Radiofrequency ablation of hepatocellular carcinoma in difficult locations: Strategies and long-term outcomes

Radiofrequency ablation for peribiliary hepatocellular carcinoma: propensity score matching analysis

OBJECTIVES

At present, there are no established clinical guidelines for radiofrequency ablation (RFA) of peribiliary hepatocellular carcinoma (HCC). Therefore, the aim of this study was to compare the long-term outcomes of RFA for peribiliary vs. non-peribiliary HCC.

METHODS

This retrospective study included 282 patients with peribiliary HCC (n = 109) or non-peribiliary HCC (n = 173) who received RFA between February 2013 and May 2021. Local tumor progression (LTP), overall survival (OS), disease-free survival (DFS), and complications were compared before and after propensity score matching (PSM).

RESULTS

Before PSM, there were no significant differences in 5-year LTP rates (26.3% vs. 23.6%, p = 0.602), OS rates (56.6% vs. 68.0%, p = 0.586), or DFS rates (22.9% vs. 25.7%, p = 0.239) between the peribiliary and non-peribiliary groups. After PSM, there were no significant differences in the 1-, 3-, and 5-year LTP rates (13.0%, 23.1%, and 26.3% vs. 12.1%, 25.1%, and 28.2%, respectively, p = 0.857), OS rates (97.2%, 73.5%, and 56.6% vs. 95.3%, 79.5%, and 70.6%, p = 0.727), or DFS rates (59.4%, 29.4%, and 22.9% vs. 64.2%, 33.1%, and 23.8%, p = 0.568) between the peribiliary non-peribiliary groups. Peribiliary location was not a significant prognostic factor for LTP (p = 0.622) or OS (p = 0.587). In addition, mild intrahepatic bile duct dilatation was more frequent in the peribiliary group (9.2% vs. 2.8%, p = 0.045).

CONCLUSION

Long-term outcomes of RFA were similar for peribiliary and non-peribiliary HCC. RFA is a viable alternative for treatment of peribiliary HCC.

CRITICAL RELEVANCE STATEMENT

The local tumor progression (LTP), overall survival (OS), and disease-free survival (DFS) rates after radiofrequency ablation (RFA) were similar for peribiliary and non-peribiliary hepatocellular carcinoma (HCC).

KEY POINTS

There are currently no clinical guidelines for radiofrequency ablation (RFA) of peribiliary hepatocellular carcinoma (HCC). Local tumor progression, overall survival, and disease-free survival after RFA were similar for peribiliary and non-peribiliary HCC. RFA is a viable alternative for the treatment of peribiliary HCC.

Comparative Efficacy of Microwave versus Radiofrequency Ablation in Hepatocellular Carcinoma: Systematic Review and Meta-Analysis of Randomized-Controlled Trials

Introduction: Hepatocellular carcinoma (HCC) is a leading global cause of cancer-related deaths. Thermal ablation techniques, especially radiofrequency ablation (RFA) and microwave ablation (MWA), have become pivotal treatments for HCC. This systematic review and meta-analysis aim to compare these modalities, highlighting their efficacy, strengths, and limitations in treating HCC. Methods: A comprehensive literature search was conducted across major databases (PubMed, MEDLINE, Springer, ProQuest, EBSCOhost, Cochrane, and EMBASE) targeting studies on hepatocellular carcinoma with RFA and MWA. Heterogeneity analyses and pooled outcomes using random-effect models with were evaluated to compare both thermal ablation methods. Results: Nine studies, which consists of 368 patients underwent RFA and 387 patients underwent MWA, were included in review. The findings showed no significant differences in pooled analysis of volume of ablation, complete ablation rate, local tumor progression, survival rates, major complications, and adverse events. Subgroup analysis showed significantly higher risk of local tumor progression in RFA in African populations. Conclusion: No statistically significant difference was seen between outcomes across studies. MWA may offer a potential for longer therapeutic response with comparable risk of complications and adverse outcomes.

Contrast-enhanced ultrasonography guidance avoids US-CT/MR fusion error for percutaneous radiofrequency ablation of hepatocellular carcinoma

BACKGROUND

This study evaluated the impact of contrast-enhanced ultrasonography (CEUS) combined with CT or MRI fusion imaging on percutaneous radiofrequency ablation (RFA) outcomes for hepatocellular carcinoma (HCC) inconspicuous on conventional ultrasonography (US).

METHODS

Patients were categorized into US-inconspicuous (USI) and US-conspicuous (USC) groups based on US imaging. The parameters of viable HCCs ⎯ including diameter, location, and RFA efficacy ⎯ were compared between USI and USC groups. Moreover, the breathing fusion imaging errors were measured. The differences in technical success, technical efficacy, local tumor progression, new tumor occurrence, and overall survival rate between USI and USC groups were analyzed.

RESULTS

Sixty-five patients with 106 lesions were included. CEUS showed high consistency with CT/MRI but revealed larger diameters (p < 0.001) and more feeding arteries (p = 0.019) than CT/MRI. Breathing fusion imaging errors averaged 17 ± 4 mm, significantly affecting lesions in segments II, III, V, and VI (p < 0.001). The USI group had more lesions ablated per patient in a single RFA procedure (p = 0.001) than the USC group. No significant differences were observed in technical success rate, technical efficacy rate, local tumor progression rate, and overall survival rate between the two groups.

CONCLUSIONS

CEUS combined with fusion imaging provides detailed information on viable HCCs and their feeding arteries. CEUS-guided RFA avoids fusion imaging errors and achieves comparable efficacy in both US-conspicuous and US-inconspicuous HCCs.

Locoregional Therapies for Hepatocellular Carcinoma in Patients with Nonalcoholic Fatty Liver Disease

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death worldwide with an average five-year survival rate in the US of 19.6%. With the advent of HBV and HCV treatment and prevention, along with the rising rates of obesity, nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome are set to overtake infectious causes as the most common cause of HCC. While surgical resection and transplantation can be curative when amenable, the disease is most commonly unresectable on presentation, and other treatment approaches are the mainstay of therapy. In these patients, locoregional therapies have evolved as a vital tool in both palliation for advanced disease and as a bridge to surgical resection and transplantation. In this review, we will be exploring the primary locoregional therapies for HCC in patients with NAFLD, including transarterial chemoembolization (TACE), bland transarterial embolization (TAE), transarterial radioembolization (TARE), and percutaneous ablation.

Examining the Efficacy and Safety of Combined Locoregional Therapy and Immunotherapy in Treating Hepatocellular Carcinoma

More than 800,000 people worldwide are diagnosed with HCC (hepatocellular carcinoma) each year, with approximately 700,000 deaths alone occurring in that same year. Treatment of HCC presents complex therapeutic challenges, particularly in intermediate and advanced stages. LRTs such as transarterial chemoembolization (TACE) and ablations have been the mainstay treatment for early to intermediate-stage HCC, and systemic therapies are used to treat intermediate-late-stage HCC. However, novel literature describing combining LRT with systemic therapies has shown promising results. This review explores recent advances in both liver-directed techniques for hepatocellular carcinoma, including bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies in conjunction as well as with systemic therapies, with a focus on combination therapies, patient selection, procedural technique, periprocedural management, and outcomes. Our findings suggest that LRT combined with systemic therapies is a viable strategy for improving progression-free survival and time to progression for patients with intermediate-to-late-stage HCC. However, further investigation is required to refine treatment protocols and define patient cohorts that would benefit the most.

Percutaneous ultrasound-guided radiofrequency ablation for patients with liver metastases from gastrointestinal stromal tumors

OBJECTIVES

This study aimed to analyze the survival outcomes and prognostic factors of radiofrequency ablation (RFA) for liver metastases from gastrointestinal stromal tumors (GISTs).

METHODS

Between March 2011 and November 2022, 34 patients (16 males; age range, 25-72 [median age, 52.5] years) who underwent RFA for liver metastasis from GISTs were included. The mean maximum diameter of metastatic lesions was 2.4 ± 1.0 (range, 1.1-5.2) cm. Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. Multivariate analyses were performed using a Cox proportional hazards model.

RESULTS

For 79 lesions among 34 patients, all targeted lesions were completely ablated. The mean hepatic progression-free survival (HPFS) period was 28.4 ± 3.8 (range, 1.0-45.7) months. The 1-, 3-, and 5-year HPFS rates were 67.2%, 60.5%, and 20.2%, respectively. Based on the univariate analysis, the number of metastatic tumors and tyrosine kinase inhibitors(TKI) therapy before RFA were prognostic factors for HPFS. Multivariate analysis showed that pre-RFA TKI therapy was associated with a better HPFS(p = 0.030). The mean overall survival (OS) period was 100.5 ± 14.1 (range, 3.8-159.5) months and the 1-, 3-, and 5-year survival rates were 96.9%, 77.1%, and 58.7%, respectively. Both univariate and multivariate analysis indicated that extrahepatic metastasis before RFA (p = 0.044) was a significant prognostic factor for OS.

CONCLUSIONS

Liver metastases from GIST exhibit relatively mild biological behavior. RFA is safe and effective, particularly in patients without pre-RFA extrahepatic metastases. Patients received targeted therapy before RFA can obtain an extended HPFS.

Application and evaluation of hydrodissection in microwave ablation of liver tumours in difficult locations

Objective

To investigate the safety and mid-term outcomes of hydrodissection-assisted microwave ablation (MWA) of hepatocellular carcinoma (HCC) in various difficult locations.

Methods

A total of 131 HCC patients who underwent ultrasound-guided MWA from March 2017 to March 2019 were included. Following ultrasound examination, patients with tumors at difficult locations were treated with hydrodissection-assisted MWA (hydrodissection group), while those with tumors at conventional locations received MWA (control group). Both groups were compared concerning baseline characteristics, ablation parameters, complete ablation rates, and complication rates. Kaplan-Meier curves analyzed local tumor progression and overall survival, with stratified analysis for different difficult locations (adjacent to gastrointestinal tract, diaphragm, and subcapsular tumors). Additionally, Cox regression analyses were conducted to assess the impact of different difficult locations on these outcomes.

Results

Complete ablation rates were similar between the hydrodissection and control groups (91.4% vs. 95.2%, P>0.05). Postoperative complications occurred in three patients, including liver abscess and biliary injury. No significant differences in major or minor complication rates were found between the groups (P>0.05). Local tumor progression was detected in 11 patients (8.4%) at the end of the follow-up period. Neither cumulative local tumor progression rate (P=0.757) nor overall survival rate (P=0.468) differed significantly between the groups. Stratified analysis showed no effect of tumor location difficulty on cumulative local tumor progression or overall survival. Tumor number and size served as independent predictors for overall survival, while minimal ablation margin ≤ 5mm independently predicted local tumor progression. In contrast, the tumor location was not statistically significant. Sensitivity analyses corroborated the robustness of the models.

Conclusion

Hydrodissection-assisted MWA for HCC in various difficult locations demonstrated safe and effective, with complete ablation and mid-term outcomes comparable to those for tumors in conventional locations.

Comparable and Complimentary Modalities for Treatment of Small-Sized HCC: Surgical Resection, Radiofrequency Ablation, and Microwave Ablation

BACKGROUND

Over the past decade, there has been continual improvement in both ablative and surgical technologies for the treatment of hepatocellular carcinoma (HCC). The efficacy of ablative therapy compared to surgical resection for HCC has not been thoroughly evaluated using multiple large-scale randomized controlled trials. By international consensus, if a patient is eligible, surgery is the primary curative treatment option, as it is believed to confer superior oncologic control.

OBJECTIVE

to determine the efficacies of percutaneous ablative therapies and surgical resection (SR) in the treatment of HCC. Data sources, study appraisal, and synthesis methods: A meta-analysis using 5 online databases dating back to 1989 with more than 31,000 patients analyzing patient and tumor characteristics, median follow-up, overall survival, and complication rate was performed.

RESULTS

Ablative therapies are suitable alternatives to surgical resection in terms of survival and complication rates for comparable patient populations. For the entire length of the study from 1989-2019, radiofrequency ablation (RFA) produced the highest 5-year survival rates (59.6%), followed by microwave ablation (MWA) (50.7%) and surgical resection (SR) (49.9%). In the most recent era from 2006 to 2019, surgical resection has produced the highest 5-year survival rate of 72.8%, followed by RFA at 61.7% and MWA at 50.6%. Conclusions and key findings: Depending on the disease state and comorbidities of the patient, one modality may offer superior overall survival rates over the other available techniques. Interventional ablative methods and surgical resection should be used in conjunction for the successful treatment of small-sized HCC.

Case report: Acute pericarditis following hepatic microwave ablation for liver metastasis

Hepatic microwave ablation (MWA) is a growing treatment modality in the field of primary and secondary liver cancer. One potential side effect is thermal damage to adjacent structures, including the pericardium if the hepatic lesion is located near the diaphragm. Hemorrhagic cardiac tamponade is known to be a rare but potentially life-threatening complication. Here we present the first case of cardiac complication following MWA treatment in a 55-year-old man who presented with late cardiac tamponade. Adequate and timely management is essential, and clinicians should be fully aware of the need to perform early transthoracic echocardiography to detect signs of pericardial effusion when cardiac involvement is suspected.

Single-center analysis of percutaneous ablation in the treatment of hepatocellular carcinoma: long-term outcomes of a 7-year experience

PURPOSE

The objective of this study is to examine the safety and efficacy of ablative therapy for hepatocellular carcinoma (HCC).

METHODS

A retrospective review of 419 consecutive patients diagnosed with HCC, treated with percutaneous ablation at a tertiary academic medical center from June 2015 to June 2022, was conducted. Data evaluated included demographics, disease and tumor burden scores, and functional status. Procedural outcomes included procedural course, complication rates, biochemical and radiologic response, survival, and functional status.

RESULTS

A total of 419 patients, including 313 males (74.7%) and 106 females (25.3%) with a mean age of 63.8 ± 6.64 years, made up the study cohort. 120 patients (28.6%) presented with solitary lesions and 299 patients (71.4%) had multifocal involvement, with a mean tumor size of 2.3 ± 0.92 cm. A majority of the interventions performed were microwave ablations (n = 413, 98.3%), with 6 radiofrequency ablations (1.4%). Treatment response was radiographically assessed up to 6 months post-ablation and graded as complete response (96.2%), partial response (2.6%), stable disease (0%), and progressive disease (1.2%). 97 (23.2%) of the treated patients went on to receive liver transplant. The average progression-free survival in the study population was 24 months with a survival of 85.9% (n = 360), 67.8% (n = 284), and 63.2% (n = 265) at 1 year, 3 years, and 5 years respectively. Functional outcomes, as defined by ECOG scores, were maintained or improved in 383 patients (91.4%) and 349 patients (83.3%) at 6 months and 12 months respectively.

CONCLUSIONS

This large institutional experience demonstrated safety and efficacy of ablation therapies for treatment of HCC with promising tumor response rates and enduring clinical outcomes including prolonged survival and preserved functional status.

Salvage locoregional therapies for recurrent hepatocellular carcinoma

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

Learning curve of microwave ablation for liver cancers

PURPOSE

To evaluate MWA efficacy and safety by cumulative MWA volume and interventional experience.

METHOD

3113 primary liver cancers treated by 7 operators between 2006 and 2018 were studied. Conditional logistic regression was used to estimate within-operators effects of increasing cumulative MWA volume per year on major complication, technical efficacy (TE) and local tumor progression (LTP) rates were adjusted for treatment-level characteristics. Changes were also evaluated by subgroups of tumor size and location.

RESULTS

Lower severe complication rate was detected only in higher MWA volume (HR: 0.31, P = 0.02)). TE rates increased with the increase of MWA volume ((100-150 procedures (HR: 0.33, P = 0.00); 150-200 procedures (HR: 0.08, P = 0.00)) per year. Similar results were found in subgroup analysis of interventional experience (5 to < 10 years (HR: 0.10, P = 0.00). MWA volume per year larger than 150 cases could reduce the major complication rate for tumors smaller than 5 cm (HR: 0.21, P = 0.03) and tumors in higher risk location (HR: 0.18, P = 0.03). The increase of MWA volume per year could significantly increase the TE rate in all tumor size, expect for tumors in high-risk location (100-150 procedures (HR:1.12, P = 0.84), 150-200 procedures (HR: 0.14, P = 0.08)).

CONCLUSIONS

Early and intensive performance of MWA procedures would reduce major complication rates regardless of tumor size and tumor location, but could not improve TE rate in high-risk locations.

Impact of ultrasonographic blind spots for early-stage hepatocellular carcinoma during surveillance

Background

Abdominal ultrasonography (US) is the backbone of hepatocellular carcinoma (HCC) surveillance. Although previous studies have evaluated clinical factors related to surveillance failure, none have focused specifically on US blind spots.

Methods

This study included 1,289 patients who underwent 6 months intervals surveillance using US and serum alpha-fetoprotein (AFP) and were eventually diagnosed with single-nodular HCC. Patients were divided into US-detected group (n = 1,062) and US-missed group (HCC detected only by AFP ≥ 20ng/mL; n = 227). Blind spots consisted of four locations: hepatic dome, caudate lobe or around the inferior vena cava, <1 cm beneath the ribs, and the surface of the left lateral segment. Both groups were compared by HCC location, proportional distribution, treatment method, and overall survival.

Results

A higher proportion of HCCs were located within blind spots in the US-missed group than in the US-detected group (64.3% vs. 44.6%, P < 0.001). HCC ≥ 2 cm detected in blind spots was higher than in non-blind areas (60.3% vs. 47.1%, P = 0.001). Blind spot HCCs were more treated with surgery, whereas those located in a non-blind area were more treated with local ablation. Patients with an HCC located within a blind spot in the US-detected group had better overall survival than the same in the US-missed group (P = 0.008).

Conclusions

Using the current surveillance test, blind spots affected the initially detected HCC tumor size, applicability of the treatment modality, and overall survival. Physicians should pay attention to US blind spots when performing US-based HCC surveillance.

Segmental Distribution of Hepatocellular Carcinoma in Cirrhotic Livers

Background: To evaluate the segmental distribution of hepatocellular carcinoma (HCC) according to Couinaud’s anatomical division in cirrhotic patients. Methods: Between 2020 and 2021, a total of 322 HCC nodules were diagnosed in 217 cirrhotic patients who underwent computed tomography (CT) or magnetic resonance imaging (MRI) for the evaluation of suspicious nodules (>1 cm) detected during ultrasound surveillance. For each patient, the segmental position of the HCC nodule was recorded according to Couinaud’s description. The clinical data and nodule characteristics were collected. Results: A total of 234 (72.7%) HCC nodules were situated in the right lobe whereas 79 (24.5%) were detected in the left lobe (p < 0.0001) and only 9 nodules were in the caudate lobe (2.8%). HCC was most common in segment 8 (n = 88, 27.4%) and least common in segment 1 (n = 9, 2.8%). No significant differences were found in the frequencies of segmental or lobar involvement considering patient demographic and clinical characteristics, nodule dimension, or disease appearance. Conclusions: The intrahepatic distribution of HCC differs among Couinaud’s segments, with segment 8 being the most common location and segment 1 being the least common. The segmental distribution of tumour location was similar to the normal liver volume distribution, supporting a possible correlation between HCC location and the volume of hepatic segments and/or the volumetric distribution of the portal blood flow.

Percutaneous Thermal Ablation Therapy of Hepatocellular Carcinoma (HCC): Microwave Ablation (MWA) versus Laser-Induced Thermotherapy (LITT)

The purpose of this study is to compare the efficacy and safety of microwave ablation (MWA) versus laser-induced thermotherapy (LITT) as a local treatment for hepatocellular carcinoma (HCC,) with regard to therapy response, survival rates, and complication rates as measurable outcomes. This retrospective study included 250 patients (52 females and 198 males; mean age: 66 ± 10 years) with 435 tumors that were treated by MWA and 53 patients (12 females and 41 males; mean age: 67.5 ± 8 years) with 75 tumors that were treated by LITT. Tumor response was evaluated using CEMRI (contrast-enhanced magnetic resonance imaging). Overall, 445 MWA sessions and 76 LITT sessions were performed. The rate of local tumor progression (LTP) and the rate of intrahepatic distant recurrence (IDR) were 6% (15/250) and 46% (115/250) in the MWA-group and 3.8% (2/53) and 64.2% (34/53) in the LITT-group, respectively. The 1-, 3-, and 5-year overall survival (OS) rates calculated from the date of diagnosis were 94.3%, 65.4%, and 49.1% in the MWA-group and 96.2%, 54.7%, and 30.2% in the LITT-group, respectively (p-value: 0.002). The 1-, 2-, and 3-year disease-free survival (DFS) rates were 45.9%, 30.6%, and 24.8% in the MWA-group and 54.7%, 30.2%, and 17% in the LITT-group, respectively (p-value: 0.719). Initial complete ablation rate was 97.7% (425/435) in the MWA-group and 98.7% (74/75) in the LITT-group (p-value > 0.99). The overall complication rate was 2.9% (13/445) in the MWA-group and 7.9% (6/76) in the LITT-group (p-value: 0.045). Based on the results, MWA and LITT thermal ablation techniques are well-tolerated, effective, and safe for the local treatment of HCC. However, MWA is recommended over LITT for the treatment of HCC, since the patients in the MWA-group had higher survival rates.

Radiofrequency ablation combined with transarterial chemoembolization in treatment of hepatocellular carcinoma adjacent to the second hepatic hilus

Purpose

To explore the efficacy and safety of using radiofrequency ablation (RFA) combined with transarterial chemoembolization (TACE) for treating hepatocellular carcinoma (HCC) adjacent to the second hepatic hilus.

Methods

Between February 2011 and June 2013, 17 patients with HCC underwent combination therapy of TACE and RFA under DSA and CT guidance at our institution. The 17 patients had a total of 23 hepatic tumors, 17 of which were adjacent to the second hepatic hilus.

Results

TACE combined with RFA was performed successfully in all 17 patients with no mortalities or major morbidities. During the 1-month follow-up, tumors of 15 patients (88.2%) were completely ablated after one therapy session and 2 patients had detectable tumor residue. During the follow-up time period (range 6–52 months), local tumor progression developed in 1 patient (1/17, 5.9%) and both local tumor progression and new tumors appeared in 1 patient (1/17, 5.9%). Also, new tumors developed in the untreated portions of the liver in 8 patients (8/17, 47.1%). No distant metastasis was found. Of the 17 patients, 6 (35.3%) died due to tumor progression (3/17, 17.6%), liver failure (2/17, 11.8%), or massive hemorrhage of the gastrointestinal tract (1/17, 5.9%). The overall survival rates were 94.1% (16/17), 82.4% (14/17), and 61.8% (11/17) at 12, 18, and 24 months, respectively, and the median survival time was 25 months (95% CI 18–27).

Conclusion

Treatment using combination of TACE and RFA is an effective and safe therapeutic strategy for treating HCC with tumor(s) adjacent to the second hepatic hilus.

The value of intra-operative ultrasonography on safety margin and outcome during liver resection and radio-frequency ablation in the management of hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) is an important health issue worldwide. Liver resection is the optimal management for early compensated HCC patients, but the majority of HCC patients are not candidates for resection. Several nonsurgical treatment modalities such as radio-frequency ablation (RFA), microwave ablation (MWA), trans-arterial chemoembolization, and immune therapy have been established. Intra-operative ultrasound (IOUS) is essential for accurate staging and secures both resection and RFA. We aimed to detect the value of using IOUS on safety margin and outcome during liver resection and RFA in the management of HCC patients. In the current study, 76 HCC patients, 58 males and 18 females, were included. Patients' age ranged from 49 to 69 years. Patients were divided into two groups: 52 open surgery liver resections (open resection group) and 24 laparoscopic-assisted RFA guided with laparoscopic IOUS (LARFA group). The open resection group was further subdivided into 32 cases for whom IOUS was performed and 20 patients studied retrospectively without IOUS. Surgical decisions were based on preoperative ultrasonography, computed tomography, and/or magnetic resonance imaging (MRI). We determined the size, number of lesions, and location by IOUS and compared them with preoperative imaging. Histopathology was done for resected lesions and follow-up CT for all patients.

Results

In the open resection group, the 32 cases of 52 for whom IOUS was performed, all had free surgical margin (100%) while 18 of 20 patients studied retrospectively without IOUS had free surgical margin (90%). Patients operated guided by IOUS had less morbidity and mortality with less operative time and hospital stay. In the LARFA group (24 patients with 37 lesions), the one-month follow-up showed complete ablation for all lesions in the 24 patients, while 12-month follow-up proved two cases of recurrence.

Conclusions

IOUS is a cornerstone in liver surgery. It improves outcomes with less morbidity and mortality and helps to achieve free surgical margin. Using IOUS allows the performance of radical but conservative hepatic resection.

Hepatocellular carcinoma locoregional therapies: Outcomes and future horizons

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver and has an overall five-year survival rate of less than twenty percent. For patients with unresectable disease, evolving liver-directed locoregional therapies provide efficacious treatment across the spectrum of disease stages and via a variety of catheter-directed and percutaneous techniques. Goals of locoregional therapies in HCC may include curative intent in early-stage disease, bridging or downstaging to surgical resection or transplantation for early or intermediate-stage disease, and local disease control and palliation in advanced-stage disease. This review explores the outcomes of chemoembolization, bland embolization, radioembolization, and percutaneous ablative therapies. Attention is also given to prognostic factors related to each of the respective techniques, as well as future directions of locoregional therapies for HCC.

Comparative Analysis of Radiofrequency Ablation and Microwave Ablation for Critically Located Hepatocellular Carcinomas Smaller than 5 cm

Purpose To compare the safety and efficacy of radiofrequency ablation (RFA) versus microwave ablation (MWA) for hepatocellular carcinomas (HCC) smaller than 5 cm in critical locations.

Methods Single-center retrospective study of all patients who underwent RFA/MWA for HCC from July 2015 to Dec 2019. Critical location includes exophytic tumors, tumors ≤ 5 mm from the diaphragm, heart, gallbladder, kidney, gastrointestinal tract, and ≤ 10 mm from large vessels with caliber of ≥ 3 mm. Treatment effectiveness, local tumor progression, and complication rates were evaluated.

Results Out of 119 patients with 147 HCC nodules in critical location, 65 (M:F = 49:16; mean age–61.7) were included in RFA group and 54 (M:F =43:11; mean age–60.5) in MWA group. Mean follow-up period was 16.5 and 14.8 months, respectively. At first follow-up imaging, 66/78 tumors in RFA group and 57/69 tumors in MWA group showed complete ablation with primary treatment effectiveness rates of 84.6% and 82.6%, respectively (p = 0.741). Local tumor progression (LTP) rate was 21.8% (17/78) and 20.3% (14/69), respectively (p = 0.826). Median time to LTP was 12 and 13.5 months, respectively. Fourteen tumors in RFA group and 12 in MWA group underwent reablation with a secondary treatment effectiveness rates of 78.6% (14/17) and 83.3% (12/14), respectively (p = 0.757). Mean LTP-free survival was 37.2 and 28.1 months, respectively. The total complication rate was 36.9% and 31.5%, respectively (p = 0.535) with no major complications in both the groups.

Conclusion Our data suggest that both MWA and RFA are equally safe and effective for treating HCCs < 5 cm in critical locations.

Reducing Pain by Artificial Ascites Infusion During Radiofrequency Ablation for Subcapsular Hepatocellular Carcinoma

PURPOSE

To evaluate therapeutic effects of artificial ascites (AA) infusion in patients with subcapsular hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) and to determine whether this infusion can reduce pain.

METHODS AND MATERIALS

From 2011 to 2016, 123 patients with treatment-naïve single subcapsular HCC (≤ 2.5 cm) who underwent RFA were retrospectively included. Patients were divided into two groups according to AA infusion. After RFA, medical records were used to analyze pain scores during a 24-h period and to determine the opioid used that compared using Mann-Whitney U test. We also conducted subgroup analysis of the patients with HCCs located adjacent to parietal peritoneum. After follow-up period, we analyzed local tumor progression (LTP) and recurrence-free survival using Kaplan-Meier method.

RESULTS

AA was infused in 76 patients (61.8%, 76/123). Pain score using numeric rating scale (NRS) was significantly lower in AA infusion group than in control group (2.54 ± 2.8 vs. 3.66 ± 3.2, p = 0.048). Dose of opioids used was not significantly different between two groups (1.62 ± 3.4 mg vs. 1.66 ± 3 mg, p = 0.698). However, in subgroup analysis (N = 45), NRS score and dose of opioids used were significantly lower in AA infusion group (p = 0.03, p = 0.032, respectively). LTP rate was not significantly different between two groups (p = 0.673).

CONCLUSION

AA infusion was an effective and safe way to reduce pain when performing RFA for subcapsular HCC. In particular, in patients with subcapsular HCC adjacent to parietal peritoneum, dose of opioid to use pain control was significantly lower with AA infusion.

Radiofrequency ablation and stereotactic body radiotherapy for hepatocellular carcinoma: should they clash or reconcile?

Until a few decades ago, surgical resection was the only valid option for treating hepatocellular carcinoma (HCC). However, various locoregional modalities including arterial-directed therapy, radiofrequency ablation (RFA), and radiotherapy have been recently shown to be effective. RFA is now established as a standard treatment for small localized HCCs, showing oncological results comparable to those of surgical resection in randomized studies. Stereotactic body radiotherapy (SBRT) is a modern radiotherapeutic modality that targets tumors with precision and delivers high radiation doses over a short period of time; it has particularly attracted clinical interest after its therapeutic efficacy was found to be similar to that of surgery in early-stage lung cancer. Given its potent disease control capability, SBRT has also been applied to early HCCs and demonstrated promising results in recent studies. It has also been noted for its suitability to treat tumors located in anatomical locations where RFA would be challenging. However, since its effectiveness has not been compared to that of RFA in randomized studies of patients eligible for RFA, the use of SBRT has been debated. This review was conducted to guide physicians from all fields involved in the treatment of early HCC. The therapeutic characteristics and indications of both SBRT and RFA are described, and recent comparative studies between the two modalities are discussed. In addition, we examined the factors that should be considered when selecting the appropriate treatments, and offer our recommendations.

Irreversible electroporation in patients with liver tumours: treated-area patterns with contrast-enhanced ultrasound

BACKGROUND

Familiarity with post-IRE imaging interpretation is of considerable importance in determining ablation success and detecting recurrence. CEUS can be used to assess the tumour response and characteristics of the ablation zone. It is of clinical interest to describe the ultrasonographic findings of liver tumours after irreversible electroporation (IRE) percutaneous ablation.

METHODS

A prospective study of 24 cases of malignant liver tumours (22 cases of primary liver tumours and 2 cases of liver metastases) treated by IRE ablation was conducted. Two inspectors evaluated the ablation zone in a consensus reading performed immediately, 1 day, and 1 month after IRE ablation. The gold standard method, magnetic resonance imaging (MRI), was used to evaluate the effectiveness of the treatment at 1 month.

RESULTS

Immediately after IRE ablation and up to 1 month later, the ablation zones gradually changed from hypo-echogenicity to hyper-echogenicity on conventional ultrasound and showed non-enhancement on contrast-enhanced ultrasound (CEUS). One month after IRE ablation, CEUS and MRI results were highly consistent (κ = 0.78, p < 0.05).

CONCLUSIONS

We conclude that CEUS may be an effective tool for assessing post-IRE ablation changes after 1 month. CEUS enables the depiction of tumour vascularity in real time and serves as an easy, repeatable method.

The effect of tumor location on long-term results of microwave ablation for early-stage hepatocellular carcinoma

BACKGROUND

To analyze the influence of tumor location, including tumor adjacency and located segments on long-term survival outcomes for patients with solitary hepatocellular carcinoma (HCC) after microwave ablation (MWA).

METHODS

This retrospective study evaluated 850 patients. The hepatic segments where the tumor is located, tumor adjacency (important tissues adjacent to tumor) and other clinical characteristics were collected. Overall survival (OS), local tumor progression (LTP) and disease-free survival (DFS) were compared and analyzed. Influence of tumor location was evaluated by multi-models and the effect of adjacency for OS, LTP, and DFS in different segments was analyzed by stratification analysis.

RESULTS

The OS, LTP, and DFS rates were similar in different hepatic segments, so were in high risk and safe locations. In multi-models, HCC in segment 8 showed lower death rate of 43% than that in segment 2 (HR 0.57; P = 0.01) and tumors in segment 6 seemed to have lower LTP rate. Tumors in high-risk locations were risk factors for OS, LTP, and DFS compared with tumors in safe locations, but all differences were not significant in different models. The effects of tumor adjacency on survival outcomes among subgroups of segments were limited.

CONCLUSION

The tumor adjacency was not a prognostic factor of survival outcomes for patients with solitary tumors after MWA, but tumors in segment 8 seemed to better OS rate than tumors in other segments.

The Learning Curve for Thermal Ablation of Liver Cancers: 4,363-Session Experience for a Single Central in 18 Years

This study aimed to explore the special efforts required to achieve proficiency in performing thermal ablation of liver cancers, including tumors in difficult locations, and clarify the effects of handing-down teaching on the corresponding process. Major complications of patients receiving percutaneous thermal ablation of liver cancer were analyzed. Polynomial fitting was used to describe the connection between major complication rates and special experience. Learning curve of major complications was plotted both for the whole group and for each operator, respectively. Tumors in difficult locations were further studied. A total of 4,363 thermal ablation sessions were included in this study. 143 of 4,363 patients had major complications, corresponding to an incidence rate of 3.27%. 806 thermal ablation sessions were performed for tumors in difficult locations. The major complication rate of these sessions is 6.33%. According to the trend of the learning curve of the 4363 patients, the experience of the whole group can be classified into five stages, that is, the high-risk, relatively stable, unstable, proficient and stable periods. A learning curve for an individual operator can be classified into the high-risk, proficient and stable periods. The major complication rates for the chronologically first, second and third operator of the group are 3.23, 3.35, and 3.31%, respectively. The special experience needed to bypass the first stage corresponds to 410, 510, and 440 sessions, the second stage, 1850, 850, and 870 sessions, by the three operators, respectively. The major complication rates for the tumors in difficult locations for the first, second and third operator were 7.04, 5.53, and 5.98%, respectively. For the tumors in difficult locations, the special experience needed to bypass the first stage corresponds to 150, 130, and 140 sessions, the second stage, 290, 175, and 185 sessions, by the three operators, respectively. In conclusion, the learning process of an operator percutaneous thermal ablation for liver cancer can be classified into three stages. The major complication rate for tumors in difficult locations were higher than that for all tumors. Handing-down teaching can make an operator arrive at the third stage earlier but not the second stage.

Ten-Year Outcomes of Percutaneous Radiofrequency Ablation for Colorectal Cancer Liver Metastases in Perivascular vs. Non-Perivascular Locations: A Propensity-Score Matched Study

Purpose

To compare long-term outcomes of percutaneous radiofrequency ablation for colorectal liver metastases in perivascular versus non-perivascular locations.

Methods

This retrospective study included 388 consecutive patients with colorectal liver metastases (246 men, 142 women; age range 27–86 years) who underwent percutaneous radiofrequency ablation between January 2006 and December 2018. Propensity-score matching was performed for groups with perivascular and non-perivascular colorectal liver metastases. Rates of accumulative local tumor progression, overall survival, intra/extrahepatic recurrence, and complications were compared between the two groups.

Results

We successfully matched 104 patients each in the perivascular and non-perivascular groups (mean age: 60.1 ± 11.5 and 60.1 ± 11.3 years, respectively). Cumulative local tumor progression rates at 6 months, 1 years, 3 years, and 5 years, respectively, were 8.8%,14.8%, 18.9%, and 18.9% in the perivascular group and 8.8%, 13.1%, 15.5%, and 15.5% in the non-perivascular group. The 1-, 3-, 5-, and 10-year overall survival rates, respectively, were 91.3%, 45.6%, 23.9%, and 18.7% in the perivascular group and 88.0%, 47.2%, 27.2%, and 22.6% in the non-perivascular group. No significant between-group differences were detected in cumulative local tumor progression (p=0.567, hazard ratio: 1.224) or overall survival (p = 0.801, hazard ratio: 1.047). The major complication rate was 1.0% (1/104, p > 0.999) in both groups. Tumor size was the only independent prognostic factor for local tumor progression (hazard ratio: 2.314; p = 0.002). On multivariate analysis for overall colorectal liver metastases, tumor diameter >3 cm, tumor location in the right colon, multiple tumors, and extrahepatic metastases before radiofrequency ablation (hazard ratios: 2.046, 1.920, 1.706, and 1.892, respectively; all p < 0.001) and intrahepatic recurrence (hazard ratio: 1.564; p = 0.002) were associated with poor overall survival.

Conclusion

Cumulative local tumor progression, overall survival, and major complications rates did not differ significantly between perivascular and non-perivascular colorectal liver metastases after percutaneous radiofrequency ablation. For perivascular colorectal liver metastases, percutaneous radiofrequency ablation is a safe and effective treatment option.

Directional ablation in radiofrequency ablation using a multi-tine electrode functioning in multipolar mode: An in-silico study using a finite set of states

PURPOSE

To analyse the feasibility of directional ablation using a multi-tine electrode.

METHODS

A multi-tine electrode capable of operating in multipolar mode has been used to study the directional ablation. In addition to the basic design, similar to commercially available FDA approved multi-tine electrode, tines have been insulated from each other inside the probe base and tip using a thin insulating material of thickness 0.25 mm. A cylindrical single-compartment model of size 6 cm × 6 cm has been used to model normal liver tissue. The temperature-controlled radiofrequency ablation has been employed to maintain the tine-tips at different temperatures. Electro-thermal simulations have been performed by using a commercial multi-physics software package based on finite element methods. To make this study feasible a new approach to predict the ablations have been proposed and used in this study.

RESULTS

Asymmetric ablation zone with up to 5 mm difference in ablation boundary between the intended and non-intended direction has been observed along the transverse direction. Reduction in ablation up to 5 mm along the axial direction in comparison to the monopolar mode has also been observed.

CONCLUSION

Multi-tine electrode modified to operate in multipolar mode can create directional ablations of different shapes and can be used to target position and shape specific tumours.

Locoregional Therapy Approaches for Hepatocellular Carcinoma: Recent Advances and Management Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and third leading cause of cancer-related mortality worldwide. While surgical resection and transplantation are the standard first-line treatments for early-stage HCC, most patients do not fulfill criteria for surgery. Fortunately, catheter-directed and percutaneous locoregional approaches have evolved as major treatment modalities for unresectable HCC. Improved outcomes have been achieved with novel techniques which can be employed for diverse applications ranging from curative-intent for small localized tumors, to downstaging or bridging to resection and transplantation for early and intermediate disease, and locoregional control and palliation for advanced disease. This review explores recent advances in liver-directed techniques for HCC including bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies, with a focus on patient selection, procedural technique, periprocedural management, and outcomes.

Percutaneous Radiofrequency Ablation for Liver Tumors: Technical Tips

Percutaneous radiofrequency ablation (RFA) has been accepted as a minimally invasive therapeutic treatment for liver malignancies. Although RFA is usually applied for the treatment of small liver tumors (<3 cm), several technical developments have expanded the use of RFA. RFA is now used for the treatment of large liver tumors, and the number of complications associated with this treatment has decreased. These refinements may ultimately lead to better long-term prognosis. Here, we review recent refinements of liver RFA and provide technical tips.

Percutaneous thermal ablation of subcapsular hepatocellular carcinomas: influence of tumor-surface contact and protrusion on therapeutic efficacy and safety

PURPOSE

To evaluate therapeutic efficacy and complication of percutaneous thermal ablation of subcapsular hepatocellular carcinomas (HCCs), and how these may be influenced by the degree of tumor to liver surface contact and tumor protrusion from liver surface.

MATERIALS AND METHODS

Our retrospective study was approved by the Institutional Review Board. Between January 2006 and December 2013, 290 patients (82 women, 208 men; mean age, 64.5 years; range, 33-89 years) with 474 subcapsular (within 1 cm to the liver surface) HCCs (mean size, 23.7 mm; range, 6-71 mm) underwent percutaneous thermal ablation. The HCCs were divided into surface contact group (n = 243) and non-surface contact group (n = 231). The former was further subdivided into exophytic and non-exophytic HCCs. Technical success, primary technique efficacy, local tumor progression (LTP), and secondary technique efficacy rates were analyzed and compared by the chi-square test or Fisher exact test. Prognostic factors for LTP and secondary technique efficacy were assessed using the Cox regression model. Major complications were also assessed.

RESULTS

With median follow-up of 15 months (range, 1-87 months), technical success and primary technique efficacy were 98.7% and 95.7% % in the non-surface contact group; 96.4% and 94.0% in the non-exophytic group; and 100% and 94.7% in the exophytic group (p > 0.05). Tumor size > 3 cm was a significant predictor for LTP, but not for secondary efficacy. Overall major complication rate was 3.8% (24/624) and was not different among the three groups.

CONCLUSION

Subcapsular HCCs can be effectively treated with thermal ablation techniques. Degree of tumor-surface contact including moderate protrusion does not appear to limit feasibility or procedure effectiveness.

KEY POINTS

• Subcapsular HCCs can be effectively treated with thermal therapy when proper image-guided technique and assistive techniques are applied. • Degree of tumor surface contact including moderate protrusion does not appear to limit feasibility or procedure effectiveness. • Major complications after percutaneous thermal ablation of subcapsular HCCs such as tumor seeding can be minimized by avoiding breach of the tumor capsule exposed to the peritoneal surface and use of tract ablation.

Irreversible Electroporation for Unresectable Hepatocellular Carcinoma: Initial Experience

PURPOSE

To evaluate the efficacy and safety of irreversible electroporation (IRE) in the treatment of unresectable hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A retrospective study was conducted from September 2014 to June 2017. A total of 21 HCCs in 21 patients with cirrhosis were treated with IRE. There were eight subcapsular or exophytic, ten perivascular and three peribiliary tumors. The median tumor size was 26 mm (range 14-40 mm). The technical success of the procedure was recorded. Median follow-up, median time to local recurrence, median local tumor progression-free survival (PFS) and complications were recorded.

RESULTS

Technical success was achieved in all the patients. The median follow-up was 10 months (range 2-30 months). The median time to local recurrence and local tumor PFS were 4 months (range 3-4 months) and 7 months (range 3-30 months), respectively. The tumor-related factor that was significantly associated with local PFS was the size. Maximum tumor diameter < 25 mm was significantly associated with local tumor PFS (p = 0.045). Other parameters including tumor location, segmental portal vein thrombosis, baseline alpha-fetoprotein level and underlying etiology did not affect local tumor PFS. Complications were noted in nine patients and were classified as grades 1 and 2. No procedure-related mortality was encountered.

CONCLUSION

IRE is an effective treatment for ablation of small HCCs. Larger prospective studies with strict selection criteria will establish the safety and efficacy of IRE in the treatment of unresectable HCC in patients who cannot undergo thermal ablation.

Eye Opener to EtOH Ablation for Juxta-Cardiac Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is notoriously refractory to systemic chemotherapy, mandating an interventional approach. Mortality may be avoided by neutralizing rapidly growing tumors that approach the heart and major vessels. When the risk/benefit ratio of surgery is unacceptable, percutaneous ablation can achieve remarkable results. High volumes of flowing blood adjacent to the treatment area may impact the ability to reliably achieve an adequate ablation margin for modalities that rely on extreme temperatures to destroy malignant cells. Ethanol ablation is safe, efficacious, and unaffected by this "thermal sink" effect. This report describes a juxta-cardiac (JC) HCC in segment 4a measuring 35 × 26 mm, which exhibited rapid growth until it was abutting the pericardium and 7.5 mm from the chamber of the right ventricle (RV).

Methods

One 21-gauge needle was inserted using direct CT fluoroscopy into the center of the hepatic mass. In order to confirm the position of the needle, 0.5 mL of diluted Visipaque was injected. Then, under CT fluoroscopy guidance, a mixture of 1 mL of Ethiodol and 10 mL of 98% dehydrated alcohol was slowly injected into the mass.

Results

Repeat CT scan 1 month post-ablation demonstrated decreased arterial enhancement and dense Ethiodol throughout the tumor consistent with ablation. Tumor size decreased to 30 × 23 mm with a distance of 12.4 mm from the chamber of the RV.

Conclusion

Pericardial involvement or large vessels near the treatment area may limit the use of thermal ablation techniques for JC HCC. Percutaneous, intratumoral ethanol injection provides safe and effective alternative that is not subject to the "thermal sink" effect.

Assessment of Radiofrequency Ablation Efficacy for Hepatocellular Carcinoma by Histology and Pretransplant Radiology

Radiofrequency ablation (RFA) represents a potentially curative option for early-stage hepatocellular carcinoma (HCC). This study aims at evaluating the histologic response after RFA of small HCCs arising in cirrhosis. Data were reviewed from 78 patients with de novo HCCs who were treated with RFA and subsequently transplanted. The last radiological assessment before liver transplantation (LT) was used for comparison between modified Response Evaluation Criteria in Solid Tumors (mRECIST) and histological findings. A total of 125 de novo HCCs (median diameter, 20 mm) were treated with RFA only in 92 sessions. There were 98 nodules that did not show local recurrence during follow-up (78.4%), and the remaining were retreated, except 1 because of subsequent LT. On explanted livers, complete pathological response (CPR) was observed in 61.6%, being 76.9% when <2 cm, 55.0% when 2-3 cm, and 30.8% when >3 cm. Tumors near hepatic vessels had CPR in 50% of patients versus 69.3% for tumors distant from vessels (P = 0.039). Of the 125 HCCs, 114 had available radiological assessment within a median of 3 months before LT. Complete radiological response, according to mRECIST, was observed in 77.2% of nodules before LT. The Cohen κ was 0.48 (moderate agreement). The overall accuracy was 78.1%. A total of 18 complications were recorded with only 1 graded as major. In conclusion, RFA can provide high CPR for HCC, especially in smaller tumors distant from hepatic veins or portal branches. The agreement between mRECIST and histology is only moderate. Further refinements in radiological assessment are essential to accurately assess the true effectiveness of RFA.

Needle track seeding in hepatocellular carcinoma after local ablation by high-dose-rate brachytherapy: a retrospective study of 588 catheter placements

Purpose

Needle track seeding in the local treatment of hepatocellular carcinoma (HCC) is not yet evaluated for catheter-based high-dose-rate brachytherapy (HDR-BT), a novel local ablative technique.

Material and methods

We report a retrospective analysis of 100 patients treated on 233 HCC lesions by HDR-BT (using 588 catheters in total). No needle or catheter track irradiation was used. Minimum required follow-up with imaging was 6 months. In case of suspected needle track seeding (intra- and/or extrahepatic) in follow-up, image fusion of follow-up CT/MRI with 3D irradiation plan was used to verify the location of a new tumor deposit within the path of a brachytherapy catheter at the time of treatment.

Results

We identified 9 needle track metastases, corresponding to a catheter-based risk of 1.5% for any location of occurrence. A total of 7 metastases were located within the liver (catheter-based risk, 1.2%), and 2 metastases were located extrahepatic (catheter-based risk, 0.3%). Eight out of 9 needle track metastases were successfully treated by further HDR-BT.

Conclusions

The risk for needle track seeding after interstitial HDR-BT of HCC is comparable to previous reports of percutaneous biopsies and radiofrequency ablation (RFA), especially in case of extrahepatic needle track metastases. To compensate for the risk of seeding, a track irradiation technique similar to track ablation in RFA should be implemented in clinical routine.

Iodized Oil Transarterial Chemoembolization and Radiofrequency Ablation for Small Periportal Hepatocellular Carcinoma: Comparison with Nonperiportal Hepatocellular Carcinoma

PURPOSE

This study aims to evaluate the treatment outcomes of iodized oil transarterial chemoembolization (TACE) and subsequent radiofrequency ablation (RFA) for small (≤3 cm) periportal hepatocellular carcinoma (HCC) compared with nonperiportal HCC.

METHODS

Twenty-three patients [periportal group (PG); mean age, 59.8 years; 22 men, 1 woman] with periportal HCC (in contact with the portal vein >3 mm in diameter) and 279 patients [nonperiportal group (NPG); mean age, 59.1 years; 234 men, 45 women] with nonperiportal HCC were treated between March 2010 and January 2014. All cases were contraindicated for ultrasound-guided RFA or resection. Mean tumor size was 1.2 cm in each group. The baseline characteristics were not different between the groups, except for alpha-fetoprotein level (41.0 ng/dL in NPG vs. 8.8 ng/dL in PG, p = 0.001). Local tumor progression (LTP), disease-free survival (DFS), overall survival (OS), intrasegmental recurrence, and complications were analyzed using the Kaplan-Meier method and Fisher's exact test.

RESULTS

TACE and RFA were successfully performed in all patients. Mean follow-up period of PG and NPG was 33.8 and 42.8 months, respectively. LTP (p = 0.701), DFS (p = 0.718), and OS (p = 0.359) were not different between the two groups. Intrasegmental recurrence occurred in two patients (one in each group), and its incidence was not different (p = 0.212). Complications requiring further treatment occurred in 1/23 (4.3%) in PG and 5/279 (1.8%) in NPG. No procedure-related mortality occurred.

CONCLUSIONS

Iodized oil TACE and subsequent RFA are effective alternative treatments for small periportal HCC (≤3 cm) when percutaneous ultrasound- or CT-guided RFA or resection is not feasible.

Percutaneous Cholecystostomy and Hydrodissection in Radiofrequency Ablation of Liver Subcapsular Leiomyosarcoma Metastasis Adjacent to the Gallbladder: Protective Effect

Uterine leiomyosarcoma is an uncommon pathology, predominantly found in aged population. Patients with metastatic disease have poor survival and therapy mainly consists of palliative systemic chemotherapy. However, more aggressive strategies such as radiofrequency ablation (RFA) may benefit patients with limited secondary disease. RFA is considered a simple and safe modality for treatment of hepatic lesions. The benefits related to RFA include low morbidity, short hospital stay and the possibility to repeat the procedure when necessary due to recurrences. However, minor and major complications related to mechanical and thermal damage may occur, especially in cases of tumors adjacent to extrahepatic organs and those at subcapsular position. This case report shows a successful RFA of two hepatic subcapsular leiomyosarcoma metastases neighbouring the gallbladder, without a safe cleavage plane from it. Combined hydrodissection, percutaneous cholecystostomy and continuous irrigation were performed as effective techniques to prevent thermal injury. Clinical and radiological follow up demonstrates no local complication.

Microwave ablation for hepatocellular carcinoma associated with Budd-Chiari syndrome after transarterial chemoembolization: an analysis of ten cases

PURPOSE

To evaluate the feasibility, efficacy, and safety of microwave ablation (MWA) in the treatment of hepatocellular carcinoma associated with Budd-Chiari syndrome (BCS) after transarterial chemoembolization (TACE).

METHODS

A total of 10 patients (mean 50.0 ± 7.5 years) with 15 BCS-associated HCC lesions were retrospectively evaluated. All patients received MWA treatment for residual tumors after 1 to 3 sessions of TACE. The diagnosis of residual tumors was confirmed by at least two types of enhanced imaging. CEUS images were performed to confirm the residual lesions and guide the placement of antenna before MWA. Thermal monitoring and artificial pleural effusion or ascites were used to guarantee ablative accuracy and safety for patients with tumors adjacent to vital structures. Technical success, technique efficacy, local tumor progression, survival rate, and the incidence of complications were comprehensively analyzed.

RESULTS

Technical success and technique effectiveness were achieved in all patients. Thirteen lesions achieved complete ablation for the first time, and 2 lesions needed two sessions. Thermal monitoring was used in 2 patients, artificial pleural effusion was used in 1 patient, and artificial ascites in 2 patients. In a median follow-up of 34.5 months (range 21-52 months), no LTP was founded in all patients. Intrahepatic recurrence was found in 5 patients. 1-, 2-, 3-, and 4-year survival rates were 100%, 100%, 74.1%, and 37.0%, respectively. No major or minor complications were observed.

CONCLUSION

Microwave ablation is a feasible and effective way to treat residual tumors after TACE treatment in patients with BCS-associated HCC.

Radiofrequency ablation for HCC patients with multifocal tumours meeting the Milan criteria: A single-centre experience

BACKGROUND

Radiofrequency ablation (RFA) has been recommended as a curative treatment for patients with single early-stage unifocal hepatocellular carcinomas (HCCs) for years; however, the effect of this treatment on multifocal tumours has remained uncertain.

AIMS

We conducted a retrospective study to evaluate the overall survival (OS) and recurrence-free survival (RFS) rates of early HCC patients with multiple tumours subjected to different RFA modalities.

METHODS

One hundred fifty-four HCC patients with multifocal tumours who met the Milan criteria and underwent RFA were enrolled in this study. We divided the patients into 3 groups according to the surgical approach utilised (percutaneous, laparoscopic and open RFA; selection was based on the locations of the tumours for whether they were adhered to the subhepatic inferior vena cava or the gastrointestinal tract) and into 2 subgroups according to the tumour numbers and locations.

RESULTS

No deaths occurred in the 30-day post-operation period, and there were no significant differences in the complication, OS or RFS rates between the 3 groups. The 1-, 3- and 5-year OS rates were 88.9%, 75.5% and 50.9% in the subgroup with 2 tumours, respectively, versus 91.3%, 56.3% and 17.5% in the subgroup with 3 tumours, respectively (P=0.001). The corresponding values were 93.2%, 77.4% and 50.8% in the subgroup with tumours in the same segment and 82.4%, 54.8% and 23.0% in the subgroup with tumours in different segments (P=0.001).

CONCLUSION

RFA was proven to be an effective and safe method for the treatment of multifocal HCCs. Among the patients with 2 tumours within the same segment, RFA achieved better long-term outcomes in terms of both overall and recurrence-free survival.

Angled Cool-Tip Electrode for Radiofrequency Ablation of Small Superficial Subcapsular Tumors in the Liver: A Feasibility Study

Objective

To evaluate the feasibility of angled cool-tip electrode for radiofrequency ablation of small superficial subcapsular liver tumors abutting abdominal wall, in order to traverse normal liver parenchyma, and thereby, obtain favorable configuration of ablation margin.

Materials and Methods

In this study, we retrospectively analyzed 15 small superficial subcapsular liver tumors abutting abdominal wall in 15 patients, treated with radiofrequency ablation from March 2013 to June 2015 using a cool-tip electrode manually modified to create 25–35° angle at the junction between exposed and insulated segments. The tumors were hepatocellular carcinoma (n = 13) and metastases (n = 2: cholangiocellular carcinoma and rectosigmoid cancer), with maximum diameter of 10–26 mm (mean, 15.68 ± 5.29 mm). Under ultrasonographic guidance, the electrode tip was advanced to the depth of the tumors' epicenter about 1 cm from the margin. The tip was re-directed to penetrate the tumor for radiofrequency ablation. Minimal ablation margin was measured at immediate post-treatment CT. Radiological images and medical records were evaluated for success rate, length of minimal ablation margin and complications.

Results

Technical success rate of obtaining complete necrosis of the tumors was 100%, with no procedure-related complication. Minimal ablation margin ranged from 3–12 mm (mean, 7.07 ± 2.23 mm). CT/MRI follow-up at 21–1022 days (mean, 519.47 ± 304.51 days) revealed no local recurrence, but distant recurrence in 9 patients.

Conclusion

Using an angled cool-tip electrode for radiofrequency ablation of small superficial subcapsular tumors abutting abdominal wall may be a feasible technique for obtaining adequate ablation margin and lower complication rate.

Ten-year survival of hepatocellular carcinoma patients undergoing radiofrequency ablation as a first-line treatment

AIM: To investigate the long-term survival and prognostic factors in hepatocellular carcinoma (HCC) patients undergoing radiofrequency ablation (RFA) as a first-line treatment.

METHODS: From 2000 to 2013, 316 consecutive patients with 404 HCC (1.0-5.0 cm; mean: 3.2 ± 1.1 cm) underwent ultrasonography-guided percutaneous RFA as a first-line treatment. There were 250 males and 66 females with an average age of 60.1 ± 10.8 years (24-87 years). Patients were followed for 1 year to > 10 years after RFA (234, 181, 136, and 71 for 3, 5, 7, and 10 years, respectively). Overall local response rates and long-term survival rates were assessed. Survival results were generated using Kaplan-Meier estimates, and multivariate analysis was performed using the Cox regression model.

RESULTS: In total, 548 RFA sessions were performed and major complications occurred in 10 sessions (1.8%). Local tumor progression and/or new tumor development were observed in 43.3% (132/305) of the patients during the follow-up period. Overall 5- and 10-year survival rates were 49.7% and 28.4%, respectively. Based on multivariate analysis, three factors were identified as independent prognostic factors for overall survival: Child-Pugh classification (HR = 4.054, P < 0.001), portal vein hypertension (HR = 2.743, P = 0.002), and tumor number (HR = 2.693, P = 0.003). The local progression-free 5- and 10-year survival rates were 42.7% and 19.5%. In addition to the Child-Pugh classification and the number of tumors, the number of RFA sessions (HR = 1.550, P = 0.002) was associated with local progression-free survival.

CONCLUSION: RFA can achieve acceptable outcomes for HCC patients as a first-line treatment, especially for patients with Child-Pugh class A, patients with a single tumor and patients without portal vein hypertension.

Irreversible electroporation of hepatocellular carcinoma: preliminary report on the diagnostic accuracy of magnetic resonance, computer tomography, and contrast-enhanced ultrasound in evaluation of the ablated area

OBJECTIVE

Irreversible electroporation (IRE) is a new ablation modality. Our purpose was to describe the effectiveness and the safety of the treatment and to evaluate the magnetic resonance imaging (MRI), computed tomography (CT) and contrast-enhanced ultrasound (CEUS) diagnostic accuracy in HCC patients treated with IRE at 1-, 3-, and 6-month follow-up.

MATERIALS AND METHODS

In an 18-month period, we treated 24 HCC lesions in 20 patients unfit for surgery. MRI, CT and CEUS were performed before and one, 3 and 6 month after IRE. We employed the liver-specific contrast medium Primovist (gadolinium ethoxybenzyl dimeglumine) in MRI. After IRE the lesions were classified as responders or non-responders to the treatment according to the mRECIST and the complications were recorded. We evaluated the size, shape, signal intensity (T1-W, T2-W, and DWI) in MRI, dynamic contrast enhancement pattern for CEUS, CT and MRI and signal behavior during the liver-specific phase for MRI.

RESULTS

According to mRECIST, at 1 month MRI and CEUS showed a complete response (CR) in 91.7% of cases (22/24) tumors, while there was partial response (PR) in the remaining 2/24 (8.3%) treated nodules; in CT study all ablated zone appeared as necrotic (CR 100%). The residual viable tumor in MRI and in CEUS study had similar diameter (10 mm). No new HCC were identified from MRI, CT or CEUS. At 3 months MRI and CEUS showed the same results seen after 1 month from the treatment. Twenty-two necrotic lesions, and 2 residual tumors were found (CR = 91.7% and PD = 8.3%). In MRI study the two cases of residual tumor tissue had a diameter of 11 and 12 mm each. At CEUS the diameter of residual HCC was similar to the diameter at 1 month. CT showed 23 necrotic areas and one residual viable tissue in the treated zone, with a diameter of 10 mm (CR = 95.3% and PD = 4.7%). No new foci of HCC were identified from all imaging studies. At 6 months MRI, CEUS, and CT showed 22 necrotic lesions and 2 residual tumors in ablated zone (CR = 91.7% and PD = 8.3%). At MRI the diameters of the two residual viable HCCs were 12 and 14 mm, at CEUS the diameters were 11 and 12 mm, while at CT the diameters were 10 and 10 mm. No statistical difference was evaluated between CR, PR, PD percentage values for MRI, CT and CEUS (p value > 0.05 at Chi-square test). No major vascular complication was recorded after IRE. Six out of 20 patients (30%) showed a transient hepatic intensity difference (THID) area within the normal liver parenchyma adjacent to the treated lesions. Two of the 20 patients (10%) showed an absent concentration of liver-specific contrast medium around the ablation zone. Two patients developed complications, consisting in a peripheral arteriovenous shunt and a segmental dilation of the intrahepatic biliary ducts. We found no statistically significant difference in morphology, size (variation in the largest diameter), signal intensity in T1-weighted images, in T2-weighted images, in DWI and in the related map of the apparent diffusion coefficient (ADC), presence or absence of contrast enhanced during the arterial, portal, and late phase in MRI, CT, and CEUS, and signal characteristic during the liver-specific phase in MRI of the ablation zone at 1, 3, and 6 months.

CONCLUSION

IRE is a feasible, safe and efficient modality in the treatment of patients with non-resectable HCC. We had no major complication, even when the ablated lesion was adjacent to major branches of the portal vein. All images techniques showed similar accuracy during the follow-up at 1, 3, and 6 months in the assessment ablated zone.