Percutaneous radiofrequency ablation and transcatheter arterial chemoembolization for hypervascular hepatocellular carcinoma: rate and risk factors for local recurrence

Chemoembolization versus radiofrequency ablation for single small (≤ 3 cm) hepatocellular carcinoma: a propensity score matching analysis

OBJECTIVES

To compare the efficacy of transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for patients with single small (≤ 3 cm) hepatocellular carcinoma (HCC) and preserved liver function (Child-Pugh class A).

MATERIALS AND METHODS

The clinical features of treatment-naïve patients who underwent TACE and RFA as first-line treatment were balanced through propensity score matching (PSM). The primary endpoint was overall survival (OS), and the secondary endpoints were local tumor recurrence (LTR) and recurrence-free survival (RFS).

RESULTS

The analysis included 440 patients who received TACE, and 430 patients who received RFA. After PSM adjustment (323 pairs), the 5- and 10-year OS rates were 81% and 61%, respectively, in patients who underwent RFA, and 77% and 51%, respectively, for patients who underwent TACE (p = 0.021). Subgroup analyses showed that OS, LTR, and RFS were homogeneously better in the RFA group.

CONCLUSION

RFA was associated with better survival outcomes than TACE in patients with single small HCC and preserved liver function.

CLINICAL RELEVANCE STATEMENT

This large-scale comparative study provides evidence that radiofrequency ablation has a better overall survival rate than chemoembolization for small (≤ 3 cm) hepatocellular carcinomas.

KEY POINTS

• The relative effectiveness of transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) for early HCC is unclear. • Overall survival rate was significantly higher in the RFA group. • The effects of RFA on overall survival, local tumor recurrence, and recurrence-free survival were homogeneously better in all subgroups.

Locoregional Therapies for Primary and Secondary Hepatic Malignancies

Management of hepatic malignancies is a multidisciplinary task with the involvement of hepatologists, medical/surgical/radiation oncologists, transplant surgeons, and interventional radiologists. Patients should be selected for a specific targeted therapy after multidisciplinary consensus. Interventional oncology, with image-guided locoregional cancer therapies, can decrease systemic toxicity without compromising tumoricidal effect.

Ablative and non-surgical therapies for early and very early hepatocellular carcinoma: a systematic review and network meta-analysis

Background

A wide range of ablative and non-surgical therapies are available for treating small hepatocellular carcinoma in patients with very early or early-stage disease and preserved liver function.

Objective

To review and compare the effectiveness of all current ablative and non-surgical therapies for patients with small hepatocellular carcinoma (≤ 3 cm).

Design

Systematic review and network meta-analysis.

Data sources

Nine databases (March 2021), two trial registries (April 2021) and reference lists of relevant systematic reviews.

Review methods

Eligible studies were randomised controlled trials of ablative and non-surgical therapies, versus any comparator, for small hepatocellular carcinoma. Randomised controlled trials were quality assessed using the Cochrane Risk of Bias 2 tool and mapped. The comparative effectiveness of therapies was assessed using network meta-analysis. A threshold analysis was used to identify which comparisons were sensitive to potential changes in the evidence. Where comparisons based on randomised controlled trial evidence were not robust or no randomised controlled trials were identified, a targeted systematic review of non-randomised, prospective comparative studies provided additional data for repeat network meta-analysis and threshold analysis. The feasibility of undertaking economic modelling was explored. A workshop with patients and clinicians was held to discuss the findings and identify key priorities for future research.

Results

Thirty-seven randomised controlled trials (with over 3700 relevant patients) were included in the review. The majority were conducted in China or Japan and most had a high risk of bias or some risk of bias concerns. The results of the network meta-analysis were uncertain for most comparisons. There was evidence that percutaneous ethanol injection is inferior to radiofrequency ablation for overall survival (hazard ratio 1.45, 95% credible interval 1.16 to 1.82), progression-free survival (hazard ratio 1.36, 95% credible interval 1.11 to 1.67), overall recurrence (relative risk 1.19, 95% credible interval 1.02 to 1.39) and local recurrence (relative risk 1.80, 95% credible interval 1.19 to 2.71). Percutaneous acid injection was also inferior to radiofrequency ablation for progression-free survival (hazard ratio 1.63, 95% credible interval 1.05 to 2.51). Threshold analysis showed that further evidence could plausibly change the result for some comparisons. Fourteen eligible non-randomised studies were identified (n ≥ 2316); twelve had a high risk of bias so were not included in updated network meta-analyses. Additional non-randomised data, made available by a clinical advisor, were also included (n = 303). There remained a high level of uncertainty in treatment rankings after the network meta-analyses were updated. However, the updated analyses suggested that microwave ablation and resection are superior to percutaneous ethanol injection and percutaneous acid injection for some outcomes. Further research on stereotactic ablative radiotherapy was recommended at the workshop, although it is only appropriate for certain patient subgroups, limiting opportunities for adequately powered trials.

Limitations

Many studies were small and of poor quality. No comparative studies were found for some therapies.

Conclusions

The existing evidence base has limitations; the uptake of specific ablative therapies in the United Kingdom appears to be based more on technological advancements and ease of use than strong evidence of clinical effectiveness. However, there is evidence that percutaneous ethanol injection and percutaneous acid injection are inferior to radiofrequency ablation, microwave ablation and resection.

Study registration

PROSPERO CRD42020221357.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) programme (NIHR award ref: NIHR131224) and is published in full in Health Technology Assessment; Vol. 27, No. 29. See the NIHR Funding and Awards website for further award information.

LI-RADS Classification and Outcomes of Hepatocellular Carcinoma Treated With Transcatheter Arterial Chemoembolization Plus Radiofrequency Ablation

AIM

The aim of this study was to clarify the usefulness of the Liver Imaging Reporting and Data System (LI-RADS) for predicting a patient's prognosis after transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (TACE-RFA) for hepatocellular carcinoma (HCC) of Barcelona-Clinic Liver Cancer (BCLC) stage 0 or A.

PATIENTS AND METHODS

We retrospectively analyzed cases of patients with HCC who underwent TACE-RFA (Jan 2005 to Dec 2015). Nodules were categorized based on their LI-RADS v2018 core. The LI-RADS category was assigned to each nodule using dynamic contrast-enhanced computed tomography. LR-3, LR-4 and LR-5 nodules were extracted. The overall (OS) and recurrence-free (RFS) survival was assessed among patients with BCLC 0 and BCLC A disease.

RESULTS

Of the 64 nodules extracted, 22 were LR-3 or -4 (mean±standard deviation=14.8±6.7 mm) and 42 were LR-5 (17.1±6.9 mm). Regarding OS, there was no significant difference between those with LR-3 or -4 and LR-5 (p=0.278). In terms of RFS, there was a significant difference between those with LR-3 or -4 and those with LR-5 (p=0.03). In particular, patients with BCLC A with LR-5 nodules had significantly poorer RFS than those with LR-3 or -4 (p=0.016) nodules.

CONCLUSION

For patients with BCLC A, LR-3 or -4 nodules are associated with a better prognosis than LR-5 nodules.

Gadoxetic Acid-Enhanced MRI Features for Predicting Treatment Outcomes of Early Hepatocellular Carcinoma (< 3 cm) After Transarterial Chemoembolization

RATIONALE AND OBJECTIVES

Magnetic resonance imaging (MRI) is the most useful imaging tool for small hepatocellular carcinoma (HCC) evaluation. Patients undergoing transarterial chemoembolization (TACE) might have predictive imaging prognostic factors. This study aimed to find predictive gadoxetic acid (GA)-enhanced MRI features that affect tumor response and outcomes in patients with early HCC who underwent conventional TACE.

MATERIALS AND METHODS

Among patients who underwent conventional TACE as a first-line treatment for Barcelona clinic liver cancer stage 0 or A (<3 cm), 135 patients who underwent GA-enhanced MRI before treatment were included in this retrospective study. The patients' pretreatment clinical characteristics and MRI features were evaluated. Post-treatment tumor response, progression-free survival (PFS), and overall survival (OS) were also investigated.

RESULTS

The median follow-up period was 47 (range: 7-133) months, with 90 (67%) patients showing complete remission (CR) at the 1-month follow-up after TACE. Tumor number (odds ratio [OR] 0.602, 95% confidence interval [CI]: 0.375-0.967), central location (OR: 0.349, 95% CI: 0.145-0.837) were inversely associated with CR achievement. Median PFS and OS time were 22 (range: 1-133) and 67 (range: 7-133) months, respectively. The MRI features affecting poor survival outcomes were tumor number (PFS: hazard ratio [HR]=1.444, 95% CI=1.124-1.854; OS: HR=1.459, 95% CI=1.018-2.090), central location (PFS: HR=1.664, 95% CI=1.038-2.667; OS: HR=1.890, 95% CI=1.021-3.497), and marginal irregularity (PFS: HR=3.099, 95% CI=1.953-4.979; OS: HR=1.985, 95% CI=1.084-3.634).

CONCLUSION

Multiplicity, central location, and marginal irregularity of HCC on GA-enhanced MRI were significant factors associated with poor prognosis of patients with early HCC after conventional TACE.

Combined trans-arterial embolisation and microwave ablation for the treatment of large unresectable hepatic metastases (>3 cm in maximal diameter)

PURPOSE

To assess the safety and efficacy of a two-step single-session procedure, combining transarterial embolization (TAE) and percutaneous microwave ablation (MWA), in the treatment of > 3 cm unresectable liver metastases. We also compared the final volume obtained by the two techniques (V_E-T) and the expected ablation volume of the stand-alone MWA (V_T).

METHODS

From January 2015 to December 2017, 22 consecutive patients, with a total of 24 unresectable hepatic metastases >3 cm in diameter underwent a two-step single-session combined treatment of TAE and MWA. Follow-up computed tomography scans were performed at 1-, 3-, 6-, 12, and 24 months post-procedure. V_E-T as final ablation volume induced by the combined treatment (TAE-MWA), V_N as initial nodule volume, V_T as expected ablation volume of MWA treatment alone were evaluated and compared.

RESULTS

Tumor dimensions ranged from 32 to 73 mm. Technical success was achieved in all treated tumors with no local tumor recurrence. Final ablation volumes ranged from 50 to 450 cm³ and the short-axis diameter of the ablation zone ranged from 12 to 48 mm. The mean ΔV increment in the final ablation volume with respect to the stand-alone MWA was 196% (ranging from 25 cm³ - 210 cm³) (p < 0.05). The V_E-T mean was four times the V_N mean, while the V_T mean was about twice the V_N mean. No recurrence and only one case of post-embolization bleeding were observed.

CONCLUSIONS

This study demonstrated the safety and efficacy of a combined two-step single-session TAE-MWA treatment of unresectable hepatic metastases > 3 cm in diameter.

Imaging Predictors of Survival in Patients with Single Small Hepatocellular Carcinoma Treated with Transarterial Chemoembolization

OBJECTIVE

Clinical outcomes of patients who undergo transarterial chemoembolization (TACE) for single small hepatocellular carcinoma (HCC) are not consistent, and may differ based on certain imaging findings. This retrospective study was aimed at determining the efficacy of pre-TACE CT or MR imaging findings in predicting survival outcomes in patients with small HCC upon being treated with TACE. Besides, the study proposed to build a risk prediction model for these patients.

MATERIALS AND METHODS

Altogether, 750 patients with functionally good hepatic reserve who received TACE as the first-line treatment for single small HCC between 2004 and 2014 were included in the study. These patients were randomly assigned into training (n = 525) and validation (n = 225) sets.

RESULTS

According to the results of a multivariable Cox analysis, three pre-TACE imaging findings (tumor margin, tumor location, enhancement pattern) and two clinical factors (age, serum albumin level) were selected and scored to create predictive models for overall, local tumor progression (LTP)-free, and progression-free survival in the training set. The median overall survival time in the validation set were 137.5 months, 76.1 months, and 44.0 months for low-, intermediate-, and high-risk groups, respectively (p < 0.001). Time-dependent receiver operating characteristic curves of the predictive models for overall, LTP-free, and progression-free survival applied to the validation cohort showed acceptable areas under the curve values (0.734, 0.802, and 0.775 for overall survival; 0.738, 0.789, and 0.791 for LTP-free survival; and 0.671, 0.733, and 0.694 for progression-free survival at 3, 5, and 10 years, respectively).

CONCLUSION

Pre-TACE CT or MR imaging findings could predict survival outcomes in patients with small HCC upon treatment with TACE. Our predictive models including three imaging predictors could be helpful in prognostication, identification, and selection of suitable candidates for TACE in patients with single small HCC.

Drug-Eluting Beads versus Lipiodol Transarterial Chemoembolization for the Treatment of Hypovascular Hepatocellular Carcinoma: A Single-Center Retrospective Study

Purpose

To evaluate the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) and conventional TACE (C-TACE) in treating hypovascular hepatocellular carcinoma (HCC).

Materials and Methods

The medical records based on HCC patients who underwent TACE from January 2016 to June 2019 were reviewed in the study. The diagnosis of hypovascular HCC was conducted by two senior radiologists according to imaging. We evaluated the adverse events (AEs), objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS) in the study.

Results

A total of 98 patients with hypovascular HCC were included in the study. 46 patients underwent DEB-TACE treatment, and 52 patients underwent C-TACE treatment. The PFS of DEB-TACE group and C-TACE group was 12.0 months and 7.0 months (P < 0.001), and OS was 21.0 months and 14.0 months (P = 0.035), respectively. In addition, DEB-TACE group had better ORR (76.1% vs 40.4%, P < 0.001) and DCR (91.3% vs 75.0%, P = 0.033) compared to C-TACE group. The occurrence rate of AEs showed no difference between the two groups (67.3% vs 57.7%, P = 0.323). Furthermore, we found that DEB-TACE can be identified as a positive independent prognostic factor for improved PFS and OS.

Conclusion

DEB-TACE, as an effective treatment, can yield better objective response rate, similar safety profile and improved survival for hypovascular HCC patients compared to C-TACE.

Single-centre retrospective review of risk factors for local tumour progression and complications in radiofrequency ablation of 555 hepatic lesions

INTRODUCTION

This study aimed to assess safety, local tumour progression (LTP) and risk factors for LTP after radiofrequency ablation (RFA) of liver tumours in a single centre.

METHODS

All consecutive patients treated with RFA for liver tumours between January 2009 and October 2012 were included. Previously treated lesions that progressed were excluded. Using electronic medical records, the following data was captured: patient demographics, pre-procedural laboratory results, Child-Pugh status, tumour characteristics, development of tumoral seeding, RFA complications and LTP. Possible risk factors for LTP were identified using Cox regression.

RESULTS

In total, 555 liver tumours were treated in 337 patients. 483 (87.0%) hepatocellular carcinomas, 52 (9.4%) colorectal metastases and 20 (3.6%) other tumour types were treated. Mean tumour size was 2.1 ± 1.1 (range 0.4-6.8) cm. Mean follow-up duration was 387 days. 416 (75.0%) lesions had no LTP at the last imaging. 70 (12.6%) patients had minor complications requiring observation, while 7 (1.3%) patients had significant complications requiring prolonged hospitalisation or further interventions. Only one case of tumour seeding was detected. Using multivariate Cox regression, the following factors were statistically significant in predicting LTP: hilar location (relative ratio [RR] 3.988), colorectal metastases (RR 2.075), size (RR 1.290) and younger age (RR 0.982).

CONCLUSION

RFA of liver tumours is safe and effective, with a low significant complication rate of 1.3%. Hilar lesions are most prone to LTP, followed by lesions that were larger in size and colorectal metastases. 75.0% of patients showed no LTP at the last follow-up.

Balloon-Occluded Trans-Arterial Chemoembolization Technique with Alternate Infusion of Cisplatin and Gelatin Slurry for Small Hepatocellular Carcinoma Nodules Adjacent to the Glisson Sheath

Objective

It is difficult to control small hepatocellular carcinoma (HCC) nodules adjacent to the Glisson sheath (GS) by trans-arterial chemoembolization (TACE) probably due to multiple small tumor feeders directly branching from the trunk artery. The purpose of this study was to conduct a retrospective evaluation of a new TACE technique called the repeated alternate infusion of cisplatin solution and gelatin slurry distal to balloon occlusion (RAIB-TACE), for the treatment of small HCC nodules adjacent to GS.

Materials and Methods

Small nodules less than 4 cm attached to proximal portion of the subsegmental to lobar level portal branch were retrospectively selected. Between January 2011 and April 2014, 29 nodules in 29 patients were treated by super-selective lipiodol TACE/balloon-occluded TACE (B-TACE) (Lip-TACE group). Since April 2014, treatment protocols for small nodules adjacent to GS were changed, and 14 nodules in 12 patients were treated by RAIB-TACE (RAIB-TACE group). In RAIB-TACE group, alternate infusion of cisplatin solution and sparse gelatin slurry (mixture of 80 mg of gelatin fragments and 20 mL of contrast medium) were repeated until arterial flow was ceased. In Lip-TACE group, lipiodol was used as drug carrier and dense gelatin slurry (mixture of 80 mg of gelatin fragments and 2 mL of contrast medium) as embolization material. Dynamic CT/MRI was obtained 1-3 months after TACE, and response of each nodule was evaluated basing on modified RECIST criteria.

Results

In RAIB-TACE group, all 14 nodules (100%) were diagnosed as CR or PR. In Lip-TACE group, 18 of 29 (62.1%) were diagnosed as CR or PR. There was a statistically significant difference in objective response ratio between the groups (p=0.008, Fisher's test). Biloma (n=1) and benign stricture of the right hepatic duct (n=1) were seen in RAIB-TACE group. The biloma shrunk without treatment and the patient had no symptom, but the patient with biliary stricture repeated cholangitis and was treated by administration of antibiotics.

Conclusion

The study results show that RAIB-TACE is more effective than lipiodol TACE/B-TACE for small hepatocellular carcinoma adjacent to GS. We speculate that one of the reasons to explain why Lip-TACE is inferior to RAIB-TACE is that viscous lipiodol or dense gelatin slurry could not flow into small tumor feeders effectively.

Prognostic profile of patients with non-viral hepatocellular carcinoma: A comparative study with hepatitis C virus-related hepatocellular carcinoma using data mining analysis

Various factors are associated with the prognosis of patients with non-viral hepatocellular carcinoma (HCC). The present study aimed to investigate the prognosis of patients with non-viral HCC compared with that of patients with hepatitis C virus-related (HCV)-HCC and the features associated with prognosis of patients with non-viral HCC using data mining analyses. Patients with non-viral HCC (n=182, age 70.4±8.9 years) and HCV-HCC (n=612, age 70±8.4 years) were enrolled and the overall survival was compared between the non-viral HCC and HCV-HCC groups. The present study performed random forest and decision tree analyses to identify features that distinguish prognosis between the non-viral HCC and HCV-HCC groups. The median survival of the non-viral HCC group was significantly shorter than the HCV-HCC group (1,553 vs. 2,304 days, P<0.01). In the multivariate analysis, the non-viral HCC group was an independent risk factor for survival (HR 1.42, 95% CI 1.08-1.87, P=0.013). In the random forest analysis, the high-ranking distinguishable factors were 'number of tumors' and 'HCC stage' in the non-viral HCC group and 'albumin' and 'total bilirubin' in the HCV-HCC group. The decision tree analysis revealed that, in patients with HCC stage >I, the survival period in the non-viral HCC group was significantly shorter than the HCV-HCC group (HR 1.39, 95% CI 1.07-1.81, P=0.0132). The prognosis of patients with non-viral HCC was poorer than patients with HCV-HCC. In addition, data mining analysis revealed that tumor-related variables had the highest importance for survival in patients with non-viral HCC.

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

Background and Aim

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

Materials and Methods

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

Results

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

Conclusion

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

Clinical outcomes of stereotactic body radiotherapy for elderly patients with hepatocellular carcinoma

AIM

To evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for the treatment of hepatocellular carcinoma (HCC) in elderly patients.

METHODS

From 2008 to 2015, 117 patients with HCC (≤3 nodules, ≤30 mm in diameter, Child-Pugh score ≤7, and no vascular or extracellular metastasis) were treated with SBRT at our hospital. We evaluated overall survival (OS), disease-free survival (DFS), local control, and adverse events. Patients were stratified according to age 75 years and older (elderly group, n = 54) and age younger than 75 years (young group, n = 63).

RESULTS

The median OS in the elderly group was not significantly different from that in the young group (52 months vs. not reached, P = 0.27). The 1-, 2-, and 3-year OS rates were 96.2%, 77.6%, and 63.9%, respectively, in the elderly group, and 96.8%, 84.8%, and 67.7%, respectively, in the young group. The median DFS in the elderly group was significantly shorter than that in the young group (13 vs. 25 months, respectively; P = 0.03). The 1-, 2-, and 3-year DFS rates were 50.6%, 30.4%, and 26.6%, respectively, in the elderly group and 66.5%, 50.7%, and 45.3%, respectively, in the young group. The 3-year local tumor control rate in the elderly group was 98.1%, and that in the young group was 98.4% (P = 0.83). There was no difference between groups in the incidence of any adverse events.

CONCLUSIONS

Stereotactic body radiotherapy can be effective and safe for the treatment of HCC in elderly patients.

Predictive factors of pathological vascular invasion in hepatocellular carcinoma within 3 cm and three nodules without radiological vascular invasion

AIM

The aim of this study was to determine the predictive factors of pathological vascular invasion as contra-indicators for ablation therapy in patients with hepatocellular carcinoma (HCC) within 3 cm and three nodules without radiological vascular invasion.

METHODS

Two hundred and seventeen patients with HCC within 3 cm and three nodules without radiological vascular invasion who underwent hepatic resection were retrospectively investigated.

RESULTS

Pathological vascular invasion was positive in 46 patients, consisting of 38 portal vein invasions, three hepatic vein invasions, two hepatic artery invasions, one hepatic duct invasion and two with portal and hepatic vein invasions. In univariate analysis, patients with α-fetoprotein (AFP) of more than 100 ng/mL had higher rates of pathological vascular invasion than those without. In addition, patients with protein induced by vitamin K absence (PIVKA-II) of more than 100 mAU/mL had higher rates of pathological vascular invasion than those without. Multivariate analysis revealed that AFP of more than 100 ng/mL and PIVKA-II of more than 100 mAU/mL were independent predictive factors for pathological vascular invasion. As these patients were treated with hepatic resection, cumulative 5-year recurrence-free and overall survivals were not significantly different between the pathological vascular invasion negative and positive cases.

CONCLUSION

AFP of more than 100 ng/mL and PIVKA-II of more than 100 mAU/mL can predict pathological vascular invasion in patients with HCC within 3 cm and three nodules without radiological vascular invasion. In treating such cases, hepatic resection rather than local ablation therapy is recommended.

Outcomes of laparoscopic hepatic resection versus percutaneous radiofrequency ablation for hepatocellular carcinoma located at the liver surface: A case-control study with propensity score matching

AIM

Percutaneous radiofrequency ablation (P-RFA) therapy is a widely applied treatment for small hepatocellular carcinoma (HCC); however, local recurrence is a major issue of HCC located at the surface of the liver (surface HCC). The aim of this study was to compare the outcome of laparoscopic hepatic resection (LH) and P-RFA for surface HCC in case-control patient groups using the propensity score.

METHODS

Between 2011 and 2013, 40 and 52 patients underwent LH and P-RFA for surface HCC (≤3 cm, 1-3 nodules). To correct the difference in clinicopathological factors between the two groups, propensity score matching was used at a 1:1 ratio, which resulted in a comparison of 27 patients/group. We compared outcomes between the two groups, with special reference to local recurrence.

RESULTS

Clinicopathological variables were well balanced between the two groups. One patient in the LH group was converted to open surgery due to adhesion. The incidence of complications was 0% in the P-RFA group and 15% (four patients) in the LH group (P = 0.11); however, none of these four patients in the LH group sustained severe complications. The duration of hospitalization following treatment was longer in the LH group than in the P-RFA group (12.6 vs 7.6 days, P < 0.01). The incidence of local recurrence was lower in the LH group (0%) than in the P-RFA group (eight patients [30%], P = 0.004).

CONCLUSION

LH is an effective treatment for surface HCC with regard to control of local recurrence.

Laparoscopy-Guided Transthoracic Transdiaphragmatic Radiofrequency Ablation for Hepatic Tumors Located Beneath the Diaphragm

BACKGROUND

It is often difficult to perform percutaneous radiofrequency ablation (RFA) for hepatic tumors beneath the diaphragm. Diaphragmatic thermal damage is one of the fatal late complications of percutaneous transdiaphragmatic RFA. Our experience with laparoscopic transthoracic transdiaphragmatic intraoperative RFA (LTTI-RFA) for hepatic tumors beneath the diaphragm is reported.

METHODS

Ten patients who underwent LTTI-RFA from 2009 to 2012 were evaluated. Two cases had concomitant partial hepatectomy, and one underwent RFA for two tumors at the same time. The diagnosis was hepatocellular carcinoma in eight cases and metastatic hepatic tumors in two cases. Nine of eleven tumors were located at segments 7 and 8. Nine tumors were less than 20 mm in diameter. The patients were placed in the half left lateral decubitus position with single-lumen tube intubation. After placement of four abdominal ports, a 12-mm port was inserted in the fourth or fifth intercostal space into the diaphragm. The tumor was ablated by an RFA needle through the port. The routine follow-up consisted of laboratory tests and abdominal imaging every 3-6 months.

RESULTS

The median operation time for only one tumor was 137 minutes (range, 105-187 minutes). The median number of times for ablation was three. Severe postoperative complications (>Clavien-Dindo IIIa) were observed in one case (right upper limb paralysis). The median follow-up period was 35 months (range, 11-43 months). There was no local tumor progression. Recurrent hepatic tumor appearance occurred in other parts of the liver in 6 of the 11 patients.

CONCLUSIONS

Laparoscopic transthoracic transdiaphragmatic RFA is an acceptable procedure with a low rate of local recurrence.

Locoregional Therapies for Primary and Secondary Hepatic Malignancies

Management of hepatic malignancies is a multidisciplinary task with the involvement of hepatologists, medical/surgical oncologists, transplant surgeons, and interventional radiologists. The patients should be selected for a specific targeted therapy after multidisciplinary consensus. Interventional oncology has established its role in the management of hepatic malignancies. Image-guided locoregional therapies decrease the rate of systemic toxicity without compromising tumoricidal effect.

Efficacy and safety of radiofrequency ablation and transcatheter arterial chemoembolization for treatment of hepatocellular carcinoma: A meta-analysis

AIM

To investigate the efficacy and safety of radiofrequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) for treatment of patients with hepatocellular carcinoma (HCC).

METHODS

All eligible studies were collected from PubMed, the Cochrane Libraries and Embase. The evaluation indices included overall survival (OS) rate, recurrence-free survival rate, local tumor progression rate and major complications. All statistical analysis was performed by RevMan version 5.2 software.

RESULTS

There were 21 studies with 3073 patients included in this meta-analysis. The RFA monotherapy was associated with higher 3- and 5-year OS rates (OR3-year  = 2.33, 95% confidence interval [CI] = 1.34-4.05; OR5-year  = 2.05, 95% CI = 1.48-2.85) compared with TACE alone. The combination of RFA and TACE was associated with higher 1-, 3- and 5-year OS rates (OR1-year  = 1.94, 95% CI = 1.28-2.96; OR3-year  = 1.56, 95% CI = 1.19-2.04; OR5-year  = 1.53, 95% CI = 1.13-2.07) compared with RFA alone.

CONCLUSION

The combination of TACE with RFA could obviously improve the short- and long-term survival rates and significantly provide a better prognosis for patients with intermediate-size HCC. RFA was associated with a higher long-term OS rate than that of TACE-treated patients with HCC.

Integrating contrast-enhanced sonography in the follow-up algorithm of hepatocellular carcinoma treated with radiofrequency ablation: single cancer center experience

BACKGROUND

Hepatocellular carcinoma (HCC) patients treated with percutaneous ablation require close follow-up for early detecting and treating tumor recurrence.

PURPOSE

To illustrate our single-center prospective experience on using contrast-enhanced ultrasound (CEUS) as a follow-up tool alternated with computed tomography (CT).

MATERIAL AND METHODS

In a 7-year period 588 patients with one to three HCCs were treated with radiofrequency ablation (alone or combined with ethanol injection). Patients with completely ablated tumors at 1-month CT scan were followed up serially, using alternated CEUS (one microbubbles injection per lobe) and CT every 3 months for 2 years. In few cases magnetic resonance imaging (MRI) was employed instead of or in addition to CT. The following patterns of recurrence were considered: A, enhancing tissue within the lesion; B, enhancing tissue adherent to the lesion; C, enhancing tissue within the same liver segment of the treated nodule; and D, enhancing tissue within a different segment. Patients with positive CEUS underwent confirmatory CT/MRI (standard reference).

RESULTS

Median follow-up was 19 months. There were 221 recurrences. Three pattern A recurrences (2 detected by CEUS and 1 by CT), 86 pattern B recurrences (44 detected by CEUS and 42 by CT), 70 pattern C recurrences (32 detected by CEUS and 38 by CT), and 62 pattern D recurrences (23 detected by CEUS and 39 by CT). CT detected additional nodules in 16/101 patients with positive CEUS.

CONCLUSION

CEUS follow-up of HCC patients after ablation is feasible. Since 72% recurrences develop in the same segment of the necrotic nodule, CEUS proves to be effective despite the minor visualization of the entire liver during the arterial phase when compared to CT and MRI. Including CEUS in patient follow-up may reduce the number of CT and MRI examinations.

Radiofrequency ablation combined with transcatheter therapy in rabbit VX2 liver tumors: effects and histopathological characteristics

BACKGROUND

Transarterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) treatment (TACE-RFA) has been confirmed superior to TACE or RFA alone in animal liver tumors. TACE before RFA was shown to increase hepatocellular damage. Further optimization of the combination strategy for transcatheter arterial embolization (TAE) or TACE combined with RFA is warranted.

PURPOSE

To determine the optimal strategy for radiofrequency ablation combined with transcatheter therapies in VX2 liver tumors in a rabbit model.

MATERIAL AND METHODS

Twenty-four Japanese White rabbits with VX2 liver tumors were randomly divided into four groups: TACE-RFA (TACE-RFA group), transcatheter arterial embolization (TAE) combined with RFA treatment (TAE-RFA group), RFA only group, and TACE only group. Blood samples were collected 1 day before the operation and at 3 and 7 days postoperatively. Seven days after the operation, maximal diameters of coagulation or infarcted zones in the gross specimens, CT images, histopathological characteristics, tumor necrotic rate, and growth rate were compared.

RESULTS

Significantly larger mean long-axis (P < 0.05) and short-axis (P < 0.05) diameters of coagulation and infarction were observed in the TACE-RFA group compared with the TAE-RFA, RFA, and TACE groups on day 7; and the TAE-RFA group showed a significant (P < 0.05) increase versus the RFA and TACE groups on day 7. There were no significant differences in tumor growth rate (109.3 ± 37.5 vs. 119.0 ± 43.1%, P = 0.45) and necrotic rate (89.5 ± 12.0 vs. 83.5 ± 9.3%, P = 0.73) between the TACE-RFA and TAE-RFA groups. TACE-RFA was more effective for achieving tumor destruction than the other treatment strategies, but led to increased rabbits discomfort and more severe liver dysfunction compared with TAE-RFA.

CONCLUSION

TAE-RFA appears to be a beneficial therapeutic modality for treating VX2 liver tumors in a rabbit model.

Local tumour progression after ultrasound-guided microwave ablation of liver malignancies: risk factors analysis of 2529 tumours

OBJECTIVES

To identify the incidence and risk factors that predict local tumour progression (LTP) after ultrasound-guided percutaneous microwave ablation (MWA) of liver malignancies.

MATERIALS AND METHODS

One thousand two hundred and nine patients with 2,529 malignant nodules (mean size 2.8 ± 1.4 cm, range 0.9-8.0 cm) were treated by MWA between July 2005 and December 2012. The influence of 11 factors on the risk of LTP was assessed. Univariate Kaplan-Meier and Cox proportional hazard models were used for statistical analysis.

RESULTS

The overall LTP was 4.2 % per tumour and 8.6 % per patient with a median follow-up of 20.3 months. LTP per tumour was 4.3 % for primary liver cancer and 4.1 % for metastases (p = 0.32). The survival of LTP and free-LTP patients at 1, 3, and 5 years was 92.4 %, 71.6 %, and 45.1 %, respectively, and 92.9 %, 70.1 %, and 52.4 %, respectively (p = 0.93). By univariate analysis, tumour location, size and ablation time were significant risk factors of LTP. Multivariate analysis identified tumour size (>3.0 cm) to be the only independent predictor of LTP.

CONCLUSIONS

MWA of liver malignancies achieves a relatively low-incidence LTP, although LTP risk significantly increases if tumour size >3.0 cm. The technique seems to be appropriate even for patients with a tumour at a risk location.

KEY POINTS

• Microwave ablation of liver malignancies achieves a low incidence local tumour progression. • LTP risk significantly increases if the tumour size is >3.0 cm. • MWA seems to be appropriate even for patients with a tumour at a risk location.

Radiofrequency ablation of liver tumors

Radiofrequency ablation (RFA) is an alternative therapy for hepatocellular carcinoma and liver metastases when resection cannot be performed or, in the case of hepatocellular carcinoma, when transplant cannot be performed in a timely enough manner to avoid the risk of dropping off the transplant list. RFA has the advantage of being a relatively low-risk minimally invasive procedure used in the treatment of focal liver tumors. This review article discusses the current evidence supporting RFA of liver tumors, as well as the indications, complications, and follow-up algorithms used after RFA.

Risk factors and therapeutic results of early local recurrence after transcatheter arterial chemoembolization

AIM: To identify factors affecting early local recurrence after transcatheter arterial chemoembolization (TACE) and investigate treatments and outcomes for local recurrence.

METHODS: Early local recurrence and no early local recurrence groups drawn from 134 patients who were initially diagnosed with hepatocellular carcinoma (HCC) and showed a complete response (CR) to TACE treatment between January 1, 2006, and January 31, 2012, were analyzed by univariate and multivariate analyses. Additionally, the subsequent treatment for patients with recurrence was analyzed, and in cases in which TACE had been performed, the cumulative recurrence rates were calculated using the Kaplan-Meier method and compared with those of the primary lesion.

RESULTS: The 1-, 2-, and 3-year survival rates were 92.3%, 60.2%, and 39.8%, respectively, in the early local recurrence group, which were significantly lower than those in both the late local and no local recurrence groups (P < 0.001). On multivariate analyses, non-compact lipiodol uptake, large tumor size, and an alpha-fetoprotein > 20 ng/mL after achieving a CR were significant predictors. When TACE was performed for early and late locally recurrent lesions, a CR was observed in 15 patients (41.7%) and 11 patients (78.6%), and the cumulative recurrence rates at 6, 12, and 24 mo were 17.9%, 43.3%, and 71.2%, respectively, which did not differ significantly from those after the first CR of 20.5%, 44.0%, and 58.6%, respectively (P = 0.639).

CONCLUSION: Closer monitoring and active treatments must be provided to patients with risk factors for early local recurrence of HCC.

Local recurrence after chemoembolization of hepatocellular carcinoma: uptake of gadoxetic acid as a new prognostic factor

OBJECTIVE

The purpose of this article is to investigate whether there is a difference in susceptibility to transcatheter arterial chemoembolization between hepatocellular carcinomas (HCCs) showing high uptake and those showing low uptake of gadoxetic acid in the hepatobiliary phase of MRI.

MATERIALS AND METHODS

One hundred HCCs that achieved optimal chemoembolization, as assessed by immediate CT in 60 patients, were classified as having high (n = 19) or low (n = 81) uptake of gadoxetic acid on MRI performed before chemoembolization. The local recurrence rates were estimated using the Kaplan-Meier method, and differences between the groups were compared using the log-rank test. The following factors were also correlated with the local recurrence rate using the Cox proportional hazards model for a univariate analysis: high uptake of gadoxetic acid, number of feeding arteries, extrahepatic arterial supply, Child-Pugh class, clinical tumor stage, size, location, and iodized oil accumulation in the noncancerous tissue surrounding the lesion. Parameters that were significant at p < 0.05 were entered into a multivariate model.

RESULTS

The 1- and 3-year local recurrence-free rates were 95% in high-uptake HCCs and 66% and 54%, respectively, in low-uptake HCCs (log-rank test, p < 0.01). The low uptake of gadoxetic acid was the only significant predictor of early local recurrence (hazard ratio = 9.24; p = 0.03) by multivariate analysis.

CONCLUSION

HCCs showing high uptake of gadoxetic acid appear to be susceptible to chemoembolization.

Radiofrequency ablation for hepatocellular carcinoma: the relationship between a new grading system for the ablative margin and clinical outcomes

BACKGROUND

In our previous study, we classified the radicality (R grading) of percutaneous radiofrequency ablation (RFA) therapy for single hepatocellular carcinoma (HCC) according to the extent of the ablated margin, and demonstrated that this grading system was useful for predicting local tumor progression (LTP) after RFA. The aim of this study was to measure the overall survival (OS), the recurrence free survival (RFS), and the distant recurrence (DR) rate for each R grade (A-D), and to examine the relationship between clinical outcome and R grading.

METHODS

This study involved 368 patients with solitary HCC who had undergone RFA. The mean tumor diameter was 2.0 ± 0.7 cm. We calculated the post-RFA cumulative OS, RFS, and DR rate for each R grade and analyzed the factors contributing to clinical outcomes.

RESULTS

In the multivariate analysis, significant factors were as follows: tumor size >2 cm, serum albumin >3.5 g/dL, prothrombin time >70 %, HCC recurrence within 1 year, and R grading (grade A) in OS; cause of liver disease (hepatitis B), gamma glutamyl transpeptidase (GGT) >80 IU/L, platelet count >10 × 10(4)/mm(3), and R grading (grade A or B) in RFS; GGT >80 IU/L, platelet count >10 × 10(4)/mm(3), and R grading (grade A or B) in DR. In patients with sufficient Lipiodol accumulation (n = 219), very similar results were obtained. However, in patients with grade A and B (n = 232), R grade was not a significant independent factor linked to OS, although grade A patients had lower LTP rate.

CONCLUSIONS

Our proposed R grading system appears to be useful for predicting clinical outcomes after RFA.

Diaphragmatic necrosis after radiofrequency ablation of hepatocellular carcinoma: a successful surgical repair

We report a case of complete hemidiaphragmatic necrosis with liver abscess complicating radiofrequency ablation of a large subdiaphragmatic hepatocellular carcinoma in a patient with unrecognized history of endoscopic oddi sphincterotomy. At 2-year follow-up after surgical repair using a pedicled latissimus dorsi flap, clinical examination and imaging did not show complication or cancer recurrence. The risk of complete hemidiaphragmatic necrosis resulting from both thermal and septic injuries should be considered when radiofrequency ablation is performed for liver dome tumors, particularly in patients with impaired oddi sphincter. In this septic situation, a latissimus dorsi flap appears as the unique opportunity to repair the injured hemidiaphragm.

Current status of hepatocellular carcinoma treatment in Japan: transarterial chemoembolization

Transarterial chemoembolization (TACE) is the gold standard of treatment for intermediate-stage hepatocellular carcinoma (HCC), and involves the administration of cytotoxic drugs, with or without lipiodol, by means of a catheter directly to the hepatic artery followed by the administration of embolizing agents such as spherical gelatin or polyvinyl alcohol particles. There are currently no global guidelines regarding the dose, choice or combination of cytotoxic agents for TACE; therefore it is difficult to compare data from different TACE studies. Superselective TACE with lipiodol is the primary TACE procedure that offers satisfactory levels of local control with a lower risk of complications. Approximately 40-70% of patients with HCC with tumours sized 4-5 cm or less attained complete tumour necrosis or remained local recurrence free for 3 years or longer following TACE. The early identification of unresponsiveness to TACE is important to allow for a timely switch to alternative therapies. The use of novel embolizing materials in TACE such as drug-eluting beads and radioembolization is likely to have beneficial effects. Indeed, the increase in angiogenic activity following TACE emphasizes the potential of TACE in combination with targeted molecular therapies such as the anti-angiogenesis inhibitor, sorafenib.

Percutaneous radiofrequency ablation therapy for hepatocellular carcinoma: a proposed new grading system for the ablative margin and prediction of local tumor progression and its validation

BACKGROUND

In the present study we classified the radicality of percutaneous radiofrequency thermal ablation (RFA) therapy according to the extent of the ablated margin. We measured the local recurrence rate for each radicality grade to evaluate the significance of the grading system in assessing the therapeutic effectiveness of RFA and predicting local tumor progression.

METHODS

This retrospective study involved 269 patients with solitary hypervascular hepatocellular carcinoma who had undergone RFA. The mean ± SD observation period after RFA, number of treatment sessions, and tumor diameter were 25.7 ± 19.9 months, 1.2 ± 0.5, and 2.1 ± 0.7 cm, respectively. Patients were evaluated using dynamic computed tomography. We classified the radicality of RFA treatment into four grades (R grades: A, B, C, and D) according to the extent of the ablated tumor margin, calculated the post-RFA cumulative local recurrence rate for each R grade, and analyzed the factors (patient characteristics, biochemical data, contiguous vessels, and tumor marker) contributing to local recurrence.

RESULTS

The cumulative local recurrence rates at 3 years were 6.7, 17.6, 55.8, and 82.2% for Grades A, B, C, and D, respectively. Using univariate analysis, R grade, tumor size (> 2 cm), and des-γ-carboxy prothrombin (DCP) (> 200 mA U/mL) were shown to be significant factors contributing to local recurrence. However, using multivariate analysis, only the R grade was found to be a significant independent factor.

CONCLUSIONS

The proposed R grading method is a valid and useful method for assessing treatment efficacy, and for predicting local tumor progression after RFA.

Systematic review and meta-analysis of survival and disease recurrence after radiofrequency ablation for hepatocellular carcinoma

BACKGROUND

Despite being one of the commonest causes of cancer-related death around the world, only 20 per cent of hepatocellular carcinomas (HCCs) are amenable to curative treatment (surgical resection or liver transplantation). Radiofrequency ablation (RFA) has emerged as a popular therapy for unresectable HCC. There is evidence that the disparity in survival after curative RFA and surgery for HCC, especially tumours smaller than 3 cm in diameter, is narrowing. This review examined the survival and disease recurrence rates after RFA for HCC over the past decade.

METHODS

A systematic review was conducted using MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Cochrane Methodology Register and the Database of Abstracts of Reviews of Effects from January 2000 until November 2010. Papers reporting on patients with HCC who were treated with RFA, either in comparison or in combination with other interventions, such as surgery or percutaneous ethanol injection (PEI), were eligible for inclusion. Outcome data collected were overall survival, disease-free survival and disease recurrence rates. Only randomized controlled trials (RCTs), quasi-RCTs and non-randomized comparative studies with more than 12 months' follow-up were included.

RESULTS

Forty-three articles, including 12 RCTs, were included in the review. The majority of the articles reported the use of RFA for unresectable HCC, often in combination with other treatments such as PEI, transarterial chemoembolization and/or surgery. Overall and disease-free survival rates continue to improve, despite an increase in the size and numbers of tumours treated. More recently some clinicians have used RFA to treat selected patients with resectable HCC, with good outcomes.

CONCLUSION

RFA provides a valuable treatment option for patients with unresectable HCC. It improves survival in those previously considered to have advanced disease. As progress continues to be made, RFA is gradually being used to treat resectable HCC.

Surgical treatment of hepatocellular carcinoma: expert consensus statement

As the number of effective treatment options has increased, the management of patients with hepatocellular carcinoma has become complex. The most appropriate therapy depends largely on the functional status of the underlying liver. In patients with advanced cirrhosis and tumor extent within the Milan criteria, liver transplantation is clearly the best option, as this therapy treats the cancer along with the underlying hepatic parenchymal disease. As the results of transplantation has become established in patients with limited disease, investigation has increasingly focused on downstaging patients with disease outside of Milan criteria and defining the upper limits of transplantable tumors. In patients with well preserved hepatic function, liver resection is the most appropriate and effective treatment. Hepatic resection is not as constrained by tumor extent and location to the same degree as transplantation and ablative therapies. Some patients who recur after resection may still be eligible for transplantation. Ablative therapies, particularly percutaneous radiofrequency ablation and transarterial chemoembolization have been used primarily to treat patients with low volume irresectable tumors. Whether ablation of small tumors provides long term disease control that is comparable to resection remains unclear.

Evaluation of virtual CT sonography for enhanced detection of small hepatic nodules: a prospective pilot study

OBJECTIVE

Virtual CT sonography is a system for synchronizing multiplanar reconstructed CT scans with corresponding conventional ultrasound images in real time. The aim of this study was to prospectively evaluate the feasibility of virtual CT sonography for detection of nodules difficult to detect with conventional sonography alone.

SUBJECTS AND METHODS

Fifty-nine patients with 140 nodules were included in the study. All patients underwent CT angiography then conventional sonography and finally virtual CT sonography. The number, location, and echogenicity of nodules and parenchyma were assessed.

RESULTS

Among 140 nodules detected with CT angiography, 71 were detected with conventional sonography and another 46 were detected with virtual CT sonography, increasing the overall sensitivity from 50.7% to 83.57%. The average diameter of nodules detected only with virtual CT sonography (9.7 +/- 3.3 mm) was significantly smaller than that of nodules detected with conventional sonography (16.6 +/- 6.2 mm). The results of multivariate analysis suggested that nodule size (p < 0.001), echo pattern (p = 0.004), and location (p = 0.028) are associated with the difference in detection. Interestingly, 87% of the nodules 10 mm in diameter or smaller were already dysplastic or malignant.

CONCLUSION

Nodules 10 mm in diameter or smaller have significant malignant potential and therefore are clinically important. Even though we do not consider virtual CT sonography a screening tool, we conclude it superior to conventional sonography for detection of small hepatic nodules, allowing bedside percutaneous ultrasound-guided biopsy and treatment that would not be possible with conventional sonography alone.

Evaluation of posttreatment response of hepatocellular carcinoma: comparison of ultrasonography with second-generation ultrasound contrast agent and multidetector CT

We evaluated the ability of one-month follow-up contrast-enhanced ultrasound (CEUS) with second-generation contrast agent in monitoring radio frequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) treatments of hepatocellular carcinoma (HCC). One-hundred forty-eight HCCs were studied using CEUS: 110 nodules were treated with RFA [41/110 RFA were performed using a pretreatment and an immediate postablation evaluation using CEUS (group 1); 69/110 using only US guidance (group 2)] and 38 nodules treated with TACE. For statistical analysis, McNemar test was used. Overall complete response was observed in 107/148 nodules (92/110 treated with RFA and 15/38 with TACE). A better rate of complete response was found in group 1 compared to group 2 (92.7% vs. 78.3%). In RFA treatment, CEUS showed a sensitivity of 83.3% and a specificity of 100% (diagnostic accuracy of 97%) using MDCT as reference standard with no statistical difference (p > 0.05). CEUS detected all cases of incomplete response in HCC treated with TACE using angiography as reference standard (diagnostic accuracy 100%). We recommend assessing residual intratumoral flow on CEUS during RFA procedure to determine the necessity of immediate additional treatment. In case of positive CEUS results, HCC treated with TACE should be considered still viable.

Effect of radio frequency ablation on vascular endothelial growth factor expression in rabbit liver VX2 tumor models

AIM: To investigate the effect of radio frequency ablation (RFA) on vascular endothelial growth factor (VEGF) expression in rabbit liver VX2 tumor models.

METHODS: The liver VX2 tumor models were established by planting the tumor tissue suspension into rabbits' liver and then divided into three groups: Control group were killed directly to obtain liver specimens; treat group were treated with RFA and executed after 4 h and 24 h randomly. And normal rabbit livers were used as the normal group. The expression of VEGF in all groups was detected by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS: VX2 liver tumor showed infiltrative growth. After RFA, large necrosis in the central ablation area, surrounded by inflammatory response belt and peripheral residual tumor tissue, was observed in the specimens from tumors. By immunohistochemistry and RT-PCR, the protein and gene expressions of VEGF in the control group were higher than those in the normal group (VEGF-mRNA/GAPDH-mRNA 1.3048 ± 0.1936 vs 0.8993 ± 0.1107, P < 0.05), while those in treatment group (4 h: 0.7388 ± 0.1503; 24 h: 0.8935 ± 0.1936) were decreased obviously as compared with the control group (both P < 0.05). However, there was no significant difference in the expression of VEGF in the tumor tissue among the different time points of the RFA group (P > 0.05).

CONCLUSION: RFA treatment can effectively down-regulate the protein and gene expression of VEGF, inhibit the angiopoiesis and reduce the blood supply, thus may reduce tumor relapse and metastasis.