Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma

Image-Guided Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma: A Multicenter Experience

Clinical question

Is image-guided thermal ablation safe and effective in patients with hepatic epithelioid hemangioendothelioma?

Take away point

Based on this retrospective multicenter review of 18 patients with 31 ablations, image-guided thermal ablation is a feasible and safe treatment option for patients with HEHE that resulted in local tumor control and a favorable long-term prognosis

Reference

Zeng, Q., Luo, Y., Yu, J., Li, X., Jiang, T.A., Xie, X., Dong, G. and Liang, P., 2024. Image-Guided Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma: A Multicenter Experience. Journal of Vascular and Interventional Radiology.

Click here for abstract

Study design

Retrospective, observational, descriptive study

Funding Source

None

Setting

Academic

Figure

Summary

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular neoplasm with an incidence of less than 1 per million people and constitutes under 1% of hepatic malignancies. Despite its low-to-intermediate malignant potential, HEHE often necessitates treatment due to its multifocal presentation, potential for aggressive progression, and tendency for recurrence and metastasis. The European Society for Medical Oncology recommended surgical resection for stable unifocal or locoregional disease and liver transplantation for unresectable HEHE without extrahepatic disease. For patients ineligible for surgery, alternative treatments such as chemotherapy, radiation, immunotherapy, and antiangiogenic therapy are considered, albeit with varying outcomes. Image-guided thermal ablation has emerged as a potential treatment, particularly for those not suitable for surgery or as a bridge to transplantation. This retrospective study aims to evaluate the feasibility, safety, and effectiveness of thermal ablation for HEHE based on a multicenter experience.

The study involved a retrospective investigation across four hospitals. Informed consent was obtained from 18 patients with pathologically proven HEHE who underwent microwave or radiofrequency ablation between January 2013 and February 2023. Surgical treatment was initially recommended, but ablation was performed on patients ineligible for surgery due to contraindications such as low platelet counts, high international normalized ratios, severe organ dysfunction, or refusal of surgery. Procedures were performed under general anesthesia. Technical success and adverse events were evaluated with contrast-enhanced imaging three days post-ablation, with longer-term follow-ups approximately every three months to monitor intrahepatic distant metastasis, extrahepatic metastasis, local tumor progression, and progression-free survival. Post-ablation adverse events were categorized using the Clavien-Dindo classification within one month of the procedure.

22.2% of the included patients had extrahepatic involvement at diagnosis. Prior treatments included hepatic resection, transcatheter arterial chemoembolization, and systemic therapy. A total of 51 tumors, with a median size of 23.2 mm, were treated with image-guided thermal ablation in 31 sessions, resulting in a 93.5% technical success rate. The median hospitalization was 7 days, with no major adverse events reported. Over a median follow-up of 37.2 months, the median overall survival (OS) was 90.5 months, with OS rates at 1, 3, and 5 years estimated at 87.6%, 75.5%, and 75.5%, respectively. Recurrence occurred in 10 patients, with a median progression-free survival (PFS) of 23.8 months. Larger tumor size was significantly associated with decreased PFS. Patients without extrahepatic involvement had better PFS rates, and early-stage patients had higher PFS rates compared to intermediate-to-advanced-stage patients, although this was not statistically significant.

This multicenter investigation demonstrated that image-guided thermal ablation is a safe and effective treatment for patients with HEHE, achieving a 93.5% technical success rate and manageable minor adverse events. The 1-, 3-, and 5-year OS rates for ablation patients were comparable to those for hepatic resection or liver transplantation, although PFS rates were shorter, likely due to the higher tumor burden and aggressive disease progression in the ablation cohort. Extrahepatic involvement was associated with poorer outcomes, and larger tumor size was a predictor of decreased PFS. Despite these challenges, the repeatability of ablation sessions contributed to favorable OS rates, underscoring its potential as a treatment option. The study's limitations include its retrospective design, potential selection bias, and small sample size due to the rarity of HEHE. Further research is needed to evaluate the benefits of combining ablation with neoadjuvant therapies for larger or multifocal tumors and to determine its role on the HEHE treatment management pathway. In summary, thermal ablation offers favorable local tumor control and long-term effectiveness for HEHE patients ineligible for surgery or transplantation.

Commentary

The use of image-guided thermal ablation for patients with unresectable hepatic epithelioid hemangioendothelioma represents a promising and viable treatment option, as evidenced by the findings of this multicenter, albeit small, investigation. This study highlights the procedure’s safety and effectiveness, showcasing a high technical success rate of 93.5% and favorable overall survival rates comparable to those achieved through more invasive treatments like hepatic resection and liver transplantation.

One significant advantage of thermal ablation is its minimally invasive nature, which makes it suitable for patients who are not candidates for surgical management due to various contraindications. The repeatability of ablation also stands out, allowing for multiple sessions to manage recurrences effectively, potentially contributing to sustained overall survival rates.

However, the shorter progression-free survival rates observed in this study, compared to more invasive treatments, underscore the need for careful patient selection, intra-procedural ablation confirmation software, and potentially the integration of ablation with other therapies. The study's identification of larger tumor size as a predictor of worsened progression-free survival suggests that combining ablation with therapies such as chemoembolization could enhance outcomes for patients with larger or multifocal tumors.

In conclusion, this study provides preliminary evidence that image-guided thermal ablation is a valuable treatment for patients with unresectable hepatic epithelioid hemangioendothelioma, offering a balance of efficacy and safety. Further research will optimize its clinical utility and potentially expand its role in the management of hepatic epithelioid hemangioendothelioma.