Small single perivascular hepatocellular carcinoma: comparisons of radiofrequency ablation and microwave ablation by using propensity score analysis

Complication Rates and Risk of Recurrence After Percutaneous Radiofrequency Ablation and Microwave Ablation for the Treatment of Liver Tumors: a Meta-analysis

RATIONALE AND OBJECTIVES

The rate of complications and risk of local recurrence following percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for liver tumors varies significantly between investigations. This meta-analysis aimed to assess complication rates and risk of local recurrence after percutaneous RFA and MWA.

MATERIALS AND METHODS

PubMed, Medline, Web of Science, the Cochrane Library, Embase, Google Scholar, and CINAHL were systematically searched from database inception until August 2022 to retrieve articles reporting the complication rates and risk of recurrence after percutaneous RFA and MWA for the treatment of liver tumors. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated and displayed by forest plots. To measure heterogeneity, Cochran Q and I2 statistics were also applied. Egger's test and funnel plots were also performed to assess any potential publication bias. Additionally, subgroup analysis was done to investigate the source of heterogeneity.

RESULTS

26 studies including 2026 and 1974 patients for RFA and MWA, respectively, were included. The rate of minor complications was significantly higher after MWA compared to RFA, yielding an overall OR of 0.688 (95% CI: 0.549-0.862, P = 0.001). Similarly, the rate of major complications was significantly higher after MWA than RFA (P = 0.012), yielding an overall OR of 0.639 (95% CI: 0.450-0.907). No significant difference was found between RFA and MWA in terms of local recurrence after ablation (P > 0.05). In addition, there was no statistical evidence of publication bias.

CONCLUSION

When most factors are considered equally, percutaneous RFA and MWA can be considered safe modalities for the treatment of liver tumors, with RFA superior in terms of the incidence of minor and major complications.

Computed tomography-guided percutaneous cryoablation and microwave ablation in the treatment of perivascular hepatocellular carcinoma: A comparative study with propensity score matching

OBJECTIVE

To evaluate the safety and efficacy of cryoablation (CYA) and microwave ablation (MWA) in the treatment of patients with perivascular hepatocellular carcinoma (HCC).

METHODS

Patients with perivascular HCC who underwent computed tomography (CT)-guided percutaneous CYA or MVA treatment in our hospital from August 2009 to March 2019 were included. Propensity score matching (PSM) was performed to adjust for potential baseline differences in the two groups. The technical success rate (TS), complications, and visual analog scale (VAS) were analyzed. The overall survival (OS) was evaluated using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

After PSM, 32 patients from each group were selected. The technical success rate was 94 % for CYA and 91 % for MWA, and 13 patients developed recurrence (CYA, n = 5, 2 local, 3 distant; MWA, n = 8, 6 local, 2 distant). There were no significant differences in OS (36-months OS: CYA 53.1 % vs, MWA 40.6 %; P = 0.191). No intraoperative deaths or complication-related deaths were observed, and 19 patients (CYA, n = 8; MWA, n = 11) experienced complications (P = 0.435). The VAS in the MWA group (5.38 ± 1.21) was significantly higher than that in the CYA group (2.22 ± 0.87; P < 0.001).

CONCLUSIONS

While CYA has equal safety and high primary efficacy as MWA in the treatment of perivascular HCC, it is associated with less periprocedural pain.

Microwave Hyperpolarization Effect─An Orthogonal Incoherent Microwave Field Heating Study

In our previous study, the incoherent combined microwave sources possess a higher water heating rate than a single microwave source. This novel discovery may blaze a new trail in the pursuit of energy conservation. In this paper, a particular orthogonal microwave field device was designed to quantitatively study the effect of incoherent combined microwave heating on 17 solvents. Experimental results indicate that the solvents irradiated with incoherent combined microwaves absorb more microwave energy and experience a faster temperature rise. The multiphysics simulations of water with different microwaves show that the higher heating rate is not caused by the improvement of heating uniformity. In this regard, molecular dynamics simulations of ethanol under the irradiation of incoherent microwave electric fields with perpendicular polarization directions were carried out. The molecular dynamics simulations demonstrate that the main reason for this effect is the higher collision frequency of molecules with incoherent microwave electric fields. This study demonstrates a novel effect of incoherent combined microwave heating and contributes to the development of efficient microwave heating for industrial applications.

Perfluorobutane application value in microwave ablation of Small Hepatocellular Carcinoma (<3 cm)

BACKGROUND

No studies have been retrieved comparing perfluorobutane with sulfur hexafluoride for microwave ablation (MWA) in small hepatocellular carcinoma(sHCC).

OBJECTIVE

To retrospective investigate the value of perfluorobutane ultrasonography contrast agent in ultrasonography (US)-guided MWA of sHCC.

METHODS

We conducted a retrospective clinical controlled study about US-guided percutaneous MWA in patients with sHCC, and in patients undergoing intra-operative treatment with perfluorobutane or sulfur hexafluoride. In both groups, a contrast agent was injected to clear the tumor and then a needle was inserted. A 5-point needle prick difficulty score was developed to compare needle prick difficulty in the two groups of cases.

RESULTS

A total of 67 patients were included: 25 patients in group perfluorobutane, aged 41-82 (60.64±9.46), tumor size 1.1-2.8 (1.78±0.45) cm. 42 patients in group sulfur hexafluoride, aged 38-78 (62.26±9.27), with tumor size of 1.1-3.0 (1.89±0.49) cm. There was no significant difference in age or tumor size in both groups (P >  0.05). Puncture difficulty score (5-point): 2.0-2.7 (2.28±0.29) in group perfluorobutane, and 2.0-4.7 (2.95±0.85) in group sulfur hexafluoride, and the difference between the two groups was statistically significant (P <  0.05). Enhanced imaging results within 3 months after surgery: complete ablation rate was 100% (25/25) in the group perfluorobutane, 95.2% (40/42 in the group sulfur hexafluoride), with no significant difference between the two groups (P >  0.05).

CONCLUSION

Perfluorobutane kupffer phase can make the operator accurately deploy the ablation needle and reduce the difficulty of operation.

SAGES/AHPBA guidelines for the use of microwave and radiofrequency liver ablation for the surgical treatment of hepatocellular carcinoma or colorectal liver metastases less than 5 cm

BACKGROUND

Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the liver's two most common malignant neoplasms. Liver-directed therapies such as ablation have become part of multidisciplinary therapies despite a paucity of data. Therefore, an expert panel was convened to develop evidence-based recommendations regarding the use of microwave ablation (MWA) and radiofrequency ablation (RFA) for HCC or CRLM less than 5 cm in diameter in patients ineligible for other therapies.

METHODS

A systematic review was conducted for six key questions (KQ) regarding MWA or RFA for solitary liver tumors in patients deemed poor candidates for first-line therapy. Subject experts used the GRADE methodology to formulate evidence-based recommendations and future research recommendations.

RESULTS

The panel addressed six KQs pertaining to MWA vs. RFA outcomes and laparoscopic vs. percutaneous MWA. The available evidence was poor quality and individual studies included both HCC and CRLM. Therefore, the six KQs were condensed into two, recognizing that these were two disparate tumor groups and this grouping was somewhat arbitrary. With this significant limitation, the panel suggested that in appropriately selected patients, either MWA or RFA can be safe and feasible. However, this recommendation must be implemented cautiously when simultaneously considering patients with two disparate tumor biologies. The limited data suggested that laparoscopic MWA of anatomically more difficult tumors has a compensatory higher morbidity profile compared to percutaneous MWA, while achieving similar overall 1-year survival. Thus, either approach can be appropriate depending on patient-specific factors (very low certainty of evidence).

CONCLUSION

Given the weak evidence, these guidelines provide modest guidance regarding liver ablative therapies for HCC and CRLM. Liver ablation is just one component of a multimodal approach and its use is currently limited to a highly selected population. The quality of the existing data is very low and therefore limits the strength of the guidelines.

Ablative and non-surgical therapies for early and very early hepatocellular carcinoma: a systematic review and network meta-analysis

Background

A wide range of ablative and non-surgical therapies are available for treating small hepatocellular carcinoma in patients with very early or early-stage disease and preserved liver function.

Objective

To review and compare the effectiveness of all current ablative and non-surgical therapies for patients with small hepatocellular carcinoma (≤ 3 cm).

Design

Systematic review and network meta-analysis.

Data sources

Nine databases (March 2021), two trial registries (April 2021) and reference lists of relevant systematic reviews.

Review methods

Eligible studies were randomised controlled trials of ablative and non-surgical therapies, versus any comparator, for small hepatocellular carcinoma. Randomised controlled trials were quality assessed using the Cochrane Risk of Bias 2 tool and mapped. The comparative effectiveness of therapies was assessed using network meta-analysis. A threshold analysis was used to identify which comparisons were sensitive to potential changes in the evidence. Where comparisons based on randomised controlled trial evidence were not robust or no randomised controlled trials were identified, a targeted systematic review of non-randomised, prospective comparative studies provided additional data for repeat network meta-analysis and threshold analysis. The feasibility of undertaking economic modelling was explored. A workshop with patients and clinicians was held to discuss the findings and identify key priorities for future research.

Results

Thirty-seven randomised controlled trials (with over 3700 relevant patients) were included in the review. The majority were conducted in China or Japan and most had a high risk of bias or some risk of bias concerns. The results of the network meta-analysis were uncertain for most comparisons. There was evidence that percutaneous ethanol injection is inferior to radiofrequency ablation for overall survival (hazard ratio 1.45, 95% credible interval 1.16 to 1.82), progression-free survival (hazard ratio 1.36, 95% credible interval 1.11 to 1.67), overall recurrence (relative risk 1.19, 95% credible interval 1.02 to 1.39) and local recurrence (relative risk 1.80, 95% credible interval 1.19 to 2.71). Percutaneous acid injection was also inferior to radiofrequency ablation for progression-free survival (hazard ratio 1.63, 95% credible interval 1.05 to 2.51). Threshold analysis showed that further evidence could plausibly change the result for some comparisons. Fourteen eligible non-randomised studies were identified (n ≥ 2316); twelve had a high risk of bias so were not included in updated network meta-analyses. Additional non-randomised data, made available by a clinical advisor, were also included (n = 303). There remained a high level of uncertainty in treatment rankings after the network meta-analyses were updated. However, the updated analyses suggested that microwave ablation and resection are superior to percutaneous ethanol injection and percutaneous acid injection for some outcomes. Further research on stereotactic ablative radiotherapy was recommended at the workshop, although it is only appropriate for certain patient subgroups, limiting opportunities for adequately powered trials.

Limitations

Many studies were small and of poor quality. No comparative studies were found for some therapies.

Conclusions

The existing evidence base has limitations; the uptake of specific ablative therapies in the United Kingdom appears to be based more on technological advancements and ease of use than strong evidence of clinical effectiveness. However, there is evidence that percutaneous ethanol injection and percutaneous acid injection are inferior to radiofrequency ablation, microwave ablation and resection.

Study registration

PROSPERO CRD42020221357.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) programme (NIHR award ref: NIHR131224) and is published in full in Health Technology Assessment; Vol. 27, No. 29. See the NIHR Funding and Awards website for further award information.

Comparing Long-Term survival benefits of hepatocellular carcinoma between thermal ablation monotherapy and combined therapy with transarterial Chemoembolization: A propensity score matched study

PURPOSE

To compare the long-term survival benefits of hepatocellular carcinoma (HCC) in thermal ablation (TA) monotherapy and TA combined with transarterial chemoembolization (TACE) using propensity score matching (PSM).

MATERIALS AND METHODS

Between 1 January 2015 and 28 February 2021, 432 consecutive patients (357 men, 75 women; age range, 20-87 years) with HCC (Barcelona Clinic Liver Cancer stage 0-B) underwent ultrasonography-guided percutaneous TA, which included radiofrequency ablation (n = 340) and microwave ablation (n = 92). The association between combined treatment of TACE prior to TA versus TA monotherapy and survival prognosis was evaluated, including (a) local tumor progression (LTP) by using a logistic regression model, and (b) disease-free survival (DFS) and (c) overall survival (OS) by using a Cox proportional hazards model according to propensity score matched data.

RESULTS

After PSM, the final matched cohort consisted of 146 patients, with 73 receiving TA monotherapy and 73 receiving TA combined with TACE. The cumulative LTP rates did not show a significant difference between the two groups (P = 0.960). Neither the DFS nor OS rate was significantly different between the two groups (P = 0.070 and P = 0.680, respectively). The multivariate analysis identified two significant findings. Firstly, ultrasound echo, minimal ablative margin, and high risk of tumor burden score were found to be associated with LTP. Secondly, the type of TA, Child-Turcotte-Pugh grade, ablation time, and lymphocyte-monocyte ratio were identified as independent prognostic factors for OS.

CONCLUSION

The differences in LTP, DFS, and OS rates of HCC patients were found to be statistically non-significant between TA monotherapy and TACE + TA groups. For HCC patients with BCLC stage 0-B, the combination treatment of TACE prior to TA may be not associated with long-term survival benefits relative to TA monotherapy.

Microwave ablation is superior to radiofrequency ablation in the treatment of hepatocellular carcinoma below 5 cm - A systematic review and meta-analysis

The purpose of this study was to systematically evaluate the prognosis of patients with hepatocellular carcinoma (HCC) smaller than 5 cm using microwave ablation (MWA) versus radiofrequency ablation (RFA). PubMed, Cochrane Library and Embase databases were searched for studies reporting comparisons of two interventions (MWA versus RFA) for patients with early-stage HCC published up to 31 December, 2022. The analysis evaluated the recurrence-free survival (RFS), overall survival (OS) and complications. A total of 894 patients were enrolled in six studies (two randomised controlled trials and four propensity score cohort studies). There were 446 patients in the MWA group and 448 patients in the RFA group. Compared with RFA, MWA had a significant advantage in the post-operative 1-, 2-, 3- and 5-year RFS (odds ratios [OR] = 0.58, 95% confidence interval [CI]: 0.40, 0.84; OR = 0.60, 95% CI: 0.45, 0.80; OR = 0.56, 95% CI: 0.33, 0.93; and OR = 0.44, 95% CI: 0.30, 0.65). The OS of MWA was significantly higher than that of RFA in 5 years after ablation (OR = 0.48, 95% CI: 0.34, 0.68). Moreover, MWA had an advantage in the incidence of complications (OR = 2.23, 95% CI: 1.16, 4.29). In the comparison of percutaneous MWA and RFA in the treatment of HCC with a diameter smaller than 5 cm, MWA may have more advantages in improving the prognosis.

The Effect of Cooling Fluid Composition on Ablation Size in Hepatic Laser Ablation: A Comparative Study in an Ex Vivo Bovine Setting

PURPOSE

Hyperthermic ablation is a minimally invasive mode of tumour therapy which serves as a viable alternative to surgical intervention. However, one of the major drawbacks, besides the heat sink effect and the risk of damaging adjacent organs, is limited ablation size. The use of a cooling fluid during ablation has been shown to increase the ablation volume and decrease the carbonisation rate. The aim of this study was to investigate whether the composition of the cooling fluid has an effect on ablation size and carbonisation rate during hepatic laser ablation in an ex vivo bovine setting.

METHOD

In this study bovine hepatic tissue was ablated in an ex vivo setting using an internally cooled laser applicator. A total of 45 tissue samples were assigned to three groups: 0.9% saline infusion (n = 15), distilled water infusion (n = 15) and a 50%/50% mixture of 0.9% saline and distilled water (n = 15). Ablation was conducted using a 1064 nm Nd:YAG laser at a wattage of 25 W and time interval of 10 min. The ablation volume and carbonisation rate were then measured and recorded through postprocedural MRI. One-way ANOVA and post-hoc testing were performed to assess the effect of the cooling fluid composition on the ablation volumes.

RESULTS

We found that using a mixture of saline and distilled water as a cooling fluid during hyperthermic ablation resulted in a larger ablation volume (mean ± SD: 22.64 ± 0.99 cm3) when compared to saline infusion (21.08 ± 1.11 cm3) or distilled water infusion (20.92 ± 0.92 cm3). This difference was highly significant (p < 0.001). There was no significant difference in ablation size between the saline group and the distilled water group. The highest carbonisation rate occurred in the saline group (12/15), followed by the mixed infusion group (3/15) and the distilled water group (1/15).

CONCLUSIONS

The results of this study suggest that cooling fluid composition during hepatic laser ablation affects ablation volume in an ex vivo bovine setting. There was no statistically significant difference when comparing ablation volumes during saline infusion and distilled water infusion, but the carbonisation rate was significantly higher when using saline. The combination of saline and distilled water in a 50%/50% mixture as cooling fluid appears to be an auspicious alternative, as ablation volumes created with it are larger when compared to saline and distilled water alone, while carbonisation rate remains low. This might improve patient outcome as well as patient eligibility for hyperthermic ablation.

Locoregional Thermal and Chemical Tumor Ablation: Review of Clinical Applications and Potential Opportunities for Use in Low- and Middle-Income Countries

This review highlights opportunities to develop accessible ablative therapies to reduce the cancer burden in LMICs.

Microwave ablation as a primary versus secondary treatment for hepatocellular carcinoma

PURPOSE

The purpose of this study was to analyze and compare the outcomes of percutaneous microwave ablation (MWA) when used as a primary vs. secondary treatment for hepatocellular carcinoma (HCC).

METHODS

The clinical data of 192 patients with HCC treated with MWA between January 2012 and July 2021 were reviewed retrospectively, with 152 patients being treatment naïve (primary treatment) vs. 40 who had residual or recurrent disease following previous trans-arterial chemoembolization or trans-arterial radioembolization (secondary treatment). The primary outcomes were primary technical efficacy, 1- and 3-year local recurrence-free survival (RFS) and overall survival (OS), local recurrence rates, and adverse events. Pre- and post-intervention liver function tests were compared using a Wilcoxon signed rank test. Univariate and multivariate analyses were also performed, looking at prognostic factors associated with OS and local RFS.

RESULTS

There was no significant difference in 1-year local RFS (primary 93.6% vs. secondary 93.7; P = 0.97) and 3-year local RFS (primary 80.6% vs. secondary 86.5%; P = 0.37) rates. There was no significant difference in 1-year OS (primary 82.4% vs. secondary 86.6%; P = 0.51) and 3-year OS (primary 68.3% vs. secondary 77.4%; P = 0.25) between the two groups. The local recurrence rate (primary 9.8% vs. secondary 14.6%; P = 0.37), primary technical efficacy (primary 96.2% vs. secondary 95%; P = 0.73), and adverse events (primary 8.0% vs. secondary 11.6%; P = 0.45) were also similar between the two groups.

CONCLUSION

Microwave ablation is safe and effective as a secondary treatment for patients with HCC in a clinical salvage scenario and should be utilized more frequently.

CT-guided 125I brachytherapy for hepatocellular carcinoma in high-risk locations after transarterial chemoembolization combined with microwave ablation: a propensity score-matched study

BACKGROUND

This study aimed to evaluate the safety and efficacy of ¹²⁵I brachytherapy combined with transarterial chemoembolization (TACE) and microwave ablation (MWA) for unresectable hepatocellular carcinoma (HCC) in high-risk locations.

PATIENTS AND METHODS

After 1:2 propensity score matching (PSM), this retrospectively study analyzed 49 patients who underwent TACE +MWA+¹²⁵I brachytherapy (group A) and 98 patients who only received TACE +MWA (group B). The evaluated outcomes were progression-free survival (PFS), overall survival (OS), and treatment complications. Cox proportional hazards regression analysis survival was used to compare the two groups.

RESULTS

The patients in group A showed a longer PFS than group B (7.9 vs. 3.3 months, P = 0.007). No significant differences were observed in median OS between the two groups (P = 0.928). The objective response rate (ORR), disease control rate of tumors in high-risk locations, and the ORR of intrahepatic tumors were 67.3%, 93.9%, and 51.0%, respectively, in group A, and 38.8%, 79.6% and 29.6%, respectively, in group B (P < 0.001, P = 0.025 and P = 0.011, respectively). TACE-MWA-¹²⁵I (HR = 0.479, P < 0.001) was a significant favorable prognostic factor that affected PFS. The present of portal vein tumor thrombosis was an independent prognostic factor for PFS (HR = 1.625, P = 0.040). The Barcelona clinic liver cancer (BCLC) stage (BCLC C vs. B) was an independent factor affecting OS (HR = 1.941, P = 0.038). The incidence of complications was similar between the two groups, except that the incidence of abdominal pain was reduced in the group A (P = 0.007).

CONCLUSIONS

TACE-MWA-¹²⁵I resulted in longer PFS and better tumor control than did TACE-MWA in patients with unresectable hepatocellular carcinoma in high-risk locations.

Comparisons of Radiofrequency Ablation, Microwave Ablation, and Irreversible Electroporation by Using Propensity Score Analysis for Early Stage Hepatocellular Carcinoma

BACKGROUND

Despite the diversity of thermal ablations, such as radiofrequency ablation (RFA) and microwave ablation (MWA), and non-thermal ablation, such as irreversible electroporation (IRE) cross-comparisons of multiple ablative modalities for hepatocellular carcinoma (HCC) treatment remain scarce. Thus, we investigated the therapeutic outcomes of different three ablation modalities in the treatment of early stage HCC.

METHODS

A total of 322 consecutive patients with 366 HCCs (mean tumor size ± standard deviation: 1.7 ± 0.9 cm) who underwent RFA (n = 216, 59.0%), MWA (n = 91, 28.3%), or IRE (n = 15, 4.7%) were included. Local tumor progression (LTP) rates for LTP were compared among the three modalities. Propensity score-matched analysis was used to reduce selection bias.

RESULTS

A significant difference in 2-year LTP rates between the IRE and RFA groups (IRE, 0.0% vs. RFA, 45.0%; p = 0.005) was found. There was no significant difference in 2-year LTP rates between the IRE and MWA groups (IRE, 0.0% vs. MWA, 25.0%; p = 0.103) as well as between the RFA and MWA groups (RFA, 18.2% vs. MWA, 20.6%; p = 0.586).

CONCLUSION

IRE provides better local tumor control than RFA as a first-line therapeutic option for small perivascular HCC.

Retrospective Evaluation and Significance of Neutrophil-to-Lymphocyte Ratio Prior to and 1 month Following Microwave Ablation of Hepatocellular Carcinoma

PURPOSE

Neutrophil-to-lymphocyte ratio (NLR) recently demonstrated predictive value for hepatocellular carcinoma (HCC) recurrence after thermal ablation. Microwave ablation (MWA) has been shown to induce changes in the immune landscape after HCC treatment. This study aims at identifying predictors of local tumor progression (LTP) and post-treatment NLR kinetics after MWA.

MATERIALS AND METHODS

Data from 108 consecutive patients who underwent percutaneous MWA of 119 HCCs with a 2450 Hz/100 W generator in two institutions from October 2014 to September 2021 were retrospectively reviewed. Forty-five HCCs (42 patients) met inclusion criteria for analysis (technique efficacy, pre- and post-treatment NLR availability, follow-up > 6 months, absence of complications). NLR was analyzed prior to therapy and at 1-month follow-up; difference between the two time points was defined as ΔNLR_1stFU.

RESULTS

After a median follow-up of 25 months, LTP occurred in 18 HCCs (40%) and 18 patients (42.9%). Multivariate competing risk regression comprising ΔNLR_1stFU > 0, cirrhosis etiology and subcapsular location showed that the only independent predictor of LTP was ΔNLR_1stFU > 0, on both a per-patient (HR = 2.7, p = 0.049) and per-tumor (HR = 2.8, p = 0.047) analysis. ΔNLR_1stFU > 0 occurred in 24/42 patients (57.1%). In this subgroup, higher rates of female patients (p = 0.026), higher mean baseline NLR (p < 0.0001) and lower mean energy/size (p = 0.006) were observed. Upon ROC curve analysis, energy/size < 1414 J/mm predicted ΔNLR_1stFU > 0 with 76% sensitivity and 70% specificity (AUC = 0.74).

CONCLUSION

NLR increase after ablation was the only independent predictor of LTP, supporting the role of balance between systemic inflammation and immunity in recurrence after MWA. Ablation energy/tumor size predicted NLR increase, reinforcing the concept of immune ablation.

LEVEL OF EVIDENCE

III.

Long-term efficacy and safety of microwave ablation for hepatocellular carcinoma adjacent to the gallbladder with a diameter ≤ 5 cm: a multicenter, propensity score matching study

OBJECTIVE

To compare the long-term efficacy and safety of microwave ablation (MWA) as first-line therapy for hepatocellular carcinoma (HCC) adjacent versus nonadjacent to the gallbladder.

MATERIALS AND METHODS

From 2006 to 2018, 657 patients with ≤5 cm HCC who underwent percutaneous ultrasound-guided MWA as first-line therapy from 5 hospitals were enrolled in this retrospective study. Patients were grouped into the adjacent group (n = 49) and the nonadjacent group (n = 608) according to whether the tumor was adjacent to the gallbladder. Propensity score matching (PSM) was used to balance baseline variables between the two groups.

RESULTS

Forty-eight patient pairs were matched after PSM. For the PSM cohort, during a median follow-up time of 60 months, there were no differences in PFS (hazard ratio [HR], 1.011; 95% confidence interval [CI], 0.647-1.578; p = 0.963) or OS (HR 0.925; 95% CI 0.522-1.639; p = 0.789) between the adjacent and nonadjacent groups. Univariate and multivariate analyses revealed that the tumor adjacent to the gallbladder was not an independent risk factor for PFS or OS (all p > 0.05). Subgroup analysis showed comparable PFS and OS between the two groups in the <3 cm subgroup and the 3-5 cm subgroups (all p > 0.05). In addition to more use of assistive technology (p < 0.05), the adjacent group shared comparable local tumor progression, complications, technical success rate, and hospital stay (all p > 0.05) to the nonadjacent group.

CONCLUSION

There were comparable long-term efficacy and complications between patients with HCC adjacent and nonadjacent to the gallbladder treated with MWA.

Surgical approach to microwave and radiofrequency liver ablation for hepatocellular carcinoma and colorectal liver metastases less than 5 cm: a systematic review and meta-analysis

BACKGROUND

Primary hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) represent the two most common malignant neoplasms of the liver. The objective of this study was to assess outcomes of surgical approaches to liver ablation comparing laparoscopic versus percutaneous microwave ablation (MWA), and MWA versus radiofrequency ablation (RFA) in patients with HCC or CRLM lesions smaller than 5 cm.

METHODS

A systematic review was conducted across seven databases, including PubMed, Embase, and Cochrane, to identify all comparative studies between 1937 and 2021. Two independent reviewers screened for eligibility, extracted data for selected studies, and assessed study bias using the modified Newcastle Ottawa Scale. Random effects meta-analyses were subsequently performed on all available comparative data.

RESULTS

From 1066 records screened, 11 studies were deemed relevant to the study and warranted inclusion. Eight of the 11 studies were at high or uncertain risk for bias. Our meta-analyses of two studies revealed that laparoscopic MW ablation had significantly higher complication rates compared to a percutaneous approach (risk ratio = 4.66; 95% confidence interval = [1.23, 17.22]), but otherwise similar incomplete ablation rates, local recurrence, and oncologic outcomes. The remaining nine studies demonstrated similar efficacy of MWA and RFA, as measured by incomplete ablation, complication rates, local/regional recurrence, and oncologic outcomes, for both HCC and CRLM lesions less than 5 cm (p > 0.05 for all outcomes). There was no statistical subgroup interaction in the analysis of tumors < 3 cm.

CONCLUSION

The available comparative evidence regarding both laparoscopic versus percutaneous MWA and MWA versus RFA is limited, evident by the few studies that suffer from high/uncertain risk of bias. Additional high-quality randomized trials or statistically matched cohort studies with sufficient granularity of patient variables, institutional experience, and physician specialty/training will be useful in informing clinical decision making for the ablative treatment of HCC or CRLM.

Local-Regional Treatment of Hepatocellular Carcinoma: A Primer for Radiologists

The treatment planning for patients with hepatocellular carcinoma (HCC) relies predominantly on tumor burden, clinical performance, and liver function test results. Curative treatments such as resection, liver transplantation, and ablative therapies of small lesions should be considered for all patients with HCC. However, many patients are ineligible for these treatments owing to advanced disease stage and comorbidities. Despite efforts to increase screening, early-stage HCC remains difficult to diagnose, which decreases the possibility of curative therapies. In this context, local-regional treatment of HCC is accepted as a form of curative therapy in selected patients with early-stage disease, as a therapeutic option in patients who are not eligible to undergo curative therapies, as a downstaging approach to decrease tumor size toward meeting the criteria for liver transplantation, and as a bridging therapy to avoid tumor growth while the patient is on the waiting list for liver transplantation. The authors review the indications, types, mechanism of action, and possible complications of local-regional treatment, as well as the expected postprocedural imaging features of HCC. Furthermore, they discuss the role of imaging in pre- and postprocedural settings, provide guidance on how to assess treatment response, and review the current limitations of imaging assessment. Finally, the authors summarize the potential future directions with imaging tools that may add value to contemporary practice at response assessment and imaging biomarkers for patient selection, treatment response, and prognosis. ©RSNA, 2022.

Hepatic arterial infusion chemotherapy and sequential ablation treatment in large hepatocellular carcinoma

AIM

To investigate the individualized survival benefit of hepatic arterial infusion chemotherapy (HAIC) and sequential ablation treatment in large hepatocellular carcinoma (HCC) patients.

METHODS

Between February 2016 and December 2020, a total of 228 HCC patients (diameter > 5 cm) who underwent HAIC alone (HAIC group, n = 135) or HAIC and sequential ablation (HAIC-ablation group, n = 93) treatment were reviewed. We applied the inverse probability of treatment weighting (IPTW) to adjust for potential bias of two treatment groups. The overall survival (OS) and progression-free survival (PFS) were compared with Kaplan-Meier curves. The Cox regression model was used to identify independent prognostic factors. And a prediction nomogram based on these independent prognostic factors was built, aiming to make probabilistic survival predictions and estimate personalized ablation benefits.

RESULTS

After a median follow-up of 17.9 months, HCC patients in the HAIC-ablation group have longer significantly OS and PFS than those in the HAIC alone group (median OS: 22.2 months vs. 14.5 months; median PFS: 8.5 months vs. 4.6 months; both, p < 0.001). The IPTW-adjusted analysis revealed similar findings (both, p < 0.001). Tumor size, tumor number, and treatment modality were identified as independent prognostic factors for OS. The nomogram based on these factors showed favorable discrimination and well calibration.

CONCLUSIONS

HAIC and sequential ablation provided significant survival benefits in patients with large HCC. The nomogram could help predict individual survival probabilities and estimate personalized sequential ablation benefits.

Efficacy of percutaneous ethanol injection versus radiofrequency ablation for single hepatocellular carcinoma no larger than 5 cm

Objective

To compare the efficacy of percutaneous ethanol injection (PEI) and radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC) of no larger than 5 cm.

Methods

The data used in this study were retrieved from the SEER database. In total, 3510 patients diagnosed with HCC of no larger than 5 cm who received PEI or RFA were included.

Results

The median overall survival (mOS) and median cancer-specific survival (mCSS) of RFA-treated patients were not significantly longer than those of PEI-treated patients either before or after propensity score matching (PSM). The subgroup analysis showed that patients with HCC of no larger than 2 cm, HCC of larger than 2 cm, American Joint Committee on Cancer (AJCC) stage I and II, and AJCC stage III and IV who received RFA had mOS and mCSS similar to those of patients who received PEI after PSM. Multivariable regression analysis showed that PEI did not increase the all-cause mortality risk or cancer-specific mortality risk after PSM.

Conclusion

RFA is still the better choice for patients with a single HCC of no more than 5 cm. However, PEI might be a good choice for these patients who cannot be treated with RFA.

Comparison of Efficacy and Safety of TACE Combined with Microwave Ablation and TACE Combined with Cryoablation in the Treatment of Large Hepatocellular Carcinoma

Purpose

To retrospectively evaluate the efficacy and safety of TACE combined with microwave ablation (MWA) and TACE combined with cryoablation (CRA) in the treatment of large hepatocellular carcinoma.

Methods

A retrospective analysis was performed on 81 patients with large hepatocellular carcinoma (tumor diameter 5～8 cm cm) who received TACE combined with ablation in our hospital from February 2015 to February 2019. The study patients were divided into TACE combined with MWA group (T-MWA, n = 41) and TACE combined with CRA group (T-CRA, n = 40) according to the treatment plan. Overall survival (OS) and progress free survival (PFS) were compared between the two groups, and complications were observed. Survival curves for OS and PFS were constructed by the Kaplan-Meier method. Differences in overall survival were compared using the log-rank test.

Results

There was no statistical difference in general conditions between the two groups of patients. The results showed that 30 (73.2%) patients in T-MWA group achieved objective response (OR) and 39 (95.1%) patients achieved disease control (DC), compared with 24 (60.0%) patients in T-CRA group who achieved objective response (OR) and 37 (92.5%) patients who achieved disease control (DC). The median OS was 19.2 months in the T-MWA group and 18.6 months in the T-CRA group (P=0.64). The median PFS was 9.3 months in the T-MWA group and 12.3 months in the T-CRA group (P=0.6). Univariate and multivariate analysis showed that portal vein tumor thrombus (PVTT), intrahepatic tumor diameter, and the number of tumor lesions were common prognostic factors for OS and PFS. In terms of surgery-related complications and adverse reactions, abdominal pain and gastrointestinal reactions were observed in 13 (31.7%) and 11(26.8%) cases in the T-MWA group, while we observed 4 (10.0%) and 2 (5.0%) cases in the T-CRA group, respectively. The difference between the two was statistically significant (P < 0.05).

Conclusion

TACE combined with MWA and TACE combined with CRA were equally effective in the treatment of large hepatocellular carcinoma. TACE-CRA can effectively reduce the incidence of abdominal pain and gastrointestinal reactions in patients. However, compared with TACE-MWA, TACE-CRA is more likely to cause thrombocytopenia.

Loco-Regional Treatments for Hepatocellular Carcinoma in People Living with HIV

Hepatocellular carcinoma (HCC) accounts for approximately 75–90% of primary liver cancers and is the sixth most common cancer and the third leading cause of cancer-related deaths worldwide. In the HIV-positive population, the risk of HCC is approximately four times higher than in the general population, with higher cancer-specific mortality than in HIV-negative patients. In most cases, HCC diagnosis is made in patients younger than the HIV-negative population and in the intermediate-advanced stage, thus limiting the therapeutic possibilities. Treatment choice in HIV-positive patients with HCC is subject to cancer staging, liver function and health status, as for HIV-negative and non-HIV-negative HCC patients. There are relatively few studies on the efficacy and safety in HIV-positive patients to date in loco-regional treatments for HCC. So far, literature shows that curative treatments such as radiofrequency ablation (RFA) have no significant differences in overall survival between HIV-positive and HIV-negative patients, as opposed to palliative treatments such as TACE, where there is a significant difference in overall survival. Although it can be assumed that the most recently discovered loco-regional therapies are applicable to HIV-positive patients with HCC in the same way as HIV-negative patients, further studies are needed to confirm this hypothesis. The purpose of our review is to evaluate these treatments, their efficacy, effectiveness, safety and their applicability to HIV-positive patients.

Combination of Ablation and Immunotherapy for Hepatocellular Carcinoma: Where We Are and Where to Go

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and is increasing in incidence. Local ablative therapy plays a leading role in HCC treatment. Radiofrequency (RFA) is one of the first-line therapies for early local ablation. Other local ablation techniques (e.g., microwave ablation, cryoablation, irreversible electroporation, phototherapy.) have been extensively explored in clinical trials or cell/animal studies but have not yet been established as a standard treatment or applied clinically. On the one hand, single treatment may not meet the needs. On the other hand, ablative therapy can stimulate local and systemic immune effects. The combination strategy of immunotherapy and ablation is reasonable. In this review, we briefly summarized the current status and progress of ablation and immunotherapy for HCC. The immune effects of local ablation and the strategies of combination therapy, especially synergistic strategies based on biomedical materials, were discussed. This review is hoped to provide references for future researches on ablative immunotherapy to arrive to a promising new era of HCC treatment.

Long-term outcome of percutaneous radiofrequency ablation for periportal hepatocellular carcinoma: tumor recurrence or progression, survival and clinical significance

Background/aim

Recent studies have suggested that periportal location of percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) is considered as one of the independent risk factors for local tumor progression (LTP). However, the long-term therapeutic outcomes of percutaneous RFA as the first-line therapy for single periportal HCCand corresponding impacts on tumor recurrence or progression are still unclear.

Materials and methods

From February 2011 to October 2020, a total of 233 patients with single nodular HCC ≤ 5 cm who underwent RFA ± transarterial chemoembolization (TACE) as first-line therapy was enrolled and analyzed, including 56 patients in the periportal group and 177 patients in the nonperiportal group. The long-term therapeutic outcomes between the two groups were compared, risk factors of tumor recurrence or progression were evaluated.

Results

The LTP rates at 1, 3, and 5 years were significantly higher in the periportal group than those in the nonperiportal group (15.7, 33.7, and 46.9% vs 6.0, 15.7, and 28.7%, respectively, P = 0.0067). The 1-, 3- and 5-year overall survival (OS) rates in the periportal group were significantly worse than those in the nonperiportal group (81.3, 65.1 and 42.9% vs 99.3, 90.4 and 78.1%, respectively, P<0.0001). In the subgroup of single HCC ≤ 3 cm, patients with periportal HCC showed significantly worse LTP P = 0.0006) and OS (P<0.0001) after RFA than patients with single nonperiportal HCC; The univariate and multivariate analyses revealed that tumor size, periportal HCC and AFP ≥ 400ug/ml were independent prognostic factors for tumor progression after RFA. Furthermore, patients with single periportal HCC had significantly higher risk for IDR(P = 0.0012), PVTT(P<0.0001) and extrahepatic recurrence(P = 0.0010) after RFA than those patients with single nonperiportal HCC. .

Conclusion

The long-term therapeutic outcomes of RFA as the first-line therapy for single periportal HCC were worse than those for single nonperiportal HCC, an increased higher risk of tumor recurrence or progression after RFA was significantly associated with periportal HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00442-2.

Ablation Difficulty Score: Proposal of a new tool to predict success rate of percutaneous ablation for hepatocarcinoma

PURPOSE

Identify the factors related to failure ablation after percutaneous ultrasound guided single electrode radiofrequency ablation (RFA) for hepatocarcinoma (HCC) and propose a score for improving patient selection and treatment allocation.

METHODS

From 2010 to 2020 585 HCC nodules treated with RFA were prospectively collected. Ablation Difficulty Score (ADS) was built-up according to clinical and radiological factors related to failure ablation identified by Cox-logistic regression analysis. The study population was stratified in low risk (ADS 0), intermediate risk (ADS 1), and high risk (ADS ≥ 2) of failure ablation.

RESULTS

Overall ablation success rate was 85.5%. Morbidity and mortality rates were 3.5% and 0.0%. According to per nodule analysis the following factors resulted related to failure ablation: size > 20 mm (p = 0.002), sub-capsular location (p = 0.008), perivascular location (p = 0.024), isoechoic appearance (p = 0.008), and non-cirrhotic liver (p = 0.009). The ablation success rate was 93.5% in ADS 0, 85.8% in ADS 1 and 71.3% in ADS ≥ 2 (p < 0.001). The 1-year local tumor progression (LTP) free survival was 90.2% in ADS 0, 80.6% in ADS 1, and 72.3% in ADS ≥ 2 (p = 0.009). Nodule's size > 20 mm (p = 0.014), isoechoic appearance (p = 0.012), perivascular location (p = 0.012) resulted related to lower LTP free survival.

CONCLUSION

Ablation Difficulty Score could be a simple and useful tool for guiding the treatment decision making of HCC. RFA in high risk nodules (ADS ≥ 2) should be carefully evaluated and reserved for patients not suitable for surgery or liver transplantation.

Effect of Severity of Liver Cirrhosis on Surgical Outcomes of Hepatocellular Carcinoma After Liver Resection and Microwave Coagulation

BACKGROUND

Liver resection (LR) and percutaneous microwave coagulation therapy (PMCT) are both considered as radical treatments for small hepatocellular carcinoma (HCC). However, it is still unclear whether to select LR or PMCT in HCC patients with different degrees of liver cirrhosis. The purpose of this study was to compare the efficacy of LR and PMCT in the treatment of solitary and small HCC accompanied with different degrees of liver cirrhosis.

METHODS

In this study, 230 patients with solitary HCC lesions ≤ 3 cm and Child-Pugh A liver function were retrospectively reviewed. Among these patients, 122 patients underwent LR, and 108 received PMCT. The short- and long-term outcomes were compared between these two procedures. Severity of liver cirrhosis was evaluated by using clinical scoring system (CSS) as previously published. Subgroup analysis based on CSS was performed to evaluate the effect of severity of liver cirrhosis on surgical outcomes after LR and PMCT.

RESULTS

There was no mortality within 90 days in both groups. Major complications were significantly more frequent in the LR group than in the PMCT group (18.8% vs. 4.6%, p<0.001). However, LR provided better surgical outcomes than PMCT. The 5-year overall survival (OS) rates for the LR and PMCT groups were 65.2% and 42%, respectively (p=0.006), and the corresponding disease-free survival (DFS) rates were 51.7% and 31.5%, respectively (p=0.004). Nevertheless, subgroup analysis showed that PMCT provided long-term outcomes that were similar to LR and lower surgical complications in HCC patients with CSS score≥4.

CONCLUSIONS

LR may provide better OS and DFS rates than PMCT for patients with solitary HCC lesions ≤ 3 cm and Child-Pugh A liver function irrespective of liver cirrhosis. PMCT should be viewed as the optimal treatment for solitary and small HCC with severe cirrhosis.

New next-generation microwave thermosphere ablation for small hepatocellular carcinoma

Background/Aims

In July 2017, the EmprintTM next-generation microwave ablation system using thermosphere technology (Covidien, Boulder, CO, USA) was approved for use in Japan. This system can produce a predictable spherical ablation zone at higher temperatures than radiofrequency ablation (RFA). The aim of the present study was to elucidate whether this new microwave thermosphere ablation (MTA) could safely improve outcome compared to RFA, which is the standard of care for small hepatocellular carcinoma (HCC).

Methods

This retrospective study analyzed 513 patients with 630 HCCs (≤3 cm) who were performed by percutaneous RFA (174 patients, 214 HCCs) or MTA (339 patients, 416 HCCs) between January 2016 and March 2020.

Results

Median ablation time was significantly shorter for MTA (240 s) than for RFA (721 s; p<0.001). A significant difference in 3-year local tumor progression rate was evident between the RFA group (22%) and MTA group (8%; p<0.001) Multivariate analysis revealed ablation procedure and tumor diameter as independent factors contributing to local tumor progression (MTA, p<0.001, hazard ratio 0.565, 95% confidence interval 0.437-0.731). In patients with primary HCC, a significant difference in overall survival was evident (RFA vs MTA, 3-year, 77% vs 95%, p=0.029). Ablation procedure and Child-Pugh score were independent factors contributing to survival. The total complication rate was significantly lower for MTA (8%) than for RFA (14%, p<0.05), particularly for bile duct injury (3% vs 9%, respectively; p<0.05).

Conclusions

Next-generation MTA for small HCC could provide safer, more curative treatment in a shorter ablation time than RFA.

Clinical efficacy of systemic chemotherapy combined with radiofrequency ablation and microwave ablation for lung cancer: a comparative study

OBJECTIVE

Local thermal ablation, a minimally invasive technique, has been widely used in clinical treatment of lung cancer. This study aimed to discuss the clinical efficacy of systemic chemotherapy combined with radiofrequency ablation (RFA) versus systemic chemotherapy combined with microwave ablation (MWA) in treating lung cancer.

METHODS

A retrospective analysis involving 124 lung cancer patients, who received RFA (n = 68) and MWA (n = 56) combined with systemic chemotherapy in Cangzhou People's Hospital from August 2017 to December 2019, was conducted. Before comparative analysis for therapeutic efficacy, the two groups of patients were matched with propensity score matching method at a ratio of 1:1. Indicators including progression-free survival (PFS), overall survival (OS), short-term efficacy, tumor marker level, local tumor control rate, and postoperative complications were comparatively analyzed.

RESULTS

There was no statistical difference in disease control rate and objective response rate (90.6% and 78.1% vs 93.8% and 84.4%) between RFA group and MWA group. The incidence of complications was 12.5% in RFA group and 18.8% in MWA group with no statistically significant difference. In addition, the local tumor control rate in MWA group (90.6%) was significantly higher than that in RFA group (78.1%). Regarding survival, a statistically significant difference was observed in median PFS of RFA and MWA groups (9.2 months vs 10.4 months, p < 0.05), while OS in two groups slightly varied.

CONCLUSION

MWA was superior to RFA over local tumor control rate and PFS and showed great potential in lung cancer ablation treatment.