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

Development and validation of a prognostic nomogram for early hepatocellular carcinoma treated with microwave ablation

Objective

An effective model for risk stratification and prognostic assessment of early hepatocellular carcinoma (HCC) patients following microwave ablation (MWA) is lacking in clinical practice. The aim of this study is to develop and validate a prognostic model specifically for these patients.

Methods

Between January 2008 and December 2018, 345 treatment-naïve patients with HCC conforming to the Milan criteria who underwent MWA were enrolled and randomly assigned to the training (n=209) and validation (n=136) cohorts. The nomogram model was constructed based on the predictors assessed by the multivariate Cox proportional hazards model and validated. Predictive accuracy and discriminative ability were further evaluated and compared with other prognostic models.

Results

After a median follow-up of 59.0 months, 52.5% (187/356) of the patients had died. Prognostic factors for overall survival (OS) were α-fetoprotein (AFP), albumin-bilirubin (ALBI) score, platelets, and ablation margins, which generated the nomograms. The nomogram model consistently achieved good calibration and discriminatory ability with a concordance index of 0.64 (95% confidence interval (CI): 0.59-0.69) and 0.69 (95% CI: 0.63-0.75) in both the training and validation cohorts. The performance of the nomogram model also outperformed other prognostic models. By using the nomogram model, the patient population could be correctly divided into low- and high-risk strata presenting significantly different median OS of 105.0 (95% CI: 84.1-125.9) months, and 45.0 (95% CI: 28.0-62.0) months, respectively.

Conclusion

The nomogram model based on AFP, PLT, ablation margins, and ALBI score was a simple visualization model that could stratify patients with early-stage HCC after MWA and predict individualized long-term survival with favorable performance.

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.

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

ABSTRACT

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

Long-term survival analysis of ultrasound-guided percutaneous microwave ablation for hepatocellular carcinoma conforming to the Milan criteria: primary versus recurrent HCC

BACKGROUND

This study compared long-term outcomes between patients with initial hepatocellular carcinoma (IHCC) and those with recurrent HCC (RHCC) treated with microwave ablation (MWA).

METHODS

This retrospective study included 425 patients with HCCs (294 IHCCs and 131 RHCCs) within the Milan criteria who were treated with ultrasound-guided percutaneous MWA between January 2008 and November 2021. All patients with RHCC had previously undergone MWA for initial HCC. Overall survival (OS) and recurrence-free survival (RFS) rates were compared between the IHCC and RHCC groups before and after propensity score matching (PSM).

RESULTS

Before matching, the 1-, 3-, 5-, and 10-year OS rates in the IHCC group were 95.9%, 78.5%, 60.2%, and 42.5%, respectively, which were significantly higher than those in the RHCC group (93.8%, 70.0%, 42.0%, and 6.6%, respectively). This difference remained significant after PSM. However, subgroup analyses suggested that there were no significant differences in OS rates between IHCC and RHCC in patients with solitary HCC ≤3.0 cm, AFP ≤200 ng/mL, ablative margins ≥0.5 cm, or Albumin-Bilirubin (ALBI) grade 1. RFS was significantly higher in IHCC than in RHCC before and after PSM, as well as in subgroup analyses. ALBI grade (hazard ratio (HR), 2.38; 95% CI: 1.46-3.86; p < 0.001), serum AFP level (HR, 2.07; 95% CI: 1.19-3.62; p = 0.010) and ablative margins (HR, 0.18; 95% CI: 0.06-0.59; p = 0.005) were independent prognostic factors for OS of RHCC. Serum AFP(HR, 1.29; 95% CI: 1.02-1.63, p = 0.036) level was the only factor associated with RFS in RHCC.

CONCLUSIONS

MWA yielded comparable OS in IHCC and RHCC patients with solitary HCC ≤3.0 cm, AFP ≤200 ng/mL, ablative margins ≥0.5 cm, or ALBI grade 1.

Thermal ablation for hepatic tumors in high-risk locations

Thermal ablative techniques such as radiofrequency and microwave ablation are minimally invasive and cost-effective approaches that are currently being adopted as alternatives to surgical resection for primary and metastatic liver malignancies. However, they are considered to be relatively contraindicated for tumors in high-risk locations due to technical difficulties and a perceived increased risk of perioperative complications. Several techniques, including artificial ascites, non-touch multibipolar ablation, and laparoscopically assisted ablation, can be used to improve the outcomes of ablation for high-risk tumors. This review aims to provide a comprehensive summary of the techniques currently used to improve thermal ablation outcomes for high-risk liver tumors.

Perfluoropentane/apatinib-encapsulated metal-organic framework nanoparticles enhanced the microwave ablation of hepatocellular carcinoma

Microwave ablation (MWA) is a promising minimally invasive therapy for hepatocellular carcinoma (HCC). However, the efficiency of MWA in treating HCC is evidently limited by the incomplete ablation of large tumors and tumors in high-risk locations. Here we designed an iron-based metal-organic framework nanomedicine (PFP-Apa-MOF) by loading perfluoropentane (PFP) and apatinib (Apa). After being absorbed by HCC, iron could induce ferroptosis. PFP could be activated into bubbles and act as an ultrasound agent for detecting the ablation margin. As an effective antiangiogenic drug, Apa could inhibit tumor residual growth after MWA. The high efficiency of PFP-Apa-MOF was fully demonstrated in vitro and in vivo. The results showed that MWA combined with PFP-Apa-MOF clearly enhanced the ablation efficiency, leading to apparent tumor inhibition, and increased tumor apoptosis and lipid peroxide. PFP-Apa-MOF could play a valuable role in enhancing MWA to achieve better therapeutic efficacy in HCC.

Long-term efficacy and safety of microwave ablation for hepatocellular carcinoma adjacent to the gallbladder with a diameter ≤ 5 cm: a multicenter, propensity score matching study

OBJECTIVE

To compare the long-term efficacy and safety of microwave ablation (MWA) as first-line therapy for hepatocellular carcinoma (HCC) adjacent versus nonadjacent to the gallbladder.

MATERIALS AND METHODS

From 2006 to 2018, 657 patients with ≤5 cm HCC who underwent percutaneous ultrasound-guided MWA as first-line therapy from 5 hospitals were enrolled in this retrospective study. Patients were grouped into the adjacent group (n = 49) and the nonadjacent group (n = 608) according to whether the tumor was adjacent to the gallbladder. Propensity score matching (PSM) was used to balance baseline variables between the two groups.

RESULTS

Forty-eight patient pairs were matched after PSM. For the PSM cohort, during a median follow-up time of 60 months, there were no differences in PFS (hazard ratio [HR], 1.011; 95% confidence interval [CI], 0.647-1.578; p = 0.963) or OS (HR 0.925; 95% CI 0.522-1.639; p = 0.789) between the adjacent and nonadjacent groups. Univariate and multivariate analyses revealed that the tumor adjacent to the gallbladder was not an independent risk factor for PFS or OS (all p > 0.05). Subgroup analysis showed comparable PFS and OS between the two groups in the <3 cm subgroup and the 3-5 cm subgroups (all p > 0.05). In addition to more use of assistive technology (p < 0.05), the adjacent group shared comparable local tumor progression, complications, technical success rate, and hospital stay (all p > 0.05) to the nonadjacent group.

CONCLUSION

There were comparable long-term efficacy and complications between patients with HCC adjacent and nonadjacent to the gallbladder treated with MWA.

Biliary complications and efficacy after ablation of peribiliary tumors using irreversible electroporation (IRE) or radiofrequency ablation (RFA)

OBJECTIVE

To evaluate the biliary complication rates and efficacy of peribiliary tumor ablation using irreversible electroporation (IRE) or radiofrequency ablation (RFA).

MATERIAL AND METHODS

This is a retrospective study of 42 consecutive patients with 44 peribiliary tumors (≤5 mm distance between the tumor margin and the primary or secondary bile duct). Data were collected between January 2014 and September 2020 from patients who underwent percutaneous liver ablation using IRE (n = 13) or RFA (n = 31).

RESULTS

The median length of follow-up was 23.1 months. The mean tumor size was 17.2 ± 5.2 mm in IRE vs. 18.4 ± 7.0 mm in RFA (p= .56). Complete tumor ablation was achieved in 100% with a significantly larger ablation zone in the IRE group (3.8 ± 0.3 cm vs. 2.6 ± 0.6 cm, p<.001). Significant biliary complications occurred in one patient (7.7%) of the IRE group and in five patients (16.1%) of the RFA group. Significant risk factors for biliary complications included the RFA procedure (HR 9.71, p=.032) and proximity of the tumor to the bile duct (HR 0.63, p=.048). The local tumor progression (LTP) rates were 7.7% (IRE) vs. 21.5% (RFA) at 1 year, 23.1% (IRE) vs. 32.7% (RFA) at 2 years and 23.1% (IRE) vs. 44% (RFA) at 3 years, respectively (p=.289).

CONCLUSIONS

The IRE and RFA procedures are safe and effective to treat peribiliary liver tumors. However, the RFA may have a higher risk of significant bile duct injury than IRE. The shorter distance between the bile duct and the tumor is a strong risk factor for biliary complications.

Combination therapy with PD-1 blockade and radiofrequency ablation for recurrent hepatocellular carcinoma: a propensity score matching analysis

BACKGROUND

This study aimed to evaluate whether combined therapy with PD-1 blockade (anti-PD-1) and radiofrequency ablation (RFA) is superior to RFA monotherapy for recurrent hepatocellular carcinoma (HCC).

METHODS

A total of 127 patients who underwent anti-PD-1 plus RFA treatment (n = 41) or RFA alone (n = 86) for recurrent HCC were included in this retrospective study. A matched cohort comprising 40 patients from each group was selected after propensity score matching analysis. Clinical data including post-RFA HCC recurrence (primary endpoint), overall survival (OS) (secondary endpoint), adverse events, and toxic effects were retrospectively analyzed.

RESULTS

The 1-year recurrence-free survival rates for the anti-PD-1 plus RFA and RFA groups were 32.5% and 10.0% after propensity score matching. There were statistically significant differences between the two groups in terms of the recurrence-free survival rate (p = 0.001) and OS rate (p = 0.016). Tumor number, tumor-node metastasis (TNM) stage, antiviral therapy, and anti-PD-1 treatment were demonstrated to be important factors associated with 1-year recurrence-free survival probability by univariate and multivariate analyses. Univariate and multivariate analyses demonstrated that tumor number, TNM stage and anti-PD-1 treatment were significant prognostic factors for OS. RFA treatment-related adverse events included pleural effusions that require drainage and a mild or moderate increase in body temperature. Grade 3 or higher events related to anti-PD-1 treatment occurred in 12.8% (6) of patients and were infrequent.

CONCLUSIONS

Combination therapy with anti-PD-1 plus RFA was superior to RFA alone in improving survival in patients with recurrent HCC.

Advances in Diagnostic and Interventional Radiology in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths, and radiological imaging and locoregional therapies are essential for the management of patients with HCC.

SUMMARY

In cirrhotic patients, a characteristic imaging pattern establishes the noninvasive diagnosis of HCC with acceptable sensitivity and high specificity. In addition to diagnosis, imaging is used in the staging of patients and treatment allocation. Multiparametric MRI with hepatospecific contrast agents improves lesion detection, characterization, and treatment allocation; recently described imaging criteria allow identification of precursor lesions. Radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) have been established in the treatment of patients with HCC at the early and intermediate stages, respectively. Microwave ablation has been described as an alternative to RFA in selected cases. Imaging-guided brachytherapy, a catheter-based radiotherapy technique, offers advantages to overcome some limitations of the aforementioned therapies, including the tumor location and size. Currently, no adjuvant therapy is recommended after RFA or TACE, but several new drugs are under evaluation. Furthermore, although the exact role of selective internal radiation therapy (SIRT) in HCC still needs to be defined, it is an alternative to systemic agents in patients with intolerance, and additional benefit has been shown in selected subgroups. Additionally, SIRT offers an alternate to TACE with higher objective response rates in patients who needs bridging before transplantation.

KEY MESSAGES

New imaging criteria improved lesion detection in patients at a risk for HCC, and advances in interventional therapies expanded the range of patients eligible for locoregional treatments.