Diffuse intrahepatic recurrence after percutaneous radiofrequency ablation for solitary and small hepatocellular carcinoma

Local Ablation Therapy for Hepatocellular Carcinoma: Clinical Significance of Tumor Size, Location, and Biology

ABSTRACT

Local ablation therapy, encompassing radiofrequency ablation (RFA), microwave ablation, and cryoablation, has emerged as a crucial strategy for managing small hepatocellular carcinomas (HCCs), complementing liver resection and transplantation. This review delves into the clinical significance of tumor size, location, and biology in guiding treatment decisions for HCCs undergoing local ablation therapy, with a focus on tumors smaller than 3 cm. Tumor size significantly influences treatment outcomes, with larger tumors associated with poorer local tumor control due to challenges in creating sufficient ablative margins and the likelihood of microvascular invasion and peritumoral satellite nodules. Advanced ablation techniques such as centripetal or no-touch RFA using multiple electrodes, cryoablation using multiple cryoprobes, and microwave ablation offer diverse options for HCC treatment. Notably, no-touch RFA demonstrates superior local tumor control compared with conventional RFA by achieving sufficient ablative margins, making it particularly promising for hepatic dome lesions or tumors with aggressive biology. Laparoscopic RFA proves beneficial for treating anterior subphrenic HCCs, whereas artificial pleural effusion-assisted RFA is effective for controlling posterior subphrenic HCCs. However, surgical resection generally offers better survival outcomes for periportal HCCs compared with RFA. Cryoablation exhibits a lower incidence of vascular or biliary complications than RFA for HCCs adjacent to perivascular or periductal regions. Additionally, aggressive tumor biology, such as microvascular invasion, can be predicted using magnetic resonance imaging findings and serum tumor markers. Aggressive HCC subtypes frequently exhibit Liver Imaging Reporting and Data System M features on magnetic resonance imaging, aiding in prognosis. A comprehensive understanding of tumor size, location, and biology is imperative for optimizing the benefits of local ablation therapy in managing HCCs.

Suppression of popping rates in radiofrequency ablation under perfluorobutane microbubbles for hepatocellular carcinoma

Aim of the study

Popping during radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) can cause complications such as bleeding and tumor seeding. Perfluorobutane microbubbles (Sonazoid, GE Healthcare) are employed to enhance visualization through the use of vascular and Kupffer imaging. This study aimed to assess the impact of Sonazoid on popping during RFA for HCC and evaluate popping and local recurrence rates.

Material and methods

We examined 135 patients and 308 nodules undergoing RFA for HCC using a unipolar needle electrode between December 2019 and December 2023. Popping and local recurrence rates were compared between RFA groups with and without Sonazoid.

Results

The cohort comprised 99 males and 36 females, with a mean age of 72 (range: 35-93) years. Background liver conditions included 21 hepatitis B virus (HBV), 44 hepatitis C virus (HCV), and 70 non-HBV/HCV cases. The group without Sonazoid had 267 nodes, while the Sonazoid group had 41 nodes. In energy-related comparisons, the Sonazoid group exhibited lower power (p = 0.039) and energy delivery (p = 0.013) and shorter cauterization time (p = 0.021). The popping rate during cauterization was significantly lower in the Sonazoid group (28.8% vs. 12.2%, p = 0.023). There was no significant difference in local recurrence rate between the two groups.

Conclusions

RFA with Sonazoid using a unipolar needle-type electrode reduced power output, enabling lower-energy ablation and shorter ablation times. This suggests a potential for suppressing the popping phenomenon. Low-power ablation did not affect local recurrence rates, highlighting RFA as a less invasive treatment strategy. Further studies with larger cohorts are needed to evaluate treatment efficacy.

Complications of Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma

Radiofrequency ablation (RFA) is a potentially curative treatment option for early Hepatocellular carcinoma. The RFA is considered safe with a relatively low incidence of complications ranging from 2%-7.9%. Though most of the complications are self-limiting, sometimes they can be life-threatening. The occurrence of the particular complication depends on various factors like tumour location and morphology, underlying disease and ablation technique. A detailed understanding of potential complications along with the associated risk factors will help to employ strategies to prevent them, identify them early and manage them when they occur. This article demonstrates various radiofrequency ablation-related complications and discusses the risk factors and technical strategies to minimise them and achieve complete ablation of the tumour.

Hepatocellular carcinoma recurrence: Predictors and management

Hepatocellular carcinoma (HCC), the sixth most common cancer globally, is associated with high mortality rates and more than 830,000 annual deaths. Despite advances in the available management options including surgical resection and local ablative therapies, recurrence rates after the initial treatment exceed 50%, even among patients who have undergone curative-intent therapy. Moreover, postsurgical HCC recurrence occurs in about 70% of cases five years postoperatively. The management of recurrent HCC remains undefined. This review discusses different predictors for HCC recurrence after each treatment modality and different approaches available to stratify these patients. More specific guidelines for managing HCC recurrence and strict surveillance protocols for such recurrence after initial HCC management are needed.

Radiofrequency ablation induces tumor cell dissemination in a mouse model of hepatocellular carcinoma

BACKGROUND

We tested the hypothesis that radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) promotes tumor cell release and explored a method for reducing these effects.

METHODS

A green fluorescent protein-transfected orthotopic HCC model was established in 99 nude mice. In vivo flow cytometry was used to monitor circulating tumor cell (CTC) dynamics. Pulmonary fluorescence imaging and pathology were performed to investigate lung metastases. First, the kinetics of CTCs during the periablation period and the survival rate of CTCs released during RFA were investigated. Next, mice were allocated to controls, sham ablation, or RFA with/without hepatic vessel blocking (ligation of the portal triads) for evaluating the postablation CTC level, lung metastases, and survival over time. Moreover, the kinetics of CTCs, lung metastases, and mice survival were evaluated for RFA with/without ethanol injection. Pathological changes in tumors and surrounding parenchyma after ethanol injection were noted. Statistical analysis included t-test, ANOVA, and Kaplan-Meier survival curves.

RESULTS

CTC counts were 12.3-fold increased during RFA, and 73.7% of RFA-induced CTCs were viable. Pre-RFA hepatic vessel blocking prevented the increase of peripheral CTCs, reduced the number of lung metastases, and prolonged survival (all p ≤ 0.05). Similarly, pre-RFA ethanol injection remarkably decreased CTC release during RFA and further decreased lung metastases with extended survival (all p ≤ 0.05). Histopathology revealed thrombus formation in blood vessels after ethanol injection, which may clog tumor cell dissemination during RFA.

CONCLUSION

RFA induces viable tumor cell dissemination, and pre-RFA ethanol injection may provide a prophylactic strategy to reduce this underestimated effect.

RELEVANCE STATEMENT

RFA for HCC promotes viable tumor cell release during ablation, while ethanol injection can prevent RFA induced tumor cell release.

KEY POINTS

• RFA induced the release of viable tumor cells during the ablation procedure in an animal model. • Hepatic vessel blocking can suppress tumor cells dissemination during RFA. • Ethanol injection can prevent RFA-induced tumor cell release, presumably because of the formation of thrombosis.

Predicting Outcome after Percutaneous Ablation for Early-Stage Hepatocellular Carcinoma Using Various Imaging Modalities

Percutaneous ablation is a low-invasive, repeatable, and curative local treatment that is now recommended for early-stage hepatocellular carcinoma (HCC) that is not suitable for surgical resection. Poorly differentiated HCC has high-grade malignancy potential. Microvascular invasion is frequently seen, even in tumors smaller than 3 cm in diameter, and prognosis is poor after percutaneous ablation. Biopsy has a high risk of complications such as bleeding and dissemination; therefore, it has limitations in determining HCC tumor malignancy prior to treatment. Advances in diagnostic imaging have enabled non-invasive diagnosis of tumor malignancy. We describe the usefulness of ultrasonography, computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography for predicting outcome after percutaneous ablation for HCC.

An Investigation of Popping During Radiofrequency Ablation After Lenvatinib Administration for Hepatocellular Carcinoma

BACKGROUND/AIM

Lenvatinib is available as a molecular target agent for hepatocellular carcinoma (HCC). In this study, we investigated the popping phenomena in patients with HCC who underwent radiofrequency ablation (RFA) after taking lenvatinib.

PATIENTS AND METHODS

Fifty-nine patients with HCC between 21-30 mm in diameter and no history of systemic treatment were enrolled in the study. The patients underwent RFA using a VIVA RFA SYSTEM with an ablation tip of 30 mm in length. For the initial lenvatinib administration, 16 patients had an adequate course of treatment and were treated with RFA as add-on therapy (combination group). The other 43 patients were treated by RFA monotherapy (monotherapy group). The popping frequency during RFA was recorded and compared.

RESULTS

Popping frequency in the combination group (RFA combined with lenvatinib) was significantly higher than that in the monotherapy group. There was no significant difference between the combination group and the monotherapy group in ablation time, maximum output level, tumour temperature after ablation, or initial resistance value.

CONCLUSION

Popping frequency was significantly higher in the combination group. It is possible that the intra-tumour temperature increased rapidly during RFA in the combination group due to the inhibitory effect of lenvatinib on tumour angiogenesis, leading to the occurrence of popping. Further studies are needed to investigate popping after RFA, and precise protocols need to be developed.

Myofibroblasts: A key promoter of tumorigenesis following radiofrequency tumor ablation

Radiofrequency ablation (RFA) of intrahepatic tumors induces distant tumor growth through activation of interleukin 6/signal transducer and activator of transcription 3 (STAT3)/hepatocyte growth factor (HGF)/tyrosine-protein kinase Met (c-MET) pathway. Yet, the predominant cellular source still needs to be identified as specific roles of the many types of periablational infiltrating immune cells requires further clarification. Here we report the key role of activated myofibroblasts in RFA-induced tumorigenesis and successful pharmacologic blockade. Murine models simulating RF tumorigenic effects on a macrometastatic tumor and intrahepatic micrometastatic deposits after liver ablation and a macrometastatic tumor after kidney ablation were used. Immune assays of ablated normal parenchyma demonstrated significantly increased numbers of activated myofibroblasts in the periablational rim, as well as increased HGF levels, recruitment other cellular infiltrates; macrophages, dendritic cells and natural killer cells, HGF dependent growth factors; fibroblast growth factor-19 (FGF-19) and receptor of Vascular Endothelial Growth Factor-1 (VEGFR-1), and proliferative indices; Ki-67 and CD34 for microvascular density. Furthermore, macrometastatic models demonstrated accelerated distant tumor growth at 7d post-RFA while micrometastatic models demonstrated increased intrahepatic deposit size and number at 14 and 21 days post-RFA. Multi-day atorvastatin, a selective fibroblast inhibitor, inhibited RFA-induced HGF and downstream growth factors, cellular markers and proliferative indices. Specifically, atorvastatin treatment reduced cellular and proliferative indices to baseline levels in the micrometastatic models, however only partially in macrometastatic models. Furthermore, adjuvant atorvastatin completely inhibited accelerated growth of macrometastasis and negated increased micrometastatic intrahepatic burden. Thus, activated myofibroblasts drive RF-induced tumorigenesis at a cellular level via induction of the HGF/c-MET/STAT3 axis, and can be successfully pharmacologically suppressed.

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

Background/aim

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

Materials and methods

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

Results

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

Conclusion

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

Supplementary Information

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

Construction of a novel radiomics nomogram for the prediction of aggressive intrasegmental recurrence of HCC after radiofrequency ablation

OBJECTIVES

To construct a precise prediction model of preoperative magnetic resonance imaging (MRI)-based nomogram for aggressive intrasegmental recurrence (AIR) of hepatocellular carcinoma (HCC) patients treated with radiofrequency ablation (RFA).

METHODS

Among 891 patients with HCC treated by RFA, 22 patients with AIR and 36 patients without AIR (non-AIR) were finally enrolled in our study, and each patient was followed up for more than 6 months to determine the occurrence of AIR. The laboratory indicators and MRI features were compared and assessed. Preoperative contrast-enhanced T1-weighted images (CE-T1WI) were used for radiomics analysis. The selected clinical indicators and texture features were finally screened out to generate the novel prediction nomogram.

RESULTS

Tumor shape, ADC Value, DWI signal intensity and ΔSI were selected as the independent factors of AIR by univariate and multivariate logistic regression analysis. Meanwhile, two radiomics features were selected from 396 candidate features by LASSO (P < 0.05), which were further used to calculate the Rad-score. The selected clinical factors were further integrated with the Rad-score to construct the predictive model, and the AUCs were 0.941 (95% CI: 0.876-1.000) and 0.818 (95% CI: 0.576-1.000) in the training (15 AIR and 25 non-AIR) and validation cohorts (7 AIR and 11 non-AIR), respectively. The AIR predictive model was further converted into a novel radiomics nomogram, and decision curve analysis showed good agreement.

CONCLUSIONS

The predictive nomogram integrated with clinical factors and CE-T1WI -based radiomics signature could accurately predict the occurrence of AIR after RFA, which could greatly help individualized evaluation before treatment.

Feeding artery ablation before radiofrequency ablation for hepatocellular carcinoma may reduce critical recurrence

Background and Aim

Percutaneous radiofrequency ablation (RFA) is a minimally invasive and curative local treatment for hepatocellular carcinoma (HCC). However, serious concerns remain regarding critical recurrences such as metastasis, dissemination, and/or seeding due to RFA. In August 2006, we introduced selective feeding artery ablation before tumor ablation to reduce the risk of critical recurrence by blocking tumor blood flow. The aim of the present study was to clarify whether feeding artery ablation before tumor ablation can reduce the risk of critical recurrence after RFA.

Methods

This study retrospectively analyzed 279 patients with primary, solitary, and hypervascular HCC ≤5 cm in diameter who were treated with RFA alone between April 2001 and August 2013. Critical recurrence was defined as intra‐ or extrahepatic metastasis, dissemination, or seeding that was difficult to treat radically.

Results

Of the 279 HCC patients, 157 patients were treated with conventional RFA alone, and 122 patients underwent RFA with prior feeding artery ablation. Although no significant differences were seen in the rates of local tumor progression‐free survival, overall recurrence‐free survival, or overall survival between a conventional RFA group and a prior feeding artery ablation group, significant differences were seen in rates of critical recurrence‐free survival and cancer‐specific survival (5‐year, 69 vs 81%, P = 0.01 and 76 vs 88%, P = 0.03, respectively). On multivariate analysis, prior feeding artery ablation, tumor diameter, and alpha‐fetoprotein were independent factors related to critical recurrence.

Conclusions

Feeding artery ablation before tumor ablation may reduce the risk of critical recurrence.

Monitoring radiofrequency therapy-induced tumor cell dissemination by in vivo flow cytometry

Clinical and experimental findings have disclosed a high recurrence rate after radiofrequency ablation (RFA), which might be due to the dissemination of malignant cells into the vasculature during ablation. Here, we apply in vivo flow cytometry (IVFC) to monitor circulating tumor cells (CTCs) while performing ablation in a real-time and noninvasive way in an orthotopic model of prostate cancer. We report that CTCs are dramatically increased during RFA. The CTCs induced by ablation eventually translate into enhanced distant metastasis and reduced survival as compared to resection. Immunofluorescence analysis reveals that RFA significantly increases the infiltration of tumor-associated macrophages (TAMs) in the lung. Our study thus suggests that the ablative procedure of prostate tumors causes immediate tumor cell dissemination and increases distant metastasis.

Switching Monopolar No-Touch Radiofrequency Ablation Using Octopus Electrodes for Small Hepatocellular Carcinoma: A Randomized Clinical Trial

INTRODUCTION

A switching monopolar no-touch radiofrequency ablation (RFA) technique is used for small hepatocellular carcinoma (HCC); however, there have not been any randomized clinical trials comparing this technique to the conventional RFA technique.

OBJECTIVE

This study aims to compare the results of two RFA techniques, and to comparatively identify more effective methods to reduce the progression of local tumors associated with small HCC (≤2.5 cm).

METHODS

This prospective randomized clinical trial (NCT03375281) recruited a total of 116 participants (M:F, 93:23; 68.3 ± 8.4 years) between October 2016 and September 2017. The primary outcome was the cumulative incidence of local tumor progression (LTP) after RFA. Secondary outcomes included technical success rate, technique efficacy, and RFA procedure characteristics. Kaplan-Meier analysis and the Cox proportional hazard regression model were used.

RESULTS

The mean follow-up period was 24.1 months. A sufficient ablative margin was more frequently achieved in the no-touch RFA group (57/60 = 95%) than in the conventional RFA group (50/64 = 78.1%) on immediate follow-up CT (p = 0.01). The cumulative incidence of LTP in the no-touch RFA group was significantly lower than that in the conventional RFA group (p = 0.02). In multivariable analysis, no-touch RFA was the only predictive factor for LTP (p = 0.04, hazard ratio = 0.2, 95% confidence interval = 0.04-0.94).

CONCLUSIONS

A switching monopolar no-touch RFA technique is a favorable treatment option and provides lower LTP after RFA compared with conventional RFA for small HCC.

Effect of Perfluorobutane Microbubbles on Radiofrequency Ablation for Hepatocellular Carcinoma: Suppression of Steam Popping and Its Clinical Implication

Objective

To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping during radiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatment outcomes.

Materials and Methods

The institutional review board approved this retrospective study, which included 90 consecutive patients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided into two groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with a simultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factors contributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression (LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performing comparisons between the two groups.

Results

The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) in the popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariable analysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (odds ratio = 0.10, p = 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p = 0.479 and p = 0.424, respectively).

Conclusion

The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients with HCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography in patients with small hepatocellular carcinoma treated by radiofrequency ablation

BACKGROUND

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake in hepatocellular carcinoma (HCC) is significantly associated with early recurrence and survival after curative surgical resection. However, there are no reports regarding the relationship between ¹⁸F-FDG uptake and outcomes after radiofrequency ablation (RFA). A prospective cohort study was conducted to evaluate the prognostic value of ¹⁸F-FDG positron emission tomography (PET) in HCC patients after RFA.

METHODS

A total of 121 consecutive patients with primary HCC (≤3 tumors, of diameter ≤ 3 cm) without vascular invasion on imaging were examined by ¹⁸F-FDG-PET computed tomography prior to RFA. An HCC with a component of ¹⁸F-FDG uptake visibly stronger than that of surrounding liver was defined as ¹⁸F-FDG-PET positive.

RESULTS

The median follow-up period was 1267 days. There were 110 ¹⁸F-FDG-PET negative and 11 positive tumors. The cumulative 1-year recurrence rates in the ¹⁸F-FDG negative and positive groups were 30 and 64% (P = 0.017), respectively, and cumulative 1-year metastatic recurrence rates were 6 and 36% (P < 0.001), respectively. The cumulative 5-year survival rates were 88 and 22% (P < 0.001), respectively. Multivariate analysis revealed ¹⁸F-FDG-PET positivity and tumor size as independent factors related to metastatic recurrence and survival after RFA.

CONCLUSIONS

¹⁸F-FDG-PET positivity was significantly associated with outcomes after RFA. RFA should not be readily selected as the first-line treatment for small HCC that includes a component of visually strong ¹⁸F-FDG uptake.

Ultrasound-guided percutaneous microwave ablation for hepatocellular carcinoma adjacent to large vessels: a propensity score matching analysis

PURPOSE

This study aimed to compare the efficacy and safety of ultrasound-guided percutaneous microwave ablation (MWA) for hepatocellular carcinoma (HCC) adjacent to large vessels with those far from large vessels.

METHODS

The clinical data of patients who underwent ultrasound-guided percutaneous MWA for HCC were retrospectively analyzed between January 2011 and December 2018 in Shengjing Hospital. Patients with HCC adjacent to large vessels were included in the Vessel group, the remaining patients were included in the Control group. Propensity score matching analysis was used to reduce confounding bias. The rates of complete ablation, local recurrence, recurrence-free survival (RFS), overall survival (OS) and complications were compared between the two groups.

RESULTS

A total of 134 patients with 157 nodules (size range, 0.6-3.8 cm) were enrolled in this study, 23 in the Vessel group and 111 in the Control group. A total of 21 patients in the Vessel group (91.3%) and 105 patients in the Control group (94.6%) achieved complete ablation (p = .902). Following 1:2 propensity score matching, 22 patients were included in the Vessel group and 40 patients were enrolled in the Control group. Local recurrence was observed in 2 (9.1%) patients in the Vessel group and 5 (12.5%) in the Control group (p = .86). No significant difference in local recurrence rate, RFS and OS were observed between the two groups.

CONCLUSIONS

Ultrasound-guided percutaneous MWA appears to be a safe procedure and can achieve comparable oncological efficacy for HCC abutting large vessels.

Radiofrequency Ablation (RFA) Combined with Transcatheter Arterial Chemoembolization (TACE) for Patients with Medium-to-Large Hepatocellular Carcinoma: A Retrospective Analysis of Long-Term Outcome

BACKGROUND The aim of this study was to investigate the prognostic value of radiofrequency ablation (RFA) plus transcatheter arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) patients with tumor size ranging from 3.0 to 10.0 cm. MATERIAL AND METHODS We retrospectively analyzed data on 201 patients with medium-to-large HCC. According to treatment procedure, the patients were divided into the TACE group (n=124) and the TACE+RFA group (n=77). We recorded data on patient safety, subcapsular hepatic hematoma, large amount of ascites, liver abscess, gallbladder injury, and local skin infection. The overall survival (OS) and progression-free survival (PFS) in the 2 groups were analyzed and compared between groups. RESULTS The median PFS was 4.00 months (3.00-5.00 months) in the TACE group and 9.13 months (6.64-11.62 months) in the TACE+RFA group (P<0.001). Median OS was 12.00 months (8.88-15.13 months) in the TACE group and 27.57 months (20.06-35.08 months) in the TACE+RFA group (P<0.001). In the TACE+RFA group, multivariate Cox regression analysis showed that tumor size ≤5 cm) (HR: 1.952, 95% CI: 1.213-3.143, P=0.006), hepatitis B (HR: 2.323, 95% CI: 1.096-4.923, P=0.028), TACE times (1 or >1) (HR: 1.867, 95% CI: 1.156-3.013, P=0.011), alpha-fetoprotein (AFP) level >200 ng/ml (HR: 2.426, 95% CI: 1.533-3.839, P<0.001), and AST level >40 U/L (HR: 1.946, 95% CI: 1.196-3.166, P=0.007) were independent prognostic factors for overall survival. CONCLUSIONS Combination therapy of TACE with RFA is a safe and effective treatment for patients with medium-to-large HCC, with the long-term beneficial effect of retarding tumor progression and improving PFS and OS.

Radiofrequency Ablation of Hepatocellular Carcinoma (≤ 5 cm) with Saline-Perfused Electrodes: Factors Affecting Local Tumor Progression

Purpose

We aimed to assess local tumor progression (LTP) rate and associated prognostic factors in 92 patients who underwent radiofrequency ablation (RFA) using saline-perfused electrodes to treat hepatocellular carcinoma (HCC) (≤ 5 cm).

Materials and Methods

Total 92 patients with 148 HCCs were treated with RFA using salineperfused electrodes, from 2009 to 2015. We retrospectively evaluated technical success, technique efficacy, and LTP rates. Potential prognostic factors for LTP were perivascular tumor, subphrenic tumor, artificial ascites, tumor size (≥ 2 cm), and previous treatment of transarterial chemoembolization. Analysis was performed by lesion, rather than by person.

Results

During follow-up period from 1 to 97.4 months, total cumulative LTP rates were 7.9%, 11.4%, and 14.6% at 1, 3, and 5 years, respectively. These values were significantly higher in the perivascular (35.1%; p = 0.009) and subphrenic group (38.9%; p = 0.002) at 5-year. We did not observe any significant difference in LTP according to other prognostic factors (p > 0.05).

Conclusion

RFA with saline-perfused electrode is a safe and effective treatment modality for HCC (≤ 5 cm), with lower LTP rates. Nevertheless, perivascular and subphrenic HCCs demonstrated higher LTP rate than other sites. It is imperative to note that perivascular and subphrenic location of HCC are associated with a high risk of local recurrence, despite the use of salineperfused electrodes.

Hepatic resection versus operative microwave ablation for single hepatocellular carcinoma ≤5 cm: A propensity score-matched analysis

BACKGROUND

Little evidence exists regarding the perioperative and oncologic benefits of microwave ablation for hepatocellular carcinoma. The aim of this study was to compare the efficacy of hepatic resection and operative microwave ablation (microwave coagulo-necrotic therapy) for single hepatocellular carcinoma ≤5 cm.

METHODS

Between 1994 and 2015, a total of 551 patients with a single hepatocellular carcinoma ≤5 cm were treated in our institution (hepatic resection: n = 128; microwave coagulo-necrotic therapy: n = 423). We compared overall survival and recurrence-free survival between hepatic resection and microwave coagulo-necrotic therapy. Propensity score matching analysis identified 94 matched pairs of patients to compare outcomes.

RESULTS

After propensity score matching, baseline variables, including liver function and tumor size, were well-balanced between the 2 groups. The 5- and 10-year overall survival rates were 76% and 47% for hepatic resection and 77% and 48% for microwave coagulo-necrotic therapy, respectively (P = .865). The 5- and 10-year recurrence-free survival rates were 55% and 41% for hepatic resection and 47% and 32% for microwave coagulo-necrotic therapy, respectively (P = .377). In the subgroup analysis, the hepatic resection group had better recurrence-free survival than the microwave coagulo-necrotic therapy group in patients with tumor size >3 cm, with 5-year recurrence-free survival rates of 56.5% and 32.4% in the hepatic resection and microwave coagulo-necrotic therapy group, respectively (P = .029).

CONCLUSION

Our propensity score matching study confirmed no statistically significant differences in both overall survival and recurrence-free survival between hepatic resection and microwave coagulo-necrotic therapy for single hepatocellular carcinoma ≤5 cm; however, hepatic resection is recommended for hepatocellular carcinoma with tumor size >3 cm when patients have good liver function.

Percutaneous ablation for perivascular hepatocellular carcinoma: Refining the current status based on emerging evidence and future perspectives

Various therapeutic modalities including radiofrequency ablation, cryoablation, microwave ablation, and irreversible electroporation have attracted attention as energy sources for effective locoregional treatment of hepatocellular carcinoma (HCC); these are accepted non-surgical treatments that provide excellent local tumor control and favorable survival. However, in contrast to surgery, tumor location is a crucial factor in the outcomes of locoregional treatment because such treatment is mainly performed using a percutaneous approach for minimal invasiveness; accordingly, it has a limited range of ablation volume. When the index tumor is near large blood vessels, the blood flow drags thermal energy away from the targeted tissue, resulting in reduced ablation volume through a so-called “heat-sink effect”. This modifies the size and shape of the ablation zone considerably. In addition, serious complications including infarction or aggressive tumor recurrence can be observed during follow-up after ablation for perivascular tumors by mechanical or thermal damage. Therefore, perivascular locations of HCC adjacent to large intrahepatic vessels can affect post-treatment outcomes. In this review, we primarily focus on physical properties of perivascular tumor location, characteristics of perivascular HCC, potential complications, and clinical outcomes after various locoregional treatments; moreover, we discuss the current status and future perspectives regarding percutaneous ablation for perivascular HCC.

Novel treatment strategy with radiofrequency ablation and surgery for pregnant patients with hepatocellular carcinoma: a case report

BACKGROUND

Hepatocellular carcinoma (HCC) during pregnancy is rare, with a poor prognosis. Recently, however, increasing resection rates have improved survival rate. Currently, various surgeries are safely performed after the second trimester and termination of pregnancy is not always necessary. However, surgery is sometimes limited by gestational age or the patient's will. When patients with HCC refuse surgery during pregnancy, we face specific problems with respect to curability and fetal life. Meanwhile, previous studies have revealed radiofrequency ablation (RFA) as a possible alternative to surgery for the treatment of early HCC and shown its favorable local control rate for advanced HCC. However, no case of HCC treated with RFA during pregnancy has yet been reported.

CASE PRESENTATION

Here, we present the case of a 33-year-old woman, who was a hepatitis B virus carrier. The patient had been followed up because HBV carrier could develop hepatitis or HCC. And she was diagnosed with a 40-mm HCC tumor at 17 weeks of gestation. She refused surgery because she was pregnant and wanted to continue her pregnancy; therefore, we performed RFA for the local control of her HCC at 17 weeks of gestation and radical surgery at postpartum. She delivered a healthy baby and has survived without recurrence for 6 years after the surgery.

CONCLUSIONS

Surgery is potentially a curative treatment for HCC whether the patient is pregnant or not. However, various problems unique to pregnancy make it difficult to perform a straightforward surgery. Our case revealed that RFA can be safely performed in pregnant patients during the second trimester, and the combination of RFA and surgery can radically increase the resection rate of HCC during pregnancy.

Outcomes of microwave ablation for hepatocellular carcinoma adjacent to large vessels: a propensity score analysis

The aim of this study was to retrospectively compare the long-term efficacy of MW ablation as a curative therapy for hepatocellular carcinoma(HCC) adjacent to large vessels(≥3 mm) with that in safe location. Between 2010 and 2016, 406 patients diagnosed with early-stage HCC at Chinese PLA general hospital were enrolled. One-to-one matched pairs between the vessel group and the safe group were generated using propensity score matching. The associations of treatment strategy with overall survival and local tumor progression were determined by Cox regression. Before matching, 113 patients were classified into the vessel group and 293 patients were classified into the vessel group. The patients in the vessel group were more frequently classified as larger tumor size (P<0.05) and higher AFP level (P<0.05) than patients in the safe group. After propensity score matching, 113 pairs of well-matched HCC patients were selected from different treatment groups. No significant differences were found in local tumor progression, overall survival and complication rates for MW ablation as a first-line treatment for the early-stage HCC between two groups. In conclusion, MW ablation provides an effective and safe way to treat early-stage HCC adjacent to large vessels.

Short-term and long-term outcomes of laparoscopic hepatectomy, microwave ablation, and open hepatectomy for small hepatocellular carcinoma: a 5-year experience in a single center

AIM

Laparoscopic hepatectomy (LH), microwave ablation (MWA), and open hepatectomy (OH) are three widely used methods to treat small hepatocellular carcinoma (HCC). However, few studies have compared the short- and long-term outcomes of these three treatments. The aim of this study was to investigate their effectiveness.

METHODS

The data were reviewed from 280 patients with HCCs measuring ≤3 cm (Barcelona Clinic Liver Cancer stage 0 or A) who received LH (n = 133), OH (n = 87), or MWA (n = 60) in our research center from 2005 to 2010. Short-term outcomes included intraoperative blood loss, operation time, and length of hospital stay. The disease-free survival and overall survival rates were analyzed as long-term outcomes.

RESULTS

The patients in the MWA and LH groups showed better short-term outcomes compared with those in the OH group. There were no significant differences in overall survival rates among the three treatments. The LH group showed significantly lower recurrence rates than the MWA group (P = 0.0146).

CONCLUSIONS

Laparoscopic hepatectomy may be a better option for patients with small HCC located on the liver surface and left lateral lobe. The short-term outcome of MWA is promising, although the high risk of local recurrence after the operation should be considered when planning treatment.

Aggressive tumor recurrence after radiofrequency ablation for hepatocellular carcinoma

Image-guided radiofrequency ablation (RFA) is an evolving and growing treatment option for patients with hepatocellular carcinoma (HCC) and hepatic metastasis. RFA offers significant advantages as it is less invasive than surgery and carries a low risk of major complications. However, serious complications, including aggressive tumor recurrence, may be observed during follow-up, and recently, mechanical or thermal damage during RFA has been proposed to be one of the causes of this kind of recurrence. Although the exact mechanism of this still remains unclear, physicians should be familiar with the imaging features of aggressive tumor recurrence after RFA for HCC and its risk factors. In addition, in order to prevent or minimize this newly recognized tumor recurrence, a modified RFA technique, combined RFA treatments with transarterial chemoembolization, and cryoablation can be used as alternative treatments. Ultimately, combining an understanding of this potential complication of RFA with an understanding of the possible risk factors for aggressive tumor recurrence and choosing alternative treatments are crucial to optimize clinical outcomes in each patient with HCC.

Clinical significance and predictive factors of early massive recurrence after radiofrequency ablation in patients with a single small hepatocellular carcinoma

Background/Aims

Radiofrequency ablation (RFA) is one of the most frequently applied curative treatments in patients with a single small hepatocellular carcinoma (HCC). However, the clinical significance of and risk factors for early massive recurrence after RFA—a dreadful event limiting further curative treatment—have not been fully evaluated.

Methods

In total, 438 patients with a single HCC of size ≤3 cm who underwent percutaneous RFA as an initial treatment between 2006 and 2009 were included. Baseline patient characteristics, overall survival, predictive factors, and recurrence after RFA were evaluated. In addition, the incidence, impact on survival, and predictive factors of early massive recurrence, and initial recurrence beyond the Milan criteria within 2 years were also investigated.

Results

During the median follow-up of 68.4 months, recurrent HCC was confirmed in 302 (68.9%) patients, with early massive recurrence in 27 patients (6.2%). The 1-, 3-, and 5-year overall survival rates were 95.4%, 84.7%, and 81.8%, respectively, in patients with no recurrence, 99.6%, 86.4%, and 70.1% in patients with recurrence within the Milan criteria or late recurrence, and 92.6%, 46.5%, and 0.05% in patients with early massive recurrence. Multivariable analysis identified older age, Child-Pugh score B or C, and early massive recurrence as predictive of poor overall survival. A tumor size of ≥2 cm and tumor location adjacent to the colon were independent risk factors predictive of early massive recurrence.

Conclusion

Early massive recurrence is independently predictive of poor overall survival after RFA in patients with a single small HCC. Tumors sized ≥2 cm and located adjacent to the colon appear to be independent risk factors for early massive recurrence.

Aggressive Intrasegmental Recurrence of Hepatocellular Carcinoma After Combined Transarterial Chemoembolization and Radiofrequency Ablation

OBJECTIVE

The goal of this study is to evaluate the outcomes of combined transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) in terms of the frequency of aggressive intrasegmental recurrence.

MATERIALS AND METHODS

Sixty-one patients (43 men and 18 women; mean [± SD] age, 65.8 ± 8.6 years; age range, 44-82 years) with 71 HCCs (mean [± SD] size, 2.8 ± 0.9 cm; range, 0.7-4.2 cm) underwent combined TACE and RFA. Aggressive intrasegmental recurrence was defined as initial tumor recurrence at least 6 months after treatment and the simultaneous development of recurrence of multiple (at least three) nodular or infiltrative tumors in the treated segment. Tumor contact with a thick (diameter, ≥ 3 mm) portal vein (i.e., periportal HCC) was evaluated. The frequency of aggressive intrasegmental recurrence, the local tumor progression (LTP) rate, and the complication rate were assessed.

RESULTS

The median follow-up period was 25.6 months (range, 6.1-75.5 months). Twenty-two HCCs (31%) were in contact with a thick portal vein. Aggressive intrasegmental recurrence was observed in one patient (representing 1.4% of all treated HCCs and 4.5% of periportal HCCs) after treatment of a 4.0-cm periportal HCC. The cumulative LTP rates at 1, 3, and 5 years were 6.7%, 21.0%, and 30.5%, respectively. The rate of major complications was 6.6%.

CONCLUSION

The frequency of aggressive intrasegmental recurrence after combined TACE and RFA for HCCs was very low.

Strategic overview on the best treatment option for intrahepaitc hepatocellular carcinoma recurrence

INTRODUCTION

The long-term survival after hepatectomy for HCC remains unsatisfactory because of the high incidence of recurrence. The cumulative 5-year recurrence rate ranged from 60-100% in previous studies and majority of them remains intrahepatic recurrence. The therapeutic modalities commonly used for primary tumors, including surgical resection, liver transplantation, TACE, local ablative therapy and radiotherapy have been used to treat recurrent tumors in the liver remnant and the outcomes with the heterogeneous therapeutic options are reviewed. It is important to note that the level of evidence for most therapeutic options is limited to cohort investigations with few RCTs and most were limited due to enrollment of various tumor stages and did not compare treatment modalities for specific tumor stages.

AREAS COVERED

A literature search for recurrent HCC was performed using Medline and PubMed up to May 2016. Expert commentary: The long term survival results after re-resection for recurrent HCC were favourable and aggressive management of postoperative intrahepatic recurrence remains the most important strategy in prolonging the survival of patients after resection of HCC.

Kupffer Imaging by Contrast-Enhanced Sonography With Perfluorobutane Microbubbles Is Associated With Outcomes After Radiofrequency Ablation of Hepatocellular Carcinoma

OBJECTIVES

An ultrasound contrast agent consisting of perfluorobutane microbubbles (Sonazoid; Daiichi Sankyo, Tokyo, Japan) accumulates in Kupffer cells, which thus enables Kupffer imaging. This study aimed to elucidate the association of defect patterns of hepatocellular carcinoma during the Kupffer phase of Sonazoid contrast-enhanced sonography with outcomes after radiofrequency ablation (RFA).

METHODS

For this study, 226 patients with initial hypervascular hepatocellular carcinoma, who could be evaluated by contrast-enhanced sonography with Sonazoid before RFA, were analyzed. Patients were divided into 2 groups according to the tumor defect pattern during the Kupffer phase. The irregular-defect group was defined as patients with hepatocellular carcinoma that had a defect with an irregular margin, and the no-irregular-defect group was defined as patients with hepatocellular carcinoma that had either a defect with a smooth margin or no defect. Critical recurrence was defined as more than 3 intrahepatic recurrences, vascular invasion, dissemination, or metastasis.

RESULTS

The irregular-defect and no-irregular-defect groups included 86 and 140 patients, respectively, and had cumulative 5-year critical recurrence rates of 49% and 17% (P < .01). Multivariate analysis indicated that the tumor diameter, lens culinaris agglutinin- reactive α-fetoprotein level, and defect pattern were independent factors related to critical recurrence. The cumulative 5-year overall survival rates for the irregular-defect and no-irregular-defect groups were 46% and 61% (P< .01). Multivariate analysis indicated that the Child-Pugh class, tumor diameter, lens culinaris agglutinin-reactive α-fetoprotein level, and defect pattern were independent factors related to survival.

CONCLUSIONS

The defect pattern of hepatocellular carcinoma during the Kupffer phase of Sonazoid contrast-enhanced sonography is associated with critical recurrence and survival after RFA.

Prognostic impact of surgery and radiofrequency ablation on single nodular HCC ⩽5 cm: Cohort study based on serum HCC markers

BACKGROUND & AIMS

Serological markers of hepatocellular carcinoma (HCC) indicate its invasiveness. We aimed to investigate whether the prognostic impact of surgical resection (SR) and radiofrequency thermal ablation (RFA) on patients with single nodular HCC ⩽5cm were different regarding positive conditions of the following three HCC markers: alpha-fetoprotein (AFP); lens culinaris agglutinin-reactive fraction of AFP; and des-γ-carboxy prothrombin.

METHODS

This study reviewed 296 patients with single nodular HCC ⩽5cm with Child-Pugh grade A between 2001 and 2011 (SR, n=136; RFA, n=160). Based on positive conditions of previous HCC markers (defined as non-positive, single-positive, double-positive, and triple-positive), overall survival (OS) and prognostic factors were analyzed.

RESULTS

Five-year OS rates of SR and RFA among all patients were 70.1% and 69.8%, respectively (p=0.14). However, when stratified by the positive conditions of three HCC markers, their rates of non-, single-, double-, and triple-positive patients were 60.6%, 78.2%, 54.2%, and 75.9% in the SR group, whereas rates were 83.3%, 75.7%, 62.2%, and 47.6% in the RFA group (p values between SR and RFA of each tumor marker condition were 0.45, 0.10, 0.77, and <0.01, respectively). Multivariate analyses showed that RFA itself became an independent prognostic factor in the triple-positive group, with an odds ratio of 1.78 (95% confidence interval, 1.16-2.72).

CONCLUSIONS

Positive conditions of three HCC markers differently influenced survival rates of those who underwent SR and RFA when treating single nodular HCC ⩽5cm. RFA itself became an independent prognostic risk when all three HCC markers were positive. Preoperative evaluation of multiple HCC markers might become an index for selecting treatment modalities.

Surgical results for recurrent hepatocellular carcinoma after curative hepatectomy: Repeat hepatectomy versus salvage living donor liver transplantation

The aims of this study were to evaluate the efficacy of repeat hepatectomy (Hx) and salvage living donor liver transplantation (LDLT) for recurrent hepatocellular carcinoma (HCC). A retrospective cohort study was performed to analyze the surgical results of repeat Hx and salvage LDLT for patients with recurrent HCC within the Milan criteria from 1989 to 2012. A total of 159 patients were divided into 2 groups: a repeat Hx group (n = 146) and a salvage LDLT group (n = 13). Operative results and patient prognoses were compared between the 2 groups. The operative invasiveness, including the operation time (229.1 ± 97.7 versus 862.9 ± 194.4 minutes; P < 0.0001) and blood loss (596.3 ± 764.9 versus 24,690 ± 59,014.4 g; P < 0.0001), were significantly higher in the salvage LDLT group. The early surgical results, such as morbidity (31% versus 62%; P = 0.0111) and the duration of hospital stay (20 ± 22 versus 35 ± 21 days; P = 0.0180), were significantly worse in the salvage LDLT group. There was no significant difference in the overall survival (OS) rate, but the disease-free survival rate of the salvage LDLT group was significantly better (P = 0.0002). The OS rate of patients with grade B liver damage in the repeat Hx group was significantly worse (P < 0.0001), and the 5-year OS rate was quite low, that is, 20% (liver damage A, 77% for the repeat Hx group and 75% for the salvage LDLT group). The prognosis of patients with grade B liver damage after repeat Hx for recurrent HCC is poor, and salvage LDLT would be a potent option for such patients.

A measure to assess the ablative margin using 3D-CT image fusion after radiofrequency ablation of hepatocellular carcinoma

OBJECTIVES

To examine the feasibility of three-dimensional computed tomography (3D-CT) image fusion in facilitating assessment of the ablative margin (AM) after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).

METHODS

This study involved 75 patients with solitary HCC who underwent RFA. The AM was evaluated using 3D-CT image fusion. All cases were categorized into two groups based on the extent of the AM: in Group A, sufficient AM was obtained, which was greater than or equal to 5 mm; in Group B, the lesion was also ablated successfully, but a 5 mm AM was not obtained.

RESULTS

3D-CT Image Fusion was performed on 36 and 39 patients in Group A and Group B, respectively. The 1, 3, 5 year RFS was 87.6%, 63.2%, 50.6% for Group A, and 77.2%, 51.5%, 35.6% for Group B, respectively (P = 0.042); the corresponding OS was 94.3%, 73.8%, 64.6%, and 86.2%, 60.5%, 47.6%, respectively (P = 0.046). Multivariate analysis showed that the AM (P = 0.048, HR = 2.15, 95% CI 1.01-4.60) and Pre-NLR were independent prognostic factors for PFS.

CONCLUSIONS

3D-CT image fusion is a feasible and useful method to evaluate the AM after RFA of HCC.

Aggressive Intrasegmental Recurrence of Hepatocellular Carcinoma after Radiofrequency Ablation: Risk Factors and Clinical Significance

PURPOSE

To evaluate the frequency, risk factors, and clinical significance of aggressive intrasegmental recurrence (AIR) found after radiofrequency (RF) ablation for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Institutional review board approval was obtained for this retrospective study. Between March 2005 and December 2010, 539 patients (414 men, 125 women; mean age, 57.91 years; age range, 30-82 years) underwent ultrasonography-guided percutaneous RF ablation as a first-line treatment for a single HCC classified as Barcelona Clinic Liver Cancer (BCLC) stage 0 or A. AIR of HCC was defined as (a) initial tumor recurrence with disease-free status at least 6 months after initial RF ablation and (b) the simultaneous development of multiple nodular (at least three) or infiltrative tumor recurrence in the treated segment. Patients were stratified into two groups: those with AIR (n = 20) and those without AIR (n = 519) during follow-up. Risk factors for AIR were assessed with logistic regression analysis, and risk factors for long-term overall survival were assessed with time-dependent Cox proportional hazard models.

RESULTS

In a median follow-up period of 49 months (range, 6-95 months), AIR was observed in 3.7% of the patients (20 of 539 patients), with the frequency increasing to 15% in the subgroup with periportal HCC (11 of 72 patients). AIRs manifested as either multiple nodular type (n = 14, BCLC stage A or B) or diffusely infiltrative type with tumor thrombus formation (n = 6, BCLC stage C). At multivariate analysis, periportal tumor location and younger patient age were significant risk factors for AIR. The presence of AIR during the follow-up period has a significant effect on the overall survival rate (hazard ratio = 5.72, P = .002).

CONCLUSION

The overall frequency of AIR after RF ablation for HCC was low, with periportal location and patient age showing a significant relationship to the development of AIR. The occurrence of AIR had an adverse effect on overall survival rate.

Small Hepatocellular Carcinoma: Radiofrequency Ablation versus Nonanatomic Resection--Propensity Score Analyses of Long-term Outcomes

PURPOSE

To compare radiofrequency (RF) ablation with nonanatomic resection (NAR) as first-line treatment in patients with a single Barcelona Clinic Liver Cancer (BCLC) stage 0 or A hepatocellular carcinoma (HCC) and to evaluate the long-term outcomes of both therapies.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board. The requirement for informed consent was waived. Data were reviewed from 580 patients with HCCs measuring 3 cm or smaller (BCLC stage 0 or A) who underwent ultrasonographically (US) guided percutaneous RF ablation (n = 438) or NAR (n = 142) as a first-line treatment. Local tumor progression, intrahepatic distant recurrence, disease-free survival, and overall survival rates were analyzed by using propensity score matching to compare therapeutic efficacy. In addition, major complications and length of postoperative hospital stay were compared.

RESULTS

Before propensity score matching (n = 580), the 5-year cumulative rates of local tumor progression for RF ablation and NAR (20.9% vs 12.7%, respectively; P = .093) and overall survival rates (85.5% vs 90.9%, respectively; P = .194) were comparable, while the 5-year cumulative intrahepatic distant recurrence rates (62.7% vs 36.6%, respectively; P < .001) and disease-free survival rates (31.7% vs 61.1%, respectively; P < .001) in the NAR group were significantly better than those in the RF ablation group. After matching (n = 198), there were no significant differences in therapeutic outcomes between the RF ablation and NAR groups, including 5-year cumulative intrahepatic distant recurrence (47.0% vs 40.2%, respectively; P = .240) and disease-free survival rates (48.9% vs 54.4%, respectively; P = .201). RF ablation was superior to NAR for major complication rates and length of postoperative hospital stay (P < .001).

CONCLUSION

In patients with one BCLC stage 0 or A (≤ 3 cm) HCC who received RF ablation or NAR as first-line treatment, there were no significant differences in long-term therapeutic outcomes; however, RF ablation was associated with fewer major complications and a shorter hospital stay after treatment.

Signal intensity of small hepatocellular carcinoma on apparent diffusion coefficient mapping and outcome after radiofrequency ablation

AIM

It has been reported that the apparent diffusion coefficient (ADC) value of hepatocellular carcinomas (HCC) on diffusion-weighted magnetic resonance imaging (MRI) is associated with their histological grade. The present study aimed to evaluate whether the signal intensity of small hypervascular HCC on the ADC map is related to the treatment outcome of radiofrequency ablation (RFA).

METHODS

Between February 2008 and August 2012, 136 consecutive patients with initial small hypervascular HCC (≤3 tumors and ≤3 cm in diameter) were examined by diffusion-weighted MRI before RFA. The signal intensities of HCC on the ADC map were visually compared with the surrounding liver and categorized as hypointense and non-hypointense. Critical recurrence was defined as more than three intrahepatic recurrences, recurrence with vascular invasion, seeding, dissemination and/or extrahepatic metastasis.

RESULTS

The median follow up was 619 days. The cumulative 2-year recurrence rates of the hypointense and non-hypointense on the ADC map groups were 79% and 50% (P < 0.001), respectively, with cumulative 2-year local recurrence rates of 18% and 7% (P = 0.014) and cumulative 2-year critical recurrence rates of 38% and 13% (P = 0.005), respectively. The cumulative 3-year survival rates were 60% and 82% (P = 0.007), respectively. On multivariate analysis, hypointensity on the ADC map was the strongest independent factor related to recurrence and survival after RFA.

CONCLUSION

The signal intensity of HCC on the ADC map was strongly associated with outcome after RFA. These results suggest that treatment strategy should be determined carefully even for small HCC when they appear hypointense on the ADC map.

Comparative study of percutaneous radiofrequency ablation and hepatic resection for small, poorly differentiated hepatocellular carcinomas

AIM

Histologically, poorly differentiated hepatocellular carcinomas (HCC) are considered highly malignant. Here, we aimed to evaluate the relative efficacy and safety of hepatic resection or radiofrequency ablation (RFA) for treating this malignancy.

METHODS

Between April 2004 and May 2011, we enrolled 48 patients who had poorly differentiated HCC that had been diagnosed postoperatively by pathological assessment. All the tumors had a maximum diameter of 3 cm and all patients had three or less tumors. Fifteen of these patients underwent hepatic resection (HR group) and 33 patients underwent RFA (RF group). The patient background, tumor characteristics, overall survival rate and recurrence-free survival rate were assessed in both groups.

RESULTS

The mean maximum tumor diameter was 2.5 and 2.0 cm in the HR and RF groups, respectively. The prothrombin activity level was 94% and 86% in the HR and RF groups, respectively. The 1-, 3- and 5-year cumulative survival rates were 89.1%, 68.7% and 68.7%, respectively, in the HR group, and 59.2%, 40.9% and 32.7%, respectively, in the RF group. The 1-, 3- and 5-year recurrence-free survival rates were 85.1%, 64.8% and 48.6%, respectively, in the HR group, and 29.0%, 7.2% and 7.2%, respectively, in the RF group. There was a significant difference between these groups (P < 0.05).

CONCLUSION

As hepatic resection has greater efficacy than RFA in the treatment of poorly differentiated HCC, even in cases with a small tumor size, we recommend its use for this malignancy.

Prediction of poorly differentiated hepatocellular carcinoma using contrast computed tomography

BACKGROUND

Percutaneous radiofrequency ablation (RFA) is a well-established local treatment for small hepatocellular carcinoma (HCC). However, poor differentiation is a risk factor for tumor seeding or intrahepatic dissemination after RFA for HCC. The present study aimed to develop a method for predicting poorly differentiated HCC using contrast computed tomography (CT) for safe and effective RFA.

METHODS

Of HCCs diagnosed histologically, 223 patients with 226 HCCs showing tumor enhancement on contrast CT were analyzed. The tumor enhancement pattern was classified into two categories, with and without non-enhanced areas, and tumor stain that disappeared during the venous or equilibrium phase with the tumor becoming hypodense was categorized as positive for washout.

RESULTS

The 226 HCCs were evaluated as well differentiated (w-) in 56, moderately differentiated (m-) in 137, and poorly differentiated (p-) in 33. The proportions of small HCCs (3 cm or less) in w-HCCs, m-HCCs, and p-HCCs were 86% (48/56), 59% (81/137), and 48% (16/33), respectively. The percentage with heterogeneous enhancement in all HCCs was 13% in w-HCCs, 29% in m-HCCs, and 85% in p-HCCs. The percentage with tumor stain washout in the venous phase was 29% in w-HCCs, 63% in m-HCCs, and 94% in p-HCCs. The percentage with heterogeneous enhancement in small HCCs was 10% in w-HCCs, 10% in m-HCCs, and 75% in p-HCCs. The percentage with tumor stain washout in the venous phase in small HCCs was 23% in w-HCCs, 58% in m-HCCs, and 100% in p-HCCs. Significant correlations were seen for each factor (p < 0.001 each). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for prediction of poor differentiation in small HCCs by tumor enhancement with non-enhanced areas were 75%, 90%, 48%, 97%, and 88%, respectively; for tumor stain washout in the venous phase, these were 100%, 55%, 22%, 100%, and 60%, respectively.

CONCLUSIONS

Tumor enhancement patterns were associated with poor histological differentiation even in small HCCs. Tumor enhancement with non-enhanced areas was valuable for predicting poorly differentiated HCC.

Rapid intra-hepatic dissemination of hepatocellular carcinoma with pulmonary metastases following combined loco-regional therapy

This manuscript describes an unusual case of rapid intra-hepatic dissemination of hepatocellular carcinoma with pulmonary metastases occurring 1 month after combined chemoembolization and radiofrequency ablation. Inferior vena cava and portal vein invasion tumor thrombus was also detected, possibly accounting for the mechanism of disease dissemination route of disease.

Treatment strategy for recurrent hepatocellular carcinoma: salvage transplantation, repeated resection, or radiofrequency ablation?

The objective of this study was to evaluate the efficacy of salvage liver transplantation (SLT), repeated hepatic resection (RR), and repeated radiofrequency ablation (rRFA) for patients with postoperative tumor recurrence. The optimal treatment strategy for patients with recurrent hepatocellular carcinoma (HCC) remains unclear. From January 1993 to September 2009, 532 patients underwent either hepatic resection or radiofrequency ablation (RFA) for HCC within the Milan criteria. In all, 219 patients experienced intrahepatic recurrence, and 87 were selected for SLT (n=19), RR (n=24), or rRFA (n=44). Their clinicopathological data were reviewed, and their survival outcomes were assessed with Kaplan-Meier methods. Seventy-four of 220 patients (33.6%) developed recurrent HCC within the Milan criteria. The median Model for End-Stage Liver Disease (MELD) scores for SLT, RR, and rRFA were 10.7, 7.2, and 8.3, respectively (P<0.001). The 1-, 3-, and 5-year tumor-free survival rates were 68.4%, 57.9%, and 57.9%, respectively, for SLT; 69.7%, 49.3%, and 49.3%, respectively, for RR; and 40.0%, 19.8%, and 10.6%, respectively, for rRFA (P=0.001). For recurrent HCC within the Milan criteria, the 1-, 3-, and 5-year tumor-free survival rates for SLT were all 60%; the corresponding rates were 70.2%, 48.0%, and 48.0% for RR and 41.0%, 20.3%, and 10.9% for RFA (P=0.004). After adjustments of the MELD score, the 5-year survival rates for SLT, RR, and rRFA were 50.0%, 48.0%, and 11.4%, respectively (P=0.003). A subgroup analysis showed that SLT and RR led to comparable survival outcomes, but both treatments led to significantly better survival outcomes than rRFA (P<0.001). In conclusion, SLT is an efficacious treatment for patients with recurrent HCC and should be considered when RR is not feasible.

Ultrasonogram of hepatocellular carcinoma is associated with outcome after radiofrequency ablation

AIM

To investigate the association between B-mode ultrasound classification of small hepatocellular carcinoma (HCC) and outcome after radiofrequency ablation (RFA).

METHODS

Ninety-seven cases of HCC treated using RFA between April 2001 and March 2006 were reviewed. Ultrasound images were classified as follows: type 1, with halo (n = 29); and type 2, without halo (n = 68). Type 2 was further categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with smooth margins (n = 43); and type 2c (n = 16), hypoechoic with irregular or unclear margins. Patients with type 2a HCC were excluded from analysis due to the small number of cases.

RESULTS

Two year recurrence rates for type 2b, type 1 and type 2c were 26%, 42% and 69%, respectively, with significant differences between type 2b and type 2c (P < 0.01), and between type 1 and type 2c (P < 0.05). Five year survival rates were 89%, 43% and 65%, respectively. Survival was significantly longer for type 2b than for other types (type 1 vs type 2b, P < 0.01; type 2b vs type 2c, P < 0.05). On univariate analysis, factors contributing to recurrence were number of tumors, tumor stage, serum level of lens culinaris agglutinin-reactive alpha-fetoprotein and ultrasound classification (P < 0.05). Factors contributing to survival were tumor stage and ultrasound classification (P < 0.05). Multivariate analysis identified ultrasound classification as the only factor independently associated with both recurrence and survival (P < 0.05).

CONCLUSION

B-mode ultrasound classification of small HCC is a predictive factor for outcome after RFA.

Ultrasonogram of hepatocellular carcinoma is associated with outcome after radiofrequency ablation

AIM: To investigate the association between B-mode ultrasound classification of small hepatocellular carcinoma (HCC) and outcome after radiofrequency ablation (RFA).

METHODS: Ninety-seven cases of HCC treated using RFA between April 2001 and March 2006 were reviewed. Ultrasound images were classified as follows: type 1, with halo (n = 29); and type 2, without halo (n = 68). Type 2 was further categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with smooth margins (n = 43); and type 2c (n = 16), hypoechoic with irregular or unclear margins. Patients with type 2a HCC were excluded from analysis due to the small number of cases.

RESULTS: Two year recurrence rates for type 2b, type 1 and type 2c were 26%, 42% and 69%, respectively, with significant differences between type 2b and type 2c (P < 0.01), and between type 1 and type 2c (P < 0.05). Five year survival rates were 89%, 43% and 65%, respectively. Survival was significantly longer for type 2b than for other types (type 1 vs type 2b, P < 0.01; type 2b vs type 2c, P < 0.05). On univariate analysis, factors contributing to recurrence were number of tumors, tumor stage, serum level of lens culinaris agglutinin-reactive alpha-fetoprotein and ultrasound classification (P < 0.05). Factors contributing to survival were tumor stage and ultrasound classification (P < 0.05). Multivariate analysis identified ultrasound classification as the only factor independently associated with both recurrence and survival (P < 0.05).

CONCLUSION: B-mode ultrasound classification of small HCC is a predictive factor for outcome after RFA.

Early diffuse recurrence of hepatocellular carcinoma after percutaneous radiofrequency ablation: analysis of risk factors

OBJECTIVE

To evaluate the risk factors affecting early diffuse recurrence within 1 year of percutaneous ultrasound-guided radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC).

METHODS

Out of 146 patients who received transcatheter arterial chemoembolisation (TACE) for treatment of recurrent HCC after percutaneous ultrasound-guided RFA, we selected 23 patients with early diffuse recurrence. Early diffuse recurrence was defined as three or more new recurrent HCCs within 1 year of initial RFA. As a control group, we selected 23 patients, matched exactly for age and sex, in which there was no local tumour progression or new recurrence after RFA. To analyse the risk factors, we examined patient factors and tumour factors.

RESULTS

Recurrent tumours occurred from 30 to 365 days after RFA (median time, 203 days). Univariate analysis indicated that larger tumour size and poorly defined margin were significant risk factors (P < 0.05). Multivariate analysis indicated that poorly defined margin was a significant risk factor (P < 0.05).

CONCLUSION

Larger tumour size and poorly defined margin may be risk factors for early diffuse recurrence of HCC within 1 year of RFA. Tumours with such risk factors should be treated with a combination of TACE to minimise the potential for therapeutic failure.

Assessment of malignant potential of small hypervascular hepatocellular carcinoma using B-mode ultrasonography

AIM

  Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B-mode ultrasonography.

METHODS

  One hundred and thirteen arterial hypervascular HCC nodules under 3 cm diagnosed by biopsy or surgical resection (20.5 ± 6.3 mm) were classified into two groups ultrasonographically: type 1 with (n = 27) and type 2 without (n = 86) a halo. Type 2 was categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with a smooth margin (n = 35); and type 2c, hypoechoic with an irregular or unclear margin (n = 42).

RESULTS

  The mean diameter of type 2a nodules was significantly smaller than that of other HCC types (P < 0.05). Overall, moderately differentiated HCC was the predominant histological type, except for type 2a, all of which were well-differentiated HCC. The percentage of poorly differentiated HCC was significantly higher in type 2c nodules (19%) than in other HCC types (P < 0.01). The percentage of Lens culinaris agglutinin-reactive α-fetoprotein (AFP-L3) positivity was significantly higher in type 2c nodules (55%) than in other HCC types (P < 0.01). Classification on B-mode ultrasonography was correlated with the histological differentiation and serum level, an indicator of a poor prognosis.

CONCLUSION

  The malignant potential of type 2a is the lowest and that of type 2c is the highest, both histologically and serologically. Assessment of the malignant potential of small, hypervascular HCC is possible by B-mode ultrasonography.

Assessment of hepatocellular carcinomas using conventional magnetic resonance imaging correlated with histological differentiation and a serum marker of poor prognosis

PURPOSE

To establish a method of assessing the malignant potential of hepatocellular carcinoma (HCC) using magnetic resonance imaging (MRI).

METHODS

For 69 nodules [12 Edmondson (Ed)-I, 48 Ed-II, 9 Ed-III] in 54 HCC patients, signal intensity patterns and enhancement patterns of gadopentate dimeglumine (Gd-DTPA) dynamic studies were correlated with histological differentiation and serum lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3) level, which is an indicator of poor prognosis.

RESULTS

Hypointensity on T1-weighted imaging was seen in 17, 72, and 89% of Ed-I, Ed-II, and Ed-III HCCs, respectively (P < 0.001). Meanwhile, hyperintensity on T2-weighted imaging was seen in 42, 88, and 89% (P < 0.005). Tumor stain during the arterial phase of Gd dynamic MRI was seen in 75, 86, and 89%. Tumor stain washout during the portal phase was seen in 43% of Ed-II and 100% of Ed-III HCCs (P < 0.005). In the Ed-II and Ed-III HCCs, hypointensity on T1-weighted imaging was seen in 65% of AFP-L3-negative HCCs and 90% of AFP-L3-positive HCCs (P = 0.071). Washout of tumor stain during the portal phase was seen in 39% of AFP-L3-negative HCCs and 75% of AFP-L3-positive HCCs (P < 0.05).

CONCLUSIONS

Although hyperintensity of tumor on T2-weighted imaging and arterial hypervascularity of tumor are considered to be useful for differential diagnosis between well differentiated HCCs and moderately/poorly differentiated HCCs, hypointensity of tumor on T1-weighted imaging and tumor stain washout during the portal phase of Gd-DTPA dynamic MRI reflected poorer histological differentiation of HCCs and correlated with AFP-L3 levels.