Risk factors for local recurrence of small hepatocellular carcinoma tumors after a single session, single application of percutaneous radiofrequency ablation

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Percutaneous radiofrequency ablation of liver metastases from colorectal cancer: Development of a prognostic score to predict overall survival

PURPOSE

To develop a model for pretreatment prediction of overall survival (OS) after radiofrequency ablation (RFA) for colorectal liver metastasis (CRLM).

METHOD

This retrospective study included 491 patients (median age, 61 years; 348 men) who underwent percutaneous RFA for CRLM between 2000 and 2021. The Kaplan-Meier method was used to estimate OS rates. Independent factors affecting OS were investigated using multivariable Cox regression analysis. Risk scores were assigned to the risk factors and pretreatment prediction models were created using the risk factors.

RESULTS

After RFA, the 5-, 10-, and 20-year OS rates were 44 %, 31 %, and 24 %, respectively, and the median OS was 46 months. Multivariate Cox regression analysis showed that a largest tumor size ≥ 2 cm (P<0.001), positive nodal status of primary tumor (P<0.001), carcinoembryonic antigen level > 30 ng/mL (P=0.049), multiple tumors (P=0.008), and T4 stage of the primary tumor (P=0.029) were independently associated with OS. In patients with a single CRLM, tumor diameter (P<0.001), positive nodal status of primary tumor (P=0.001), disease-free interval <12 months (P=0.045), and subcapsular location (P=0.03) were risk factors affecting OS. According to our prediction models, which included the aforementioned risk factors, OS rates progressively decreased as the risk scores increased, with significantly different OS rates between contiguous groups (P<0.001).

CONCLUSIONS

Our prediction models can be used as a prognostic stratification tool in patients with CRLM, and can help select those candidates who will benefit most from RFA.

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.

Radiofrequency ablation of subcapsular versus nonsubcapsular hepatocellular carcinomas ≤ 3 cm: analysis of long-term outcomes from two large-volume liver centers

OBJECTIVES

To compare the safety and efficacy of RFA for single HCCs ≤ 3 cm in subcapsular versus nonsubcapsular locations using a propensity score matched analysis.

MATERIALS AND METHODS

This retrospective study included patients with solitary HCCs ≤ 3 cm in size who underwent percutaneous RFA from 2005 to 2015 as initial treatment at two large-volume liver centers. Patients were divided into two groups, consisting of those with subcapsular and nonsubcapsular tumor locations. Complications, local tumor progression (LTP), and overall survival (OS) were compared in these two groups before and after propensity score matching (PSM).

RESULTS

The study population consisted of 964 patients (712 men [74%]) of mean age 58.3 years. Of these 964 patients, 561 (58%) had nonsubcapsular and 403 (42%) had subcapsular HCCs. PSM generated 402 pairs of patients. Major complication rate was low, but significantly higher in the subcapscular group (p = 0.047). Rates of technical effectiveness in these two groups were 99% and 98%, respectively (p = 0.315). However, during follow-up, cumulative 1-, 3-, 5-, and 10-year LTP and OS rates did significantly differ in both entire and PSM cohorts, resulting in the latter 8%, 15%, 20%, and 26% in the nonsubcapsular group vs. 13%, 24%, 30%, and 31% in the subcapsular group (p = 0.015), and 99%, 91%, 80%, and 59% vs. 98%, 85%, 73%, and 50% in the two groups (p = 0.004), respectively.

CONCLUSION

Rates of major complications, LTP, and OS differed significantly following first-line RFA treatment of single HCCs ≤ 3 cm in favor of the nonsubcapsular locations.

CLINICAL RELEVANCE STATEMENT

This large-scale study provides evidence that radiofrequency ablation for small (≤ 3 cm) hepatocellular carcinomas is safer and more effective in nonsubcapsular location than in subcapsular location.

KEY POINTS

• There exist conflicting outcomes on the effectiveness of RFA for early HCC depending on tumor location. • Rate of local tumor progression was significantly higher in the subcapsular hepatocellular carcinomas. • Overall survival rate was significantly poorer in the subcapsular hepatocellular carcinomas.

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.

Simulating radiofrequency ablation of hepatocellular carcinomas proximal to bare area of liver

PURPOSE

To numerically assess the significance of dextrose 5% in water (D5W) thermo-protection during radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs) located near the 'bare area of liver'.

MATERIAL AND METHODS

This study utilises quasi-anatomical structures extracted from CT images. A multi-tine electrode, deployed inside the extracted organs and operated under temperature-controlled mode was used as the source of ablation. Geometrically, D5W was modelled around the 'bare area' and sandwiched between the liver and diaphragm. RFA at different sites relative to the 'bare area' was simulated to answer when to consider modelling D5W.

RESULTS

For targets near the edge of 'bare area' and at 0.5 mm gap (between the electrode and the 'bare area'), ignoring D5W and using ground conditions could result in underestimation of ablation volume by almost 25%. The importance of D5W becomes negligible for ablations near the centre of the 'bare area'.

CONCLUSIONS

Consideration of D5W during RFA of HCCs proximal to the 'bare area' can significantly influence the ablation outcome, especially when ablation is performed near the edge of the 'bare area'.

Comparison of Open versus Laparoscopic Approaches in Salvage Hepatectomy for Recurrent Hepatocellular Carcinoma after Radiofrequency Ablation

Background and Objectives: Although radiofrequency ablation (RFA) is widely used as an effective local treatment for hepatocellular carcinoma (HCC), evidence on salvage hepatectomy for local recurrence after RFA is limited. This study aims to compare open and laparoscopic approaches in salvage hepatectomy for recurrent HCC after RFA. Materials and Methods: Among patients who underwent hepatectomy between January 2004 and August 2022 at a single tertiary referral center, 55 patients who underwent salvage hepatectomy for marginal recurrence after RFA were selected. An open approach was used in 23 (41.8%) patients, while 32 (58.2%) patients underwent laparoscopic surgery. Short-term and long-term outcomes were compared between the two groups. Results: Major hepatectomy was more often performed in the open group (9 [39.1%] vs. 4 [12.5%], p = 0.022). Intraoperative blood loss was also greater in the open group (450 (325-750) vs. 300 (200-600), p = 0.034). Operation time (p = 0.144) and postoperative morbidity rates (p = 0.639) were similar, and there was no postoperative mortality in either group. Postoperative hospital stay was significantly longer in the open group compared to the laparoscopy group (8 (6-11) days vs. 5 (4-7) days, p = 0.028). The 1-, 3-, and 5-year disease-free survival rates showed no difference between the two groups (44.6% vs. 62.5%, 16.5% vs. 13.5%, and 8.3% vs. 13.5%, respectively; p = 0.154). The 1-, 3-, and 5-year overall survival rates between the two groups were also similar (85.7% vs. 96.8%, 79.6% vs. 86.0%, and 79.6% vs. 79.4%, respectively; p = 0.480). Conclusions: Laparoscopic salvage hepatectomy shows oncologic outcomes comparable to the open approach with faster postoperative recovery rates. Considering that recurrence rates are high after RFA, the laparoscopic approach should be considered as a first-line option in selected patients.

Risk of Treatment Failure and Death after Ablation in Hepatocellular Carcinoma Patients-A Multiparametric Prediction

BACKGROUND

Ablation is a first-line treatment for Barcelona Clinic Liver Cancer (BCLC)-0/A hepatocellular carcinoma (HCC). However, there are scarce data about patients' outcomes after recurrence. The present study evaluates the impact of patient and tumor characteristics at baseline and at recurrence on the Clinical Decision-Making process.

METHODS

We evaluated BCLC-0/A patients treated with percutaneous ablation from January 2010 to November 2018. Clinical and radiological data such as age, tumor location at ablation, pattern of recurrence/progression, and comorbidities during follow-up were registered. Tumor location was divided into 'suboptimal' vs. 'optimal' locations for ablation. The Clinical Decision-Making was based on tumor burden, liver dysfunction, or comorbidities. The statistical analysis included the time-to-recurrence/progression, censoring at time of death, date of last follow-up or liver transplantation, and time-to-event was estimated by the Kaplan-Meier method and Cox regression models to evaluate the risk of an event of death and change of treatment strategy.

RESULTS

A total of 225 patients [39.1% BCLC-0 and 60.9% BCLC-A] were included, 190 had unifocal HCC and 82.6% were ≤3 cm. The complete response rate and median overall survival were 96% and 60.7 months. The HCC nodules number (Hazard Ratio-HR 3.1), Child-Pugh (HR 2.4), and Albumin-Bilirubin score (HR 3.2) were associated with increased risk of death during follow-up. HCC in 'suboptimal location' presented a shorter time to recurrence. When comorbidities prevented further loco-regional or systemic treatment, the risk of death was significantly increased (HR 2.0, p = 0.0369) in comparison to those who received treatment.

CONCLUSIONS

These results expose the impact of non-liver comorbidities when considering treatment for recurrence after ablation in the real-world setting and in research trials. Ultimately, we identified an orphan population for which effective interventions are needed.

Microwave ablation versus surgical resection for subcapsular hepatocellular carcinoma: a propensity score-matched study of long-term therapeutic outcomes

OBJECTIVES

The therapeutic efficacy of microwave ablation (MWA) for subcapsular hepatocellular carcinoma (HCC) has not been well characterized. We aimed to compare the long-term outcomes of MWA and surgical resection (SR) in patients with subcapsular HCC.

METHODS

This retrospective study comprised 321 patients with subcapsular HCC meeting the Milan criteria who received MWA (n = 99) or SR (n = 222). Local tumor progression (LTP), overall survival (OS), and disease-free survival (DFS) were analyzed using propensity score matching (PSM) to compare the therapeutic efficacy.

RESULTS

In the total cohort, there were no significant differences in 5-year LTP rates (14.0% vs. 8.9%, p = 0.12), OS rates (70.7% vs. 73.2%, p = 0.63), and DFS rates (38.3% vs. 41.2%, p = 0.22) between the MWA and SR groups. After PSM, the cumulative LTP rates at 1, 3, and 5 years were 9.7%, 14.0%, and 16.4% in the MWA group (n = 84) and 7.2%, 8.6%, and 10.6% in the SR group (n = 84), respectively, with no significant difference (p = 0.31). Neither corresponding OS rates (96.4%, 84.8%, and 73.0% vs. 95.2%, 85.5%, and 72.1%, p = 0.89) nor DFS rates (76.0%, 52.6%, and 38.1% vs. 76.2%, 44.7%, and 32.3%, p = 0.43) were significantly different between the MWA and SR groups. Whereas MWA obtained fewer complications for both cohorts (both p < 0.05).

CONCLUSION

MWA showed comparable long-term therapeutic outcomes to SR, and it might be an alternative curative option for subcapsular HCC within the Milan criteria.

KEY POINTS

• Microwave ablation showed comparable local tumor progression, overall survival, and disease-free survival to surgical resection for subcapsular hepatocellular carcinoma meeting the Milan criteria. • Microwave ablation obtained fewer complications and shorter postoperative hospital stay.

Deep learning model based on contrast-enhanced ultrasound for predicting early recurrence after thermal ablation of colorectal cancer liver metastasis

OBJECTIVES

To develop and validate a deep learning (DL) model based on quantitative analysis of contrast-enhanced ultrasound (CEUS) images that predicts early recurrence (ER) after thermal ablation (TA) of colorectal cancer liver metastasis (CRLM).

METHODS

Between January 2010 and May 2019, a total of 207 consecutive patients with CRLM with 13,248 slice images at three dynamic phases who received CEUS within 2 weeks before TA were retrospectively enrolled in two centres (153 for the training cohort (TC), 32 for the internal test cohort (ITC), and 22 for the external test cohort (ETC)). Clinical and CEUS data were used to develop and validate the clinical model, DL model, and DL combining with clinical (DL-C) model to predict ER after TA. The performance of these models was compared by the receiver operating characteristic curve (ROC) with the DeLong test.

RESULTS

After a median follow-up of 56 months, 49% (99/207) of patients experienced ER. Three key clinical features (preoperative chemotherapy (PC), lymph node metastasis of the primary colorectal cancer (LMPCC), and T stage) were used to develop the clinical model. The DL model yielded better performance than the clinical model in the ETC (AUC: 0.67 for the clinical model, 0.76 for the DL model). The DL-C model significantly outperformed the clinical model and DL model (AUC: 0.78 for the DL-C model in the ETC; both, p < 0.001).

CONCLUSIONS

The model based on CEUS can achieve satisfactory prediction and assist physicians during the therapeutic decision-making process in clinical practice.

KEY POINTS

• This is an exploratory study in which ablation-related contrast-enhanced ultrasound (CEUS) data from consecutive patients with colorectal cancer liver metastasis (CRLM) were collected simultaneously at multiple institutions. • The deep learning combining with clinical (DL-C) model provided desirable performance for the prediction of early recurrence (ER) after thermal ablation (TA). • The DL-C model based on CEUS provides guidance for TA indication selection and making therapeutic decisions.

Stereotactic body radiation therapy versus radiofrequency ablation in hepatocellular carcinoma: an up-date meta-analysis

PURPOSE

Radiofrequency ablation (RFA) and stereotactic body radiotherapy (SBRT) are available locoregional curative treatments for nonsurgical Hepatocellular carcinoma (HCC) patients. We aimed to compare the clinical efficacy and safety of SBRT versus RFA for HCC.

METHODS

A computerized bibliographic search was performed using PubMed, Embase, the Cochrane Library and Web of Science to identify comparative studies. The primary outcome was overall survival (OS), and the secondary outcomes were freedom from local progression (FFLP) and treatment-related complications.

RESULTS

In total, there were 17 trials involving 22,180 patients. Patients receiving RFA showed significantly better 1-, 2- year OS (OR 0.69, 95% CI 0.50-0.96, P = 0.141,OR 0.69, 95% CI 0.53-0.89, P = 0.082), whereas SBRT resulted in significantly better 1-, 2-, 3- year FFLP (OR 2.19, 95% CI 1.44-3.34, P = 0.303; OR 1.57, 95% CI 1.12-2.19, P = 0.268; OR 2.22, 95% CI 1.70-2.90, P = 0.470). There were no significant differences for 3-, 5- year OS in both groups (OR 0.94, 95% CI 0.65-1.38, P = 0.001; OR 0.98, 95% CI 0.68-1.34, P = 0.016). The overall treatment-related complication rate did not differ significantly between the two treatment arms, while SBRT was significantly associated with Child-Pugh worsening.

CONCLUSIONS

Though SBRT has excellent FFLP, RFA yields superior short-term survival for HCC. But the discrepancy between FFLP and OS requires further investigation.

Nanosecond pulsed electric field ablation-induced modulation of sphingolipid metabolism is associated with Ly6c2+ mononuclear phagocyte differentiation in liver cancer

Preclinical studies have proven that nanosecond pulsed electric field (nsPEF) ablation can be a safe and effective treatment for humans with unresectable liver cancer that are ineligible for thermal ablation. The concomitant activation of antitumor immunity by nsPEF can also potentially prevent tumor recurrence. However, whether nsPEF exhibits similar efficacy in a clinical setting remains to be investigated. A prospective clinical trial (clinicaltrials.gov identifier: NCT04039747) was conducted to evaluate the safety and efficacy of ultrasound (US)-guided nsPEF ablation in 15 patients with unresectable liver cancer that were ineligible for thermal ablation. We found that nsPEF ablation was safe and produced a 12-month recurrence-free survival (RFS) and local RFS of 60% (9/15) and 86.7% (13/15), respectively, in the enrolled patients. Integrative proteomic and metabolomic analysis showed that sphingolipid metabolism was the most significantly enriched pathway in patient sera after nsPEF without recurrence within 8 months. A similar upregulation of sphingolipid metabolism was observed in the intratumoral mononuclear phagocytes (MNPs), rather than other immune and nonimmune cells, of an nsPEF-treated mouse model. We then demonstrated that lymphocyte antigen 6 complex, locus C2-positive (Ly6c2⁺ ) monocytes first differentiated into Ly6c2⁺ monocyte-derived macrophages with an increase in sphingolipid metabolic activity, and subsequently into Ly6c2⁺ dendritic cells (DCs). Ly6c2⁺ DCs communicated with CD8⁺ T cells and increased the proportions of IFN-γ⁺  CD8⁺ memory T cells after nsPEF, and this finding was subsequently confirmed by depletion of liver Ly6c2⁺ MNPs. In conclusion, nsPEF was a safe and effective treatment for liver cancer. The alteration of sphingolipid metabolism induced by nsPEF was associated with the differentiation of Ly6c2⁺ MNPs, and subsequently induced the formation of memory CD8⁺ T cells with potent antitumor effect.

Clinical efficacy of CT-guided 125I brachytherapy in patients with local residual or recurrent hepatocellular carcinoma after thermal ablation

OBJECTIVES

Treatment methods of local residual or recurrent hepatocellular carcinoma (HCC) after thermal ablation are limited. Therefore, our study aimed to explore the efficacy and prognostic factors of ¹²⁵I brachytherapy for local residual or recurrent lesion after thermal ablation.

METHODS

A total of 114 patients with 212 local residual or recurrent HCC tumors after thermal ablation underwent ¹²⁵I brachytherapy. Local progression-free survival (LPFS) and prognostic factors were analyzed by Kaplan-Meier curves and the Cox model.

RESULTS

After a 6-month follow-up, the percentage of patients who achieved complete response (CR), partial response (PR), and stable disease (SD) was 57%, 13.2%, and 5.2%, respectively. The 1-, 2-, and 3-year LPFS rates were 58.7%, 50.0%, and 41.2%, respectively. Portal vein tumor thrombus (PVTT) (p = 0.03), the number of intrahepatic tumors (p = 0.01), and AFP level (p = 0.02) were independent risk factors for local tumor progression (LTP). The median LPFS in patients without PVTT (22 months) was much longer compared to those with PVTT (10 months). The median LPFS in patients with less than three intrahepatic lesions improved from 17 to 24 months. The median LPFS was only 5 months in the high AFP group, but was prolonged with a decrease in AFP level (24 months). No severe complications were recorded. All complications were controllable and treatable.

CONCLUSIONS

CT-guided ¹²⁵I brachytherapy was a safe and effective treatment for patients with local residual or recurrent HCC after thermal ablation to improve local control rate.

Preclinical Therapeutic Evaluation of Lenvatinib-Eluting Microspheres for Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma

PURPOSE

To evaluate the preclinical in vivo therapeutic response of Lenvatinib-eluting microspheres (LEN-EM) transcatheter arterial chemoembolization (LEN-TACE) in an hepatocellular carcinoma (HCC) rat model.

METHODS

Magnetic resonance imaging (MRI) visible LEN-EM was fabricated with poly(lactide-co-glycolide) and iron oxide nanoparticles by a double-emulsion method. The morphology, LEN loading/release kinetics, and MRI contrast effect of LEN-EM were evaluated. For in vivo study, N1S1 HCC rats were treated with LEN-TACE (LEN: 2.4 mg/kg, n = 5) using LEN-EM, systemic LEN (LEN: 0.4 mg/kg, oral gavage daily for 7 days, n = 5), control (intra-arterial (IA) saline infusion, n = 5), and non-tumor control (n = 3). Tumor size changes were measured for 2 weeks. Histology, comparative LEN plasma concentration, hematologic markers, liver profile, and serum chemistry among the groups were measured.

RESULTS

LEN-EM with 33 µm in average size was prepared in an optimized emulsion process. LEN loading efficiency was 58.7%. LEN was continuously released for 500 h. LEN-TACE showed the delivered LEN-EM surrounding tumor tissue in MRI-T2* images. The LEN-TACE group demonstrated a statistically significant larger tumor volume reduction compared to the other groups at 2 weeks post-procedure. Quantification data of Terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells confirmed increased cancer cell death in the LEN-TACE group compared to control groups. Additional histology, hematologic markers, and liver profiles showed minimal side effects of LEN-TACE.

CONCLUSION

LEN-TACE using IA delivery of LEN-EM demonstrated an effective therapeutic efficacy in an HCC rat animal model.

Comparable Outcomes in Early Hepatocellular Carcinomas Treated with Trans-Arterial Chemoembolization and Radiofrequency Ablation

The guidelines recommend radiofrequency ablation (RFA) for early hepatocellular carcinomas that are less than 3 cm and trans-arterial chemoembolization (TACE) for intermediate-stage tumors. Real-world patient and tumor factors commonly limit strict adherence to the guidelines. We aimed to compare the clinical outcomes for TACE and RFA in early HCC. All consecutive patients from 2010 to 2014 that were treated with locoregional therapy at our institution were enrolled. The decision for TACE or RFA was based on tumor location, stage and technical accessibility for ablation. A subgroup analysis was performed for patients with tumors less than 3 cm. A total of 168 patients underwent TACE while 56 patients underwent RFA. Patients treated with TACE and RFA had 1- and 5-year survival rates of 84.7% and 39.8% versus 91.5% and 51.5%, respectively (p = 0.28). In tumors less than 3 cm, there was no significant difference in overall survival (p = 0.69), time to progression (p = 0.55), or number of treatment sessions required (p = 0.12). Radiofrequency ablation had a significantly higher chance of a complete response (p = 0.004). In conclusion, TACE may be selectively considered for early-stage hepatocellular carcinoma in patients unsuitable for other modalities.

Percutaneous Ablation of Hepatic Tumors at the Hepatocaval Confluence Using Irreversible Electroporation: A Preliminary Study

Background: Tumors at the hepatocaval confluence are difficult to treat, either surgically or ablatively. Methods: A retrospective longitudinal study on patients ineligible for thermal ablation who underwent computed tomography-guided IRE for hepatic tumors at the hepatocaval confluence was conducted. Factors analyzed included patient and tumor characteristics, IRE procedure details, treatment-related complications, and prognosis. Results: Between 2017 and 2021, 21 patients at our institute received percutaneous IRE. Of the 38 lesions, 21 were at the hepatocaval confluence. Complete ablation was achieved in all cases. Local and distant recurrence was observed in 4.8% (1/21) and 42.6% (9/21) of the ablated tumors, respectively. All postcava remained perfused at follow-up, except for 1 (4.8%) hepatic vein near the lesion found to be temporarily occluded and restored within 1 month. The ratio of the maximum diameter of ablation area at 1, 3, and 6 months post procedure compared to that immediately after IRE was 0.68 (0.50–0.84), 0.49 (0.27–0.61), and 0.38 (0.25–0.59), respectively. Progression-free survival of the patients with recurrence was 121 (range, 25–566) days. Four (19.0%) patients died at the end of follow-up with median overall survival of 451.5 (range, 25–716) days. Conclusions: IRE could be a safe and effective treatment for hepatic tumors at the hepatocaval confluence. This article provides valuable prognostic data; further clinical research is needed for better prognosis.

Percutaneous radiofrequency ablation of solitary hepatic metastasis from colorectal cancer: Risk factors of local tumor progression-free survival and overall survival

Purpose

This study aimed to evaluate local tumor progression-free survival (LTPFS) and overall survival (OS) after percutaneous radiofrequency ablation (RFA) for solitary colorectal liver metastases (CLM) <3 cm and to identify the risk factors associated with poor LTPFS and OS after percutaneous RFA.

Methods

This study screened 219 patients who underwent percutaneous RFA for CLM between January 2013 and November 2020. Of these, 92 patients with a single CLM <3 cm were included. LTPFS and OS were calculated using the Kaplan-Meier method, and the differences between curves were compared using the log-rank test. Risk factors for LTPFS and OS were assessed using Cox proportional-hazard regression models.

Results

Technical efficacy was achieved in the first (n=91) or second (n=1) RFA sessions. During the follow-up (median, 20.0 months), cumulative LTPFS rates at 1, 3, and 5 years were 92.4%, 83.4%, and 76.5%, respectively. During the follow-up (median, 27.8 months), the corresponding OS rates were 97.5%, 81.3%, and 74.8%, respectively. In multivariable Cox regression analyses, the group with both tumor-puncturing RFA and a T4 stage primary tumor (hazard ratio, 3.3; 95% confidence interval, 1.1 to 10.2; P=0.037) had poor LTPFS. In the univariable analysis, no factors were significantly associated with poor OS.

Conclusion

Both LTPFS and OS were promising after percutaneous RFA for a single CLM <3 cm. The group with both tumor-puncturing RFA and a T4 stage primary tumor showed poor LTPFS. No risk factors were identified for poor OS.

Technical efficacy and local recurrence after stereotactic radiofrequency ablation of 2653 liver tumors: a 15-year single-center experience with evaluation of prognostic factors

PURPOSE

To assess the technical outcome and local tumor control of multi-probe stereotactic radiofrequency ablation (SRFA) in a large series of patients. Furthermore, to determine factors accounting for adverse outcomes.

MATERIAL AND METHODS

Between 2003 and 2018, 865 patients were treated by SRFA for 2653 primary and metastatic liver tumors with a median tumor size of 2.0 cm (0.5 - 19 cm). Primary technical efficacy (PTE) and local recurrence (LR) were evaluated, and possible predictors for adverse events analyzed using uni- and multi-variable binary logistic regression.

RESULTS

Overall, 2553 of 2653 tumors were successfully ablated at initial SRFA resulting in a PTE rate of 96.2%. Predictors of lower PTE rates were age > 70 years, tumor size > 5 cm, number of probes, location close to liver capsule/organs and segment II. LR occurred in 220 of 2653 tumors (8.3%) with the following predictors: age, tumor type/size, conglomerates, segments I/IVa/IVb, number of probes and location close to major vessels/bile duct. Multivariable analysis revealed tumor size > 5 cm (odds ratio [OR] 3.153), age > 70 years (OR 1.559), and location in segment II (OR 1.772) as independent prognostic factors for PTE, whereas tumor location close to major vessels (OR 1.653) and in segment IVb (OR 2.656) were identified as independent prognostic factors of LR.

CONCLUSIONS

Stereotactic RFA is an attractive option in the management of primary or metastatic liver tumors with good local tumor control, even in large tumors. The presented prognostic factors for adverse local oncological outcome might help to stratify unfavorable tumors for ablation.

Long-term outcomes of combined transarterial chemoembolization and radiofrequency ablation versus RFA monotherapy for single hepatocellular carcinoma ≤3 cm: emphasis on local tumor progression

PURPOSE

To compare the long-term outcomes of combined transarterial chemoembolization and radiofrequency ablation (TACE-RFA) with radiofrequency ablation (RFA) monotherapy for small (≤3 cm) hepatocellular carcinomas (HCCs).

METHODS

A total of 248 patients with 329 HCC nodules who underwent TACE-RFA or RFA monotherapy as the only first-line treatment between January 2009 and December 2020 were included in this study. The technical success, complications, survival rate, and local tumor progression (LTP) rate were compared between the two treatments.

RESULTS

The 1-, 3- and 5-year survival rates were similar between the two groups (98.7%, 93.0% and 75.9% vs 97.4%, 88.0% and 77.4%; p = 0.444). The 1-, 3-, and 5-year cumulative LTP rates were significantly lower in the TACE-RFA group than in the RFA monotherapy group (2.9%, 9.2%, and 13.8% vs. 5.2%, 17.0%, and 21.0%; p = 0.043). Subgroup analyses suggested that TACE-RFA showed significantly lower LTP rates than RFA monotherapy for small HCC with tumor size>2cm (p = 0.008), subphrenic location (p = 0.021), and perivessel (p = 0.030). Furthermore, HCC with well-defined lipiodol deposition in the TACE-RFA group showed better local tumor control than the small HCC in the RFA monotherapy group (p = 0.013). There was no significant difference in the technical success rates (p = 0.064) and complication rates (p = 0.952) between the two groups.

CONCLUSIONS

TACE-RFA is superior to RFA monotherapy in providing local tumor control for small HCC with tumor size 2-3 cm in diameter, subphrenic location, perivessel and HCCs with well-defined lipiodol deposition by TACE before RFA.

Radiofrequency Ablation versus Stereotactic Body Radiation Therapy in the Treatment of Colorectal Cancer Liver Metastases

Purpose

This study aimed to compare the treatment outcomes of radiofrequency ablation (RFA) and stereotactic body radiation therapy (SBRT) for colorectal cancer liver metastases (CRLM) and to determine the favorable treatment modality according to tumor characteristics.

Materials and Methods

We retrospectively analyzed the records of 222 colorectal cancer patients with 330 CRLM who underwent RFA (268 tumors in 178 patients) or SBRT (62 tumors in 44 patients) between 2007 and 2014. Kaplan-Meier method and Cox models were used by adjusting with inverse probability of treatment weighting (IPTW).

Results

The median follow-up duration was 30.5 months. The median tumor size was significantly smaller in the RFA group than in the SBRT group (1.5 cm vs 2.3 cm, p < 0.001). In IPTW-adjusted analysis, difference in treatment modality was not associated with significant differences in 1-year and 3-year recurrence-free survival (35% vs. 43%, 22% vs. 23%; p=0.198), overall survival (96% vs. 91%, 58% vs. 56%; p=0.508), and freedom from local progression (FFLP; 90% vs. 72%, 78% vs. 60%; p=0.106). Significant interaction effect between the treatment modality and tumor size was observed for FFLP (p=0.001). In IPTW-adjusted subgroup analysis of patients with tumor size > 2 cm, the SBRT group had a higher FFLP compared with the RFA group (hazard ratio, 0.153; p < 0.001).

Conclusion

SBRT and RFA showed similar local control in the treatment of patients with CRLM. Tumor size was an independent prognostic factor for local control and SBRT may be preferred for larger tumors.

Radiofrequency ablation of surface v/s intraparenchymal hepatocellular carcinoma in cirrhotic patients

Objective

To retrospectively evaluate the safety and technical efficacy of percutaneous radiofrequency ablation (RFA) of surface hepatocellular carcinoma (HCC) in comparison to intraparenchymal HCC in cirrhotic patients.

Materials and Methods

Surface lesions were defined as tumours located or reaching within 1cm of liver capsule including exophytic lesions. Seventy-four surface HCC including 21 exophytic in 58 patients (surface group) and 60 intraparenchymal HCC in 54 patients (intraparenchymal group) measuring up to 4 cm in maximum extent underwent percutaneous [ultrasound (US) or computed tomography-guided (CT-guided)] RFA. The response to the treatment was assessed by contrast enhanced CT/magnetic resonance imaging (MRI) done at 1, 3, 6, 9, and 12 months of RFA and thereafter every 4-6 months. In case of features suggesting residual disease, a repeat RFA was performed. The technical success after single-session RFA, complications and disease recurrence rates were calculated and compared between two groups.

Results

Technical success achieved after first session of RFA in surface HCC was 95% (70/74) and intraparenchymal HCC was 97% (58/60). Hundred percent secondary success rate was achieved in both groups after second repeat RFA in residual lesion. No major difference in complication and local recurrence rate in both group on follow-up in surface HCC and intraparenchymal HCC. No case of needle track, peritoneal seeding, and treatment mortality was found.

Conclusions

The complication rate and efficacy of RFA for surface and exophytic HCC's were comparable to that of intraparenchymal HCC. Hence surface and exophytic lesions should not be considered a contraindication for RFA in cirrhotic patients.

Microwave ablation for peribiliary hepatocellular carcinoma: propensity score analyses of long-term outcomes

OBJECTIVE

To compare the long-term outcomes of MWA as the first-line treatment for HCC in peribiliary versus non-peribiliary locations using propensity score matching analysis.

METHODS

The study participants were recruited between April 2012 and October 2016. In total, 236 patients with HCC <5 cm who underwent ultrasonography-guided percutaneous MWA as the first-line treatment were enrolled. The patients were grouped into two according to tumor location: peribiliary (n = 74) and non-peribiliary (n = 162). The progression-free survival (PFS) and overall survival (OS) rates were compared before and after propensity score matching. Subgroup analyses were conducted for the peribiliary group according to the biliary grading.

RESULTS

Propensity score matching yielded 63 matched pairs of patients. In the two matched groups, cumulative PFS rates were 29.0% and 14.0% in the peribiliary group, and 51.0% and 31.0% in the non-peribiliary group at 3 and 5 years, respectively. Corresponding OS rates were 51.0% and 49.0% in the peribiliary group, and 77.0% and 70.0% in the non-peribiliary group at 3 and 5 years, respectively. In addition, there were significant differences in major complication rates between the two groups (25.7% vs 8.0%; p < .001). In contrast to peribiliary HCCs adjacent to the second-degree branches of intrahepatic bile duct (67.1 ± 5.2 months), subgroup analysis indicated that the mean OS was significantly lower in peribiliary HCCs adjacent to the first-degree branches (51.2 ± 7.5 months) (p = .015).

CONCLUSION

The application of MWA for peribiliary HCC leads to a higher rate of complications and worse long-term tumor control than for non-peribiliary HCC.KEY POINTSThe application of MWA for peribiliary HCC leads to a higher rate of complications than for non-peribiliary HCC.The application of MWA for peribiliary HCC leads to worse long-term tumor control than for non-peribiliary HCC. Abbreviations: Hepatocellular carcinoma (HCC); microwave ablation (MWA); α-fetoprotein (α-FP); local tumor progression (LTP); intrahepatic distal recurrence (IDR); progression-free survival (PFS); overall survival (OS).

Radiofrequency ablation versus repeat hepatectomy in the treatment of recurrent hepatocellular carcinoma in subcapsular location: a retrospective cohort study

Background

Repeat hepatectomy and radiofrequency ablation (RFA) are widely used to treat early recurrent hepatocellular carcinoma (RHCC) located in the subcapsular region, but the optimal treatment strategy remains to be controversial.

Methods

A total of 126 RHCC patients in the subcapsular location after initial radical hepatectomy were included in this study between Dec 2014 and Jan 2018. These patients were divided into the RFA group (46 cases) and the repeat hepatectomy group (80 cases). The primary endpoints include repeat recurrence-free survival (rRFS) and overall survival (OS), and the secondary endpoint was complications. The propensity-score matching (PSM) was conducted to minimize the bias. Complications were evaluated using the Clavien-Dindo classification, and severe complications were defined as classification of complications of ≥grade 3.

Results

There were no significant differences in the incidence of severe complications were observed between RFA group and repeat hepatectomy group in rRFS and OS both before (1-, 2-, and 3-year rRFS rates were 65.2%, 47.5%, and 33.3% vs 72.5%, 51.2%, and 39.2%, respectively, P = 0.48; 1-, 2-, and 3-year OS rates were 93.5%, 80.2%, and 67.9% vs 93.7%, 75.8%, and 64.2%, respectively, P = 0.92) and after PSM (1-, 2-, and 3-year rRFS rates were 68.6%, 51.0%, and 34.0% vs 71.4%, 42.9%, and 32.3%, respectively, P = 0.78; 1-, 2-, and 3-year OS rates were 94.3%, 82.9%, and 71.4% vs 88.6%, 73.8%, and 59.0%, respectively, P = 0.36). Moreover, no significant differences in the incidence of severe complications were observed between the RFA group and repeat hepatectomy group.

Conclusion

Both repeat hepatectomy and RFA are shown to be effective and safe for the treatment of RHCC located in the subcapsular region.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02277-4.

Risk Factors, Patterns, and Long-Term Survival of Recurrence After Radiofrequency Ablation With or Without Transarterial Chemoembolization for Hepatocellular Carcinoma

Objectives

To classify hepatocellular carcinoma (HCC) recurrence patterns after radiofrequency ablation (RFA) or transarterial chemoembolization (TACE) combined with RFA (TACE-RFA) and analyze their risk factors and impacts on survival.

Methods

We retrospectively evaluated the medical records of HCC patients who underwent RFA or TACE-RFA from January 2006 to December 2016. HCC recurrences were classified into four patterns: local tumor progression (LTP), intra-segmental recurrence, extra-segmental recurrence, and aggressive recurrence. Risk factors, overall survival (OS), and post-recurrence survival of each pattern were evaluated.

Results

A total of 249 patients with a single, hepatitis-B virus (HBV)-related HCC ≤ 5.0 cm who underwent RFA (HCC ≤ 3.0 cm) or TACE-RFA (HCC of 3.1-5.0 cm) were included. During follow-up (median, 53 months), 163 patients experienced HCC recurrence: 40, 43, 62 and 18 patients developed LTP, intra-segmental recurrence, extra-segmental recurrence, and aggressive recurrence, respectively; the median post-recurrence survival was 49, 37, 25 and 15 months, respectively (P < .001); the median OS was 65, 56, 58 and 28 months, respectively (P < .001). Independent risk factors for each pattern were as follows: tumor sized 2.1-3.0 cm undergoing RFA alone and insufficient ablative margin for LTP, periportal tumor and non-smooth tumor margin for intra-segmental recurrence, HBV-DNA ≥ 2000 IU/mL for extra-segmental recurrence, and periportal tumor and α-fetoprotein ≥ 100 ng/mL for aggressive recurrence. Recurrence pattern (P < .001) and Child-Pugh class B (P = .025) were independent predictors for OS.

Conclusions

Based on our classification, each recurrence pattern had different recurrence risk factors, OS, and post-recurrence survival.

Comparison of Percutaneous Radiofrequency Ablation for Subcapsular and Non-Subcapsular Colorectal Cancer Liver Metastases

Purpose

To evaluate the efficacy and safety of percutaneous radiofrequency ablation (RFA) for subcapsular colorectal cancer liver metastases (CLMs).

Materials and Methods

With the approval of the Institutional Review Board, the clinical data of CLM patients who underwent percutaneous RFA for the first time from August 2010 to August 2020 were continuously collected. All CLMs were divided into subcapsular and non-capsular groups. Baseline characteristic data, technical effectiveness, minimal ablative margin, complications, local tumor progression (LTP), and overall survival (OS) between the two groups were analyzed using the t-test or chi-square test. A Cox regression model was used to evaluate the prognostic factors of LTP.

Results

One hundred and ninety-nine patients (124 males; mean age, 60.2 years) with 402 CLMs (221 subcapsular; mean size, 16.0 mm) were enrolled in the study. Technical effectiveness was achieved in 93.5% (376/402) of CLMs, with a major complication rate of 5.5%. Compared with non-subcapsular tumors, the minimal ablative margin achieved in subcapsular CLM was smaller (χ² = -8.047, P < 0.001). With a median follow-up time of 23 months (range, 3−96 months), 37.1% of the tumors had LTP. The estimated cumulative OS at 1, 3, and 5 years was 96.1%, 66.0%, and 44.2%, respectively. There were no statistically significant differences between the two groups in terms of technical effectiveness (χ² = 0.484, P = 0.487), major complications (χ² = 0.082, P = 0.775), local tumor progression-free survival (LTPFS) (χ² = 0.881, P = 0.348), and OS (χ² = 2.874, P = 0.090). Minimal ablative margin, tumor size (≥20 mm), and technical effectiveness were predictors of LTP (all P < 0.05).

Conclusion

RFA is a safe and effective technique for local tumor control of subcapsular CLMs.

Tumor attenuation and quantitative analysis of perfusion parameters derived from tri-phasic CT scans in hepatocellular carcinoma: Relationship with histological grade

The aim of the current study was to explore the value of tumor attenuation and quantitative analysis of perfusion parameters obtained from traditional tri-phasic CT scans in grading hepatocellular carcinoma (HCC).Totally 39 patients (42 lesion samples) with pathologically confirmed HCC who underwent tri-phasic CT scans were enrolled. HCC lesions were divided into non-poorly differentiated HCC (NP-HCC; n = 31) and poorly differentiated HCC (pHCC; n = 11). All lesions were divided into 5 groups according to the attenuation on different CT enhancement phase. The values of tumor attenuation on different scanning phases were measured. The following parameters were calculated: arterial enhancement fraction (AEF), portal venous supply coefficient (PVC), and hepatic arterial supply coefficient (HAC). The relationship of perfusion parameters with the histological grade of HCC was analyzed. Receiver operating characteristic curves were generated.No significant correlation was observed between the perfusion parameters and tumor grading. Only HAC showed a non-significant trend in different grades of HCC (pHCC < NP-HCC; P = .07). The pHCC cases had significantly decreased values of tumor attenuation on the unenhanced phase (TAu), tumor attenuation on the portal phase portal phase (TAp), and equilibrium phase (TAe) (P < .01). The difference of tumor attenuation between the portal phase and the unenhanced phase (TAp-TAu) of the pHCC cases was decreased than that of the NP-HCC cases (P < .01), whereas the difference of attenuation between the equilibrium phase and portal phase (TAe-TAp) was significantly higher in the pHCC cases than that in the NP-HCC cases (P < .01). TAe-TAp had the highest area under the curve. The number of tumor enhancement pattern in Group 5 of HCCs with a diameter of 3 cm or more was significantly more than that of HCCs with a diameter of less than 3 cm or with other different enhancement patterns (P < .01).Histological HCC grading cannot be predicted by the perfusion parameters derived from traditional tri-phasic CT scans, whereas the tumor attenuation on different phases and the tumor attenuation differences among different phases, especially the mean value of TAe-TAp, might be useful for non-invasive prediction on the degree of HCC differentiation.

Value of perfusion parameters and histogram analysis of triphasic computed tomography in pre-operative prediction of histological grade of hepatocellular carcinoma

BACKGROUND

Pre-operative non-invasive histological evaluation of hepatocellular carcinoma (HCC) remains a challenge. Tumor perfusion is significantly associated with the development and aggressiveness of HCC. The purpose of the study was to evaluate the clinical value of quantitative liver perfusion parameters and corresponding histogram parameters derived from traditional triphasic enhanced computed tomography (CT) scans in predicting histological grade of HCC.

METHODS

Totally, 52 patients with HCC were enrolled in this retrospective study and underwent triple-phase enhanced CT imaging. The blood perfusion parameters were derived from triple-phase CT scans. The relationship of liver perfusion parameters and corresponding histogram parameters with the histological grade of HCC was analyzed. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal ability of the parameters to predict the tumor histological grade.

RESULTS

The variance of arterial enhancement fraction (AEF) was significantly higher in HCCs without poorly differentiated components (NP-HCCs) than in HCCs with poorly differentiated components (P-HCCs). The difference in hepatic blood flow (HF) between total tumor and total liver flow (ΔHF = HFtumor - HFliver) and relative flow (rHF = ΔHF/HFliver) were significantly higher in NP-HCCs than in P-HCCs. The difference in portal vein blood supply perfusion (PVP) between tumor and liver tissue (ΔPVP) and the ΔPVP/liver PVP ratio (rPVP) were significantly higher in patients with NP-HCCs than in patients with P-HCCs. The area under ROC (AUC) of ΔPVP and rPVP were both 0.697 with a high sensitivity of 84.2% and specificity of only 56.2%. The ΔHF and rHF had a higher specificity of 87.5% with an AUC of 0.681 and 0.673, respectively. The combination of rHF and rPVP showed the highest AUC of 0.732 with a sensitivity of 57.9% and specificity of 93.8%. The combined parameter of ΔHF and rPVP, rHF and rPVP had the highest positive predictive value of 0.903, and that of rPVP and ΔPVP had the highest negative predictive value of 0.781.

CONCLUSION

Liver perfusion parameters and corresponding histogram parameters (including ΔHF, rHF, ΔPVP, rPVP, and AEFvariance) in patients with HCC derived from traditional triphasic CT scans may be helpful to non-invasively and pre-operatively predict the degree of the differentiation of HCC.

Surgical Resection vs. Percutaneous Ablation for Single Hepatocellular Carcinoma: Exploring the Impact of Li-RADS Classification on Oncological Outcomes

Background: Single hepatocellular carcinoma (HCC) benefits from surgical resection (SR) or US-guided percutaneous ablation (PA), although the best approach is still debated. We evaluated the impact of Li-RADS classification on the oncological outcomes of SR vs. PA as single HCC first-line treatment. Methods: We retrospectively and blindly classified treatment-naïve single HCC that underwent SR or PA between 2010 and 2016 according to Li-RADS protocol. Overall survival (OS), recurrence free survival (RFS) and local recurrence after SR and PA were compared for each Li-RADS subclass before and after propensity-score matching (PS-M). Results: Considering the general population, SR showed better 5-year OS (68.3% vs. 52.2%; p = 0.049) and RFS (42.5% vs. 29.8%; p = 0.002), with lower incidence of local recurrence (8.2% vs. 44.4%; p < 0.001), despite a significantly higher frequency of clinically-relevant complications (12.8% vs. 1.9%; p = 0.002) and a higher Comprehensive Complication Index (12.1 vs. 2.2; p < 0.001). Focusing on different Li-RADS subclasses, we highlighted better 5-year OS (67.1% vs. 46.2%; p = 0.035), RFS (45.0% vs. 27.0% RFS; p < 0.001) and lower incidence of local recurrence (9.7% vs. 48.6%; p < 0.001) after SR for Li-RADS-5 HCCs, while these outcomes did not differ for Li-RADS-3/4 subclasses; such results were confirmed after PS-M. Conclusions: Our analysis suggests a potential prognostic role of Li-RADS classification, supporting SR over PA especially for Li-RADS-5 single HCC.

Laparoscopic Liver Resection versus Percutaneous Radiofrequency Ablation for Small Single Nodular Hepatocellular Carcinoma: Comparison of Treatment Outcomes

BACKGROUND

Treatment outcomes of laparoscopic liver resection (LLR) and percutaneous radiofrequency ablation (p-RFA) for small single hepatocellular carcinomas (HCCs) have not yet been fully compared. The aim of this study was to compare LLR and p-RFA as first-line treatment options in patients with single nodular HCCs ≤3 cm.

METHODS

From January 2014 to December 2016, a total of 566 patients with single nodular HCC ≤3 cm treated by either LLR (n = 251) or p-RFA (n = 315) were included. The recurrence-free survival (RFS) and cumulative incidence of local tumor progression (LTP) were estimated using Kaplan-Meier methods and compared using the log-rank test. Treatment outcome of 2 treatment modalities was compared in the subgroup of patients according to the tumor location.

RESULTS

There were no significant differences in overall survival between LLR and p-RFA (p = 0.160); however, 3-year RFS was demonstrated to be significantly higher after LLR (74.4%) than after p-RFA (66.0%) (p = 0.013), owing to its significantly lower cumulative incidence of LTP (2.1% at 3 years after LLR vs. 10.0% after p-RFA, p < 0.001). The complication rate of p-RFA was significantly lower than that of LLR (5.1 vs. 10.0%, p = 0.026). LLR also provided significantly better local tumor control than p-RFA for subscapular tumors (3-year LTP rates: 1.9 vs. 8.8%, p = 0.012), perivascular tumors (3-year LTP rates: 0.0 vs. 17.2%, p = 0.007), and tumors located in anteroinfero-lateral liver portions (3-year LTP rates: 0.0 vs. 10.7%, p < 0.001). However, there were no significant differences in LTP rates between LLR and p-RFA for non-subcapsular and non-perivascular tumors (p = 0.482) and for tumors in postero-superior liver portions (p = 0.380).

CONCLUSIONS

LLR can provide significantly better local tumor control than p-RFA for small single HCCs in subcapsular, perivascular, and anteroinferolateral liver portions and thus may be the preferred treatment option for these tumors.

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.

Combinatorial effect of radium-223 and irreversible electroporation on prostate cancer bone metastasis in mice

BACKGROUND

Metastatic prostate cancer in bone is difficult to treat as the tumor cells are relatively resistant to hormonal or chemotherapies when compared to primary prostate cancer. Irreversible electroporation (IRE) is a minimally invasive ablation procedure that has potential applications in the management of prostate cancer in bone. However, a common limitation of IRE is tumor recurrence, which arises from incomplete ablation that allows remaining cancer cells to proliferate. In this study, we combined IRE with radium-223 (Ra-223), a bone-seeking radionuclide that emits short track length alpha particles and thus is associated with reduced damage to the bone marrow and evaluated the impact of the combination treatment on bone-forming prostate cancer tumors.

METHODS

The antitumor activity of IRE and Ra-223 as single agents and in combination was tested in vitro against three bone morphogenetic protein 4 (BMP4)-expressing prostate cancer cell lines (C4-2B-BMP4, Myc-CaP-BMP4, and TRAMP-C2-BMP4). Similar evaluation was performed in vivo using a bone-forming C4-2B-BMP4 tumor model in nude mice.

RESULTS

IRE and Ra-223 as monotherapy inhibited prostate cancer cell proliferation in vitro, and their combination resulted in significant reduction in cell viability compared to monotherapy. In vivo evaluation revealed that IRE with single-dose administration of Ra-233, compared to IRE alone, reduced the rate of tumor recurrence by 40% following initial apparent complete ablation and decreased the rate of proliferation of incompletely ablated tumor as quantified in Ki-67 staining (53.58 ± 16.0% for IRE vs. 20.12 ± 1.63%; for IRE plus Ra-223; p = 0.004). Histological analysis qualitatively showed the enhanced killing of tumor cells adjacent to bone by Ra-223 compared to those treated with IRE alone.

CONCLUSION

IRE in combination with Ra-223, which enhanced the destruction of cancer cells that are adjacent to bone, resulted in reduction of tumor recurrence through improved clearance of proliferative cells in the tumor region.

Virtual navigation-guided radiofrequency ablation for recurrent hepatocellular carcinoma invisible on ultrasound after hepatic resection

BACKGROUND

No reports are available on the technical efficiency and therapeutic response of virtual navigation (VN)-guided radiofrequency ablation (RFA) for patients with recurrent hepatocellular carcinoma (HCC) after hepatic resection. The aim of this study was to investigate the overall technical performance and outcome of VN-guided RFA in recurrent HCC patients. In addition, a nomogram model was developed to predict the factors influencing the overall survival (OS).

METHODS

This was a prospective study on 76 recurrent HCC patients who underwent VN-guided RFA between June 2015 and February 2018. The technical feasibility, success, and efficiency, OS, local tumor progression, and complications were evaluated. A multivariate Cox regression analysis was conducted to predict the significant factors, and a nomogram including independent predictive factors was subsequently plotted to predict OS.

RESULTS

The technical feasibility, success, and efficiency rates of VN-guided RFA were 86.4%, 94.7%, and 97.4%, respectively. The cumulative OS rates at 1-, 2-, and 3-year were 88.1%, 79.7%, and 71.0%, respectively. The cumulative local tumor progression rates at 1-, 2-, and 3-year were 5.5%, 8.7%, and 14.0%, respectively. In addition, the minor and major complication rates were 5.3% and 3.9%, respectively. No intervention-related deaths occurred during the follow-up period. The C-index of the OS nomogram in this study was 0.737.

CONCLUSIONS

VN-guided RFA is an effective therapeutic option in recurrent HCC patients and improves the long-term outcomes especially for the lesions that cannot be detected in the two-dimensional ultrasound. Besides, the nomogram may be a useful supporting tool in predicting OS to estimate the individual survival probability, optimize treatment options, and facilitate decision-making.

Percutaneous cryoablation of subcapsular hepatocellular carcinoma: a retrospective study of 57 cases

PURPOSE This study aims to evaluate the safety and effectiveness of the percutaneous cryoablation for subcapsular hepatocellular carcinoma (HCC). METHODS A total of 57 patients with subcapsular (<1 cm form the liver edge) HCCs (68 lesions), who were treated with CT-guided percutaneous cryoablation in the Department of Interventional Radiology of our hospital between July 1, 2016 and September 1, 2018, were retrospectively included. Complete ablation rate, local tumor progression (LTP) and treatment-related complications were evaluated. Furthermore, the degree of intraoperative and postoperative pain was measured with the visual analog scale (VAS), and laboratory findings were compared before and after the procedure. RESULTS All patients successfully completed the treatment. The mean follow-up period was 12.8 months (range, 3-27 months), and the complete ablation rate was 97% (66/68). Local tumor progression occurred in 11 lesions (16.2%), and the 6-, 12- and 18-month cumulative LTP rates were 4.0%, 8.2% and 20.5%, respectively. Two patients (3.5%, 2/57) developed major complications, and 12 patients had minor complications (22.8%, 12/57). The mean VAS score during the operation was 1.65 points (range, 1-3 points). Postoperative pain worsened in 3 patients, and the VAS scores reached 4-5. Transient changes in biochemical and hematologic markers were observed. CONCLUSION Percutaneous cryoablation for subcapsular HCC is safe and effective, the procedure is simple and the patients suffer less pain.

A Single-Center Retrospective Analysis of Periprocedural Variables Affecting Local Tumor Progression after Radiofrequency Ablation of Colorectal Cancer Liver Metastases

Background Local tumor progression (LTP) is associated with poorer survival in patients undergoing radiofrequency ablation (RFA) for colorectal liver metastasis (CLM). An algorithmic strategy to predict LTP may help in selection of patients who would benefit most from RFA for CLM. Purpose To estimate local tumor progression-free survival (LTPFS) following RFA of CLM and develop an algorithmic strategy based on clinical variables. Materials and Methods In this retrospective study, between March 2000 and December 2014, patients who underwent percutaneous RFA for CLM were randomly split into development (60%) and internal validation (40%) data sets. Kaplan-Meier method was used to estimate LTPFS and overall survival (OS) rates. Independent factors affecting LTPFS in the development data set were investigated by using multivariable Cox proportional hazard regression analysis. Risk scores were assigned to the risk factors and applied to the validation data set. Results A total of 365 patients (mean age, 60 years ± 11 [standard deviation]; 259 men) with 512 CLMs were evaluated. LTPFS and OS rates were 85% and 92% at 1 year, 73% and 41% at 5 years, 72% and 30% at 10 years, and 72% and 28% at 15 years, respectively. Independent risk factors for LTP included tumor size of 2 cm or greater (hazard ratio [HR], 3.8; 95% CI: 2.3, 6.2; P < .001), subcapsular tumor location (HR, 1.9; 95% CI: 1.1, 3.1; P = .02), and minimal ablative margin of 5 mm or less (HR, 11.7; 95% CI: 4.7, 29.2; P < .001). A prediction model that used the risk factors had areas under the curve of 0.89, 0.92, and 0.90 at 1, 5, and 10 years, respectively, and it showed significantly better areas under the curve when compared with the model using the minimal ablative margin of 5 mm or less alone. Conclusion Radiofrequency ablation provided long-term control of colorectal liver metastases. Although minimal ablative margin of 5 mm or less was the most dominant factor, the multifactorial approach including tumor size and subcapsular location better predicted local tumor progression-free survival. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Soulen and Sofocleous in this issue.

Frequency and risk factors for major complications after stereotactic radiofrequency ablation of liver tumors in 1235 ablation sessions: a 15-year experience

Objectives

To assess the frequency of major complications after multi-probe stereotactic radiofrequency ablation (SRFA) in a large cohort of patients over 15 years and to elucidate risk factors for adverse events.

Materials and methods

A retrospective study was carried out between July 2003 and December 2018. Seven hundred ninety-three consecutive patients (median 65.0 years (0.3–88), 241 women and 552 men, were treated in 1235 SRFA sessions for 2475 primary and metastatic liver tumors with a median tumor size of 3.0 cm (0.5–18 cm). The frequency of major complications was evaluated according to SIR guidelines and putative predictors of adverse events analyzed using simple and multivariable logistic regression.

Results

Thirty-day mortality after SRFA was 0.5% (6/1235) with an overall major complication rate of 7.4% (91/1235). The major complication rate decreased from 11.5% (36/314) (before January 2011) to 6.0% (55/921) (p = 0.001). 50.5% (46/91) of major complications were successfully treated in the same anesthetic session by angiographic coiling for hemorrhage and chest tube insertion for pneumothorax. History of bile duct surgery/intervention, number of coaxial needles, and location of tumors in segment IVa or VIII were independent prognostic factors for major complications following multivariable logistic regression analysis. Simple logistic regression revealed the number of tumors, tumor size, location close to the diaphragm, tumor conglomerate, and segment VII as other significant predictors.

Conclusion

SRFA of liver tumors is safe and can extend the treatment spectrum of conventional RFA. Adaptations over time combined with increasing experience resulted in a significant decrease in complications.

Key Points

• In 1235 ablation sessions in 793 patients over 15 years, we found a mortality rate of 0.5% (6/1235) and an overall major complication rate of 7.4%, which fell from 11.5 (36/314) to 6.0% (55/921, p = 0.001) after January 2011, likely due to procedural adaptations.

• History of bile duct surgery/intervention (p = 0.013, OR = 3.290), number of coaxial needles (p = 0.026, OR = 1.052), and location of tumors in segment IVa (p = 0.016, OR = 1.989) or VIII (p = 0.038, OR = 1.635) were found to be independent prognostic factors.

• Simple logistic regression revealed that number of tumors, tumor size, location close to the diaphragm, tumor conglomerates, and segment VII were other significant predictors of major complications.

Computed tomography-guided percutaneous microwave ablation with artificial ascites for problematic hepatocellular tumors

Background: The aim of this study was to assess the feasibility, safety and efficacy of computed tomography (CT)-guided percutaneous microwave ablation with artificial ascites for problematic hepatocellular tumors.Methods: Forty-eight patients with 61 problematic hepatocellular carcinomas who underwent CT-guided percutaneous microwave ablation with artificial ascites were reviewed retrospectively. Lesions less than 5 mm away from the gastrointestinal system, diaphragm, pericardium or kidney were defined as problematic tumors with the potential risk of thermal damage. Microwave ablation was performed after artificial ascites was established between tumors and the adjacent high-risk organs. The technical effectiveness of microwave ablation, local tumor progression and complications was assessed.Results: Microwave ablation with artificial ascites was successfully performed in all 61 tumors. The technical effectiveness rate was 100% with contrast-enhanced CT performed immediately after the ablation procedure. Local tumor progression occurred in three (6%) of the 48 patients during the follow-up period (mean, 15 months; range, 6-24 months). No major complications related to the procedure occurred.Conclusion: CT-guided percutaneous microwave ablation with artificial ascites is a feasible, safe and effective choice for treating problematic hepatocellular tumors, avoiding potential thermal damage to the adjacent high-risk organs.

Prognosis of Early-Stage Hepatocellular Carcinoma: Comparison between Trans-Arterial Chemoembolization and Radiofrequency Ablation

Radiofrequency ablation (RFA) is a curative treatment for early-stage hepatocellular carcinoma (HCC) ineligible for surgery or liver transplantation. However, trans-arterial chemoembolization (TACE) might be an alternative when RFA is contraindicated due to structural problems. Here, we aimed to compare their long-term outcomes. Treatment-naive HCC patients fulfilling the Milan criteria who underwent RFA (n = 136) or TACE (n = 268) were enrolled. Complete response (CR) and 5-year recurrence-free survival (RFS) rates were higher in the RFA group than in the TACE group (94.1% vs. 71.6% and 35.8% vs. 17.0%, respectively; both p < 0.001), whereas 5-year overall survival (OS) rates were not significantly different (65.5% vs. 72.3%, respectively; p = 0.100). Multivariate analysis showed that RFA was associated with better RFS (adjusted hazard ratio [aHR] 0.628; p = 0.001) than TACE, but not with better OS (aHR 1.325; p = 0.151). The most common 1st-line treatment after recurrence were TACE (n = 53), followed by RFA (n = 21) among the RFA group and TACE (n = 150), followed by RFA (n = 44) among the TACE group. After propensity-score matching, similar results were reproduced. Hence, TACE could be an effective alternative to RFA in terms of OS rates. However, TACE should be confined only to RFA-difficult cases, given its lower CR and RFS rates and multi-disciplinary approaches are desirable in decision-making.

Outcome of Laparoscopic Assisted Percutaneous Microwave Ablation for Exophytic Versus Non-exophytic Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies and is the third cause of cancer-related death worldwide. Surgery is the optimal treatment for early HCC; however, the majority of cases are not suitable for curative resection at the time of diagnosis. Surgical resection difficulties may be related to size, site, number of tumors, extrahepatic involvement, and patient general condition. Exophytic tumors were considered as relative contraindication for thermal ablation because of the risk of incomplete ablation or major complications as hemorrhage and seeding.

AIM OF THIS STUDY

to evaluate the safety and efficacy of microwave ablation (MWA) of exophytic HCC in comparison with non-exophytic HCC.

METHODS

Prospective comparative study carried on 30 patients having 30 exophytic (six of those patients had another non-exophytic lesion) and 32 patients having 44 non-exophytic HCC lesions (22 had single lesion, 8 patients had 2 lesions, and 2 patients had 3 lesions) within Milan criteria. All patients were child A or B, they were subjected to full clinical assessment, laboratory investigations, and radiological investigations. Laparoscopic assisted percutaneous MWA was the procedure of choice in our study for all patients either having exophytic or non-exophytic lesions using no-touch wedge technique for exophytic lesions and direct puncture for non-exophytic lesions.

RESULTS

Technical success was 100% in both groups, all lesions were completely ablated as confirmed by LIOUS. There were no major complications or perioperative mortality and low incidence of local tumor progression in both exophytic and non-exophytic groups.

CONCLUSION

Laparoscopic assisted MWA of exophytic HCC is safe and effective with comparable results to non-exophytic HCC. Exophytic HCC is not contraindication for MWA with proper technique selection.

Comparison of radiofrequency and microwave ablation and identification of risk factors for primary treatment failure and local progression

PURPOSE

To compare percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) for treatment of Hepatocellular carcinoma (HCC) and to identify risk factors for treatment failure and local progression.

METHODS

145 unique HCC [87 (60%) RFA, 58 (40%) MWA] were retrospectively reviewed from a single tertiary medical center. Adverse events were classified as severe, moderate, or mild according to the Society of Interventional Radiology Adverse Event Classification system. Primary and secondary efficacy, as well as local progression, were determined using mRECIST. Predictors of treatment failure and time to local progression were analyzed using generalized estimating equations and Cox regression, respectively.

RESULTS

Technical success was achieved in 143/145 (99%) HCC. There were 1 (0.7%) severe and 2 (1.4%) moderate adverse events. Of the 143 technically successful initial treatments, 136 (95%) completed at least one follow-up exam. Primary efficacy was achieved in 114/136 (84%). 9/22 (41%) primary failures underwent successful repeat ablation, so secondary efficacy was achieved in 128/136 (90%) HCC. Local progression occurred in 24 (19%) HCC at a median of 25 months (95% CI = 19-32 months). There was no difference in technical success, primary efficacy, or time to local progression between RFA and MWA. In HCC treated with MWA, same-day biopsy was associated with primary failure (RR = 9.0, 95% CI: 1.7-47, P = 0.015), and proximity to the diaphragm or gastrointestinal tract was associated with local progression (HR = 2.40, 95% CI:1.5-80, P = 0.017).

CONCLUSION

There was no significant difference in primary efficacy or time to local progression between percutaneous RFA and MWA.

Ablative therapies for hepatic and biliary tumors: endohepatology coming of age

Ablative therapies refer to minimally invasive procedures performed to destroy abnormal tissue that may arise with many conditions, and can be achieved clinically using chemical, thermal, and other techniques. In this review article, we explore the different ablative therapies used in the management of hepatic and biliary malignancies, namely hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), with a particular focus on radiofrequency ablation (RFA) and photodynamic therapy (PDT) techniques.

Thermally sensitive fluorescence imaging system for radiofrequency ablation guidance

Radiofrequency ablation (RFA) has been clinically used as a minimally invasive procedure for the treatment of many solid tumors. However, the current imaging techniques have some shortages in RFA guidance, especially for the assessment of the margin of ablation. Herein, we developed a novel optical imaging platform to guide RFA utilizing fluorescence resonance energy transfer from a thermally sensitive fluorescent protein conjugated to a near-infrared fluorescent dye. Additionally, attaching receptor-targeting ligands further equipped the system with high specificity to tumors overexpressing the targeted receptor.

Stereotactic radiofrequency ablation of subcardiac hepatocellular carcinoma: a case-control study

Purpose: The purpose of this study is to evaluate the safety and efficacy of stereotactic radiofrequency ablation (SRFA) for the treatment of subcardiac hepatocellular carcinoma (HCC). Material and methods: From 2003 to 2018, 79 consecutive patients underwent 104 multi-probe SRFA sessions for the treatment of 114 subcardiac HCC with a median size of 2.5 cm (0.5-9.5 cm). The results were compared with a randomly selected control group of 79 patients with 242 HCC with a median size of 2.0 cm (0.5-12 cm) following SRFA in other (non-subcardiac) locations with propensity score matching. Results: The 95.6% of the tumors were successfully treated by the first ablation session (primary technical efficacy rate) and 99.1% after the second session (secondary technical efficacy rate). Local tumor recurrence developed in 8 nodules (7.0%). Major complication and perioperative mortality rates were 7.7% (8/104) and 1% (1/104), respectively. The overall survival (OS) rates from the date of the first SRFA with single subcardiac HCCs were 92%, 77% and 65% at 1, 3 and 5 years, respectively, with a median OS of 90.6 months. The disease-free survival (DFS) after SRFA was 75, 34 and 34%, at 1, 3 and 5 years, respectively, with a median DFS of 19.1 months. There was no statistically significant difference with the control group in terms of local tumor control, safety, OS and DFS. Conclusion: SRFA of subcardiac tumors is as safe and efficacious as when treating tumors remote from the heart.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

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.

Improved clinical outcome using transarterial chemoembolization combined with radiofrequency ablation for patients in Barcelona clinic liver cancer stage A or B hepatocellular carcinoma regardless of tumor size: results of a single-center retrospective case control study

Background

To determine the safety and efficacy of transarterial chemoembolization (TACE) combined with radiofrequency ablation (hereafter, TACE-RFA) in treating Barcelona Clinic Liver Cancer (BCLC) Stage A or B (hereafter, BCLC A/B) hepatocellular carcinoma (HCC) patients, and to explore the range of tumor sizes suitable for combination therapy.

Methods

This retrospective study assessed the consecutive medical records of HCC patients with BCLC A/B who received TACE-RFA or TACE from September 2009 to September 2018. Progression-free survival (PFS), overall survival (OS), therapeutic response, and complications were compared between the two groups.

Results

Among 2447 patients who received TACE-RFA or TACE, 399 eligible patients were enrolled in our study, including 128 patients in the TACE-RFA group and 271 patients in the TACE group. Compared with the TACE group, the PFS and OS rates of 1,3,5,8 years in the TACE-RFA group were significantly better, with higher objective tumor regression rate and better disease control rate. RFA treatment did not increase the risk of death in patients with HCC, and both liver subcapsular hematoma and bile duct injury were improved by symptomatic treatment. Serum α-fetoprotein level and treatment method were important independent prognostic factors for OS, whereas albumin, hepatitis B and treatment method were important independent prognostic factors for PFS. Subgroup analysis showed that patients in the TACE-RFA group always showed better OS and PFS.

Conclusions

TACE-RFA had an advantage over TACE alone in prolonging PFS and improving OS in HCC patients with BCLC A/B, and can benefit patients regardless of tumor size.