Radiofrequency thermal ablation vs. percutaneous ethanol injection for small hepatocellular carcinoma in cirrhosis: meta-analysis of randomized controlled trials

Ablation therapy for hepatocellular carcinoma: past, present and future perspectives

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and is most commonly found in the setting of liver cirrhosis. Treatment of HCC must consider both the tumors present, as well as the remaining dysfunctional liver that both hinders treatment and can produce additional HCC over time. Ablation is an evolving part of the multimodality treatment approach to HCC that can effectively destroy tumors while preserving surrounding liver parenchyma. New technologies have made ablation an indispensable tool in the treatment of all stages of HCC. This review presents the history, present technologies and future potential of ablation in the treatment of HCC.

Mechanisms of cryoablation: clinical consequences on malignant tumors

While the destructive actions of a cryoablative freeze cycle are long recognized, more recent evidence has revealed a complex set of molecular responses that provides a path for optimization. The importance of optimization relates to the observation that the cryosurgical treatment of tumors yields success only equivalent to alternative therapies. This is also true of all existing therapies of cancer, which while applied with curative intent; provide only disease suppression for periods ranging from months to years. Recent research has led to an important new understanding of the nature of cancer, which has implications for primary therapies, including cryosurgical treatment. We now recognize that a cancer is a highly organized tissue dependent on other supporting cells for its establishment, growth and invasion. Further, cancer stem cells are now recognized as an origin of disease and prove resistant to many treatment modalities. Growth is dependent on endothelial cells essential to blood vessel formation, fibroblasts production of growth factors, and protective functions of cells of the immune system. This review discusses the biology of cancer, which has profound implications for the diverse therapies of the disease, including cryosurgery. We also describe the cryosurgical treatment of diverse cancers, citing results, types of adjunctive therapy intended to improve clinical outcomes, and comment briefly on other energy-based ablative therapies. With an expanded view of tumor complexity we identify those elements key to effective cryoablation and strategies designed to optimize cancer cell mortality with a consideration of the now recognized hallmarks of cancer.

Radiofrequency ablation is superior to ethanol injection in early-stage hepatocellular carcinoma irrespective of tumor size

Background

Randomized trials suggest that radiofrequency ablation (RFA) may be more effective than percutaneous ethanol injection (PEI) in the treatment of hepatocellular carcinoma (HCC). However, the survival advantage of RFA needs confirmation in daily practice.

Methods

We conducted a population-based cohort study using the Taiwan Cancer Registry, National Health Insurance claim database and National Death Registry data from 2004 through 2009. Patients receiving PEI or RFA as first-line treatment for newly-diagnosed stage I-II HCC were enrolled.

Results

A total of 658 patients receiving RFA and 378 patients receiving PEI treatment were included for final analysis. The overall survival (OS) rates of patients in the RFA and PEI groups at 5-year were 55% and 42%, respectively (p < 0.01). Compared to patients that received PEI, those that received RFA had lower risks of overall mortality and first-line treatment failure (FTF), with adjusted hazard ratios (HRs) [95% confidence interval (CI)] of 0.60 (0.50-0.73) for OS and 0.54 (0.46-0.64) for FTF. The favorable outcomes for the RFA group were consistently significant for patients with tumors > 2 cm as well as for those with tumors < 2 cm. Consistent results were also observed in other subgroup analyses defined by gender, age, tumor stage, and co-morbidity status.

Conclusion

RFA provides better survival benefits than PEI for patients with unresectable stage I-II HCC, irrespective of tumors > 2 cm or ≤ 2 cm, in contemporary clinical practice.

Imaging appearance of treated hepatocellular carcinoma

Surgical resection and imaging guided treatments play a crucial role in the management of hepatocellular carcinoma (HCC). Although the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and has a key role in HCC decision-making process. However, radiological assessment of HCC treatment efficacy is often controversial. There are few doubts on the evaluation of surgical resection; in fact, all known tumor sites should be removed. However, an unenhancing partial linear peripheral halo, in most cases, surrounding a fluid collection reducing in size during follow-up is demonstrated in successfully resected tumor with bipolar radiofrequency electrosurgical device. Efficacy assessment of locoregional therapies is more controversial and differs between percutaneous ablation (e.g., radiofrequency ablation and percutaneous ethanol injection) and transarterial treatments (e.g., conventional transarterial chemoembolization, transarterial chemoembolization with drug eluting beads and radioembolization). Finally, a different approach should be used for new systemic agent that, though not reducing tumor mass, could have a benefit on survival by delaying tumor progression and death. The purpose of this brief article is to review HCC imaging appearance after treatment.

Survival of patients with hepatocellular carcinoma (HCC) treated by percutaneous radio-frequency ablation (RFA) is affected by complete radiological response

Background

Radio-frequency ablation (RFA) has been employed in the treatment of Barcelona Clinic Liver Cancer (BCLC) early stage hepatocellular carcinoma (HCC) as curative treatments.

Aim

To assess the effectiveness and the safety of RFA in patients with early HCC and compensated cirrhosis.

Methods

A cohort of 151 consecutive patients with early stage HCC (122 Child-Pugh class A and 29 class B patients) treated with RFA were enrolled. Clinical, laboratory and radiological follow-up data were collected from the time of first RFA.

A single lesion was observed in 113/151 (74.8%), two lesions in 32/151 (21.2%), and three lesions in 6/151 (4%) of patients.

Results

The overall survival rates were 94%, 80%, 64%, 49%, and 41% at 12, 24, 36, 48 and 60 months, respectively. Complete response (CR) at 1 month (p<0.0001) and serum albumin levels (p = 0.0004) were the only variables indipendently linked to survival by multivariate Cox model. By multivariate analysis, tumor size (p = 0.01) is the only variable associated with an increased likehood of CR.

The proportion of major complications after treatment was 4%.

Conclusions

RFA is safe and effective for managing HCC with cirrhosis, especially for patients with HCC ≤3 cm and higher baseline albumin levels. Complete response after RFA significantly increases survival.

Consider the perspectives: interventional radiology

Image-guided percutaneous local and regional modalities are major treatments for hepatocellular carcinoma. Patients having better liver function and performance are usually eligible and can gain significant survival benefit, especially with more limited tumor burden. The most common local therapies are ethanol and radiofrequency ablation, with the latter providing better local tumor control and survival. Radiofrequency ablation has also occasionally been found to be equivalent to surgical resection for appropriate tumors, with additionally lower morbidity. Chemoembolization is the prevalent transarterial therapy and has been shown to increase survival compared with conservative management. Chemoembolization using drug-eluting beads and radioembolization with β-emitting yttrium-90 microspheres seems to reduce side effects and expand the pool of eligible patients, whereas controversy remains regarding the role of bland particle embolization. Combinations of local and regional therapies may be appropriate for treating a particular tumor or different tumors over time and they may be combined with surgical and medical options.

Clinical and epidemiological aspects of hepatocellular carcinoma in Brazil

The global hepatocellular carcinoma (HCC) incidence is widely variable, depending on geographic region and the prevalence of major risk factors. In Brazil, two large multicentre retrospective studies were performed to investigate clinical and epidemiological aspects of HCC. In the first study, performed in 1997, HCC was found in cirrhotic livers in 71% of cases. Chronic alcoholism was present in 36% of cases, chronic hepatitis B in 35% and hepatitis C in 25%. In a 2010 survey, cirrhosis was present in 98% of cases and HCV was the main aetiology (54%). Differences in HBV prevalence were found among regions. Selection of HCC treatment depends on tumour burden, liver function and performance status. Liver transplantation (LT) is the best available curative treatment for HCC in its early stage and with compromised liver function. After modifications in priority policy, the number of patients with early HCC submitted for LT has increased in the past 5 years in Brazil. Chemoembolization is the most common initial HCC therapy in early and intermediate stages of HCC in Brazil.

The size of the problem: clinical algorithms

Hepatocellular carcinoma (HCC) is a highly prevalent and lethal neoplasia. Current data show that it is the main cause of death in patients with cirrhosis. A better knowledge of the natural history of the tumor and the development of staging systems have led to a better prediction of prognosis and to a most appropriate treatment approach. The Barcelona Clinic Liver Cancer (BCLC) system has become the preferred staging system since it takes into account the characteristics of the tumor, the degree of liver impairment and the physical performance. In addition, it is the only one that links prognosis assessment with treatment recommendation. Curative therapies such as resection, transplantation and ablation can improve survival in patients diagnosed at an early HCC stage and may offer a long-term cure. Patients with intermediate-stage HCC benefit from chemoembolization and those diagnosed at an advanced stage benefit from sorafenib, an oral available, multikinase inhibitor with antiangiogenic and antiproliferative effects. Further efforts are needed to improve the survival of this lethal neoplasia.

ACR Appropriateness Criteria radiologic management of hepatic malignancy

Management of hepatic malignancy is a challenging clinical problem involving several different medical and surgical disciplines. Because of the wide variety of potential therapies, treatment protocols for various malignancies continue to evolve. Consequently, development of appropriate therapeutic algorithms necessitates consideration of medical options, such as systemic chemotherapy; surgical options, such as resection or transplantation; and locoregional therapies, such as thermal ablation and transarterial embolization. The authors discuss treatment strategies for the 3 most common subtypes of hepatic malignancy treated with locoregional therapies: hepatocellular carcinoma, neuroendocrine metastases, and colorectal metastases. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Impact of microbubble-enhanced ultrasound on liver ethanol ablation

Ethanol ablation (EA) is a safe and effective method for treating small liver cancer. However, the ethanol is rapidly washed out by blood perfusion, preventing its accumulation within tumors. Microbubble-enhanced ultrasound (MEUS) is capable of disrupting tumor and liver circulation. We hypothesized that this disruption could be used to enhance EA of normal liver tissue. We treated surgically exposed rabbit liver with a combination of MEUS and EA. The controls were treated with only MEUS or 0.05 mL EA. MEUS treatment was administered with a high-pressure-amplitude, pulsed therapeutic ultrasound device and intra-venous injection of microbubbles. Therapeutic ultrasound was delivered at an acoustic pressure of 4.3 MPa and a duty cycle of 0.22%. Contrast-enhanced ultrasound was performed to estimate liver blood perfusion. Livers were harvested for necrotic volume measurements 48 h after treatment. Contrast-enhanced ultrasound demonstrated that liver perfusion was temporally arrested, with a significant peak intensity decline from -46.9 ± 3.8 to -64.0 ± 3.3 dB, after MEUS treatment. The mean volume ablated in MEUS + EA-treated livers (3.3 ± 2.3 cm(3)) was more than 10 times larger than that in livers treated only with EA (0.3 ± 0.2 cm(3)). The volume of liver ablated by MEUS treatment alone was minor, scattered and immeasurable. These results indicate that MEUS disruption of the liver circulation can greatly promote EA of liver.

Systematic review of radiofrequency ablation versus percutaneous ethanol injection for small hepatocellular carcinoma up to 3 cm

BACKGROUND AND AIM

Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) have been used for patients with hepatocellular carcinomas (HCCs) < 3 cm, but there is controversy which of the two methods is superior. Therefore, we aimed to conduct a systematic review to assess survival, complete tumor necrosis, recurrence and metastasis, major complications, costs, hospital stays, and posttreatment survival quality of RFA versus PEI for treating small HCCs < 3 cm.

METHODS

We conducted a search for published articles in PubMed, Embase, and the Cochrane Library until March 2012. Only randomized controlled trials (RCTs) and quasi-randomized clinical trials were included.

RESULTS

Four RCTs with 766 patients were included in this review. We found that RFA is significantly better than PEI with respect to a 3-year overall survival for small HCCs (RFA vs PEI, hazard ratios [HR] = 0.66, 95% confidence interval [CI]: 0.48-0.90, P = 0.009), especially for HCCs > 2 cm (HR = 0.56, 95% CI: 0.31-0.99, P = 0.045). RFA had a lower risk of local recurrence (HR = 0.38, 95% CI: 0.15-0.96, P = 0.040), but no difference is seen for distant intrahepatic recurrence. RFA had higher rates of complete tumor necrosis, but RFA also caused more major complications and was more costly than PEI. Begg's and Egger's tests detected no significant publication bias among the four RCTs.

CONCLUSIONS

RFA appears superior to PEI with respect to local tumor control and 3-year survival for small HCCs < 3 cm. RFA was more feasible in patients with HCCs > 2 cm or Child-Pugh A liver function.

Effect of alginate-chitosan sustained release microcapsules for transhepatic arterial embolization in VX2 rabbit liver cancer model

Two lipid-solid dispersion loading Norcantharidin sustained-released microspheres of alginate-chitosan (NCTD/LSD-ACMs) were prepared via the emulsification-gelation method. The effects of microspheres for transarterial hepatic chemoembolization were evaluated in VX2 rabbit liver cancer model. The VX2 animal model was established by biopsy needle, divided randomly into four groups, and disposed with three preparations including NCTD/LSD-ACMs (60-120 μm), NCTD/LSD-ACMs(120-200 μm), and NCTD solution through the hepatic arteries compared with the untreated group (control group). The serum of all rabbits before and at 3, 7, and 14 days after embolization was collected to determine the level of aspartate aminotransferase (AST). The AST level increased in the three treated groups on the first day compared with the control group (p < 0.05), and was higher in the two embolization groups (with no significant difference, p >0.05) than that in the NCTD group (p < 0.05). The tumor growth rates, which were significantly decreased in the two embolization groups compared with that in the control group, and the degree of liver cell necrosis assessed by the histopathological specimens, were used to evaluate the embolization effect. Liquefactive necrosis and coagulative necrosis were observed in the two embolization groups. The results showed that NCTD/LSD-ACMs are a potential candidate for embolization of liver cancer.

Simultaneous resection of disseminated hepatocellular carcinoma and colon cancer

A 75-year-old woman with abdominal pain and vomiting was admitted to our hospital. Colonoscopy showed an advanced colon cancer that encompassed the entire circumference of the descending colon's lumen. The patient was diagnosed with occlusive ileus associated with the colon cancer. She had been watched for liver cirrhosis due to the hepatitis C virus and received radiofrequency ablation therapy for hepatocellular carcinoma (HCC) 6 years previously. Although she exhibited a gradual increase in serum levels of α-fetoprotein and PIVKA-II starting 2 years before admission, no tumors were detected in the liver by abdominal ultrasonography and computed tomography. On admission, contrast-enhanced computed tomography revealed not only the colon cancer but also a tumor adjacent to the cecum. Both tumors were successfully removed by surgery and a pathological analysis revealed that the cecum tumor was poorly-differentiated HCC. The serum levels of α-fetoprotein and PIVKA-II declined markedly after the operation and no masses considered as peritoneal metastasis have been detected to date. This is the first report of the simultaneous resection of disseminated HCC and colon cancer.

Therapeutic efficacy and safety of percutaneous ethanol injection with or without combined radiofrequency ablation for hepatocellular carcinomas in high risk locations

OBJECTIVE

To evaluate the therapeutic efficacy and safety of percutaneous ethanol injection (PEI) alone and combined with radiofrequency ablation (RFA) for hepatocellular carcinomas (HCCs) in high risk locations.

MATERIALS AND METHODS

We performed PEI for HCCs in RFA-high risk locations, either alone or in combination with RFA. There were 20 HCCs (1.7 ± 0.9 cm) in 20 patients (PEI group: n = 12; PEI + RFA group: n = 8). We evaluated technical success, local tumor progression and complications in both groups.

RESULTS

Technical success was achieved in all HCCs in both groups. During follow-up, local tumor progression was found in 41.7% (5/12) in the PEI group, whereas 12.5% (1/8) for the PEI + RFA group (p = 0.32). Bile duct dilatation was the most common complication, especially when the tumors were in periportal locations; 55% (5/9) in the PEI group and 50% (2/4) in the PEI + RFA group (p = 1.00). One patient in the PEI group developed severe biliary stricture and upstream dilatation that resulted in atrophy of the left hepatic lobe. One patient treated with PEI + RFA developed cholangitis and an abscess.

CONCLUSION

Combined PEI and RFA treatment has a tendency to be more effective than PEI alone for managing HCCs in high risk locations, although the difference is not statistically significant. Even though PEI is generally accepted as a safe procedure, it may cause major biliary complications for managing HCCs adjacent to the portal vein.

Effectiveness, safety, and local progression after percutaneous laser ablation for hepatocellular carcinoma nodules up to 4 cm are not affected by tumor location

OBJECTIVE

A high-risk location--defined as the tumor margin being less than 5 mm from large vessels or vital structures--represents a well-known limitation and contraindication for radiofrequency ablation of hepatocellular carcinoma (HCC) nodules. The aim of this study was to verify whether HCC nodule location negatively affected the outcome of percutaneous laser ablation in terms of its primary effectiveness, safety, and ability to prevent local tumor progression.

MATERIALS AND METHODS

The medical records and radiologic examinations of 164 cirrhotic patients (90 men, 74 women; mean age ± SD, 68.6 ± 8.3 years) with 182 HCC nodules 4 cm or smaller (mean diameter ± SD, 2.7 ± 0.78 cm) that had been treated by laser ablation between 1996 and 2008 were retrospectively analyzed. One hundred six patients had 116 nodules in high-risk sites (high-risk group), whereas 58 patients had 66 tumors located elsewhere (standard-risk group).

RESULTS

The overall median follow-up was 81 months (range, 6-144 months). The initial complete ablation rate per nodule did not significantly differ between the high-risk group and the standard-risk group (92.2% vs 95.5%, respectively; p = 0.2711). Rates of major complications (high-risk group vs standard-risk group, 1.9% [including one death] vs 0%) and minor complications (5.6% vs 1.0%) were not statistically different between the two groups. Only side effects were recorded significantly more often in high-risk patients than in standard-risk patients (31.5% vs 19.8%; p = 0.049). There was no significant difference in either cumulative incidence of local tumor progression (p = 0.499) or local tumor progression-free survival (p = 0.499, log rank test) between the high-risk group and the standard-risk group.

CONCLUSION

When laser ablation is used to treat small HCC nodules, tumor location does not have a significant negative impact on the technique's primary effectiveness or safety or on its ability to achieve local control of disease.

New progress of non-surgical treatments for hepatocellular carcinoma

Many non-surgical treatments of hepatocellular carcinoma (HCC) have significantly improved in the last few decades and have shown survival benefits for selected patients with HCC. Today ablation can improve survival in individuals diagnosed in early HCC and even offer a curative treatment in selected candidates. Patients with intermediate-stage HCC benefit from transarterial chemoembolization (TACE). Drug-eluting bead transarterial chemoembolization (DEB-TACE) has shown a better combined ischemic and cytotoxic effect locally and less system toxicity when compared with conventional TACE. Those diagnosed at advanced stage benefit from sorafenib. In addition to TACE and sorafenib which could improve survival for selected patients, three-dimensional conformal radiotherapy treatment (3-DCRT), selection internal radiation therapy and systemic chemotherapy have also shown anti-tumor activity in the treatment of advanced HCC, but their survival benefit have not been proven. The limited effects of single therapy suggested that the combination would enhance the overall treatment effect. Other potential non-surgical therapies like gene therapy and immunotherapy are still in testing phases, except for some small-scale clinical trials which have been reported to show some beneficial effect. Here, we review the current non-surgical treatments in HCC and the new advances in this field.

Image-guided ablation for hepatocellular carcinoma

Image-guided ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma (HCC) when surgical options-including resection and transplantation-are precluded. The term image-guided tumor ablation is defined as the direct application of chemical substances or sources of energy to a focal tumor in an attempt to achieve eradication or substantial tumor destruction. Over the past 25 years, several methods for local tumor destruction have been developed and clinically tested. Radiofrequency ablation (RFA) has shown superior anticancer effect and greater survival benefit with respect to the seminal percutaneous technique, ethanol injection, in meta-analyses of randomized controlled trials, and is currently established as the standard ablative modality. Nevertheless, novel thermal and nonthermal techniques for tumor ablation-including microwave ablation and irreversible electroporation-seem to have potential to improve the efficacy of RFA and are currently undergoing clinical investigation.

Imaging and Imaging-Guided Interventions in the Diagnosis and Management of Hepatocellular Carcinoma (HCC)-Review of Evidence

The imaging of hepatocellular carcinoma (HCC) is challenging and plays a crucial role in the diagnosis and staging of the disease. A variety of imaging modalities, such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine are currently used in evaluating patients with HCC. Although the best option for the treatment of these cases is hepatic resection or transplantation, only 20% of HCCs are surgically treatable. In those patients who are not eligible for surgical treatment, interventional therapies such as transcatheter arterial chemoembolization (TACE), percutaneous ethanol injection (PEI), radio-frequency ablation (RFA), percutaneous microwave coagulation therapy (PMC), laser ablation or cryoablation, and acetic acid injection are indicated. In this paper, we aimed to review the evidence regarding imaging modalities and therapeutic interventions of HCC.

Linear enhancement after radio-frequency ablation for hepatocellular carcinoma: is it a sign of recurrence?

This prospective study was performed in 179 hepatocellular carcinoma (HCC) lesions treated by radio-frequency ablation (RFA) to explore the clinical outcome of "linear enhancement" on contrast-enhanced sonogram. Thirty-three lesions (18.4%) showed linear enhancement, a linear-shaped positive enhancement in the RFA-treated area. Seventeen of them were followed up with no treatment (remaining 16; dropout in eight, additional RFA in six and ineffective treatment in two) and three lesions (3/17, 17.6%) showed local tumor progression corresponding to linear enhancement at 7, 14, 19 months after RFA. Although there was no significant difference in local recurrence rate between the lesions with (3/17) and without linear enhancement (10/35), local tumor progression inside the ablation zone occurred only in the lesions with linear enhancement. In conclusion, linear enhancement inside the RFA-treated area should be followed up within 7 months because it has a risk of local tumor progression. Histology of linear enhancement and its influence on distant recurrence remain to be solved.

Spectroscopic and Calorimetric Evaluation of Chemically Induced Protein Denaturation in HuH-7 Liver Cancer Cells and Impact on Cell Survival

Solid tumors such as hepatocellular carcinoma are very often not amenable to chemotherapy and radiotherapy. Local ablation methods, including chemical ablation with absolute ethanol, are therefore an option for treatment but lack of information about the mechanism of devitalization leading to cell death is a hindrance to further adoption. Systemic toxicity also has limited the amount of ethanol that can be used in a single treatment session. Therefore we evaluated the mechanism of urea, a denaturant with little or no systemic toxicity, for potential use in chemical ablation. In this study we report on the use of three methods to analyze the effects in cell culture with a view towards eventual clinical application. Human hepatoma HuH-7 cells were analyzed at several time points after treatment using FTIR, DSC, and Raman microspectroscopy based on MTT and PI-exclusion viability assays. Time course fractional denaturation data plotted against viability show that a 50% viability drop occurs after only a 10–20% drop in overall protein denaturation. Other methods of cell death such as apoptosis may also be operative, but this result implies that protein denaturation is one of the major mechanisms of cell death. This is in line with what has been previously suggested for purely thermal methods, and opens the way to mechanism-based improvements in chemical ablation of solid tumors.

Imaging of HCC

Imaging techniques play a crucial role in the management of patients with liver cirrhosis in whom a nodular hepatic lesion is detected. The most severe complication of patients with liver cirrhosis is the development of a hepatocellular carcinoma (HCC), and the prognosis of the disease depends on the tumoral stage. Surveillance programs based on ultrasonography (US) are recommended in cirrhotic patients with possibility to be treated if an HCC is detected, in order to improve the patient's survival. Nevertheless, early detection and diagnostic confirmation of HCC remains a challenge despite technological advances. The non-invasive criteria to characterize small HCCs in patients with cirrhosis are based on the evaluation of the vascular profile of the lesion. Dynamic multidetector computed tomography (MDCT) and dynamic magnetic resonance imaging (MRI) are the suitable techniques for this purpose. When diagnosis is not achieved, fine US-guided fine needle biopsy (FNB) is indicated. Cellular-MRI contrast agents may have a role in lesions with atypical vascular pattern in which FNB is not feasible. The assessment of the disease extent is another important goal for imaging techniques. Again, dynamic MDCT and dynamic MRI may be used for staging purposes. Although MRI is more accurate in the detection of additional nodules ranging 1-2 cm, both remain relatively insensitive for the detection of tiny satellite nodules below 1 cm. The therapeutic decision can be made in any particular patient on the basis of the tumoral extension, the liver function, and the general status. After curative and palliative therapeutic procedures, the monitoring of the response is mandatory to decide the next approach: to follow-up, to repeat the treatment, to modify the treatment indication, or to suspend the treatment. In this review, we discuss the most recent information on the imaging of HCC.

Hepatocellular carcinoma: natural history, current management, and emerging tools

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and represents the third-leading cause of cancer-related death in the world. The incidence of HCC continues to increase worldwide, with a unique geographic, age, and sex distribution. The most important risk factor associated with HCC is liver cirrhosis, with the majority of cases caused by chronic infection with hepatitis B (HBV) and C (HCV) viruses and alcohol abuse, although nonalcoholic fatty liver disease is emerging as an increasingly important cause. Primary prevention in the form of HBV vaccination has led to a significant decrease in HBV-related HCC, and initiation of antiviral therapy appears to reduce the incidence of HCC in patients with chronic HBV or HCV infection. Additionally, the use of ultrasonography enables the early detection of small liver tumors and forms the backbone of recommended surveillance programs for patients at high risk for the development of HCC. Cross-sectional imaging studies, including computed tomography and magnetic resonance imaging, represent further noninvasive techniques that are increasingly employed to diagnose HCC in patients with cirrhosis. The mainstay of potentially curative therapy includes surgery – either resection or liver transplantation. However, most patients are ineligible for surgery, because of either advanced disease or underlying liver dysfunction, and are managed with locoregional and/or systemic therapies. Randomized controlled trials have demonstrated a survival benefit with both local therapies, either ablation or embolization, and systemic therapy in the form of the multikinase inhibitor sorafenib. Despite this, median survival remains poor and recurrence rates significant. Further advances in our understanding of the molecular pathogenesis of HCC hold promise in improving the diagnosis and treatment of this highly lethal cancer.

Management of HCC

Hepatocellular carcinoma (HCC) is a highly prevalent and lethal neoplasia, the management of which has significantly improved during the last few years. A better knowledge of the natural history of the tumor and the development of staging systems that stratify patients according to the characteristics of the tumor, the liver disease, and the performance status, such as the BCLC (Barcelona Clinic Liver Cancer) system, have led to a better prediction of prognosis and to a most appropriate treatment approach. Today curative therapies (resection, transplantation, ablation) can improve survival in patients diagnosed at an early HCC stage and offer a potential long-term cure. Patients with intermediate stage HCC benefit from chemoembolization and those diagnosed at advanced stage benefit from sorafenib, a multikinase inhibitor with antiangiogenic and antiproliferative effects. In this article we review the current management in HCC and the new advances in this field.

Survival after locoregional treatments for hepatocellular carcinoma: a cohort study in real-world patients

Evidence of relative effectiveness of local treatments for hepatocellular carcinoma (HCC) is scanty. We investigated, in a retrospective cohort study, whether surgical resection, radiofrequency ablation (RFA), percutaneous ethanol injection (PEI), and transarterial embolization with (TACE) or without (TAE) chemotherapy resulted in different survival in clinical practice. All patients first diagnosed with HCC and treated with any locoregional therapy from 1998 to 2002 in twelve Italian hospitals were eligible. Overall survival (OS) was the unique endpoint. Three main comparisons were planned: RFA versus PEI, surgical resection versus RFA/PEI (combined), TACE/TAE versus RFA/PEI (combined). Propensity score method was used to minimize bias related to non random treatment assignment. Overall 425 subjects were analyzed, with 385 (91%) deaths after a median followup of 7.7 years. OS did not significantly differ between RFA and PEI (HR 1.11, 95% CI 0.79-1.57), between surgery and RFA/PEI (HR 0.95, 95% CI 0.64-1.41) and between TACE/TAE and RFA/PEI (HR 0.88, 95% CI 0.66-1.17). 5-year OS probabilities were 0.14 for RFA, 0.18 for PEI, 0.27 for surgery, and 0.15 for TACE/TAE. No locoregional treatment for HCC was found to be more effective than the comparator. Adequately powered randomized clinical trials are still needed to definitely assess relative effectiveness of locoregional HCC treatment.

Interventional therapies for hepatocellular carcinoma

Hepatocellular carcinoma is the third most common cause of cancer-related death. In the past few years, staging systems have been developed that enable patients to be stratified into treatment algorithms in a multidisciplinary setting. Several of these treatments involve minimally invasive image-guided therapy that can be performed by radiologists.

Hepatocellular carcinoma

Hepatocellular carcinoma is the sixth most prevalent cancer and the third most frequent cause of cancer-related death. Patients with cirrhosis are at highest risk of developing this malignant disease, and ultrasonography every 6 months is recommended. Surveillance with ultrasonography allows diagnosis at early stages when the tumour might be curable by resection, liver transplantation, or ablation, and 5-year survival higher than 50% can be achieved. Patients with small solitary tumours and very well preserved liver function are the best candidates for surgical resection. Liver transplantation is most beneficial for individuals who are not good candidates for resection, especially those within Milano criteria (solitary tumour ≤5 cm and up to three nodules ≤3 cm). Donor shortage greatly limits its applicability. Percutaneous ablation is the most frequently used treatment but its effectiveness is limited by tumour size and localisation. In asymptomatic patients with multifocal disease without vascular invasion or extrahepatic spread not amenable to curative treatments, chemoembolisation can provide survival benefit. Findings of randomised trials of sorafenib have shown survival benefits for individuals with advanced hepatocellular carcinoma, suggesting that molecular-targeted therapies could be effective in this chemoresistant cancer. Research is active in the area of pathogenesis and treatment of hepatocellular carcinoma.

Saudi guidelines for the diagnosis and management of hepatocellular carcinoma: technical review and practice guidelines

Recognizing the significant prevalence of hepatocellular carcinoma (HCC) in Saudi Arabia, and the difficulties often faced in early and accurate diagnoses, evidence-based management, and the need for appropriate referral of HCC patients, the Saudi Association for the Study of Liver diseases and Transplantation (SASLT) formed a multi-disciplinary task force to evaluate and update the previously published guidelines by the Saudi Gastroenterology Association. These guidelines were later reviewed, adopted and endorsed by the Saudi Oncology Society (SOS) as its official HCC guidelines as well. The committee assigned to revise the Saudi HCC guidelines was composed of hepatologists, oncologists, liver surgeons, transplant surgeons, and interventional radiologists. Two members of the task force served as guidelines editors. A wide based search on all published reports on all aspects of the epidemiology, natural history, risk factors, diagnosis, and management of HCC was performed. All available literature was critically examined and available evidence was then classified according to its strength. The whole document and the recommendations were then discussed in detail by members and consensus was obtained. All recommendations in these guidelines were based on the best available evidence, but were tailored to the patients treated in Saudi Arabia. We hope that these guidelines will improve HCC patient care and enhance the multidisciplinary care needed for these patients.

Endoscopic treatment of duodenal bleeding caused by direct hepatocellular carcinoma invasion with an ethanol injection

We report a case of a man who developed duodenal bleeding caused by direct hepatocellular carcinoma (HCC) invasion, which was successfully treated with endoscopic ethanol injection. A 57-year-old man with known HCC was admitted for melena and exertional dyspnea. He had been diagnosed with inoperable HCC a year ago. Urgent esophagogastroduodenoscopy (EGD) showed two widely eroded mucosal lesions with irregularly shaped luminal protruding hard mass on the duodenal bulb. Argon plasma coagulation and Epinephrine injection failed to control bleeding. We injected ethanol via endoscopy to control bleeding two times with 14 cc and 15 cc separately without complication. Follow-up EGD catched a large ulcer with necrotic and sclerotic base but no bleeding evidence was present. He was discharged and he did relatively well during the following periods. In conclusion, Endoscopic ethanol injection can be used as a significantly effective and safe therapeutic tool in gastrointestinal tract bleeding caused by HCC invasion.

Local-regional treatment of hepatocellular carcinoma

Local-regional treatments play a key role in the management of hepatocellular carcinoma (HCC). Image-guided tumor ablation is recommended in patients with early-stage HCC when surgical options are precluded and can replace resection in selected patients. Radiofrequency (RF) ablation has shown superior anticancer effects and greater survival benefit with respect to the seminal percutaneous technique, ethanol injection, in meta-analyses of randomized controlled trials and is currently established as the standard method for local tumor treatment. Novel thermal and nonthermal techniques for tumor ablation, including microwave ablation and irreversible electroporation, seem to have potential to overcome the limitations of RF ablation and warrant further clinical investigation. Transcatheter arterial chemoembolization (TACE) is the standard of care for patients with asymptomatic noninvasive multinodular tumors in intermediate-stage disease. Embolic microspheres that have the ability to release a drug in a controlled and sustained fashion have been shown to substantially increase the safety and efficacy of TACE in comparison to conventional ethiodized oil-based regimens. The available data for radioembolization with yttrium 90 suggest that this is a potential new option for patients with HCC, and future studies should be devoted to assessments of the role of radioembolization in the treatment algorithm for HCC.

The current role of minimally invasive therapies in the management of liver tumors

This is a review of minimally invasive therapy options for liver tumors, such as highly focused ultrasound, microwave ablation, and irreversible electroporation, as well as new aspects of radiofrequency ablation. Radiofrequency ablation is recommended for patients with early-stage HCC with up to 3 lesions with a tumor diameter within 3 cm and for patients with non-resectable liver metastasis. Indications and contraindications to treatment are designated, and different modalities for image-based therapy guidance are compared. Options for therapy monitoring and controlling are reviewed, namely intraprocedural tools, imaging and functional parameters and their evolution during therapy. Prevention and control of local recurrences is discussed. We also present a short review of current clinical results in treating liver metastasis and primary liver tumors.

Interventional radiological treatment of hepatocellular carcinoma: an update

Hepatocellular carcinoma is the commonest primary liver tumor and its incidence is on an increase.Transplantation and surgical resection are the gold standard curative treatment options but less than 20%patients are surgical candidates because of advanced liver disease and/or co-morbidities.Various interventional radiological procedures have been developed and intensively investigated for treatment of inoperable HCC.This review summarizes the various interventional radiological treatments in HCC including patient selection, procedural considerations and response evaluation. Transarterial chemoembolization, radioembolization and radiofrequency ablation are mainly discussed.

Survival in patients with recurrent hepatocellular carcinoma after primary hepatectomy: comparative effectiveness of treatment modalities

BACKGROUND

Insufficient data are available on the survival of recurrent hepatocellular carcinoma after primary hepatectomy in patients receiving different treatments. We evaluated retrospectively the effects of treatment modalities on long-term survival.

METHODS

Between 2001 and 2007, 435 posthepatectomy hepatocellular carcinoma patients who developed recurrence were grouped by treatment modality into re-resection, radiofrequency ablation, transarterial chemoembolization, and supportive treatment groups. Treatment strategies for both primary hepatocellular carcinoma and its recurrence were selected using the same criteria. Postrecurrence survival was estimated using the Kaplan-Meier method and compared using the Cox proportional hazard model with adjusted independent prognostic factors. Survival rates after primary resection without recurrence were also compared.

RESULTS

In re-resection, radiofrequency ablation, transarterial chemoembolization, and supportive treatment groups, the 2-year postrecurrence survival rates were 90%, 96%, 75%, and 20%, respectively, and the 5-year survival rates were 72%, 83%, 56%, and 0%, respectively. The adjusted hazard of death was less for the re-resection and radiofrequency ablation groups than for the transarterial chemoembolization group, and the adjusted hazard ratios for the re-resection and radiofrequency ablation groups were 0.45 (95% confidence interval, 0.20-0.98) and 0.25 (0.08-0.81), respectively. The adjusted hazard ratio (95% confidence interval) of death for the radiofrequency ablation group compared to the re-resection group was 0.64 (0.19-2.19). Survival in the single resection group did not differ from that in the re-resection and radiofrequency ablation groups.

CONCLUSION

Postrecurrence survival in the re-resection and radiofrequency ablation groups was significantly better than that in the transarterial chemoembolization group and similar to that of patients in the primary resection without recurrence group.

Percutaneous tumor ablation for hepatocellular carcinoma

OBJECTIVE

This report reviews the current clinical status of percutaneous ablation of hepatocellular carcinoma (HCC).

CONCLUSION

HCC is increasing in incidence. Multiple percutaneous ablation methods are now available for primary treatment or for bridging to transplantation. Percutaneous ethanol instillation and radiofrequency ablation are the most extensively evaluated percutaneous treatments for HCC. Newer technologies are being evaluated and may change future practice patterns.

Threshold-based prediction of the coagulation zone in sequential temperature mapping in MR-guided radiofrequency ablation of liver tumours

OBJECTIVE

To evaluate different cut-off temperature levels for a threshold-based prediction of the coagulation zone in magnetic resonance (MR)-guided radiofrequency (RF) ablation of liver tumours.

METHODS

Temperature-sensitive measurements were acquired during RF ablation of 24 patients with primary (6) and secondary liver lesions (18) using a wide-bore 1.5 T MR sytem and compared with the post-interventional coagulation zone. Temperature measurements using the proton resonance frequency shift method were performed directly subsequent to energy application. The temperature maps were registered on the contrast-enhanced follow-up MR images acquired 4 weeks after treatment. Areas with temperatures above 50°, 55° and 60°C were segmented and compared with the coagulation zones. Sensitivity and positive predictive value were calculated.

RESULTS

No major complications occurred and all tumours were completely treated. No tumour recurrence was observed at the follow-up examination after 4 weeks. Two patients with secondary liver lesions showed local tumour recurrence after 4 and 7 months. The 60°C threshold level achieved the highest positive predictive value (87.7 ± 9.9) and the best prediction of the coagulation zone.

CONCLUSIONS

For a threshold-based prediction of the coagulation zone, the 60°C cut-off level achieved the best prediction of the coagulation zone among the tested levels.

KEY POINTS

• Temperature monitoring can be used to survey MR-guided radiofrequency ablation • The developing ablation zone can be estimated based on post-interventional temperature measurements • A 60°C threshold level can be used to predict the ablation zone • The 50°C and 55°C temperature zones tend to overestimate the ablation zone.

Multidisciplinary Canadian consensus recommendations for the management and treatment of hepatocellular carcinoma

Globally, hepatocellular carcinoma (hcc) is the third most common cause of death from cancer, after lung and stomach cancer. The incidence of hcc in Canada is increasing and is expected to continue to increase over the next decade. Given the high mortality rate associated with hcc, steps are required to mitigate the impact of the disease. To address this challenging situation, a panel of 17 hcc experts, representing gastroenterologists, hepatologists, hepatobiliary surgeons, medical oncologists, pathologists, and radiologists from across Canada, convened to provide a framework that, using an evidence-based approach, will assist clinicians in optimizing the management and treatment of hcc. The recommendations, summarized here, were developed based on a rigorous methodology in a pre-specified process that was overseen by the steering committee. Specific topics were identified by the steering committee and delegated to a group of content experts within the expert panel, who then systematically reviewed the literature on that topic and drafted the related content and recommendations. The set of recommendations for each topic were reviewed and assigned a level of evidence and grade according to the levels of evidence set out by the Centre for Evidence-based Medicine, Oxford, United Kingdom. Agreement on the level of evidence for each recommendation was achieved by consensus. Consensus was defined as agreement by a two-thirds majority of the 17 members of the expert panel. Recommendations were subject to iterative review and modification by the expert panel until consensus could be achieved.

Ethanol injection is highly effective for hepatocellular carcinoma smaller than 2 cm

AIM: To analyze the long-term prognosis in a cohort of western cirrhotic patients with single hepatocellular carcinoma treated with ethanol injection.

METHODS: One-hundred forty-eight patients with solitary hepatocellular carcinoma were enrolled. The tumor diameter was lower than 2 cm in 47 patients but larger in the remaining 101 patients. The impact of some pre-treatment clinical and laboratory parameters and of tumor recurrence on patients’ survival was assessed.

RESULTS: Among the pre-treatment parameters, only a tumor diameter of less than 2 cm was an independent prognostic factor of survival. The occurrence of new nodules in other liver segments and the neoplastic portal invasion were linked to a poorer prognosis at univariate analysis. Patients with a single hepatocellular carcinoma smaller than 2 cm showed a better 5-year cumulative survival (73.0% vs 47.9%) (P = 0.009), 3-year local recurrence rate (29.1% vs 51.5%) (P = 0.011), and 5-year distant intrahepatic recurrence rate (52.9% vs 62.8%) (P = 0.054) compared to patients with a larger tumor.

CONCLUSION: The 5-year survival rate of patients with single hepatocellular carcinoma < 2 cm undergoing ethanol injection is excellent and comparable to that achieved using radiofrequency ablation.

Radiofrequency ablation of hepatocellular carcinoma

Radiofrequency ablation (RFA), usually performed under percutaneous ultrasound guidance, is considered the gold standard among minimally invasive therapies. On the strength of some recent randomized trials, its indications include operable patients with small hepatocellular carcinoma and inoperable patients with more advanced disease also in combination with other therapies. RFA has lower complication rates and costs less than surgery.

Locoregional radiological treatment for hepatocellular carcinoma; Which, when and how?

Hepatocellular carcinoma (HCC) is one of the most frequent and deadliest cancers worldwide. Liver transplantation, surgical resection or local ablation offer the best survival advantages but most patients either present when the tumor is in an advanced stage or the degree of underlying liver disease precludes these options. Several therapies have been proposed for these patients with proven survival benefits. These therapies comprise the locoregional treatment for HCC, and include percutaneous ethanol injection (PEI), radiofrequency ablation (RFA), transarterial chemoembolization (TACE), transarterial radioembolization (TARE), and drug-eluting bead (DEB). PEI and RFA are considered curative treatments for early stage HCC; whereas TACE is a standard of care for intermediate stages. Additionally, evaluation of response to locoregional treatment in HCC is important, as objective response may become a surrogate marker for improved survival. Currently, there are several criteria for response assessment, including the World Health Organization (WHO), the Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver Criteria (EASL), and the modified RECIST (mRECIST); however, there has been poor correlation between the clinical benefit provided by locoregional interventional therapies and conventional methods of response assessment. The aim of our study was to review and analyze the current evidence for radiological interventions in HCC, and to propose evidence based recommendations to improve the management of these patients.

Treatment options in hepatocellular carcinoma today

Hepatocellular carcinoma (HCC) is the third most common cause of cancer related death worldwide. As over 90% of HCCs arise in cirrhotic livers preventive methods and surveillance policies have been adopted in most countries with high prevalence of hepatitis B or C infected people. Poor prognosis of HCC has shown some improvement during the last years. Targeted therapy with radiofrequency ablation (RFA), hepatic resection (HR), liver transplantation (LT), and transcatheter arterial chemoembolisation (TACE) seems to have an influence on this development. The heterogeneity of cirrhotic patients with HCC is still a big challenge. A patient with a small tumour in a cirrhotic liver may have a worse prognosis than a patient with a large tumor in a relatively preserved liver after "curative" HR. The choice of the treatment modality depends on the size and the number of tumours, the stage and the cause of cirrhosis and finally on the availability of various modalities in each centre.

Combined treatment of large hepatocellular carcinoma with transcatheter arterial chemoembolization and percutaneous ethanol injection with a multipronged needle: experimental and clinical investigation

PURPOSE

This study was designed to evaluate the usefulness of percutaneous ethanol injection (PEI) with a multipronged needle for the treatment of large hepatocellular carcinoma (HCC). An experimental animal study and a clinical investigation were performed.

METHODS

In the experimental study, 20 ml of 99.5% ethanol was injected into porcine liver in vivo with a multipronged needle (n = 5) or a straight needle (n = 5), and the volumes of coagulation necrosis were compared. In the clinical investigation, PEI was performed in 17 patients (10 men, 7 women; mean age 73.4 ± 6.7 years) with single, large HCC (mean tumor diameter, 47.2 ± 11.5 mm; range, 32-70 mm) by using a multipronged needle. Fifteen of 17 patients received transarterial chemoembolization (TACE) before PEI.

RESULTS

The volume of coagulation in porcine liver in vivo was significantly increased with the multipronged needle compared with the straight needle (longest perpendicular diameters, 34.2 ± 3.6 mm × 30.2 ± 3.6 mm vs. 22.6 ± 2.5 mm × 19 ± 2.2 mm, respectively; P < 0.05). In the clinical trial, initial complete response (CR) of the tumor was achieved in 17 of 17 patients, 7 of whom required two PEI sessions. During the follow-up, local recurrence was detected in 4 of 17 patients at 3-19 months after the procedure, for a rate of sustained local CR of 76%. No major complication occurred.

CONCLUSIONS

Use of a multipronged needle substantially increases the volume of coagulation in vivo with respect to the conventional PEI technique. Combined TACE and PEI with multipronged needles is a safe and effective option for percutaneous treatment of single, large HCC.

Locoregional therapy for hepatocellular carcinoma

Locoregional therapies for hepatocellular carcinoma have progressed greatly in the last 30 years, beginning with the introduction of chemoembolization. Embolization techniques have evolved with the use of drug-eluting beads and radioembolization with yttrium-90. In the last 10 years, several new ablation techniques were developed including radiofrequency ablation, microwave ablation, cryoablation, laser ablation, and irreversible electroporation. Isolated or in combination, these techniques have already shown that they can improve patient survival and/or provide acceptable palliation.