High local recurrence of early-stage hepatocellular carcinoma after percutaneous thermal ablation in routine clinical practice

Multicenter Integration of MR Radiomics, Deep Learning, and Clinical Indicators for Predicting Hepatocellular Carcinoma Recurrence After Thermal Ablation

Background

To develop and validate an innovative predictive model that integrates multisequence magnetic resonance (MR) radiomics, deep learning features, and clinical indicators to accurately predict the recurrence of hepatocellular carcinoma (HCC) after thermal ablation.

Methods

This retrospective multicenter cohort study enrolled patients who were diagnosed with HCC and treated via thermal ablation. We extracted radiomic features from multisequence 3T MR images, analyzed these images using a 3D convolutional neural network (3D CNN), and incorporated clinical data into the model. Model performance was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

Results

The study included 535 patients from three hospitals, comprising 462 males and 43 females. The RDC model, which stands for the Radiomics-Deep Learning-Clinical data model, demonstrated high predictive accuracy, achieving AUCs of 0.794 in the training set, 0.777 in the validation set, and 0.787 in the test set. Statistical analysis confirmed the model's robustness and the significant contribution of the integrated features to its predictive capabilities.

Conclusion

The RDC model effectively predicts HCC recurrence after thermal ablation by synergistically combining advanced imaging analysis and clinical parameters. This study highlights the potential of such integrative approaches to enhance prognostic assessments in HCC patients and offers a promising tool for clinical decision-making.

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.

Evolution of Response-Based Radiotherapy for Hepatocellular Cancer

ABSTRACT

Stereotactic body radiation therapy has emerged as a safe and effective treatment modality for properly selected hepatocellular cancer (HCC) patients with normal liver function. However, many HCC patients have reduced baseline liver function due to underlying cirrhosis or prior liver-directed therapies. Therefore, because of the increased risk of hepatotoxicity, the use of stereotactic body radiation therapy for patients with reduced liver function has been approached with caution. Individualized, response-based radiotherapy incorporates models, imaging tools, and biomarkers that determine the dose-response relationship of the liver before, during, and after treatment and has been useful in reducing the likelihood of liver damage without sacrificing tumor control. This review discusses the evolution of response-based radiotherapy for HCC and highlights areas for further investigation.

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.

Detection of Ablation Boundaries Using Different MR Sequences in a Swine Liver Model

PURPOSE

To determine the magnetic resonance (MR) sequences best suited for the assessment of ablation zones after radiofrequency ablation (RFA).

METHODS

Three percutaneous MR-guided RFA of the liver were performed on three swine. Four pre-contrast and two hepatobiliary post-contrast sequences were obtained after ablation. Tissue samples were extracted and stained for nicotinamide adenine dinucleotide diaphorase hydride (NADH) and with hematoxylin and eosin. Post-ablation MR images and NADH slides were segmented to determine the total ablation zone, their Dice similarity coefficient (DSC), and the contrast-to-noise ratio (CNR) of the visible ablation boundary to normal liver tissue.

RESULTS

Two distinct layers were combined to determine the ablation zone: an inner layer of coagulation necrosis and an outer layer defined as the peripheral transition zone. Corresponding zones could be found in the MR images as well. Compared to histology, the total area of the MR ablation zone was significantly smaller on the pre-contrast T1 images (p < 0.01) and significantly larger with T2 turbo spin-echo (p = 0.025). No significant difference in size of the ablation zone depiction could be found between histology, post-contrast T1 volumetric interpolated breath-hold examination (VIBE), and post-contrast T1 3D Turboflash (TFL) as well as T2 SPACE images. All sequences but the pre-contrast T1 VIBE sequence showed a DSC above 80% and a high CNR.

CONCLUSIONS

Post-contrast T1 3DTFL performs best when assessing ablation zones after RFA. Since the sequence requires a long acquisition time, T1 VIBE post-contrast offers the best compromise between acquisition time and estimation accuracy.

Percutaneous radiofrequency ablation of solitary hepatic metastasis from colorectal cancer: Risk factors of local tumor progression-free survival and overall survival

Purpose

This study aimed to evaluate local tumor progression-free survival (LTPFS) and overall survival (OS) after percutaneous radiofrequency ablation (RFA) for solitary colorectal liver metastases (CLM) <3 cm and to identify the risk factors associated with poor LTPFS and OS after percutaneous RFA.

Methods

This study screened 219 patients who underwent percutaneous RFA for CLM between January 2013 and November 2020. Of these, 92 patients with a single CLM <3 cm were included. LTPFS and OS were calculated using the Kaplan-Meier method, and the differences between curves were compared using the log-rank test. Risk factors for LTPFS and OS were assessed using Cox proportional-hazard regression models.

Results

Technical efficacy was achieved in the first (n=91) or second (n=1) RFA sessions. During the follow-up (median, 20.0 months), cumulative LTPFS rates at 1, 3, and 5 years were 92.4%, 83.4%, and 76.5%, respectively. During the follow-up (median, 27.8 months), the corresponding OS rates were 97.5%, 81.3%, and 74.8%, respectively. In multivariable Cox regression analyses, the group with both tumor-puncturing RFA and a T4 stage primary tumor (hazard ratio, 3.3; 95% confidence interval, 1.1 to 10.2; P=0.037) had poor LTPFS. In the univariable analysis, no factors were significantly associated with poor OS.

Conclusion

Both LTPFS and OS were promising after percutaneous RFA for a single CLM <3 cm. The group with both tumor-puncturing RFA and a T4 stage primary tumor showed poor LTPFS. No risk factors were identified for poor OS.

Theoretical Evaluation of Microwave Ablation Applied on Muscle, Fat and Bone: A Numerical Study

(1) Background: Microwave ablation (MWA) is a common tumor ablation surgery. Because of the high temperature of the ablation antenna, it is strongly destructive to surrounding vital tissues, resulting in high professional requirements for clinicians. The method used to carry out temperature observation and damage prediction in MWA is significant; (2) Methods: This work employs numerical study to explore temperature distribution of typical tissues in MWA. Firstly, clinical MWA based on isolated biological tissue is implemented. Then, the Pennes models and microwave radiation physics are established based on experimental parameters and existing related research. Initial values and boundary conditions are adjusted to better meet the real clinical materials and experimental conditions. Finally, clinical MWA data test this model. On the premise that the model is matched with clinical MWA, fat and bone are deduced for further heat transfer analysis. (3) Results: Numerical study obtains the temperature distribution of biological tissue in MWA. It observes the heat transfer law of ablation antenna in biological tissue. Additionally, combined with temperature threshold, it generates thermal damage of biological tissues and predicts the possible risks in MWA; (4) Conclusions: This work proposes a numerical study of typical biological tissues. It provides a new theoretical basis for clinically thermal ablation surgery.

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.

A Novel Scoring System for Patients with Recurrence of Hepatocellular Carcinoma After Undergoing Minimal Invasive Therapies

Background

The higher recurrence rate of hepatocellular carcinoma (HCC) needs to be urgently controlled. However, definitive markers are lacking for patients with recurrence of HCC after undergoing minimal invasive therapies-local ablation combined with transcatheter arterial chemoembolization (TACE).

Materials and methods

Demographic and clinicopathological data of 234 subjects receiving combined therapies as the initial treatment were retrospectively analyzed. Univariate and multivariate Cox regression analysis was used to assess independent risk factors of recurrence. Selected variables were divided into low-, intermediate-, and high-risk groups of recurrence according to the scores assigned to them based on their respective hazard ratio (HR) values. The area under the curve (AUC) was used to evaluate the predictive value of the scoring system. Cumulative recurrence-free survival (RFS) and overall survival rates were calculated by the Kaplan-Meier estimator. Finally, a correlation analysis was performed on demographic and clinical data among the three groups.

Results

The AUC of predicting 1-, 2-, and 3-year recurrence rates was 0.680, 0.728, and 0.709, respectively. The cumulative RFS rate in the low-risk group at 1, 2, and 3 years after undergoing combined treatments was 4%, 12.2%, and 30.6%, while that in the intermediate-risk group and high-risk group was 23.4%, 51.6%, 60.0%, and 47.3%, 78.2%, 83.6%, respectively. Gamma-glutamyltransferase (γ-GT), blood urea nitrogen (BUN), and total cholesterol (TC) levels among the three groups were statistically different.

Conclusion

The scoring system of the present study for patients with the recurrence of HCC after undergoing TACE combined with local ablation may help physicians make a reasonable clinical decision, providing ideal management for diagnosis and treatment.

Microwave ablation compared with radiofrequency ablation for treatment of hepatocellular carcinoma and liver metastases: a systematic review and meta-analysis

Purpose

Percutaneous ablation techniques, including microwave ablation (MWA) and radiofrequency ablation (RFA), have become important minimally invasive treatment options for liver cancer. This systematic review compared MWA with RFA for treatment of liver cancer.

Methods

The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials was conducted for randomized and observational studies published from 2006 onwards. A random-effects model was used for meta-analyses and local tumor progression (LTP), technique efficacy, overall survival (OS), disease-free survival (DFS), intrahepatic de novo lesions (IDL), extrahepatic metastases (EHM), length of stay (LOS), and complications were analyzed. Subgroup and sensitivity analyses were also conducted.

Results

Of 1379 studies identified, 28 randomized and observational studies met inclusion criteria. The main analysis demonstrated that LTP was significantly reduced by 30% with MWA versus RFA (RR=0.70; P=0.02) (all studies) and by 45% with MWA versus RFA (RR=0.55; P=0.007) (randomized studies only). There were no significant differences between MWA and RFA for other efficacy and safety outcomes. Higher frequency (2450 MHz) and larger tumor size (≥2.5 cm) are amongst variables that may be associated with improved outcomes for MWA. Sensitivity analyses were generally congruent with the main results.

Conclusion

MWA is at least as safe and effective as RFA for treating liver cancer and demonstrated significantly reduced LTP rates. Future studies should assess time and costs associated with these two treatment modalities.

Predictive factors of treatment outcomes after percutaneous ablation of hepatocellular carcinoma in the caudate lobe: a retrospective study

Background

Hepatocellular carcinomas (HCC) arising in the caudate lobe is rare and the treatment is difficult. The aim of this study is to summarize the experience of ultrasound-guided percutaneous ablation therapy for HCC located in the caudate lobe and to investigate the predictive factors of the treatment outcomes.

Methods

From August 2006 to June 2017, 73 patients (63 males and 10 females; mean age, 54.9 ± 11.6 years; age range, 25–79 years) with 73 caudate lobe HCCs (mean size, 2.6 ± 1.1 cm; size range, 1.0–5.0 cm) were treated with percutaneous ablation, including 33 patients with radiofrequency ablation (RFA), 23 patients with ethanol ablation (EA), and 17 patients with combination of RFA and EA. The treatment outcome and survival after ablation for caudate lobe HCC were assessed and the predictive factors were calculated by univariate and multivariate analyses.

Results

A total of 72 patients achieved complete ablation after the first or second session of ablation. The treatment effectiveness was 98.6% (72/73). During the follow-up, 16 tumors developed local tumor progression (LTP) and a total of 61 patients (61/73, 83.6%) were detected distant recurrence (DR). According to univariate and multivariate analyses, tumor size > 2 cm (hazard ratio[HR] = 3.667; 95% confidence interval[CI], 1.043–12.889; P = 0.043) was a significant prognostic factor of LTP after ablation for HCC in the caudate lobe, while tumor number (HR = 2.245; 95%CI, 1.168–4.317; P = 0.015) was a significant prognostic factor of DR. The mean overall survival time after ablation was 28.7 ± 2.8 months, without independent predictive factors detected. Four patients (4/73, 5.5%) were detected treatment-related major complications, without independent predictive factor detected.

Conclusion

Ultrasound-guided percutaneous ablation is a feasible treatment for a selected case with HCC in the caudate lobe. Tumor size > 2 cm increases the risk of LTP and intrahepatic tumor number is associated with DR after ablation.

Stereotactic body radiation therapy for early hepatocellular carcinoma: a retrospective analysis of the South Australian experience

BACKGROUND

Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver tumours unsuitable for established curative treatment such as ablation or surgery. The aim of the study is to evaluate the efficacy and safety of SBRT in the treatment of small hepatocellular carcinoma (HCC) in South Australia.

METHODS

From 2014 to 2018, 13 HCC patients were treated with SBRT. Eligibility criteria for SBRT included: unsuitable for standard curative therapies (resection or percutaneous ablation), lack of complete response to prior transarterial chemoembolization, Child-Pugh classification ≤B7, tumours ≤5 cm and minimum of up to 6 months follow-up post-SBRT. The prescribed radiation dose was determined by liver function with doses ranging from 40 to 45 Gy in three or five fractions. Records for all patients were reviewed, and treatment response was scored according to the modified response evaluation criteria in solid tumours. Toxicity was graded according to the Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

The median follow-up time was 22.7 months, and the median tumour size was 40 mm. The 1 year local control was 92.3%, recurrence-free survival was 67.7% and overall survival was 86.4% at end of study. Three patients underwent liver transplant. No grade ≥3 non-haematological toxicities were observed. One patient experienced acute grade ≥3 haematological toxicity.

CONCLUSION

SBRT is a safe, effective and non-invasive alternative treatment option for patients with small HCCs, unsuitable for standard, evidence-based therapies and lacking complete response to transarterial chemoembolization. Randomized controlled trials are required to further investigate the role of SBRT in HCC.

Comparison of microwave ablation and radiofrequency ablation for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Microwave ablation (MWA) has several advantages over radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC). We aimed to compare the efficacy and safety of MWA with those of RFA for HCC from the perspectives of percutaneous and laparoscopic approaches.

METHODS

PubMed/MEDLINE, Embase, the Cochrane library, and China Biology Medicine databases were searched. Studies comparing the efficacy and safety of MWA with those of RFA in patients with HCC were considered eligible. Complete ablation (CA), local recurrence (LR), disease-free survival (DFS), overall survival (OS), and the major complication rate were compared between MWA and RFA.

RESULTS

Four randomized controlled trials and 10 cohort studies were included. For percutaneous ablation, no significant difference was found between MWA and RFA regarding CA, LR, DFS, OS, and the major complication rate. A subgroup analysis of tumors measuring ≥3 cm revealed no difference in CA and LR for percutaneous ablation. For laparoscopic ablation, a significantly lower LR rate and a non-significant trend toward a higher major complication rate were observed for the MWA group (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.16-4.02, p = .01 for LR; OR 0.21, 95% CI 0.04-1.03, p = .05 for major complication rate). CA, DFS, and OS were similar between the two groups.

CONCLUSIONS

Percutaneous (P)-MWA had similar therapeutic effects compared with P-RFA for HCC. Patients undergoing laparoscopic MWA had a lower LR rate; however, their major complication rate appeared to be higher. The superiority of MWA over RFA remains unclear and needs to be confirmed by high-quality evidence.

Radiofrequency ablation of hepatocellular carcinoma: a meta-analysis of overall survival and recurrence-free survival

Background and aims

So far, no randomized trial or meta-analysis has been conducted on overall survival (OS) and recurrence-free survival (RFS) factors in patients treated with radiofrequency ablation (RFA) alone. The purpose of this meta-analysis was to evaluate prognostic factors of OS and RFS in patients treated with RFA.

Methods

A primary analysis was planned to evaluate the clinical prognostic factor of OS. RFS was the secondary aim. Thirty-four studies published from 2003 to 2017 were analyzed. They included 11,216 hepatocellular carcinoma patients.

Results

The results showed that Child-Pugh B vs Child-Pugh A (HR =2.32; 95% CI: 2.201-2.69; P<0.0001) and albumin-bilirubin score 1 vs 0 (HR =2.69; 95% CI: 2.10-3.44; P<0.0001) were predictive of poor OS. Tumor size as a continuous variable was not predictive of OS, although it was predictive of OS when we considered the size as a cutoff value (.2 cm vs <2 cm: HR =1.41; 95% CI: 1.23-1.61; P<0.0001; >3 cm vs <3 cm: HR =1.43; 95% CI: 1.17-1.74; P<0.0001) and in presence of >1 nodule (HR =1.59; 95% CI: 1.46-1.74; P<0.0001). Alpha-fetoprotein >20 ng/mL (HR =1.46; 95% CI: 1.25-1.70; P<0.0001) was the only predictive factor of poor prognosis.

Conclusion

Our meta-analysis highlighted that the maximum benefit of RFA in terms of OS and RFS is reached in the presence of Child-Pugh A, albumin-bilirubin score 1, single-nodule tumor sized <2 cm, and alpha-fetoprotein <20 ng/mL.

The local liver ablation with pulsed electric field stimulate systemic immune reaction against hepatocellular carcinoma (HCC) with time-dependent cytokine profile

AIM

How irreversible electroporation (IRE) affect immune status is still kept unknown. This preclinical study is to investigate its local and systemic immune reaction both on tumor-bearing and tumor free animals.

METHODS

Liver ablation was performed by a standard IRE instrument and proposal. Altogether 57 tumor bearing mice and 10 tumor-free porcine livers were ablated. The reaction of survival, radiology image, pathologically and immunologically were followed up. The detailed cytokines and chemokines responses were recorded dynamically post IRE ablation.

RESULTS

IRE ablation induced coagulation and necrosis in liver. It caused macrophages infiltration, in ablation zone. IRE ablation caused cellular inflammation. It, corrected the abnormal drifted Th2 in HCC back to Th1 status, promoting tumor eradication and host survival. The quantified cytokines and chemokines indicate IRE can stimulate both local immune reaction and systemic immune reaction.

CONCLUSION

Local IRE ablation changes the abnormal drifted Th2 in HCC back to Th1 status, facilitating tumor eradication and host survival.

High-Frequency Irreversible Electroporation: Safety and Efficacy of Next-Generation Irreversible Electroporation Adjacent to Critical Hepatic Structures

Irreversible electroporation (IRE) is a nonthermal ablation modality employed to induce in situ tissue-cell death. This study sought to evaluate the efficacy of a novel high-frequency IRE (H-FIRE) system to perform hepatic ablations across, or adjacent to, critical vascular and biliary structures. Using ultrasound guidance H-FIRE electrodes were placed across, or adjacent to, portal pedicels, hepatic veins, or the gall bladder in a porcine model. H-FIRE pulses were delivered (2250 V, 2-5-2 pulse configuration) in the absence of cardiac synchronization or intraoperative paralytics. Six hours after H-FIRE the liver was resected and analyzed. Nine ablations were performed in 3 separate experimental groups (major vessels straddled by electrodes, electrodes placed adjacent to major vessels, electrodes placed adjacent to gall bladder). Average ablation time was 290 ± 63 seconds. No electrocardiogram abnormalities or changes in vital signs were observed during H-FIRE. At necropsy, no vascular damage, coagulated-thermally desiccated blood vessels, or perforated biliary structures were noted. Histologically, H-FIRE demonstrated effective tissue ablation and uniform induction of apoptotic cell death in the parenchyma independent of vascular or biliary structure location. Detailed microscopic analysis revealed minor endothelial damage within areas subjected to H-FIRE, particularly in regions proximal to electrode insertion. These data indicate H-FIRE is a novel means to perform rapid, reproducible IRE in liver tissue while preserving gross vascular/biliary architecture. These characteristics raise the potential for long-term survival studies to test the viability of this technology toward clinical use to target tumors not amenable to thermal ablation or resection.

Microwave ablation is as effective as radiofrequency ablation for very-early-stage hepatocellular carcinoma

BACKGROUND

Percutaneous radiofrequency ablation (RFA) is a first-line treatment for very-early-stage hepatocellular carcinoma (HCC), whereas the efficacy of percutaneous microwave ablation (MWA) for very-early-stage HCC remains unclear. The purpose of this study was to clarify this issue by comparing the safety and efficacy of percutaneous MWA with percutaneous RFA in treating very-early-stage HCC.

METHODS

Clinical data of 460 patients who were diagnosed with very-early-stage HCC and treated with percutaneous MWA or RFA between January 2007 and July 2012 at the Eastern Hepatobiliary Surgery Hospital, The Second Military Medical University, in Shanghai, China were retrospectively analyzed. Of these 460 patients, 159 received RFA, 301 received MWA. Overall survival (OS), recurrence-free survival (RFS), local tumor progression (LTP), complete ablation, and complication occurrence rates were compared between the two groups, and the prognostic factors associated with survival were analyzed.

RESULTS

No significant differences were observed between the two groups in terms of the 1-, 3-, or 5-year OS rates (99.3%, 90.4%, and 78.3% for MWA vs. 98.7%, 86.8%, and 73.3% for RFA, respectively; P = 0.331). Furthermore, no significant differences were observed between the two groups in terms of the corresponding RFS rates (94.4%, 71.8%, and 46.9% for MWA vs. 89.9%, 67.3%, and 54.9% for RFA, respectively; P = 0.309), the LTP rates (9.6% vs. 10.1%, P = 0.883), the complete ablation rates (98.3% vs. 98.1%, P = 0.860), or the occurrence rates of major complications (0.7% vs. 0.6%, P = 0.691). By multivariate analysis, LTP, antiviral therapy, and treatment of recurrence were independent risk factors for OS (P < 0.001), and the alpha-fetoprotein level was an independent prognostic factor for RFS (P = 0.002).

CONCLUSIONS

MWA is as safe and effective as RFA in treating very-early-stage HCC, supporting MWA as a first-line treatment option for this disease.

Comparison of Laparoscopic Microwave to Radiofrequency Ablation of Small Hepatocellular Carcinoma (≤3 cm)

BACKGROUND

Laparoscopic thermal ablation is a common alternative to surgical resection in treating hepatic tumors, particularly in those located in difficult-to-reach locations.

OBJECTIVE

The aim of this study was to compare the safety and long-term efficacy of laparoscopic radiofrequency ablation (RFA) and microwave ablation (MWA) in treating hepatocellular carcinoma (HCC).

METHOD

From February 2009 to May 2015, data from patients with HCC nodules who had undergone either laparoscopic MWA or laparoscopic RFA were examined. Complications, complete ablation rates, local tumor progression (LTP) rates, and disease-free and cumulative survival rates were compared between the two treatment groups.

RESULTS

A total of 154 patients with HCC (60 MWA and 94 RFA) were treated via the laparoscopic approach. Major complication rates were identified as 1 and 2 % in the RFA and MWA groups, respectively (p = 0.747). Complete ablation rates were 95 % for both treatment groups (p = 0.931), and LTP rates were 21.2 % for RFA and 8.3 % for MWA (p = 0.034). Disease-free survival rates at 5 years were 19 % in the RFA group and 12 % in the MWA group (p = 0.434), while cumulative survival rates at 5 years were 50 % in the RFA group and 37 % in the MWA group (p = 0.185).

CONCLUSION

Laparoscopic RFA and MWA appear to be safe in the treatment of early-stage HCC. The LTP rates were lower in the laparoscopic MWA group compared with the laparoscopic RFA group, but their respective overall and disease-free survival rates remained similar.

A Comparison between Three-Dimensional Visualization Guided Hepatectomy and Ultrasonography Guided Radiofrequency Ablation in the Treatment of Small Hepatocellular Carcinoma within the Milan Criteria

Background. Treatment selection for small hepatocellular carcinoma (sHCC) is controversial. We aimed to compare the outcomes of medical imaging three-dimensional visualization system (MI-3DVS) guided surgical resection (SR) and ultrasonography guided radiofrequency ablation (RFA) for sHCC. Methods. In total, 194 patients who underwent SR or RFA in our hospital between January 2006 and May 2010 were retrospectively enrolled. Overall survival (OS), recurrence-free survival (RFS), and postoperative complications were compared. Cox regression was used to estimate the benefits of MI-3DVS-guided SR on OS and RFS. Results. Ninety-two patients underwent SR and 102 underwent RFA. The SR group experienced more complications (41.3% versus 19.6%) and longer hospital stay (18.04 ± 7.11 versus 13.06 ± 5.59) (both p < 0.05). The 1-, 2-, 3-, 4-, and 5-year OS was 96.7%, 95.7%, 93.5%, 83.5%, and 61.1% in the SR group and 95.0%, 88.1%, 72.7%, 56.9%, and 39.5% in the RFA group. Corresponding RFS was 95.7%, 94.6%, 84.7%, 59.8%, and 40.2% in SR group and 91.2%, 80.3%, 60.5%, 32.3%, and 22.3% in RFA group. The 5-year OS and RFS were higher in SR group (both p < 0.001). Interestingly, there was no significance in OS and RFS among subgroups aged >60 years. Independent predictors of OS and RFS, respectively, were intervention (HR, 2.769 and 1.933), tumor number (HR, 5.128 and 3.903), and serum alpha-fetoprotein (AFP) (HR, 1.871 and 1.474) (all p < 0.05). Conclusions. MI-3DVS based hepatectomy should be considered primary treatment while RFA can be treated as alternative therapy for older patients. Intervention, tumor number, and AFP are independent predictors for both survival and recurrence.

Percutaneous thermal ablation for primary hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Percutaneous thermal ablation using radiofrequency ablation (RFA) and microwave ablation (MWA) are both widely available curative treatments for hepatocellular carcinoma. Despite significant advances, it remains unclear which modality results in better outcomes. This meta-analysis of randomized controlled trials (RCT) and observational studies was undertaken to compare the techniques in terms of effectiveness and safety.

METHODS

Electronic reference databases (Medline, EMBASE and Cochrane Central) were searched between January 1980 and May 2014 for human studies comparing RFA and MWA. The primary outcome was the risk of local tumor progression (LTP). Secondary outcomes were complete ablation (CA), overall survival, and major adverse events (AE). The ORs were combined across studies using the random-effects model.

RESULTS

Ten studies (two prospective and eight retrospective) were included, and the overall LTP rate was 13.6% (176/1298). There was no difference in LTP rates between RFA and MWA [OR (95% CI): 1.01(0.67-1.50), P = 0.9]. The CA rate, 1- and 3-year overall survival and major AE were similar between the two modalities (P > 0.05 for all). In subgroup analysis, there was no difference in LTP rates according to study quality, but LTP rates were lower with MWA for treatment of larger tumors [1.88(1.10-3.23), P = 0.02]. There was no significant publication bias or inter-study heterogeneity (I(2) < 50% and P > 0.1) observed in any of the measured outcomes.

CONCLUSION

Overall, both RFA and MWA are equally effective and safe, but MWA may be more effective compared to RFA in preventing LTP when treating larger tumors. Well-designed, larger, multicentre RCTs are required to confirm these findings.

New horizons in ablation therapy for hepatocellular carcinoma

Historically ablative treatment for hepatocellular cancer (HCC) has been regarded as inferior to transplantation and resection and has therefore been reserved for patients not suitable for surgical intervention in stage 0-A HCC according to the Barcelona Clinic Liver Cancer classification system. In the wake of surgical strategies challenging the current Barcelona Clinic Liver Cancer treatment guidelines and improvements in imaging, targeting and ablation technologies, ablation is likely to occupy a more central role in the management of patients with HCC, challenging its historically perceived inferiority to resection.