Efficacy and survival analysis of percutaneous radiofrequency versus microwave ablation for hepatocellular carcinoma: an Egyptian multidisciplinary clinic experience

Comparative Efficacy of Microwave versus Radiofrequency Ablation in Hepatocellular Carcinoma: Systematic Review and Meta-Analysis of Randomized-Controlled Trials

Introduction: Hepatocellular carcinoma (HCC) is a leading global cause of cancer-related deaths. Thermal ablation techniques, especially radiofrequency ablation (RFA) and microwave ablation (MWA), have become pivotal treatments for HCC. This systematic review and meta-analysis aim to compare these modalities, highlighting their efficacy, strengths, and limitations in treating HCC. Methods: A comprehensive literature search was conducted across major databases (PubMed, MEDLINE, Springer, ProQuest, EBSCOhost, Cochrane, and EMBASE) targeting studies on hepatocellular carcinoma with RFA and MWA. Heterogeneity analyses and pooled outcomes using random-effect models with were evaluated to compare both thermal ablation methods. Results: Nine studies, which consists of 368 patients underwent RFA and 387 patients underwent MWA, were included in review. The findings showed no significant differences in pooled analysis of volume of ablation, complete ablation rate, local tumor progression, survival rates, major complications, and adverse events. Subgroup analysis showed significantly higher risk of local tumor progression in RFA in African populations. Conclusion: No statistically significant difference was seen between outcomes across studies. MWA may offer a potential for longer therapeutic response with comparable risk of complications and adverse outcomes.

Comparison of Microwave and Radiofrequency Ablation for the Treatment of Small- and Medium-Sized Hepatocellular Carcinomas in a Prospective Randomized Trial

PURPOSE

 To compare the therapeutic response and clinical outcome of CT-guided percutaneous microwave (MWA) and radiofrequency ablation (RFA) for the treatment of small- and medium-sized HCC.

MATERIALS AND METHODS

 In this prospective trial, 50 patients with HCC were randomly assigned to MWA or RFA treatment. MRI was performed 24 h before and after ablation and subsequently in 3-month intervals. Ablation volumes, ablation durations, adverse events (AE), technique efficacy, technical success, local tumor progression (LTP), disease-free survival (DFS), intrahepatic distant recurrence (IDR), and overall survival (OS) rates were evaluated.

RESULTS

 The mean ablation volume was 66.5 cm³ for MWA and 29.2  cm³ for RFA (p < 0.01). The mean ablation durations for MWA and RFA were 11.2 ± 4.0 min and 16.3 ± 4.7 min, respectively (p < 0.01). Six mild AEs were documented (p > 0.05). All treatments had a technical success rate and a technique efficacy rate of 100 % (50/50, p = 1.00). LTP within 2 years occurred in 1/25 (4 %) in the MWA group and in 4/25 (16 %) in the RFA group (p = 0.06). IDR within 2 years was 8/25 (32 %) for MWA and 14/25 (56 %) for RFA (p < 0.05). The median DFS was 24.5 months and 13.4 months for MWA and RFA, respectively (p = 0.02). The 1-, 2-, 3-year OS rates were 100 %, 80 %, 72 % in the MWA group and 72 %, 64 %, 60 % in the RFA group, respectively (p ≥ 0.14).

CONCLUSION

 The clinical outcome after MWA or RFA for HCC treatment was very similar with no significant differences in LTP or OS. However, MWA shows a trend toward better DFS with fewer IDRs than RFA.

KEY POINTS

  · MWA allows for larger ablation volumes and a shorter treatment duration compared to RFA in patients with HCC.. · MWA shows a trend toward better disease-free survival and fewer intrahepatic distant recurrences compared to RFA.. · The three-year survival rates show no significant difference between the two methods..

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.

Reproducible spectral CT thermometry with liver-mimicking phantoms for image-guided thermal ablation

Objectives. Evaluate the reproducibility, temperature tolerance, and radiation dose requirements of spectral CT thermometry in tissue-mimicking phantoms to establish its utility for non-invasive temperature monitoring of thermal ablations.Methods. Three liver mimicking phantoms embedded with temperature sensors were individually scanned with a dual-layer spectral CT at different radiation dose levels during heating (35 °C-80 °C). Physical density maps were reconstructed from spectral results using varying reconstruction parameters. Thermal volumetric expansion was then measured at each temperature sensor every 5 °C in order to establish a correlation between physical density and temperature. Linear regressions were applied based on thermal volumetric expansion for each phantom, and coefficient of variation for fit parameters was calculated to characterize reproducibility of spectral CT thermometry. Additionally, temperature tolerance was determined to evaluate effects of acquisition and reconstruction parameters. The resulting minimum radiation dose to meet the clinical temperature accuracy requirement was determined for each slice thickness with and without additional denoising.Results. Thermal volumetric expansion was robustly replicated in all three phantoms, with a correlation coefficient variation of only 0.43%. Similarly, the coefficient of variation for the slope and intercept were 9.6% and 0.08%, respectively, indicating reproducibility of the spectral CT thermometry. Temperature tolerance ranged from 2 °C to 23 °C, decreasing with increased radiation dose, slice thickness, and iterative reconstruction level. To meet the clinical requirement for temperature tolerance, the minimum required radiation dose ranged from 20, 30, and 57 mGy for slice thickness of 2, 3, and 5 mm, respectively, but was reduced to 2 mGy with additional denoising.Conclusions. Spectral CT thermometry demonstrated reproducibility across three liver-mimicking phantoms and illustrated the clinical requirement for temperature tolerance can be met for different slice thicknesses. The reproducibility and temperature accuracy of spectral CT thermometry enable its clinical application for non-invasive temperature monitoring of thermal ablation.

Thermal ablation of hepatocellular carcinoma

Percutaneous treatment of hepatocellular carcinoma (HCC) by means of thermal ablation (TA) has been introduced in clinical guidelines as a potentially curative treatment for the early stages of the disease since the early 2000s. Due to its safety profile and cost-effectiveness, TA can be offered as a first-line treatment for patients with HCC smaller than 3 cm. Thermal ablative techniques are in fact widely available at many centres worldwide and include radiofrequency (RF) and microwave (MW) ablation, with the latter increasingly applied in clinical practice in the last decade. Pre-clinical studies highlighted, as potential advantages of MW-based ablation, the ability to achieve higher temperatures (>100°C) and larger ablation zones in shorter times, with less susceptibility to blood flow-induced heat sink effects. Despite these advantages, there is no evidence of superior overall survival in patients treated with MW as compared to those treated with RF ablation. Local control has been proven to be superior to MW ablation with a similar complication rate. It is expected that further improvement of TA results in the treatment of HCC will result from the refinement of guidance and monitoring tools and the careful assessment of ablation margins. Thermal ablative treatments may also be performed on nodules larger than 3 cm by applying multiple devices or combining percutaneous and intra-arterial approaches. The role of novel immunotherapy regimens in combination with ablation is also currently under evaluation in clinical trials, with several potential benefits. In this review, indications, technical principles, results, and future prospects of TA for the treatment of HCC will be examined.

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.

The effectiveness of ablative and non-surgical therapies for early hepatocellular carcinoma: Systematic review and network meta-analysis of randomised controlled trials

BACKGROUND & AIMS

Non-surgical therapies are frequently used for patients with early or very early hepatocellular carcinoma (HCC). The aim of this systematic review and network meta-analysis (NMA) was to evaluate and compare the effectiveness of ablative and non-surgical therapies for patients with small HCC.

METHODS

Nine databases were searched (March 2021) along with clinical trial registries. Randomised controlled trials (RCTs) of any ablative or non-surgical therapy versus any comparator in patients with HCC ≤3 cm were eligible. Risk of bias (RoB) was assessed using the Cochrane RoB 2 tool. The effectiveness of therapies was compared using NMA. Threshold analysis was undertaken to identify which NMA results had less robust evidence.

RESULTS

Thirty-seven eligible RCTs were included (including over 3700 patients). Most were from China (n = 17) or Japan (n = 7). Sample sizes ranged from 30 to 308 patients. The majority had a high RoB or some RoB concerns. No RCTs were identified for some therapies and no RCTs reported quality of life outcomes. The results of the NMA and treatment effectiveness rankings were very uncertain. However, the evidence demonstrated that percutaneous ethanol injection was worse than radiofrequency ablation for overall survival (hazard ratio [HR]: 1.45, 95% credible interval [CrI]: 1.16-1.82), progression-free survival (HR: 1.36, 95% CrI: 1.11-1.67), overall recurrence (relative risk [RR]: 1.19, 95% CrI: 1.02-1.39) and local recurrence (RR: 1.80, 95% CrI: 1.19-2.71). The threshold analysis suggested that robust evidence was lacking for some comparisons.

CONCLUSIONS

It is unclear which treatment is most effective for patients with small HCC because of limitations in the evidence base. It is also not known how these treatments would impact on quality of life. Further high quality RCTs are needed to provide robust evidence but may be difficult to undertake.

Reproducible spectral CT thermometry with liver-mimicking phantoms for image-guided thermal ablation

Objectives

Evaluate the reproducibility, temperature sensitivity, and radiation dose requirements of spectral CT thermometry in tissue-mimicking phantoms to establish its utility for non-invasive temperature monitoring of thermal ablations.

Materials and Methods

Three liver mimicking phantoms embedded with temperature sensors were individually scanned with a dual-layer spectral CT at different radiation dose levels during heating and cooling (35 to 80 °C). Physical density maps were reconstructed from spectral results using a range of reconstruction parameters. Thermal volumetric expansion was then measured at each temperature sensor every 5°C in order to establish a correlation between physical density and temperature. Linear regressions were applied based on thermal volumetric expansion for each phantom, and coefficient of variation for fit parameters was calculated to characterize reproducibility of spectral CT thermometry. Additionally, temperature sensitivity was determined to evaluate the effect of acquisition parameters, reconstruction parameters, and image denoising. The resulting minimum radiation dose to meet the clinical temperature sensitivity requirement was determined for each slice thickness, both with and without additional denoising.

Results

Thermal volumetric expansion was robustly replicated in all three phantoms, with a correlation coefficient variation of only 0.43%. Similarly, the coefficient of variation for the slope and intercept were 9.6% and 0.08%, respectively, indicating reproducibility of the spectral CT thermometry. Temperature sensitivity ranged from 2 to 23 °C, decreasing with increased radiation dose, slice thickness, and iterative reconstruction level. To meet the clinical requirement for temperature sensitivity, the minimum required radiation dose ranged from 20, 30, and 57 mGy for slice thickness of 2, 3, and 5 mm, respectively, but was reduced to 2 mGy with additional denoising.

Conclusions

Spectral CT thermometry demonstrated reproducibility across three liver-mimicking phantoms and illustrated the clinical requirement for temperature sensitivity can be met for different slice thicknesses. Moreover, additional denoising enables the use of more clinically relevant radiation doses, facilitating the clinical translation of spectral CT thermometry. The reproducibility and temperature accuracy of spectral CT thermometry enable its clinical application for non-invasive temperature monitoring of thermal ablation.

Loco-regional therapies competing with radiofrequency ablation in potential indications for hepatocellular carcinoma: a network meta-analysis

BACKGROUND/AIMS

There is no clear consensus on the relative ranking of interventional and radiation techniques with indications similar to those of radiofrequency ablation (RFA) for the treatment of early hepatocellular carcinoma (HCC). We used a network meta-analysis to compare the efficacy of non-surgical treatments for early HCC.

METHODS

We searched databases for randomized trials assessing the efficacy of loco-regional treatments for HCCs ≤5 cm with no extrahepatic spread or portal invasion. The primary outcome was the pooled hazard ratio (HR) for overall survival (OS), and secondary outcomes included overall and local progression-free survival (PFS). A frequentist network meta-analysis was performed, and the relative ranking of therapies was assessed with P-scores.

RESULTS

Nineteen studies comparing 11 different strategies in 2,793 patients were included. Chemoembolization plus RFA improved OS better than RFA alone (HR 0.52, 95% confidence interval [CI] 0.33-0.82; P-score=0.951). Cryoablation, microwave ablation, laser ablation, and proton beam therapy had similar effects on OS compared with RFA. For overall PFS, but not local PFS, only chemoembolization plus RFA performed significantly better than RFA (HR 0.61, 95% CI 0.42-0.88; P-score=0.964). Injection of percutaneous ethanol or acetic acid was significantly less effective than RFA for all measured outcomes, while no differences in progression outcomes were identified for other therapies included in the network.

CONCLUSION

Our results suggest that chemoembolization combined with RFA is the best option for local treatment of early HCC. Cases with potential contraindications for RFA may benefit from a tailored approach using thermal or radiation modalities.

European Society of Organ Transplantation (ESOT) Consensus Report on Downstaging, Bridging and Immunotherapy in Liver Transplantation for Hepatocellular Carcinoma

Liver transplantation offers the best chance of cure for most patients with non-metastatic hepatocellular carcinoma (HCC). Although not all patients with HCC are eligible for liver transplantation at diagnosis, some can be downstaged using locoregional treatments such as ablation and transarterial chemoembolization. These aforementioned treatments are being applied as bridging therapies to keep patients within transplant criteria and to avoid them from dropping out of the waiting list while awaiting a liver transplant. Moreover, immunotherapy might have great potential to support downstaging and bridging therapies. To address the contemporary status of downstaging, bridging, and immunotherapy in liver transplantation for HCC, European Society of Organ Transplantation (ESOT) convened a dedicated working group comprised of experts in the treatment of HCC to review literature and to develop guidelines pertaining to this cause that were subsequently discussed and voted during the Transplant Learning Journey (TLJ) 3.0 Consensus Conference that took place in person in Prague. The findings and recommendations of the working group on Downstaging, Bridging and Immunotherapy in Liver Transplantation for Hepatocellular Carcinoma are presented in this article.

Comparable and Complimentary Modalities for Treatment of Small-Sized HCC: Surgical Resection, Radiofrequency Ablation, and Microwave Ablation

BACKGROUND

Over the past decade, there has been continual improvement in both ablative and surgical technologies for the treatment of hepatocellular carcinoma (HCC). The efficacy of ablative therapy compared to surgical resection for HCC has not been thoroughly evaluated using multiple large-scale randomized controlled trials. By international consensus, if a patient is eligible, surgery is the primary curative treatment option, as it is believed to confer superior oncologic control.

OBJECTIVE

to determine the efficacies of percutaneous ablative therapies and surgical resection (SR) in the treatment of HCC. Data sources, study appraisal, and synthesis methods: A meta-analysis using 5 online databases dating back to 1989 with more than 31,000 patients analyzing patient and tumor characteristics, median follow-up, overall survival, and complication rate was performed.

RESULTS

Ablative therapies are suitable alternatives to surgical resection in terms of survival and complication rates for comparable patient populations. For the entire length of the study from 1989-2019, radiofrequency ablation (RFA) produced the highest 5-year survival rates (59.6%), followed by microwave ablation (MWA) (50.7%) and surgical resection (SR) (49.9%). In the most recent era from 2006 to 2019, surgical resection has produced the highest 5-year survival rate of 72.8%, followed by RFA at 61.7% and MWA at 50.6%. Conclusions and key findings: Depending on the disease state and comorbidities of the patient, one modality may offer superior overall survival rates over the other available techniques. Interventional ablative methods and surgical resection should be used in conjunction for the successful treatment of small-sized HCC.

Brazilian Landscape of Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the coming years, and strategies to mitigate the burden of this disease are needed in different regions. Geographic variations in epidemiology and risk factors, such as viral hepatitis and metabolic disease, pose challenges in adopting programs for early detection programs and management of patients with HCC. Brazil, like other countries, has high economic and social inequality, with heterogeneous access to health care. Viral hepatitis is the main risk factor but there is growing awareness of fatty liver disease. Risk factor monitoring and screening programs are unmet priorities because patients are often diagnosed at later stages. Advances in the management of patients with HCC have been made in recent years, including new tools for selecting patients for liver transplantation, sophisticated surgical techniques, and new systemic agents. High-volume academic centers often achieve favorable results through the adoption and application of established treatments, but this is not a reality in most regions of Brazil, because of disparities in wealth and resources. As HCC management requires a coordinated and multidisciplinary team, the role of local referral centers in decentralizing access to treatments and promoting health education in different regions should be encouraged and supported.

Clinical Results, Risk Factors, and Future Directions of Ultrasound-Guided Percutaneous Microwave Ablation for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, with a relatively poor prognosis, especially for advanced HCC. With the availability of a variety of treatment options, the treatment strategies for HCC have become more and more diversified. Microwave ablation (MWA) has gradually been considered as a viable alternative to surgical resection (SR) owing to its comparable long-term survival, reduced complications, and greater preservation of hepatic parenchyma. However, clinical outcomes, tumor progression, and recurrence of HCC after MWA remain major concerns. Here, after reviewing the current therapeutic options for HCC, we focus on MWA, describing the advantages and challenges of MWA and the clinical results after treatment. We then focused on prognostic factors that influence post-ablation clinical outcomes and briefly presented the strategy of MWA for future clinical treatment.

Evaluation of GALAD Score in Diagnosis and Follow-up of Hepatocellular Carcinoma after Local Ablative Therapy

BACKGROUND AND AIMS

Strategies for detection of early hepatocellular carcinoma (HCC) are still limited. The GALAD score is a serum biomarker-based model designed to predict the probability of having HCC. We aimed to assess the ability of GALAD score to diagnose early HCC and its validity to follow patients after local ablation therapy.

METHODS

This multicenter prospective study included 108 patients in two groups, 58 HCC patients (67 focal lesions) with local ablative therapy (study group), and a control group of 50 patients with liver cirrhosis. The GALAD scores of the study and control groups, and of the HCC patients before and after ablative therapy were compared.

RESULTS

Most patients were men (74.1% in study group and 76% in controls) with hepatitis C virus infection (98.30% in the study group, and 94% in controls). GALAD scores were significantly higher in HCC patients than in those with benign cirrhosis (2.65 vs. -0.37, p=0.001). Ablative therapy was successful in 94.4% of focal lesions <2 cm, and in 86.10% of 2-5 cm lesions. The GALAD score was also significantly lower at 1 month after ablation in patients with well-ablated tumors (2.19 vs. 0.98, p=0.001). The best cutoff values of GALAD score for diagnosis of early HCC, and for prediction of well ablation of HCC were 0.74 and ≤3.31 (areas under the curve of 0.92 and 0.75, sensitivities of 84.48% and 76.19%, specificities of 89.13% and 83.33%, positive predictive values of 90.74% and 94.1%, and negative predictive values of 82% and 35.7% respectively).

CONCLUSION

The GALAD score was effective for the diagnosis of early HCC and for follow-up after ablative therapy.

Non-invasive mass and temperature quantifications with spectral CT

Spectral CT has been increasingly implemented clinically for its better characterization and quantification of materials through its multi-energy results. It also facilitates calculation of physical density, allowing for non-invasive mass measurements and temperature evaluations by manipulating the definition of physical density and thermal volumetric expansion, respectively. To develop spectral physical density quantifications, original and parametrized Alvarez-Macovski model and electron density-physical density model were validated with a phantom. The best physical density model was then implemented on clinical spectral CT scans of ex vivo bovine muscle to determine the accuracy and effect of acquisition parameters on mass measurements. In addition, the relationship between physical density and changes in temperature was evaluated by scanning and subjecting the tissue to a range of temperatures. The parametrized Alvarez-Macovski model performed best in both model development and validation with errors within ± 0.02 g/mL. No effect from acquisition parameters was observed in mass measurements, which demonstrated accuracy with a maximum percent error of 0.34%. Furthermore, physical density was strongly correlated (R of 0.9781) to temperature changes through thermal volumetric expansion. Accurate and precise spectral physical density quantifications enable non-invasive mass measurements for pathological detection and temperature evaluation for thermal therapy monitoring in interventional oncology.

The Role of Ablative Techniques in the Management of Hepatocellular Carcinoma: Indications and Outcomes

The management of hepatocellular carcinoma (HCC) remains complex and will continue to rely on the multidisciplinary input of hepatologists, surgeons, radiologists, oncologists and radiotherapists. With the appropriate staging of patients and selection of suitable treatments, the outcomes for HCC are improving. Surgical treatments encompassing both liver resection and orthotopic liver transplantation (OLT) are the definitive curative-intent options. However, patient suitability, as well as organ availability, pose essential limitations. Consequently, non-surgical options, such as ablative techniques, play an increasingly important role, especially in small HCCs, where overall and disease-free survival can be comparable to surgical resection. Ablative techniques are globally recommended in recognised classification systems, showing increasingly promising results. Recent technical refinements, as well as the emerging use of robotic assistance, may expand the treatment paradigm to achieve improved oncological results. At present, in very early stage and early stage unresectable disease, percutaneous thermal ablation is considered the treatment of choice. Owing to their different features, various ablative techniques, including radiofrequency ablation, microwave ablation, cryotherapy ablation and irreversible electroporation, have been shown to confer different comparative advantages and applicability. We herein review the role of available ablative techniques in the current complex multidisciplinary management of HCC, with a main focus on the indications and outcomes, and discuss future perspectives.

Clinical consensus statement: Establishing the roles of locoregional and systemic therapies for the treatment of intermediate-stage hepatocellular carcinoma in Canada

BACKGROUND

Hepatocellular carcinoma (HCC) a leading cause of cancer mortality worldwide and approximately one-third of patients present with intermediate-stage disease. The treatment landscape of intermediate-stage HCC is rapidly evolving due to developments in local, locoregional and systemic therapies. Treatment recommendations focused on this heterogenous disease stage and that take into account the Canadian reality are lacking. To address this gap, a pan-Canadian group of experts in hepatology, transplant, surgery, radiation therapy, nuclear medicine, interventional radiology, and medical oncology came together to develop consensus recommendations on management of intermediate-stage HCC relevant to the Canadian context.

METHODS

A modified Delphi framework was used to develop consensus statements with strengths of recommendation and supporting levels of evidence graded using the AHA/ACC classification system. Tentative consensus statements were drafted based on a systematic search and expert input in a series of iterative feedback cycles and were then circulated via online survey to assess the level of agreement.

RESULTS & CONCLUSION

The pre-defined ratification threshold of 80 % agreement was reached for all statements in the areas of multidisciplinary treatment (n = 4), intra-arterial therapy (n = 14), biologics (n = 5), radiation therapy (n = 3), surgical resection and transplantation (n = 7), and percutaneous ablative therapy (n = 4). These generally reflected an expansion in treatment options due to developments in previously established or emergent techniques, introduction of new and more active therapies and increased therapeutic flexibility. These developments have allowed for greater treatment tailoring and personalization as well as a paradigm shift toward strategies with curative intent in a wider range of disease settings.

The latest research progress on minimally invasive treatments for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. Due to the high prevalence of hepatitis B virus (HBV) infection in China, the incidence of HCC in China is high, and liver cirrhosis caused by chronic hepatitis also brings great challenges to treatment. This paper reviewed the latest research progress on minimally invasive treatments for HCC, including percutaneous thermal ablation and new nonthermal ablation techniques, and introduced the principles, advantages, and clinical applications of various therapeutic methods in detail.

DATA SOURCES

The data of treatments for HCC were systematically collected from the PubMed, ScienceDirect, American Chemical Society and Web of Science databases published in English, using "minimally invasive" and "hepatocellular carcinoma" or "liver cancer" as the keywords.

RESULTS

Percutaneous thermal ablation is still a first-line strategy for the minimally invasive treatment of HCC. The effect of microwave ablation (MWA) on downgrading treatment before liver transplantation is better than that of radiofrequency ablation (RFA), while RFA is more widely used in the clinical practice. High-intensity focused ultrasound (HIFU) is mainly used for the palliative treatment of advanced liver cancer. Electrochemotherapy (ECT) delivers chemotherapeutic drugs to the target cells while reducing the blood supply around HCC. Irreversible electroporation (IRE) uses a microsecond-pulsed electric field that induces apoptosis and necrosis and triggers a systemic immune response. The nanosecond pulsed electric field (nsPEF) has achieved a good response in the ablation of mice with HCC, but it has not been reported in China for the treatment of human HCC.

CONCLUSIONS

A variety of minimally invasive treatments provide a sufficient survival advantage for HCC patients. Nonthermal ablation will lead to a new wave with its unique advantage of antitumor recurrence and metastasis.

Outcomes of microwave versus radiofrequency ablation for hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

Studies to date comparing outcomes of microwave ablation (MWA) with radiofrequency ablation (RFA) on patients with hepatocellular carcinoma have yielded conflicting results, with no clear superiority of one technique over the other. The aim of this systematic review and meta-analysis was to compare the efficacy and safety of MWA with RFA.

AIM

To perform a systematic review and meta-analysis comparing the efficacy and safety of MWA with RFA.

METHODS

A systematic literature search was performed using Ovid Medline, Embase, PubMed, Reference Citation Analysis, Cochrane Central and Cochrane Systematic Review databases, and Web of Science. Abstracts and full manuscripts were screened for inclusion utilising predefined inclusion and exclusion criteria comparing outcomes of MWA and RFA. A random-effects model was used for each outcome. Meta-regression analysis was performed to adjust for the difference in follow-up period between the studies. Primary outcome measures included complete ablation (CA) rate, local recurrence rate (LRR), survival [local recurrence-free survival (LRFS), overall survival (OS)] and adverse events.

RESULTS

A total of 42 published studies [34 cohort and 8 randomised controlled trials (RCT)] with 6719 patients fulfilled the selection criteria. There was no significant difference in tumour size between the treatment groups. CA rates between MWA and RFA groups were similar in prospective cohort studies [odds ratio (OR) 0.95, 95% confidence interval (CI) 0.28–3.23] and RCTs (OR 1.18, 95%CI 0.64–2.18). However, retrospective studies reported higher rates with MWA (OR 1.29, 95%CI 1.06–1.57). Retrospective cohort studies reported higher OS (OR 1.54, 95%CI 1.15–2.05 and lower LRR (OR 0.67, 95%CI 0.51–0.87). No difference in terms of LRFS or 30-d mortality was observed between both arms. MWA had an increased rate of adverse respiratory events when compared to RFA (OR 1.99, 95%CI 1.07–3.71, P = 0.03).

CONCLUSION

MWA achieves similar CA rates and as good or better longer-term outcomes in relation to LRR and OS compared to RFA. Apart from an increased rate of respiratory events post procedure, MWA is as safe as RFA.

Hepatic resection versus microwave ablation for the treatment of early hepatocellular carcinoma: a comparative analysis of treatment outcomes and survival predictors

Introduction

Liver resection and local ablation are the two primary curative treatments for early-stage hepatocellular carcinoma (HCC). Microwave ablation (MWA) shows promising performance in terms of early tumor response, recurrence, and survival. This study aims to determine whether MWA would be comparable to liver resection in treating early-stage HCC.

Methods

This study included patients with hepatitis C-related HCC attending the multidisciplinary HCC clinic, Kasr Al-Ainy Hospital (March 2018 to September 2020). We included adults with early-stage HCC (BCLC stages 0-A). We studied patients and tumor characteristics, HCC treatment response, recurrence, and overall survival.

Results

Thirty-one patients were treated with liver resection and 41 patients were treated with MWA, including 4 patients who received intraoperative MWA. By the end of the study, 21 patients (28.77%) died. Patients who underwent MWA were younger compared to the hepatectomy group with lower baseline AFP (21 (6.7–54) versus 77 (31.3–136.0), respectively, (P value 0.024) and tumor size (2.78 (0.87) cm versus 3.77 (0.97) cm, respectively, (P value < 0.001). We found no differences between the studied groups in terms of treatment response, post-treatment decompensation, recurrence, or overall survival. One-year survival probability in the MWA and resection groups was 75.5% and 76.3% respectively. Post-procedure hepatic decompensation was the only independent predictor of lower survival by multivariate logistic regression analysis (OR 37.74, 95%CI 6.251–227.87, P value < 0.001) after adjusting for age, AFP, and tumor size.

Conclusion

Liver resection and MWA showed similar satisfactory results in the treatment of early-stage HCC, in terms of treatment response, recurrence, and overall survival.

Efficacy and safety of microwave ablation and radiofrequency ablation in the treatment of hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Surgical resection is often only possible in the early stages of HCC and among those with limited cirrhosis. Radiofrequency ablation and Microwave ablation are 2 main types of percutaneous thermal ablation for the treatment of HCC. The efficacy and safety between these 2 therapy methods are still under a debate.

OBJECTIVE

To compare the efficacy and safety of Radiofrequency ablation and Microwave ablation in treating HCC.

METHODS

PubMed, EMBASE, the Cochrane databases and Web of Science were systematically searched. We included randomized controlled trials and cohort studies comparing the efficacy and safety of Radiofrequency ablation and Microwave ablation in HCC patients. Outcome measures on local tumor progression, complete ablation, disease-free survival, overall survival, or major complications were compared between the 2 groups. The random effect model was used when there was significant heterogeneity between studies, otherwise the fixed effect model was used.

RESULTS

A total of 33 studies, involving a total of 4589 patients were identified, which included studies comprised 7 RCTs, 24 retrospective observational trials, and 2 prospective observational trial. Microwave ablation had a lower local tumor progression than Radiofrequency ablation in cohort studies (OR = 0.78, 95% CI 0.64-0.96, P = .02). Complete ablation rate of Microwave ablation was higher than that of Radiofrequency ablation in cohort studies (OR = 1.54, 95% CI 1.05-2.25, P = .03). There was no significant difference in overall survival and disease-free survival between the 2 groups. Meta-analysis showed that there was no significant difference in the main complications between Microwave ablation and Radiofrequency ablation.

CONCLUSIONS

Microwave ablation has higher complete ablation and lower local tumor progression than Radiofrequency ablation in the ablation treatment of HCC nodules. There was no significant difference in overall survival between the 2 therapy methods.

Long-term outcomes following percutaneous microwave ablation for colorectal cancer liver metastases

PURPOSE

To evaluate the overall survival (OS), local progression-free survival (PFS) and prognostic factors of patients with colorectal cancer liver metastases (CRLM) undergoing microwave ablation (MWA).

METHOD

A total of 132 patients were retrospectively enrolled who had been treated between 2010 and 2018. For the evaluation of survival rates, all patients were divided according to their indications (curative n = 57 and debulking (patients with additional non-target extrahepatic metastases) n = 75). In total, 257 ablations were evaluated for prognostic factors: number of liver metastases, primary tumor origin (PTO), diameter and volume of metastases, duration and energy of ablation.

RESULTS

The OS was 32.1 months with 93.2% of patients free from recurrence at 28.3 months (median follow-up time). The one- year and three-year OS were 82.72% and 41.66%, respectively. The OS and recurrence-free survival of the curative group were statistically significantly higher than the debulking group (p < .001). Statistically significant prognostic factors for OS included the location of the primary tumor (p < .038) and the number of metastases (all p < .017). Metastasis diameter and volume and ablation duration and energy had no significant correlation with survival (p > .05).

CONCLUSIONS

Satisfactory OS and local tumor PFS can be achieved in patients with CRLM using MWA with the number of metastases and the location of the primary tumor influencing the outcome of patients. The metastasis's size and the duration and energy used for ablation were not of significant prognostic value.

Microwave ablation as bridging to liver transplant for patients with hepatocellular carcinoma: a single-center retrospective analysis

PURPOSE

To evaluate the efficacy and safety of microwave (MW) ablation as first-line locoregional therapy (LRT) for bridging patients with hepatocellular carcinoma (HCC) to liver transplant.

MATERIALS AND METHODS

This retrospective study evaluated 88 patients who received percutaneous MW ablation for 141 tumors as first-line LRT for HCC and listed for liver transplantation at a single medical center between 2011 and 2019. Overall survival rate status-post liver transplant, waitlist retention and disease progression were evaluated using Kaplan-Meier techniques.

RESULTS

Of 88 patients (72M, 16F, mean age 60 years, MELD=11.2) listed for transplant, median waitlist time was 9.4 months (IQR: 5.5 - 18.9). Seventy-one patients (80.7%) received transplant after median wait time of 8.5 months. Seventeen patients (19.3%) were removed from the waitlist, four (4.5%) due to tumors outside of the Milan criteria (HCC-specific dropout). No difference in tumor size or AFP was seen in transplanted vs. non-transplanted patients at time of ablation (2.1 vs. 2.1 cm and 34.4 vs. 34.7 ng/mL for transplanted vs. non-transplanted, respectively, p>0.05). Five of 88 patients (5.1%) experienced adverse events after ablation; however, all recovered. There were no cases of tract seeding. The local tumor progression (LTP) rate was 7.2%. The overall survival status-post liver transplant at 5-years was 76.7% and the disease-specific survival after LT was 89.6% with a median follow-up of 61 months for all patients.

CONCLUSION

MW ablation appears to be safe and effective for bridging patients with HCC to liver transplant without waitlist removal from seeding, adverse events, or local tumor progression.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma

BACKGROUND

 Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. Because many hepatocellular carcinomas are already unresectable at the time of initial diagnosis, percutaneous tumor ablation has become established in recent decades as a curative therapeutic approach for very early (BCLC 0) and early (BCLC A) HCC. The aim of this paper is to provide a concise overview of the percutaneous local ablative procedures currently in use, based on their technical characteristics as well as clinical relevance, taking into account the current body of studies.

MATERIALS AND METHODS

 The literature search included all original papers, reviews, and meta-analyses available via MEDLINE and Pubmed on the respective percutaneous ablation procedures; the primary focus was on randomized controlled trials and publications from the last 10 years.

RESULTS AND CONCLUSIONS

 Radiofrequency ablation (RFA) and microwave ablation (MWA) are well-established procedures that are considered equal to surgical resection in the treatment of stage BCLC 0 and A HCC with a diameter up to 3 cm due to their strong evidence in international and national guidelines. For tumors with a diameter between 3 and 5 cm, the current S3 guidelines recommend a combination of transarterial chemoembolization (TACE) and thermal ablation using RFA or MWA as combination therapy is superior to thermal ablation alone in tumors of this size and shows comparable results to surgical resection in terms of overall survival. Alternative, less frequently employed thermal procedures include cryotherapy (CT) and laser ablation (LA). Non-thermal procedures include irreversible electroporation (IRE), interstitial brachytherapy (IBT), and most recently, electrochemotherapy (ECT). Due to insufficient evidence, these have only been used in individual cases and within the framework of studies. However, the nonthermal methods are a reasonable alternative for ablation of tumors adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods. With advances in the technology of the respective procedures, increasingly good evidence, and advancements in supportive techniques such as navigation devices and fusion imaging, percutaneous ablation procedures may expand their indications for the treatment of larger and more advanced tumors in the coming years.

KEY POINTS

· RFA and MWA are considered equal to surgical resection as a first-line therapy for the curative treatment of stage BCLC 0 and A HCCs with a diameter of up to 3 cm.. · For HCCs with a diameter between 3 and 5 cm, a combination of TACE and RFA or MWA is recommended. This combination therapy yields results comparable to those of surgical resection in terms of overall survival.. · Due to insufficient evidence, alternative ablation methods have only been used in individual cases and within the framework of studies. However, nonthermal methods, such as IRE, IBT, and, most recently, ECT, are a reasonable alternative for ablation of HCCs adjacent to large blood vessels and bile ducts because they cause significantly less damage to these structures than thermal ablation methods..

CITATION FORMAT

· Luerken L, Haimerl M, Doppler M et al. Update on Percutaneous Local Ablative Procedures for the Treatment of Hepatocellular Carcinoma. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1768-0954.

Combined Transarterial Chemoembolization with Microwave Ablation versus Microwave Alone for Treatment of Medium Sized Hepatocellular Carcinoma

Background & Aims:

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer-related deaths. The only definitive treatment for both HCC and cirrhosis is liver transplantation, but long wait times in some regions and a relatively fixed number of donor organs negatively impact access to liver transplantation. The aim of the work was to evaluate and compare the short outcome of patients with medium-sized HCC who will undergo percutaneous microwave ablation (MWA) alone and in combination with TACE.

Methods:

This prospective study included 40 patients with medium-sized HCC lesions who were classified into two groups; Group A that included twenty patients treated by TACE followed by percutaneous MWA after 2 weeks and group B that included twenty patients treated by 2 sessions of percutaneous MWA with 2 weeks interval. Full history taking, clinical examination, laboratory investigation, abdominal ultrasonography and abdominal tri-phasic computed tomography (CT) with contrast were obtained from the two groups. Laboratory and radiological follow up of the cases were done at 1 and 3 months after the treatment.

Results:

There was no statistically significant difference in the sociodemographic criteria, laboratory measurement and clinical criteria between the cases in the two study groups before initiation of treatment. The response was slightly better in the combined treatment group, but it did not show a statistically significant difference. The incidence of complications was higher in the MWA group.

Conclusion::

Hepatocellular carcinoma is a common complication of HCV related cirrhosis. Association of TACE-MWA led to better response rates than MWA with fewer complications.

Microwave versus radiofrequency ablation for the treatment of liver malignancies: a randomized controlled phase 2 trial

Microwave (MWA) and radiofrequency ablation (RFA) are main ablative techniques for hepatocellular carcinoma (HCC) and colorectal liver metastasis (MT). This randomized phase 2 clinical trial compares the effectiveness of MWA and RFA as well as morphology of corresponding ablation zones. HCC and MT patients with 1.5–4 cm tumors, suitable for ablation, were randomized into MWA or RFA Groups. The primary endpoint was short-to-long diameter ratio of ablation zone (SLR). Primary technical success (TS) and a cumulative local tumor progression (LTP) after a median 2-year follow-up were compared. Between June 2015 and April 2020, 82 patients were randomly assigned (41 patients per group). For the per-protocol analysis, five patients were excluded. MWA created larger ablation zones than RFA (p = 0.036) although without differences in SLR (0.5 for both groups, p = 0.229). The TS was achieved in 98% (46/47) and 90% (45/50) (p = 0.108), and LTP was observed in 21% (10/47) vs. 12% (6/50) (OR 1.9 [95% CI 0.66–5.3], p = 0.238) of tumors in MWA vs. RFA Group, respectively. Major complications were found in 5 cases (11%) vs. 2 cases (4%), without statistical significance. MWA and RFA show similar SLR, effectiveness and safety in liver tumors between 1.5 and 4 cm.

Efficacy and safety of various primary treatment strategies for very early and early hepatocellular carcinoma: a network meta-analysis

BACKGROUND

Several treatments are available for treatment of early and very early-stage Hepatocellular Carcinoma, also known as small Hepatocellular Carcinoma (SHCC). However, there is no consensus with regards to the efficacies of these methods. We aimed at identifying the most effective initial treatment strategy for SHCC through Bayesian network meta-analyses.

METHODS

Studies published between January, 2010, and February, 2021 were searched in EMBASE, Cochrane Library, PubMed and Web of science databases, and conference proceedings for trials. The included studies reported the survival outcomes of very early and early Hepatocellular Carcinoma patients subjected to radiofrequency ablation (RFA), microwave ablation (MWA), surgical resection (SR), transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI), minimally invasive liver surgery (MIS), stereotactic body radiotherapy (SBRT) and cryoablation (CA). Then, data were extracted from studies that met the inclusion criteria. Patient survival data were retrieved from the published Kaplan-Meier curves and pooled. A Bayesian random-effects model was used to combine direct and indirect evidence.

RESULTS

A total of 2058 articles were retrieved and screened, from which 45 studies assessing the efficacies of 8 different treatments in 11,364 patients were selected. The included studies had high methodological quality. Recurrence free survival* (progression/recurrence/relapse/disease/tumor-free survival were combined and redefined as RFS*) and overall survival (OS) outcomes were highest in MIS-treated patients (HR 0·57, 95% confidence intervals [CI] 0·38-0·85; HR 0.48,95% CI 0.36-0.64, respectively), followed by SR-treated patients (HR 0.60, 95% CI 0.50-0.74; HR 0.62, 95% CI 0.55-0.72, respectively). TACE was highly efficacious (58.9%) at decreasing the rates of major complications. Similar findings were obtained through sensitivity analysis, and in most of the prognostic subgroups.

CONCLUSIONS

MIS and SR exhibited the highest clinical efficacies, however, they were associated with higher rates of complications. Ablation is effective in small tumors, whereas SBRT is a relatively promising treatment option for SHCC. More well-designed, large-scale randomized controlled trials should be performed to validate our findings.

Percutaneous microwave ablation versus radiofrequency ablation of hepatocellular carcinoma: a meta-analysis of randomized controlled trials

PURPOSE

Percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) are well-validated interventions for hepatocellular carcinoma (HCC). The purpose of this study was to compare their safety and efficacy through a meta-analysis of randomized controlled trials (RCT).

METHODS

MEDLINE, Pubmed, and the Cochrane Library were queried up to September 2020 using the terms "microwave", "radiofrequency", "hepatocellular", and "randomized". Only RCTs investigating MWA versus RFA for HCC were included. Baseline study characteristics, complete ablation rate, ablation time, overall survival, local recurrence, and complication rates were investigated.

RESULTS

Among the five original studies included, a total of 413 and 431 patients were treated with RFA and MWA, respectively. All studies focused on very early and early-stage HCC only (Barcelona Clinic Liver Cancer Stage 0 and A). No statistical significance was observed in terms of complete ablation rate (96.7 vs 96.9%, p = 0.882), overall survival (6 month: 95.7 vs 100%, p = 0.492; 1 year: 91.9 vs 94.1%, p = 0.264; 3 year: 77.5 vs 78.4%, p = 0.905), recurrence-free survival (6 month: 99.1 vs 99.7%, p = 0.717; 1 year: 94.6 vs 93.9%, p = 0.675; 3 year: 76.8 vs 77.1%, p = 0.935), and complication rates (p > 0.05 in all types). The mean ablation time of MWA was significantly shorter than RFA (26.9 vs 14.1 min, p < 0.001).

CONCLUSION

For very early and early-stage HCC, RFA and MWA are equally safe and effective, though the former is associated with a longer ablation time.

Radiofrequency versus microwave ablation for hepatocellular carcinoma within the Milan criteria in challenging locations: a retrospective controlled study

PURPOSE

The aim of this study was to compare the safety and efficacy of radiofrequency ablation (RFA) with microwave ablation (MWA) for hepatocellular carcinoma (HCC) within the Milan criteria in challenging locations.

METHODS

This study retrospectively investigated 201 consecutive patients with Milan criteria HCCs who underwent RFA (RFA group, n = 150) or MWA (MWA group, n = 51) between January 2012 and December 2016. Overall survival (OS), recurrence-free survival (RFS), local tumor control, and treatment-related complications were compared between the two groups. Prognostic factors were analyzed using the Cox proportional hazard regression model.

RESULTS

Median follow-up duration was 36.7 months (range: 6.2-64.0 months). Cumulative 1-, 3-, and 5-year OS rates were 97.9%, 92.3%, and 80.6% in the MWA group and 96.4%, 87.4%, and 78.2% in the RFA group, respectively, (P = 0.450). Cumulative RFS rates at 1, 3, and 5 years were 93.2%, 74.4%, and 63.7% in the MWA group and 80.3%, 57.3%, and 49.6% in the RFA group, respectively, (P = 0.097). Multivariate analyses showed that variable categories "patient age above 65 years" (P = 0.004) and "more than one tumor" (P = 0.004) were associated with overall mortality, and "patient age above 65 years" (P = 0.048) and "tumor size greater than 3 cm" (P = 0.009) were associated with inferior RFS. The incidences of major complications were not significantly different between the two groups (3.3% vs 3.9%, P = 0.843).

CONCLUSIONS

RFA and MWA were associated with comparable safety and efficacy for HCC within the Milan criteria in challenging locations. Further study in a large, multi-center patient cohort is necessary to validate the results.

Efficacy of microwave ablation versus radiofrequency ablation for hepatocellular carcinoma: a propensity score analysis

Purpose

To evaluate the efficacy and safety of radiofrequency ablation (RFA) and new-generation microwave ablation (MWA) for the treatment of hepatocellular carcinoma (HCC).

Methods

The propensity score matching method was applied to patients with HCC treated with MWA (93 patients) or RFA (156 patients) at a single institution from January 2014 to April 2020. The local tumor progression (LTP), intrahepatic distant recurrence (IDR), and recurrence-free survival (RFS) of the two matched therapies were analyzed using the Kaplan–Meier method. Cox proportional hazard models were used to identify risk factors for LTP and RFS. The therapeutic effects and complications of the two treatments were also compared.

Results

The LTP, IDR, and RFS of MWA and RFA were equivalent (LTP: hazard ratio [HR] = 0.87; 95% confidence interval [95% CI] 0.36- 2.07; P = 0.746, IDR: HR = 1.03; 95% CI 0.61–1.73; P = 0.890, RFS: HR = 1.15; 95% CI 0.69–1.91; P = 0.566). Para-vessel lesions was the only risk factor for LTP, whereas age, previous treatment, Albumin-Bilirubin score, and tumor diameter were risk factors for RFS. On the other hand, the ablation time per nodule (6.79 ± 2.73 and 9.21 ± 4.90 min; P = 0.008) and number of sessions per nodule required to achieve technical success (1.16 ± 0.39 and 1.34 ± 0.57; P = 0.009) were significantly lower in MWA than in RFA. The major complication rate of MWA and RFA was also equivalent.

Conclusion

MWA and RFA have similar therapeutic effects and safety, although MWA has advantages over RFA regarding efficacy, including shorter ablation time and fewer sessions required.

Microwave ablation determines similar survival outcomes as compared to radiofrequency ablation for the treatment of hepatocellular carcinoma

OBJECTIVES

It is still unclear whether microwave ablation (MWA) outperforms radiofrequency ablation (RFA) in the treatment of hepatocellular carcinoma (HCC). Aim of this manuscript is to compare the two treatments through a meta-analysis of randomized-controlled trials (rcts).

METHODS

Computerized bibliographic search was performed on main databases through August 2020. The primary outcome was the complete response rate, with survival rate, disease-free survival rate, and adverse event rate as secondary outcomes. Results were expressed in terms of risk ratio (RR) and 95% confidence interval (CI).

RESULTS

Seven rcts enrolling 1143 patients were included. Rates of complete response were similar (RR 1.01, 95% CI 0.99-1.02); likewise, survival rates were constantly similar, with rrs ranging from 1.05 (0.96-1.15) at 1-year to 0.91 (0.81-1.03) at 5-year. Disease-free survival at 1-, 2-, and 3-year was similar between the two groups with RR 1.00 (0.96-1.04), 0.94 (0.84-1.06), and 1.06 (0.93-1.21), respectively. On the other hand, RR for disease-free survival at 5-year was significantly in favor of MWA (3.66, 1.32-42.27). Adverse event rate was similar between the two treatments (RR 1.06, 0.48-2.34), with bleeding and hematoma as most frequent complications.

CONCLUSIONS

MWA seems to determine similar outcomes as compared to RFA.

Microwave ablation compared with radiofrequency ablation for the treatment of liver cancer: a systematic review and meta-analysis

BACKGROUND

Guidelines have reported that although microwave ablation (MWA) has potential advantages over radiofrequency ablation (RFA), superiority in efficacy and safety remain unclear. Aim of the study is to compare MWA with RFA in the treatment of liver cancer.

METHODS

Meta-analysis was conducted according to the PRISMA guidelines for studies published from 2010 onwards. A random-effects model was used for the meta-analyses. Complete ablation (CA), local tumor progression (LTP), intrahepatic distant recurrence (IDR), and complications were analyzed.

RESULTS

Four randomized trials and 11 observational studies with a total of 2,169 patients met the inclusion criteria. Although overall analysis showed no significant difference in LTP between MWA and RFA, subgroup analysis including randomized trials for patients with hepatocellular cancer (HCC) demonstrated statistically decreased rates of LTP in favor of MWA (OR, 0.40; 95% CI, 0.18-0.92; p = 0.03). No significant differences were found between the two procedures in CA, IDR, complications, and tumor diameter less or larger than 3 cm.

CONCLUSIONS

MWA showed promising results and demonstrated better oncological outcomes in terms of LTP compared to RFA in patients with HCC. MWA can be utilized as the ablation method of choice in patients with HCC.

Challenges Facing Percutaneous Ablation in the Treatment of Hepatocellular Carcinoma: Extension of Ablation Criteria

As an emerging minimally invasive treatment method, percutaneous ablation is more and more widely used in the treatment of liver tumors. It has been recommended by guidelines for diagnosis and treatment of hepatocellular carcinoma (HCC) as a curative treatment alongside surgical resection and liver transplantation. In recent years, with the continuous advancement and innovation of percutaneous ablation technologies, their clinical efficacy and safety have been significantly improved, which has led to the expanded application of percutaneous ablation in the treatment of HCC—more and more patients who were previously considered unsuitable for ablation therapies are now being treated with percutaneous ablation. Obviously, percutaneous ablation can reduce the risk of treatment changes from curative strategies to palliative strategies. Based on clinical practice experience, this review enumerates the advantages and disadvantages of different ablative modalities and summarizes the existing combinations of ablation techniques, thus will help clinicians choose the most appropriate ablative modality for each patient and will provide scientific guidance for improving prognosis and making evidence-based treatment decisions. In addition, we point out the challenges and future prospects of the ablation therapies, thereby providing direction for future research.

The (Eternal) Debate on Microwave Ablation Versus Radiofrequency Ablation in BCLC-A Hepatocellular Carcinoma

BACKGROUND/AIM

While percutaneous radiofrequency ablation (RFA) is considered the standard ablative modality for the treatment of early-stage hepatocellular carcinoma (HCC), percutaneous microwave ablation (MWA) is being increasingly used in recent years. We performed a systematic review and meta-analysis to compare percutaneous MWA versus percutaneous RFA in BCLC-A HCC across randomized controlled trials (RCTs).

PATIENTS AND METHODS

Eligible studies included RCTs assessing MWA versus RFA in BCLC-A HCC. Outcomes of interest included: complete ablation (CA) rate, local recurrence (LR) rate, 1-year overall survival (OS) rate, 3-year OS rate and major complications rate.

RESULTS

We retrieved all the relevant RCTs through PubMed/Medline, Cochrane library and EMBASE; five eligible studies involving a total of 794 patients (MWA: 409; RFA: 385) and 1008 nodules of HCC (MWA: 519; RFA: 489) were included in our analysis. No significant differences were found between MWA and RFA regarding CA, LR, 3-year OS and major complications rate. Regarding 1-year OS, a higher rate was observed in the MWA group.

CONCLUSION

MWA and RFA are effective and safe techniques in early stage, BCLC-A, HCCMWA resulted in better 1-year OS, although this benefit was not confirmed in the 3-year analysis.

Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality and has an increasing incidence worldwide. Locoregional therapies, defined as imaging-guided liver tumour-directed procedures, play a leading part in the management of 50-60% of HCCs. Radiofrequency is the mainstay for local ablation at early stages and transarterial chemoembolization (TACE) remains the standard treatment for intermediate-stage HCC. Other local ablative techniques (microwave ablation, cryoablation and irreversible electroporation) or locoregional therapies (for example, radioembolization and sterotactic body radiation therapy) have been explored, but have not yet modified the standard therapies established decades ago. This understanding is currently changing, and several drugs have been approved for the management of advanced HCC. Molecular therapies dominate the adjuvant trials after curative therapies and combination strategies with TACE for intermediate stages. The rationale for these combinations is sound. Local therapies induce antigen and proinflammatory cytokine release, whereas VEGF inhibitors and tyrosine kinase inhibitors boost immunity and prime tumours for checkpoint inhibition. In this Review, we analyse data from randomized and uncontrolled studies reported with ablative and locoregional techniques and examine the expected effects of combinations with systemic treatments. We also discuss trial design and benchmarks to be used as a reference for future investigations in the dawn of a promising new era for HCC treatment.

Treatment strategies for early stage hepatocellular carcinoma: a systematic review and network meta-analysis of randomised clinical trials

BACKGROUND

Several treatment strategies for early stage hepatocellular cancers (HCC) have been evaluated in randomised controlled trials (RCTs). This network meta-analysis (NMA) aimed to explore the relative effectiveness of these different approaches on their impact on overall (OS) and recurrence-free survival (RFS).

METHODS

A systematic review was conducted to identify RCT's reported up to 23rd January 2020. Indirect comparisons of all regimens were simultaneously compared using random-effects NMA.

RESULTS

Twenty-eight RCT's, involving 3,618 patients, reporting 13 different treatment strategies for early stage HCC were identified. Median follow-up, reported in 22 studies, ranged from 12-93 months. In this NMA, RFA in combination with iodine-125 was ranked first for both RFS (HR: 0.50, 95% CI: 0.19-1.31) and OS (HR: 0.41, 95% CI: 0.19-0.94). In subgroup with solitary HCC, lack of studies reporting RFS precluded reliable analysis. However, RFA in combination with iodine-125 was associated with markedly better OS (HR: 0.21, 95% CI: 0.05-0.93).

CONCLUSION

This NMA identified RFA in combination with iodine-125 as a treatment delivering better RFS and OS, in patients with early stage HCC, especially for those with solitary HCC. This technique warrants further evaluation in both Asia and Western regions.

A review on radiofrequency, microwave and high-intensity focused ultrasound ablations for hepatocellular carcinoma with cirrhosis

Importance

Hepatocellular carcinoma (HCC) is usually accompanied by liver cirrhosis, which makes treatment of this disease challenging. Liver transplantation theoretically provides an ultimate solution to the disease, but the maximal surgical stress and the scarcity of liver graft make this treatment option impossible for some patients. In an ideal situation, a treatment that is safe and effective should provide a better outcome for patients with the dilemma.

Objective

This article aims to give a comprehensive review of various types of loco-ablative treatment for HCC.

Evidence Review

Loco-ablative treatment bridges the gap between surgical resection and transarterial chemotherapy. Various types of ablative therapy have their unique ability, and evidence-based outcome analysis is the most important key to assisting clinicians to choose the most suitable treatment modality for their patients.

Findings

Radiofrequency ablation (RFA) has a relatively longer history and more evidence to support its effectiveness. Microwave ablation (MWA) is gaining momentum because of its shorter ablation time and consistent ablation zone. High-intensity focused ultrasound (HIFU) ablation is a relatively new technology that provides non-invasive treatment for patients with HCC. It has been carried out at centers of excellence and it is a safe and effective treatment option for selected patients with HCC and liver cirrhosis.

Conclusion and Relevance

Selective use of different loco-ablative therapies will enhance clinicians' treatment options for treatment of HCC.

Overall survival and local recurrence following RFA, MWA, and cryoablation of very early and early HCC: a systematic review and Bayesian network meta-analysis

OBJECTIVE

To compare overall survival (OS) and local recurrence (LR) following radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) for very early and early hepatocellular carcinoma (HCC).

METHODS

This systematic review was performed according to the PRISMA guidelines. MEDLINE, Embase, and Cochrane databases were searched. Randomized controlled trials (RCTs) and observational studies were included. OS and LR at 1 year and 3 years were assessed. OS was reported as hazard ratio (HR) with 95% credible intervals (CrI) and LR as relative risk (RR) with 95% CrI, to summarize effect of each comparison.

RESULTS

Nineteen studies (3043 patients), including six RCTs and 13 observational studies, met inclusion criteria. For OS at 1 year, as compared to RFA, CA had HR of 0.81 (95% CrI: 0.43-1.51), and MWA had HR of 1.01 (95% CrI: 0.71-1.43). For OS at 3 years, as compared to RFA, CA had HR of 0.90 (95% CrI: 0.48-1.64) and MWA had HR of 1.07 (95% CrI: 0.73-1.50). For LR at 1 year, CA and MWA had RR of 0.75 (95% CrI: 0.45-1.24) and 0.93 (95% CrI: 0.78-1.14), respectively, as compared to RFA. For LR at 3 years, CA and MWA had RR of 0.96 (0.74-1.23) and 0.98 (0.87-1.09), respectively, as compared to RFA. Overall, none of the comparisons was statistically significant. Age of patients and tumor size did not influence treatment effect.

CONCLUSIONS

RFA, MWA, and CA are equally effective for locoregional treatment of very early and early HCC.

KEY POINTS

• There is no significant difference in the OS and LR (at 1 year and 3 years) following ablation of very early and early HCC with RFA, MWA, and CA. • There was no effect of tumor size on the treatment efficacy. • More RCTs comparing CA with RFA and MWA should be performed.

Microwave Ablation Versus Radiofrequency Ablation for Treatment of Hepatocellular Carcinoma: A Meta-Analysis of Randomized Controlled Trials

Simple Summary

Through a meta-analysis of seven randomized-controlled trials we found difference in terms of complete response and survival rates between microwave ablation (MWA) and radiofrequency ablation (RFA). While local recurrence rate was similar between MWA and RFA, distant recurrence rate was significantly lower with MWA. As a consequence, disease-free survival at 1, 2, and 3 years was similar between the two groups whereas disease-free survival at 5 years was significantly in favor of MWA. Adverse event rate was similar between the two treatments. Our results indicate a similar efficacy and safety profile between the two techniques. MWA seems to decrease the rate of long-term recurrences, but this finding needs to be confirmed in further trials.

Abstract

There are limited and discordant results on the comparison between microwave ablation (MWA) and radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC). This meta-analysis aims to compare the two treatments in terms of efficacy and safety, based on a meta-analysis of randomized-controlled trials (RCTs). A computerized bibliographic search was performed on the main databases throughout August 2020. The primary outcome was the complete response rate, while survival rate (at 1-, 2-, 3-, and 5-year), disease-free survival rate (at 1-, 2-, 3-, and 5-year), local and distant recurrence rate, adverse event rate, and number of treatment sessions were the secondary outcomes. Seven RCTs enrolling 921 patients were included. No difference in terms of complete response between the two treatments was observed (risk ratio (RR) 1.01, 95% CI 0.99–1.02). Survival rates were constantly similar, with RRs ranging from 1.05 (0.96–1.15) at 1 year to 0.91 (0.81–1.03) at 5 years. While local recurrence rate was similar between MWA and RFA (RR 0.70, 0.43–1.14), distant recurrence rate was significantly lower with MWA (RR 0.60, 0.39–0.92). Disease-free survival at 1, 2, and 3 years was similar between the two groups with RR 1.00 (0.96–1.04), 0.94 (0.84–1.06), and 1.06 (0.93–1.21), respectively. On the other hand, RR for disease-free survival at 5 years was significantly in favor of MWA (3.66, 1.32–42.27). Adverse event rate was similar between the two treatments (RR 1.06, 0.48–2.34), with bleeding and hematoma representing the most frequent complications. Our results indicate a similar efficacy and safety profile between the two techniques. MWA seems to decrease the rate of long-term recurrences, but this finding needs to be confirmed in further trials.

Radiofrequency ablation versus microwave ablation for early stage hepatocellular carcinoma: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Several randomized control trials (RCTs) were conducted to compare microwave ablation (MWA) and radiofrequency ablation (RFA) in the treatment of hepatocellular carcinoma (HCC) over the years. The purpose of this study was to compare the efficacy of RFA and MWA for early stage HCC.

METHODS

Studies were systematically searched on Emabse, Ovid Medline, PubMed, and Cochrane Library until March 20, 2020. Continuous variables and dichotomous variables were compared using weighted mean difference (WMD) and odds ratio (OR), respectively. For the comparison of overall survival (OS) and disease-free survival (DFS), the hazard ratio (HR) and 95% confidence interval (CI) were extracted from univariate analysis or survival plots.

RESULTS

A total of 26 studies (5 RCTs and 21 cohorts) with 4396 patients (2393 patients in RFA and 2003 patients in MWA) were included in our study. Of these patients, 47% received treatment under general anesthesia in the MWA group and 84% in the RFA group (OR = 0.529, P < .001). The median ablation time was reduced in the MWA group (12 minutes) compared with RFA group (29 minutes) (WMD = -15.674, P < .001). In total, 17.6% patients exhibited progression during follow-up in the MWA group compared with 19.5% in the RFA group (OR = 0.877, P = .225). No statistically significant differences were observed between MWA and RFA groups in terms of OS and DFS (HR = 0.891 and 1.014, P = .222 and .852, respectively).

CONCLUSIONS

MWA exhibited similar therapeutic effects as RFA in the treatment of early stage HCC. Given the shorter ablation time, MWA can be performed under local anesthesia.

Unresectable Hepatocellular Carcinoma: Transcatheter Arterial Chemoembolization Combined With Microwave Ablation vs. Combined With Cryoablation

Background: Transcatheter arterial chemoembolization (TACE) combined with ablation has been widely used for treating unresectable hepatocellular carcinoma (HCC). However, the technique with which TACE should be combined for it to be more effective remains unknown. Purpose: To retrospectively evaluate the efficacy and safety of TACE combined with microwave ablation (MWA) vs. TACE combined with cryoablation (CRA) in treating unresectable HCC. Materials and Methods: From January 2011 to December 2018, 108 patients diagnosed with unresectable HCC were divided into either the TACE-MWA group (n = 48) or TACE-CRA group (n = 60). Overall survival (OS) and time to progression (TTP) were compared between the two groups. To reduce potential bias, a propensity score matching (PSM) was performed. Complications were observed. Kaplan-Meier survival curves were constructed and compared using the log-rank test. Results : The baseline characteristics of the two groups were balanced. The median OS was 20.9 months (95% CI 14.3-27.6 months) in the TACE-MWA group and 13.0 months (95% CI 8.8-17.1 months) in the TACE-CRA group (P = 0.096). The median TTP was 8.8 months (95% CI 4.3-13.4 months) in the TACE-MWA group and 9.3 months (95% CI 7.1-11.5 months) in the TACE-CRA group (P = 0.675). After PSM, 48 patients remained in each group. The median OS in the TACE-MWA and TACE-CRA groups was 20.9 months (95% CI 14.3-27.6 months), and 13.5 months (95% CI 8.4-18.6 months, P = 0.100), respectively. The median TTP in the TACE-MWA and TACE-CRA groups was 8.8 months (95% CI 4.3-13.4 months), and 8.6 months (95% CI 3.1-14.2 months, P = 0.909), respectively. The overall incidence rate of ablation-related complications was lower in the TACE-MWA group than in the TACE-CRA group (66.7 vs. 88.3%, P = 0.006). Multivariate analysis showed that the presence of portal vein tumor thrombus (PVTT) and the maximum diameter of intrahepatic tumor were significant prognostic factors for OS and TTP. Conclusion: The efficacy of TACE-MWA and TACE-CRA in the treatment of unresectable HCC was comparable. TACE-MWA was more promising because of a lower complication rate, especially with regard to thrombocytopenia. Further prospective randomized controlled trials are required to validate our findings.

Factors Associated with Tumor Progression After Percutaneous Ablation of Hepatocellular Carcinoma: Comparison Between Monopolar Radiofrequency and Microwaves. Results of a Propensity Score Matching Analysis

PURPOSE

To identify risk factors for local and distant intrahepatic tumor progression after percutaneous ablation of HCC and to compare MWA with monopolar RFA.

MATERIALS AND METHODS

Consecutive patients with early or very early HCC who underwent percutaneous monopolar RFA or MWA were included. Factors associated with local and distant tumor progression were identified. Propensity score matching (PSM) was used to limit bias. Statistical analyses were performed with the Kaplan-Meier method using the log-rank test and Cox regression models.

RESULTS

One hundred ninety HCC (mean diameter 23 ± 8.6 mm) were treated by RFA (n = 90, 47%) or MWA (n = 100, 53%) in 152 patients (mean age 63 ± 11, 79% men) between 2009 and 2016. The technical success rate was 97.4% (n = 185 HCC). After a median follow-up of 24.6 months (IQR: 9.7-37.2), 43 (23%), HCC showed local tumor progression [after a median of 13.4 months (IQR: 5.8-24.3)] and 91 (63%) patients had distant intrahepatic tumor progression (after a median of 10.4 months (IQR: 5.7-22). The cox model after PSM identified treatment by RFA (HR, 2.89; P = 0.005), HCC size ≥ 30 mm (HR, 3.12; P = 0.007) and vascular contact (HR, 3.43; P = 0.005) as risk factors for local progression. Factors associated with distant intrahepatic progression were HCC ≥ 30 mm (HR, 1.94; P = 0.013), serum AFP > 100 ng/mL (HR, 2.56; p = 0.002), and hepatitis B carrier (HR, 0.51; p = 0.047).

CONCLUSION

The rate of local HCC progression was lower after MWA than monopolar RFA, regardless of tumor size and vascular contact. The ablation technique did not influence the risk of distant intrahepatic tumor progression.

A review of conventional and newer generation microwave ablation systems for hepatocellular carcinoma

Although microwave ablation (MWA) exhibits a high thermal efficiency, the major limitation of conventional MWA systems is the lack of predictability of the ablation zone size and shape. Therefore, a specific newer generation MWA system, The Emprint™ Ablation System with Thermosphere™ Technology, was designed to create predictable large spherical zones of ablation that are not impacted by varying tissue environments. The time required for ablation with MWA systems is short, and the shape of the necrosis is elliptical with the older systems and spherical with the new system. In addition, because MWA has no heat-sink effect, it can be used to ablate tumors adjacent to major vessels. Although these factors yield a large ablation volume and result in good local control, excessive ablation of liver tissue and unexpected ablation of surrounding organs are possible. Therefore, MWA should be carefully performed. This review highlights the efficacy and complications of MWA performed with conventional systems and the newer generation system in patients with hepatocellular carcinoma (HCC). MWA with the newer generation system seems to be a promising treatment option for large HCCs and secondary hepatic malignancies, with several advantages over other available ablation techniques, including conventional MWA. However, further randomized controlled trials are necessary to fully clarify the benefits and pitfalls of this new system.

Comparisons of recurrence-free survival and overall survival between microwave versus radiofrequency ablation treatment for hepatocellular carcinoma: A multiple centers retrospective cohort study with propensity score matching

Both microwave (MW) ablation and radiofrequency (RF) ablation are widely used for hepatocellular carcinoma (HCC) treatments in clinic. However, it is still unclear if ablative methods could influence the recurrence-free survival (RFS) and overall survival (OS) of HCC patients. Therefore, we carried out this multi-center retrospective cohort study to investigate the differences of recurrence-free survival (RFS) and overall survival (OS) between MW ablation and RF ablation by survival analysis. From January 2014 to December 2016, patients who received thermal ablation surgery for HCC treatment were screened. Finally, 452 patients met the eligibility criteria and finished the follow-up. Univariable and multivariable regression analyses were used to identify independent predictive factors of the RFS and OS. Also, propensity score matching (PSM) was used to balance the bias between two groups. Finally, we found that before the PSM, the univariable and multivariable regression analyses revealed that there were no significant differences on the RFS between two groups. Same results were obtained for the OS. After PSM, 115 pairs of patients were created, and both the univariable and multivariable regression analyses suggested that there were still no significant differences on the RFS between two groups. Same results were obtained for the OS. In conclusion, our present study showed that there were no significant differences between MW ablation and RF ablation for HCC patients on the RFS or OS.

Radiofrequency Ablation, Where It Stands in Interventional Radiology Today

Radiofrequency ablation (RFA) is one of the first developed minimally invasive definitive cancer therapies. The safety and efficacy of RFA is well documented and has led to its incorporation into multiple international societal guidelines. By expanding on the body of knowledge acquired during the clinical use of RFA, alternative ablative technologies have emerged and are successfully competing for locoregional therapy market share. The adaption of newer ablative technologies is leading to a rapid decline in the utilization of RFA by interventional radiologists despite the lack of proven superiority. In their 2010 article, Hong and Georgiades stated "… RFA is likely to remain the mainstay of ablations for small tumors until sufficient experience emerges for the widespread acceptance for alternative ablative modalities." Within a decade of this publication, has this time arrived?