumor recognition and increase checkpoint inhibitor response rates. In this review, we examine the current state of preclinical and clinical evidence examining the combination of checkpoint inhibitor therapies and thermal ablation modalities as well as discuss remaining the unanswered questions and directions for future research.

Pulsed Electric Field Ablation versus Radiofrequency Thermal Ablation in Murine Breast Cancer Models: Anticancer Immune Stimulation, Tumor Response, and Abscopal Effects.

PURPOSE: To compare the immune response and survival after size-matched radiofrequency (RF) ablation and a proprietary form of pulsed electric field (PEF) ablation in murine tumors. MATERIAL AND METHODS: Orthotopically inoculated EMT6 or 4T1 murine tumors received sham, RF ablation, or PEF ablation. 4T1 tumor ablations included subgroups with intraperitoneal checkpoint inhibition immunotherapy (αPD-1). Blood was collected for cytokine profiling and flow cytometry. Tumor size was measured and survival was monitored. Tumor samples were processed for histology, immunohistochemistry, flow cytometry, and cytokine profiling. Lungs were collected from 4T1-bearing mice for hematoxylin and eosin histology to assess metastatic spread and abscopal effect induced by ablation. RESULTS: PEF elicited distinct immunomodulatory effects, with clear differences in serum and tumor cytokine profiles compared with RF ablation, including intratumoral downregulation of vascular endothelial growth factor, hypoxia-inducible factor 1α, c-MET, interleukin-10, Ki67, and tumor necrosis factor-α (all P < .05). PEF increased innate immune activation, with enhanced recruitment of dendritic cells, M1 macrophages, and natural killer cells coupled with a reduction in M2 macrophages and myeloid-derived suppressor cells (all P < .05). Concurrently, PEF strengthened adaptive immunity compared with RF ablation, characterized by increased antigen-specific T cells and decreased regulatory T cells (all P < .05). PEF stalled tumor growth and increased survival at the end of the study (≥4× versus RFA). Finally, PEF promoted an abscopal effect of clearing metastases in the lungs, which was stronger in combination with αPD-1 than with PEF alone. CONCLUSIONS: The proprietary form of PEF used in this study evoked a preferential immunostimulatory profile versus RF ablation thermal ablation in mice, with implications for enhancing the therapeutic effectiveness of checkpoint inhibition immunotherapy for immunotherapy-unresponsive tumors.