Radiofrequency ablation of hepatocellular carcinoma: Current status

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.

Salvage locoregional therapies for recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death worldwide. Despite the advent of screening efforts and algorithms to stratify patients into appropriate treatment strategies, recurrence rates remain high. In contrast to first-line treatment for HCC, which relies on several factors, including clinical staging, tumor burden, and liver function, there is no consensus or general treatment recommendations for recurrent HCC (R-HCC). Locoregional therapies include a spectrum of minimally invasive liver-directed treatments which can be used as either curative or neoadjuvant therapy for HCC. Herein, we provide a comprehensive review of recent evidence using salvage loco-regional therapies for R-HCC after failed curative-intent.

A Case of Adrenocortical Carcinoma With a Favorable Tumor Control by Radiofrequency Ablation for Liver Metastasis

A 57-year-old woman was diagnosed with adrenocortical carcinoma. Following the adrenalectomy, she underwent adjuvant radiation and mitotane therapy; however, liver metastases were observed. Repeated radiofrequency ablation (RFA) was performed for liver metastases. In addition, a multidisciplinary approach combining systemic chemotherapy, radiotherapy, and surgery was used for lung and distant lymph node metastases that arose during the course of treatment. Notably, 49 months have passed since the adrenalectomy and 36 months since the recurrence of the liver metastases, and the patient remains on multidisciplinary therapy. Thus, RFA for liver metastasis of adrenocortical carcinoma may be an effective component of a multidisciplinary treatment.

One-Step Method in Creation of Artificial Ascites

Background

The study aims to improve the success rate and the rapidity in creating artificial ascites before starting the treatment for subcapsular hepatocellular carcinomas.

Methods

Two hundred and forty-six consecutive hepatocellular carcinoma patients who required the instillation of artificial ascites for better visualization or prevention from organ injury were recruited between November 2011 and September 2017. Initially, 95 patients were using the Seldinger technique, while the remaining 151 patients were using the one-step method. The proportions of patients who had undergone surgery, transarterial chemoembolization, or radiofrequency ablation therapy before performing artificial ascites infusion were 11.6% (11/95), 3% (3/95), and 37% (35/95) in the Seldinger group, and 15.9% (24/151), 15.2% (23/151), and 52.3% (79/151), respectively, in the one-step group.

Results

The complete success rate, partial success rate, and failure rate in creating artificial ascites using the Seldinger technique and the one-step method were 76.8% (73/95), 11.6% (11/95), 11.6% (11/95) and 88.1% (133/151), 7.9% (12/151), 4% (6/151), respectively. The complete success rate was significantly higher in the one-step method group (P < 0.05) than that of the Seldinger group. The mean time required from starting the procedure to successful intraperitoneal instillation of glucose water was 145.79 ± 133.37 s in the one-step method, which was statistically shorter than that of 238.68 ± 95.58 s in the Seldinger group (P < 0.05).

Conclusion

The one-step method has a higher success rate than the Seldinger method in creating artificial ascites and is faster, especially in treatment-experienced patients.

Radiofrequency ablation in the treatment of hepatocellular carcinoma

OBJECTIVE

The purpose of this article is to discuss the use, comparative efficacy, and research progress of radiofrequency ablation (RFA), alone or in combination with other therapies, for the treatment of hepatocellular carcinoma (HCC).

METHOD

To search and summarize the basic and clinical studies of RFA in recent years.

RESULTS

RFA is one of the radical treatment methods listed in the guidelines for the diagnosis and treatment of HCC. It has the characteristics of being minimally invasive and safe and can obtain good local tumor control, and it can improve the local immune ability, improve the tumor microenvironment and enhance the efficacy of chemotherapy drugs. It is commonly used for HCC treatment before liver transplantation and combined ALPPS and hepatectomy for HCC. In addition, the technology of RFA is constantly developing. The birth of noninvasive, no-touch RFA technology and equipment and the precise RFA concept have improved the therapeutic effect of RFA.

CONCLUSION

RFA has good local tumor control ability, is minimally invasive, is safe and has other beneficial characteristics. It plays an increasingly important role in the comprehensive treatment strategy of HCC. Whether RFA alone or combined with other technologies expands the surgical indications of patients with HCC and provides more benefits for HCC patients needs to be determined.

ARID1A expression in hepatocellular carcinoma and relation to tumor recurrence after microwave ablation

Aim of the study

AT-rich interactive domain 1A (ARID1A) is a subunit of the switch/sucrose non-fermentable chromatin remodeling complex, which is commonly mutated in human cancers. The clinical and pathological significance of ARID1A alteration in hepatocellular carcinoma (HCC) has not yet been clarified. The present study aimed to evaluate the clinical significance of the ARID1A gene signature in HCC and its relation to the likelihood of tumor recurrence after microwave ablation (MWA).

Material and methods

This study included 50 patients with cirrhotic HCC of Barcelona Clinic Liver Cancer stages 0/A eligible for MWA. Tumor and peri-tumor biopsies were obtained just prior to MWA and assessed for tumor pathological grade and ARID1A expression by immunohistochemistry. Patients were followed for one year after complete tumor ablation to detect any recurrence.

Results

Tumor size (^MCp = 0.010) and α-fetoprotein level (p = 0.013) can effectively predict the response to MWA. Nuclear expression of ARID1A was significantly lower in HCC compared to the corresponding peri-tumor cirrhotic liver tissues (p = 0.002), but no significant difference in ARID1A cytoplasmic expression was found. Nuclear ARID1A expression level in HCC showed a significantly negative relation to tumor size (^MCp = 0.006), pathological grade (^MCp = 0.046) and post-MWA tumor recurrence (^FEp = 0.041).

Conclusions

ARID1A loss may enhance HCC aggressiveness and post-MWA tumor recurrence. ARID1A could be a potential target to select HCC patients for future therapies.

Green-Synthesized Silver Nanoparticle-Assisted Radiofrequency Ablation for Improved Thermal Treatment Distribution

Thermal ablation therapy is known as an advantageous alternative to surgery allowing the treatment of multiple tumors located in hard-to-reach locations or treating patients with medical conditions that are not compatible with surgery. Appropriate heat propagation and precise control over the heat propagation is considered a weak point of thermal ablation therapy. In this work, silver nanoparticles (AgNPs) are used to improve the heat propagation properties during the thermal ablation procedure. Green-synthesized silver nanoparticles offer several attractive features, such as excellent thermal conductivity, biocompatibility, and antimicrobial activity. A distributed multiplexed fiber optic sensing system is used to monitor precisely the temperature change during nanoparticle-assisted radiofrequency ablation. An array of six MgO-based nanoparticles doped optical fibers spliced to single-mode fibers allowed us to obtain the two-dimensional thermal maps in a real time employing optical backscattering reflectometry at 2 mm resolution and 120 sensing points. The silver nanoparticles at 5, 10, and 20 mg/mL were employed to investigate their heating effects at several positions on the tissue regarding the active electrode. In addition, the pristine tissue and tissue treated with agarose solution were also tested for reference purposes. The results demonstrated that silver nanoparticles could increase the temperature during thermal therapies by propagating the heat. The highest temperature increase was obtained for 5 mg/mL silver nanoparticles introduced to the area close to the electrode with a 102% increase of the ablated area compared to the pristine tissue.

Recent update on comprehensive therapy for advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. The treatment methods for HCC are diverse, mainly including surgical resection, ablation, and liver transplantation. The curative effect can be achieved only for early stage HCC, and it is easy to recur and metastasize after surgery, with a 5-year recurrence rate as high as 70%. Most patients with HCC are in the middle and advanced stage at the time of diagnosis and lose the chance of surgical resection. In recent years, with the in-depth study of the pathogenesis of HCC and the progress of medical science and technology, the systemic treatment of advanced HCC has made a breakthrough. At present, multidisciplinary comprehensive treatment including targeted therapy and immunotherapy has become an effective strategy and inevitable trend for the treatment of advanced HCC. Combined therapy has greatly improved the prognosis of HCC patients and opened up a new milestone in the treatment of this malignancy. In this article, we focus on the treatment progress of advanced HCC to further guide clinical practice.

Machine Learning Can Predict Total Death After Radiofrequency Ablation in Liver Cancer Patients

Objective:

Over 1 million new cases of hepatocellular carcinoma (HCC) are diagnosed worldwide every year. Its prognosis remains poor, and the 5-year survival rate in all disease stages is estimated to be between 10% and 20%. Radiofrequency ablation (RFA) has become an important local treatment for liver cancer, and machine learning (ML) can provide many shortcuts for liver cancer medical research. Therefore, we explore the role of ML in predicting the total mortality of liver cancer patients undergoing RFA.

Methods:

This study is a secondary analysis of public database data from 578 liver cancer patients. We used Python for ML to establish the prognosis model.

Results:

The results showed that the 5 most important factors were platelet count (PLT), Alpha-fetoprotein (AFP), age, tumor size, and total bilirubin, respectively. Results of the total death model for liver cancer patients in test group: among the 5 algorithm models, the highest accuracy rate was that of gbm (0.681), followed by the Logistic algorithm (0.672); among the 5 algorithms, area under the curve (AUC) values, from high to low, were Logistic (0.738), DecisionTree (0.723), gbm (0.717), GradientBoosting (0.714), and Forest (0.693); Among the 5 algorithms, gbm had the highest precision rate (0.721), followed by the Logistic algorithm (0.714). Among the 5 algorithms, DecisionTree had the highest recall rate (0.642), followed by the GradientBoosting algorithm (0.571).

Conclusion:

Machine learning can predict total death after RFA in liver cancer patients. Therefore, ML research has great potential for both personalized treatment and prognosis of liver cancer.

Three-Dimensional Radiological Assessment of Ablative Margins in Hepatocellular Carcinoma: Pilot Study of Overlay Fused CT/MRI Imaging with Automatic Registration

BACKGROUND

We investigate the feasibility of image fusion application for ablative margin assessment in radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) and possible causes for a wrong initial evaluation of technical success through a side-by-side comparison.

METHODS

A total of 467 patients with 1100 HCCs who underwent RFA were reviewed retrospectively. Seventeen patients developed local tumor progressions (LTPs) (median size, 1.0 cm) despite initial judgments of successful ablation referring to contrast-enhanced images obtained in the 24 h after ablation. The ablative margins were reevaluated radiologically by overlaying fused images pre- and post-ablation.

RESULTS

The initial categorizations of the 17 LTPs had been grade A (absolutely curative) (n = 5) and grade B (relatively curative) (n = 12); however, the reevaluation altered the response categories to eight grade C (margin-zero ablation) and nine grade D (existence of residual HCC). LTP occurred in eight patients re-graded as C within 4 to 30.3 months (median, 14.3) and in nine patients re-graded as D within 2.4 to 6.7 months (median, 4.2) (p = 0.006). Periablational hyperemia enhancements concealed all nine HCCs reevaluated as grade D.

CONCLUSION

Side-by-side comparisons carry a risk of misleading diagnoses for LTP of HCC. Overlay fused imaging technology can be used to evaluate HCC ablative margin with high accuracy.

Currently available treatment options for neuroendocrine liver metastases

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

Resection or radiofrequency ablation for hepatocellular carcinoma? Assessment of validity of current studies, meta-analyses and their influence on guidelines

BACKGROUND

Two Cochrane reviews compared overall survival following liver resection (LR) or radiofrequency ablation (RFA) for patients with hepatocellular carcinoma. The first from 2013, found moderate evidence for a survival advantage for LR over RFA when limiting the analysis to trials at low risk of bias. The second (2017), found no evidence for a difference in all-cause mortality for LR versus RFA. Aim was to assess the validity of the randomized controlled trials included in both Cochrane reviews and to investigate their impact on current guidelines.

METHODS

The validity of the studies was analyzed using the CONSORT checklist. Two meta-analyses were then performed with all eligible studies from both meta-analyses. Finally, the impact of the result of the original meta-analyses on eight international guidelines was assessed.

RESULTS

The four randomized controlled trials showed several inconsistencies (unclear or inadequate randomization, absence of sample-size calculation, missing blinded setup and/or conflicts of interest). All guidelines used recommendations based on the results of the meta-analyses or on studies included in the meta-analyses.

CONCLUSION

The analyzed studies showed a substantial lack of overall validity. However the results of these studies and subsequent meta-analyses are used as the evidence base for the majority of current guidelines.

Predictors for hepatocellular carcinoma recurrence after microwave ablation

Aim of the study

Microwave ablation (MWA) for treatment of hepatocellular carcinoma (HCC) is a new promising modality. The prognosis after treatment is mainly linked to the recurrence. We aimed to investigate the predictive value of α-fetoprotein (AFP) score and Aurora B kinase (AURKB) in HCC recurrence after MWA.

Material and methods

A cross-sectional study where 25 early-stage HCC patients (Barcelona Clinic Liver Cancer 0/A-B) were treated with MWA. Tumor biopsies were obtained just prior to MWA and assessed for WHO pathological grade and AURKB expression by immunohistochemistry. AFP score was calculated and a cut-off value of 2 classifies patients into high and low risk of recurrence. After achieving complete ablation, patients were followed every 3 months for 1 year by triphasic CT to detect recurrence.

Results

Child-Pugh classification has no significant impact on prognosis of HCC after MWA (χ² = 1.924, p = 0.165). Serum AFP level and AFP score can effectively predict the response to MWA among HCC patients (χ² = 6.451, ^MCp = 0.031) (χ² = 9.0, p = 0.003), respectively. AFP score was strongly associated with the pathological grade of the tumor (r = 0.467, p = 0.019). AURKB was over-expressed in tumoral more than non-tumoral specimens (p < 0.001). It was correlated with the size of the tumor, the number of tumor nodules and the pathological grade of the tumor (p < 0.05) but has no role in predicting recurrence after MWA (p = 0.869).

Conclusions

AFP score but not AURKB can predict the risk of recurrence of HCC after MWA.

Impact of an ultrasound-guided radiofrequency ablation training program on the outcomes in patients with hepatocellular carcinoma

PURPOSE

The aim of this study was to retrospectively evaluate the impact of a training program on the safety and efficacy of percutaneous ultrasound-guided radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 227 patients with 296 HCC nodules who underwent percutaneous RFA with or without transcatheter arterial chemoembolization at our institution were included. There were 163 men and 64 women with a mean age of 74.2±8.3 (SD) years (range: 41-89 years). Percutaneous ultrasound-guided RFA was performed by three trainees (205 HCC nodules in 157 patients) or a mentor (91 HCC nodules in 70 patients) after preprocedural preparation including planning ultrasonography. We compared background-related, tumor-related, and treatment-related factors, and local recurrence and complication rates between the trainee group and the mentor group. Similarly, we compared these variables among the years 2015, 2016, and 2017 for trainee group.

RESULTS

The proportion of easy-to-treat tumors in the trainee group (109/205; 53.2%) was greater than that in the mentor group (33/91; 36.3%) (P=0.020). No significant differences were observed in procedure difficulty among the years 2015, 2016, and 2017 for trainee group (easy-to-treat HCC nodules: 25/47; 53.2% vs. 39/79; 49.4% vs. 45/79; 57.0%. P=0.775). The local recurrence rate in the trainee group was 8.8% (18/205 HCC nodules) which was equivalent to 7.7% in the mentor group (7/91 HCC nodules). No significant differences were observed in local recurrence rate (8.8% vs. 7.7%, respectively; P=0.621) and major complication rate (1.3% vs. 1.4%, respectively; P=0.999) between the trainee group and the mentor group. No significant differences were observed in local recurrence rates ([5/47; 10.6%] vs. [11/79; 13.9%] vs. [2/79; 2.5%]) (P=0.109) and major complication rates ([1/36; 2.8%] vs. [1/62; 1.6%] vs. [0/59; 0%]) (P=0.701) between the years 2015, 2016, and 2017 for trainee group.

CONCLUSION

A well supervised training program that includes planning ultrasonography fosters the efficacy and treatment quality of RFA for HCC.

Simultaneous radiofrequency ablation combined with laparoscopic splenectomy: a safe and effective way for patients with hepatocellular carcinoma complicated with cirrhosis and hypersplenism

Purpose: This study aimed to evaluate the safety and effectiveness of simultaneous radiofrequency ablation (RFA) combined with laparoscopic splenectomy (Lap-Sp) for patients with hepatocellular carcinoma (HCC) complicated with cirrhosis and hypersplenism.Material and methods: Between January 2013 and June 2014, 42 patients with primary HCC complicated with cirrhosis and hypersplenism who underwent simultaneous RFA combined with Lap-Sp were enrolled at the Department of General Surgery, Beijing Di Tan Hospital. The median number of tumors ablated using RFA was one (range 1-3), and the median sum of the maximum diameter of tumors was 2.5 cm (range 1.2-5.4 cm). The related indicators before and after surgery, complications, and long-term effects were retrospectively analyzed.Results: The median operative time for 42 patients undergoing simultaneous RFA combined with Lap-Sp was 4.5 h (range 2.5-8.5 h), and the median blood loss was 120 mL (range 5-2200 mL). The incidence of moderate-to-severe postoperative complications and the perioperative mortality after surgery were 31.0 and 0%, respectively. The disease-free survival rate for one, three, and five years was 73.8, 19.7, and 16.4%, respectively. The overall survival rate was 90.5, 73.3, and 60.4%, respectively.Conclusion: Simultaneous RFA combined with Lap-Sp was safe and effective for patients with HCC complicated with cirrhosis and hypersplenism.

The Effects of Thoracic Epidural Analgesia during Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma

Background

Percutaneous radiofrequency ablation (PRFA) is a useful and safe treatment for hepatocellular carcinoma (HCC). Pain management, during and after PRFA, is a critical component of patient care.

Objectives

This study reviewed the efficacy of thoracic epidural analgesia, during and after PRFA, for patients with HCC.

Study Design

A retrospective, observational chart review.

Setting

Tertiary medical center/teaching hospital.

Methods

Patients who had undergone PRFA for HCC in the past 5 years were divided into two groups, based on the type of anesthesia administered: thoracic epidural anesthesia group (Group E) and local anesthesia with monitored anesthesia care group (Group C). We retrospectively reviewed changes in the numeric rating scale (NRS) score during and after PRFA, opioid consumption, length of the procedure, length of hospital stay, changes in blood pressure during PRFA, and the incidence of adverse events.

Results

The NRS score in Group E was significantly lower than that in Group C (P < 0.05). The opioid consumption in Group E was lower than that in Group C after PRFA (P < 0.05). The procedure time was shorter in Group E (P < 0.05). Neither of the groups showed significant difference with respect to the length of hospital stay and the incidence of respiratory depression, fever, and blood pressure elevation. The incidence of nausea, vomiting, and voiding difficulty was higher in Group E.

Limitations

This study is limited by its retrospective design.

Conclusions

Thoracic epidural analgesia was associated with shorter procedure times, lower postprocedural pain, and lower opioid consumption during and after PRFA for HCC.

Radiofrequency ablation with systemic chemotherapy in the treatment of colorectal cancer liver metastasis: a 10-year single-center study

Objective

To retrospectively evaluate the long-term efficacy and safety of radiofrequency ablation (RFA) with systemic chemotherapy (CT) in treatment of solitary liver metastasis after surgery for colorectal cancer (CRC).

Methods

This single-center study was conducted at the Hunan Provincial Cancer Hospital from June 2006 to December 2015 with median follow-up time of 26 months. Percutaneous ultrasound-guided RFA was carried out on eligible patients with solitary liver metastasis after surgery for CRC. After a week, ablation status was confirmed by MRI. Post MRI, all patients received systemic CT with or without molecular-targeted therapy. Survival rate was evaluated and survival curve was constructed with Kaplan-Meier analysis. Log-rank test and Cox regression model were used for univariate and multivariate analysis, respectively, to determine the independent prognostic factors for survival rate.

Results

A total of 109 eligible patients (mean age, 53.84±11.71; mean tumor mass diameter, 3.4+2.01 cm) were enrolled in this 10-year study. After RFA, 95 patients achieved complete ablation, and 14 patients achieved partial ablation, with median ablation time of 26 minutes (range: 12-120 minutes). The median survival time required for achieving complete and partial ablation was 56.0 and 19.0 months, respectively (P<.01). After RFA and adjuvant systemic CT, the 1-, 3-, and 5-year survival rates were 92.3%, 50.7%, and 41.6%, respectively, with the median (mean) survival time of 39.0 (56.5) months. Age was the only significant independent prognostic factor with better survival rate observed in patients aged ≥50 years than those aged <50 years (P<0.05). The incidence of complications was minimal (1.8%) with only two cases: one biliary fistula and one liver hemorrhage.

Conclusion

RFA combination with systemic CT was safe; it showed long-term efficacy in patients with solitary liver metastasis after surgery for CRC and can be a preferred treatment.

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.

Radiofrequency Ablation versus Hepatic Resection for Small Hepatocellular Carcinoma: Systematic Review of Randomized Controlled Trials with Meta-Analysis and Trial Sequential Analysis

Purpose To compare the benefits and harms of radiofrequency ablation (RFA) and hepatic resection (HR) and to test the consistency of currently available evidence. Materials and Methods PubMed, Embase, and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) that compared the effects of HR and RFA for Barcelona Clinic Liver Cancer very early or early stage hepatocellular carcinoma (HCC). The primary outcome was overall survival, and secondary outcomes were recurrence rate, complication rate, and hospitalization duration. A random- or fixed-effects model according to the level of heterogeneity was applied. The meta-analysis was performed by using software, and trial sequential analysis (TSA) was performed. Results Five trials examining 742 patients were included in this study (sizes of trials: 161, 230, 168, 120, and 63 patients). The meta-analysis showed that RFA and HR had similar overall survival at 1 year (relative risk [RR], 1.39; 95% confidence interval [CI]: 0.36, 5.33; P = .63) and 3 years (RR, 1.40; 95% CI: 0.75, 2.62; P = .29), whereas RFA resulted in decreased overall survival compared with HR at 5 years (RR: 1.91; 95% CI: 1.32, 2.79; P = .001). The TSA showed that more trials were needed to control random errors. The incidence of overall recurrence was markedly higher and the hospitalization duration was significantly shorter in the RFA group than in the HR group, which was confirmed by TSA. Complications may have been less frequent in the RFA group, but TSA showed that additional trials were necessary to confirm this conclusion. Conclusion The indication for RFA as a primary treatment for patients who are eligible for HR with early stage HCC is unclear, and additional well-designed RCTs are needed. ^© RSNA, 2017 Online supplemental material is available for this article.

Efficacy and mechanism of steep pulse irreversible electroporation technology on xenograft model of nude mice: a preclinical study

Background

Steep pulse therapy can irreversible electrically brackdown of tumor membrance and cause cell death. In previous studies, we investigated the effect of steep pulsed electroporation on the killing of large cell lung cancer cell line L981- in vitro, and determined the best parameters for killing lung cancer cells by steep pulse technology. But the optimal parameters and the mechanisms of steep pulse irreversible electroporation technology on nude mouse tumor model are unclear.

Methods

Three settings of steep pulse therapy parameters were applied to the nude mouse model. An in vivo imaging system was employed to observe the effect of different parameters on the mouse model. The pathological changes of the tumor tissue and immunofluorescence data on Caspase-3 protein expression were recorded.

Results

Under the in vivo imaging system, the steep pulse had an obvious inhibitory effect on the transplanted tumor in the nude mouse model. Pathological tests showed that occurrence of necrosis and apoptosis and expression of Caspase-3 protein in the tumor tissue were increased compared to those in the normal tissue.

Conclusions

Steep pulse irreversible electroporation technology showed a promising antitumor effect in the nude mouse tumor model. With splint-type electrode, the best treatment parameters determined for the nude mouse tumor model were voltage amplitude 2000 V/cm, pulse width 100 μs, pulse frequency 1 Hz, pulse number 60, and repeat time 3. Moreover, steep pulse induced coagulative necrosis of tumor tissue by cell apoptosis.

Transarterial chemoembolization as a substitute to radiofrequency ablation for treating Barcelona Clinic Liver Cancer stage 0/A hepatocellular carcinoma

Background and Aim

Transarterial chemoembolization (TACE) is the standard procedure for treating Barcelona clinic liver cancer (BCLC) stage B hepatocellular carcinoma (HCC). However, it is often carried out in the treatment of BCLC stage 0/A HCC for various reasons. This study aimed to elucidate the prognosis for BCLC stage 0/A HCC patients treated with TACE or with radiofrequency ablation (RFA).

Materials and Methods

The prognosis of 242 BCLC stage 0/A HCC patients within Milan criteria who underwent initially TACE or RFA were retrospectively analyzed using propensity score matching analysis.

Results

The analyses of baseline patient characteristics revealed that the maximum tumor size and the proportion of BCLC stage A patients were significantly higher in patients treated with TACE than in those treated with RFA (P<0.001 and 0.047, respectively). After adjusting these factors using propensity score matching (1:3 matching), patients treated with TACE (n=32) and those treated with RFA (n=96) were further analyzed. The local recurrence rate was significantly higher in the TACE group than in the RFA group (P<0.001). However, the overall survival (OS) in HCC patients treated with TACE was comparable to that in HCC patients treated with RFA (1 year, 93.5 vs. 95.8%; 3 years, 75.4 vs. 85.8%; 5 years, 61.8 vs. 70.7%; P=0.196). Multivariate analyses followed by univariate analyses revealed that serum bilirubin level (P=0.032), serum albumin level (P=0.008), HBV-DNA (P=0.013), and tumor number (P=0.021) were independent predictors of OS.

Conclusion

TACE can substitute RFA at least in some patients with BCLC 0/A HCC.

Individualized laparoscopic B-ultrasound-guided microwave ablation for multifocal primary liver cancer

Introduction

Liver cancer is one of the most common malignancies of the digestive system. Minimally invasive ablation procedures have become one of the major means for treating unresectable multifocal liver cancer and have been extensively applied in primary and metastatic liver cancer treatment. Laparoscopic B-ultrasound-guided microwave ablation is an example of the progress made in this field.

Aim

To analyze and summarize the results of and experience with laparoscopic B-ultrasound-guided microwave ablation for multifocal primary liver cancer; moreover, the ablation effects were compared between tumors of different sizes.

Material and methods

Laparoscope-guided needle ablation was conducted on 84 lesions from 32 patients with primary liver cancer based on tumor size, quantity, and location. Moreover, the perioperative data, ablation effects according to tumor size, and long-term follow-up results were analyzed.

Results

Among the 84 nodules treated via microwave ablation, tumors measuring ≤ 3 cm demonstrated complete ablation upon imaging analysis conducted 1 month after surgery. Moreover, 5 of the tumors measuring > 3 cm demonstrated incomplete ablation. In these cases, a second procedure was performed, until imaging studies confirmed that complete ablation was achieved.

Conclusions

Laparoscopic microwave ablation allows for precise puncture positioning, an effective ablation range, and safe and feasible surgery, which is especially suitable for liver tumors located in sites difficult to access.

Fusion imaging with contrast-enhanced ultrasonography for evaluating the early therapeutic efficacy of radiofrequency ablation for small hypervascular hepatocellular carcinomas with iso-echoic or unclear margins on conventional ultrasonography

PURPOSE

We evaluated the efficacy of fusion imaging combining contrast-enhanced ultrasonography (CEUS) images and arterial phase contrast-enhanced CT (CECT) or hepatobiliary phase magnetic resonance imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (EOB-MRI) images for the early evaluation of the effectiveness of radiofrequency ablation (RFA) for small hypervascular hepatocellular carcinoma (HCC) with iso-echoic or unclear margins on conventional US.

METHODS

Forty HCCs (22 iso-echoic and 18 unclear margin lesions) with mean diameters of 13.7 mm were treated using RFA under the guidance of fusion imaging with CEUS. The adequacy of RFA was evaluated using fusion imaging with CEUS 1 day after RFA. CECT or EOB-MRI was performed 1 month after RFA. We reviewed the images obtained using both modalities.

RESULTS

When the 1-month CECT or EOB-MRI scans were used as the reference standard, the sensitivity, specificity, and accuracy of the 1-day fusion imaging for the diagnosis of the adequate ablation of these HCCs were 97, 100, and 98%, respectively; the kappa value for the agreement between the findings using the two modalities was 0.655.

CONCLUSION

Fusion imaging with CEUS appears to be a useful method for the early evaluation of the efficacy of RFA for the treatment of HCCs with iso-echoic or unclear margins on conventional US.

Ultrasound-ultrasound image overlay fusion improves real-time control of radiofrequency ablation margin in the treatment of hepatocellular carcinoma

OBJECTIVES

To assess the clinical feasibility of US-US image overlay fusion with evaluation of the ablative margin in radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).

METHODS

Fifty-three patients with 68 HCCs measuring 0.9-4.0 cm who underwent RFA guided by US-US overlay image fusion were included in this retrospective study. By an overlay of pre-/postoperative US, the tumor image could be projected onto the ablative hyperechoic zone. Therefore, the ablative margin three-dimensionally could be shown during the RFA procedure. US-US image overlay was compared to dynamic CT a few days after RFA for assessment of early treatment response. Accuracy of graded response was calculated, and the performance of US-US image overlay fusion was compared with that of CT using a Kappa agreement test.

RESULTS

Technically effective ablation was achieved in a single session, and 59 HCCs (86.8 %) succeeded in obtaining a 5-mm margin on CT. The response with US-US image overlay correctly predicted early CT evaluation with an accuracy of 92.6 % (63/68) (k = 0.67; 95 % CI: 0.39-0.95).

CONCLUSION

US-US image overlay fusion can be proposed as a feasible guidance in RFA with a safety margin and predicts early response of treatment assessment with high accuracy.

KEY POINTS

• US-US image overlay fusion visualizes the ablative margin during RFA procedure. • Visualizing the margin during the procedure can prompt immediate complementary treatment. • US image fusion correlates with the results of early evaluation CT.

Enhanced efficacy of radiofrequency ablation for hepatocellular carcinoma using a novel vascular disrupting agent, CKD-516

BACKGROUND

CKD-516 is a novel vascular disrupting agent that shuts down intratumoral blood flow. We therefore hypothesized that concomitant administration of CKD-516 would enhance the therapeutic efficacy of radiofrequency ablation (RFA) by reducing heat sink effects. We assessed the effects of the combination of CKD-516 and RFA in a rat orthotopic hepatocellular carcinoma (HCC) model.

METHODS

Rat HCC cells (N1-S1) were engrafted into the hepatic lobe of Sprague-Dawley (SD) rats. Mice were randomly divided into two groups: RFA-only and CKD-RFA. In the CKD-RFA group, CKD-516 was administered by intraperitoneal injection 2 h before RFA. Ablation zone size was measured on triphenyltetrazolium chloride-stained specimens. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to evaluate the area of apoptosis/necrosis in the ablation zone. Immunohistochemistry with anti-CD31 antibody was performed to evaluate the effect of CKD-516 on tumor vessels.

RESULTS

Ablation zone size was significantly larger in the CKD-RFA group than in the RFA-only group (243.10 ± 74.39 versus 123.30 ± 28.17 mm², p < 0.001). On TUNEL staining, the area of apoptosis/necrosis was also significantly larger in the CKD-RFA group than in the RFA-only group (274.44 ± 140.78 versus 143.74 ± 90.13 mm²; p = 0.006). Immunohistochemistry with anti-CD31 antibody revealed patent tumor vessels in the RFA-only group, while collapsed vessels were seen in the CKD-RFA group, indicating a vascular shutdown effect of CKD-516.

CONCLUSION

Concomitant administration of CKD-516 during RFA can increase the ablation zone of tumors due to its vascular disrupting effect.

Evaluation of hepatocellular carcinoma tumor vascularity using contrast-enhanced ultrasonography as a predictor for local recurrence following radiofrequency ablation

PURPOSE

The purpose of this study was to evaluate whether the hypervascularity of hepatocellular carcinomas (HCCs) on contrast-enhanced ultrasonography (CEUS) prior to radiofrequency ablation (RFA) is a significant risk factor for local recurrence after RFA.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. Overall, 208 patients (mean age, 71.7 years; range, 50-87 years; 137 men, 71 women) with 282 HCCs treated with RFA were analyzed retrospectively. The mean maximum tumor diameter was 15.7mm. We compared the abilities of CEUS and contrast-enhanced computed tomography (CECT) to detect hypervascularity in HCCs. We then classified the HCCs into two groups according to the arterial-phase CEUS findings: a "hypervascular group" with whole or partial hypervascular areas within the lesions compared with the surrounding liver parenchyma, and a "non-hypervascular group" with isovascular or hypovascular areas within the lesions. We assessed the cumulative rate of local recurrence after RFA, and we also evaluated the risk factors for local recurrence using a univariate analysis.

RESULTS

The detection rate for hypervascular HCCs was significantly higher using CEUS (78%, 221/282) than that using CECT (66%, 186/282) (P<0.001). Using the CEUS findings, the cumulative rate of local recurrence was significantly higher in the hypervascular group (41.2%, 56/221) than in the non-hypervascular group (18.4%, 6/61) (P=0.007). A univariate analysis revealed that hypervascularity on CEUS was an independent risk factor for local recurrence (P=0.010).

CONCLUSION

Hypervascularity in HCCs as observed using CEUS is a significant risk factor for local recurrence after RFA.

Current role of microwave ablation in the treatment of small hepatocellular carcinomas

Percutaneous radiofrequency ablation (RFA) can be as effective as surgical resection in terms of overall survival and recurrence-free survival rates in patients with small hepatocellular carcinoma (HCC). Effectiveness of RFA is adversely influenced by heat-sink effect. Other ablative therapies could be considered for larger tumors or for tumors located near the vessels. In this regard, recent improvements in microwave energy delivery systems seem to open interesting perspectives to percutaneous ablation, which could become the ablation technique of choice in the near future. Microwave ablation (MWA) has the advantages of possessing a higher thermal efficiency. It has high efficacy in coagulating blood vessels and is a relatively fast procedure. The time required for ablation is short and the shape of necrosis is elliptical with the older systems and spherical with the new one. There is no heat-sink effect and it can be used to ablate tumors adjacent to major vessels. These factors yield a large ablation volume, and result in good local control and fewer complications. This review highlights the most relevant updates on MWA in the treatment of small (<3 cm) HCC. Furthermore, we discuss the possibility of MWA as the first ablative choice, at least in selected cases.

Hepatocellular carcinoma ≤ 4 cm treated with radiofrequency ablation with or without percutaneous ethanol injection

BACKGROUND

To compare the survival of Chinese cirrhotic patients with hepatocellular carcinoma (HCC) ≤ 4 cm who underwent radiofrequency ablation (RFA) alone or a combination of RFA with percutaneous ethanol injection (PEI).

MATERIAL AND METHODS

Retrospective analysis was performed for 681 cases with HCC ≤ 4 cm who were treated with RFA alone or RFA combined with PEI (RFA + PEI) between 2004 and 2011.

RESULTS

As a result, 180 patients in each group were selected after propensity score matching (PSM). Higher overall survival (OS) and recurrence-free survival (RFS) rates were achieved by RFA + PEI compared with RFA alone (P = 0.019 and 0.009, respectively). The 1-, 3-, and 5-year cumulative OS rates were 78.0, 44.4, and 30.1% for patients in RFA group and 88.2, 58.0, and 41.1% for patients in RFA + PEI group, respectively. Besides, the 1-, 3-, and 5-year cumulative RFS rates were 77.0, 43.8, and 29.2% in RFA group, and 87.9, 57.6, and 38.4% in RFA + PEI group, respectively. The local recurrence, complete ablation and five-year mortality showed no distinct differences between RFA and RFA + PEI groups in three subgroups classified with tumor size. Moreover, Cox regression multivariate analysis results showed that sex and treatment approach were significantly related to OS, whereas sex, status of HBsAg, local recurrence, and number of tumor nodule were related to RFS.

CONCLUSION

Therefore, the combination of RFA and PEI yielded better OS and RFS rates than RFA alone for Chinese patients with HCC ≤ 4 cm.

Radiofrequency ablation vs. hepatic resection for resectable colorectal liver metastases

The treatments of resectable colorectal liver metastases (CRLM) are controversial. This study aimed to evaluate the relative efficacy and safety of hepatic resection (HR) and radiofrequency ablation (RFA) for treating resectable CRLM. Between January 2004 and May 2010, the enrolled patients were given hepatic resection (HR group; n=32) or percutaneous RFA (RFA group; n=21) as a first-line treatment for CRLM. All the tumors had a maximum diameter of 3.5 cm and all patients had five or less tumors. The patient background, tumor characteristics, cumulative survival rate and recurrence-free survival rate were assessed in both groups. There were significantly more patients with comorbidities in the RFA group than those in the HR group (17 in RFA group vs. 10 in HR group; P<0.000). The mean maximum tumor diameter in the HR group and RFA group was 2.25±0.68 and 1.89±0.62 cm (P=0.054), and the mean number of tumors was 2.28±1.05 and 2.38±1.12 (P=0.744), respectively. The 1-, 3- and 5-year cumulative survival rates in the HR group were 87.5%, 53.1% and 31.3%, respectively, and those in the RFA group were 85.7%, 38.1% and 14.2%, respectively with the differences being not significant between the two groups (P=0.062). The 1-, 3- and 5-year recurrence-free survival rates in the HR group were 90.6%, 56.3% and 28.1%, respectively, and those in the RFA group were 76.1%, 23.8% and 4.8%, respectively, with the differences being significant between the two groups (P=0.036). In conclusion, as HR has greater efficacy than RFA in the treatment of resectable CRLM, we recommend it as the first option for this malignancy.

Imaging evaluation of residual cancer after radiofrequency ablation of hepatocellular carcinoma

Primary liver cancer is one of the most common malignant tumors in the world, and only a few patients have the chance of surgical resection. Radiofrequency ablation (RFA) is a good treatment for patients with unresectable liver cancer. The existence of residual cancer after radiofrequency ablation has a direct impact on the prognosis of patients, so it is important to accurately determine whether there is residual cancer after RFA treatment in order to reduce the local recurrence and prolong the survival time of patients. In this paper, we discuss the evaluation of residual cancer after radiofrequency ablation of hepatocellular carcinoma by ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), digital subtraction angiography (DSA) and nuclear medicine modalities.

Delayed bronchobiliary fistula following radiofrequency ablation in a patient with hepatocellular carcinoma: A case report and lesson regarding treatment

Bronchobiliary fistula (BBF) is a rare complication of radiofrequency ablation (RFA) of hepatocellular carcinoma. The rupture of a biloma following RFA may result in the development of BBF, with their early detection and timely management important in the prevention of BBF. The current study presents a case of BBF, which developed at 17 months after radiofrequency ablation (RFA), due to biloma rupture in a patient with hepatocellular carcinoma. Despite the percutaneous drainage of the biloma following BBF, the persistent fever did not resolve due to biliary infection. Finally, an extensive surgical intervention was performed. The magnetic resonance imaging (MRI) scans that had been performed following RFA were reviewed, and it was found that the biloma and increased bile leakage had presented prior to biloma rupture. For that reason, it is advised that patients who present with biloma following RFA should receive regular follow-up MRI scans. Biloma enlargement could be a predictor for the development of BBF; therefore, timely drainage of an enlarging biloma may be able to prevent this complication.

Radiofrequency ablation-combined multimodel therapies for hepatocellular carcinoma: Current status

Radiofrequency ablation (RFA) is widely accepted as a first-line interventional oncology approach for hepatocellular carcinoma (HCC) and has the advantages of high treatment efficacy and low complication risk. Local control rates equivalent to hepatic resection can be reached by RFA alone when treating small HCCs (<2 cm) in favorable locations. However, local tumor progression and recurrence rates with RFA monotherapy increase sharply when treating larger lesions (>3 cm). To address this clinical problem, recent efforts have focused on multimodel management of HCC by combining RFA with different techniques, including percutaneous ethanol injection, transarterial chemo-embolization, targeted molecular therapy, nanoparticle-mediated therapy, and immunotherapy. The combination strategy indeed leads to better outcomes in comparison to RFA alone. In this article, we review the current status of RFA-combined multimodal therapies in the management of HCC.

CT-Guided Percutaneous Step-by-Step Radiofrequency Ablation for the Treatment of Carcinoma in the Caudate Lobe

The location of the caudate lobe and its complex anatomy make caudate lobectomy and radiofrequency ablation (RFA) under ultrasound guidance technically challenging. The objective of the exploratory study was to introduce a novel modality of treatment of lesions in caudate lobe and discuss all details with our experiences to make this novel treatment modality repeatable and educational. The study enrolled 39 patients with liver caudate lobe tumor first diagnosed by computerized tomography (CT) or magnetic resonance imaging (MRI). After consultation of multi-disciplinary team, 7 patients with hepatic caudate lobe lesions were enrolled and accepted CT-guided percutaneous step-by-step RFA treatment. A total of 8 caudate lobe lesions of the 7 patients were treated by RFA in 6 cases and RFA combined with percutaneous ethanol injection (PEI) in 1 case. Median tumor diameter was 29 mm (range, 18-69 mm). A right approach was selected for 6 patients and a dorsal approach for 1 patient. Median operative time was 64 min (range, 59-102 min). Median blood loss was 10 mL (range, 8-16 mL) and mainly due to puncture injury. Median hospitalization time was 4 days (range, 2-5 days). All lesions were completely ablated (8/8; 100%) and no recurrence at the site of previous RFA was observed during median 8 months follow-up (range 3-11 months). No major or life-threatening complications or deaths occurred. In conclusion, percutaneous step-by-step RFA under CT guidance is a novel and effective minimally invasive therapy for hepatic caudate lobe lesions with well repeatability.

Synthesis and characterization of image-able polyvinyl alcohol microspheres for image-guided chemoembolization

Therapeutic embolization of blood vessels is a minimally invasive, catheter-based procedure performed with solid or liquid emboli to treat bleeding, vascular malformations, and vascular tumors. Hepatocellular carcinoma (HCC) affects about half a million people per year. When unresectable, HCC is treated with embolization and local drug therapy by transarterial chemoembolization (TACE). For TACE, drug eluting beads (DC Bead(®)) may be used to occlude or reduce arterial blood supply and deliver chemotherapeutics locally to the tumor. Although this treatment has been shown to be safe and to improve patient survival, the procedure lacks imaging feedback regarding the location of embolic agent and drug coverage. To address this shortcoming, herein we report the synthesis and characterization of image-able drug eluting beads (iBeads) from the commercial DC Bead(®) product. Two different radiopaque beads were synthesized. In one approach, embolic beads were conjugated with 2,3,5-triiodobenzyl alcohol in the presence of 1,1'-carbonyldiimidazol to give iBead I. iBead II was synthesized with a similar approach but instead using a trimethylenediamine spacer and 2,3,5-triiodobenzoic acid. Doxorubicin was loaded into the iBeads II using a previously reported method. Size and shape of iBeads were evaluated using an upright microscope and their conspicuity assessed using a clinical CT and micro-CT. Bland and Dox-loaded iBeads II visualized with both clinical CT and microCT. Under microCT, individual bland and Dox loaded beads had a mean attenuation of 7904 ± 804 and 11,873.96 ± 706.12 HU, respectively. These iBeads have the potential to enhance image-guided TACE procedures by providing localization of embolic-particle and drug.

Radiofrequency ablation versus percutaneous ethanol injection for hepatocellular carcinoma: a meta-analysis of randomized controlled trials

BACKGROUND

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) are treatment methods for patients with early-stage hepatocellular carcinoma (HCC) who are not suitable for surgery. Although some reports indicate that RFA is better than PEI, results from previous reviews and analyses are inconsistent. Therefore, this meta-analysis was performed to more thoroughly evaluate the effects of these treatments in patients with HCC.

METHODS

A literature search was conducted using the Excerpta Medica dataBASE, PubMed, the Cochrane Library, the American Society of Clinical Oncology database, the China National Knowledge Infrastructure database, the Wanfang database, the Chinese Biomedical Literature Database, and the Chongqing VIP database without language limitations. The primary outcome evaluated was overall survival, and secondary outcomes included complete response and local recurrence. Comparisons were made between Asian and European studies.

RESULTS

Total pooled and subgroup analyses of Asian studies that included selection biases revealed that RFA is superior to PEI with respect to overall survival (hazard ratio (HR), 0.54; 95% confidence interval (CI), 0.37 to 0.80; P < 0.01) and complete response (relative risk (RR), 1.10; 95% CI 1.03 to 1.18; P < 0.01). However, no significant difference was observed between RFA and PEI in the European studies. In Asian studies, RFA was associated with a lower local recurrence rate than PEI at 1 year (RR, 0.44; 95% CI 0.20 to 0.95; P < 0.05) and 3 years (RR, 0.35; 95% CI 0.22 to 0.55; P < 0.01). However, local recurrence was significantly lower after only 3 years in European studies (RR, 0.50; 95% CI 0.32 to 0.78; P < 0.05).

CONCLUSIONS

RFA was only superior to PEI in Asian studies that included selection bias. Thus, there is insufficient evidence to support the idea that RFA is superior to PEI for patients with cirrhotic HCC. Additional large-scale, multicenter, randomized controlled trials that control for selection bias are needed to fully elucidate the optimal treatment method for HCC.

Pain control in patients with hepatocellular carcinoma treated by percutaneous radiofrequency ablation: comparison of the efficacy of one-shot and continuous intravenous fentanyl delivery

BACKGROUND

Hepatic percutaneous radiofrequency ablation (RFA) is usually performed with the patient under deep intravenous (i.v.) sedation or general anesthesia. Nonetheless, many patients report pain during and/or after the procedure.

PURPOSE

To perform a prospective study of pain control obtained by the i.v. one-shot delivery and the continuous i.v. infusion of fentanyl in patients with hepatocellular carcinoma (HCC) treated by RFA.

MATERIAL AND METHODS

Between April 2007 and March 2010, 83 patients with 106 HCCs underwent percutaneous RFA. All HCCs were addressed by computed tomography (CT)-guided percutaneous RFA performed within 5 h of embolization of the tumor vessels with iodized oil and gelatin sponges. Standard anesthesia consisted of 10 mL of 1% lidocaine injected locally. For conscious sedation, group one patients (n = 41) were injected i.v. with 100 µg of fentanyl before and 100 µg of fentanyl 30 min after percutaneous RFA. In group two (n = 42) we delivered fentanyl by continuous i.v. infusion at 100 µg/h during RFA. Upon request, patients in both groups also received 5 mg of diazepam i.v. for pain during the RFA procedure. The severity of pain experienced by all patients was evaluated on a visual analogue scale (VAS) and complications elicited by the anesthesia regimens were recorded. We also assessed the effectiveness of the treatment on sequential follow-up CT and/or magnetic resonance imaging (MRI) at 3-month intervals.

RESULTS

Percutaneous RFA was technically successful in all 83 patients. Two patients in group one (4.8%) and one patient in group two (2.4%) manifested residual enhancement 3 months post RFA. There was no significant difference in the local recurrence rate between the two groups. At 4.0 ± 1.8 for group one and 3.4 ± 1.9 for group two, the VAS score was not significantly different. Major fentanyl or diazepam toxicity was recorded in 11 patients (24.4%) in group one and two patients (4.8%) in group two; the difference was statistically significant (P < 0.01).

CONCLUSION

The continuous infusion of fentanyl provided effective and safe analgesia in HCC patients undergoing percutaneous RFA.

Comparative analysis of Laparoscopic versus open surgical radiofrequency ablation for malignant liver tumors

Backgrounds/Aims

This study aims to evaluate the comparative effectiveness of two surgical approaches on the treatment outcomes of radiofrequency ablation (RFA) for malignant liver tumors.

Methods

Fifty-seven patients with malignant liver tumors, hepatocellular carcinoma, cholangiocarcinoma and liver metastases, who were candidates for RFA, underwent laparoscopic or open surgical treatments.

Results

The patients' characteristics were comparable in the two groups that received open (n=33, 57.9%) and laparoscopic (n=24, 42.1%) surgical treatments. There were no statistically significant differences between the two groups in terms of recurrence rate (p=0.337) and overall survival (p=0.423). However, patients in the laparoscopic RFA group had significantly shorter hospital stay (14.1 vs. 5.9 days, p<0.05) and experienced fewer complications (Grade I: 62.5% vs. 26.3%, p=0.102).

Conclusions

Laparoscopic RFA can be performed for malignant liver tumors with lower morbidity rates, less invasiveness and lower expense compared to open surgical approach.