Change in Imaging Findings on Angiography-Assisted CT During Balloon-Occluded Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma

A novel method for predicting hepatocellular carcinoma response to chemoembolization using an intraprocedural CT hepatic arteriography-based enhancement mapping: a proof-of-concept analysis

BACKGROUND

To evaluate the feasibility of a novel approach for predicting hepatocellular carcinoma (HCC) response to drug-eluting beads transarterial chemoembolization (DEB-TACE) using computed tomography hepatic arteriography enhancement mapping (CTHA-EM) method.

METHODS

This three-institution retrospective study included 29 patients with 46 HCCs treated with DEB-TACE between 2017 and 2020. Pre- and posttreatment CTHA-EM images were generated using a prototype deformable registration and subtraction software. Relative tumor enhancement (T_Post/pre-RE) defined as the ratio of tumor enhancement to normal liver tissue was calculated to categorize tumor response as residual (T_Post-RE > 1) versus non-residual (T_Post-RE ≤ 1) enhancement, which was blinded compared to the response assessment on first follow-up imaging using modified RECIST criteria. Additionally, for tumors with residual enhancement, CTHA-EM was evaluated to identify its potential feeding arteries.

RESULTS

CTHA-EM showed residual enhancement in 18/46 (39.1%) and non-residual enhancement in 28/46 (60.9%) HCCs, with significant differences on T_Post-RE (3.05 ± 2.4 versus 0.48 ± 0.23, respectively; p < 0.001). The first follow-up imaging showed non-complete response (partial response or stable disease) in 19/46 (41.3%) and complete response in 27/46 (58.7%) HCCs. CTHA-EM had a response prediction sensitivity of 94.7% (95% CI, 74.0-99.9) and specificity of 100% (95% CI, 87.2-100). Feeding arteries to the residual enhancement areas were demonstrated in all 18 HCCs (20 arteries where DEB-TACE was delivered, 2 newly developed collaterals following DEB-TACE).

CONCLUSION

CTHA-EM method was highly accurate in predicting initial HCC response to DEB-TACE and identifying feeding arteries to the areas of residual arterial enhancement.

Microballoon Interventions for Liver Tumors: Review of Literature and Future Perspectives

Background: Microballoon interventions (MBIs) have been proposed as useful tools to improve the efficacy of locoregional liver treatments. The aim of this systematic review was to summarize the existing evidence on procedural characteristics, safety, and efficacy of MBIs. Methods: PubMed and Cochrane Central Register of Controlled Trials were queried for original research articles evaluating MBIs in patients with liver malignancies from 2012 to August 2022. Search terms employed were liver malignancies, hepatocellular carcinoma, cholangiocarcinoma, liver metastases, microballoon transarterial chemoembolization, balloon-occluded trans-arterial chemoembolization, balloon-occluded selective internal radiation therapies, balloon-occluded TACE and ablation, and safety or oncological results or efficacy. Merely technical studies and animal studies were excluded. Results: Thirty-four original research studies and one abstract involving 744 patients treated with MBIs were included; 76% of the studies were retrospective, with low risk of bias and moderate-to-poor levels of evidence. Heterogeneity precluded meta-analysis. All studies proved MBI safety, which was not inferior to non-occlusive procedures. Balloon employment ameliorates oncological results, improving time to recurrence, objective response rate, and lowers need for retreatment. Conclusions: MBIs appear to be potential game changers in the treatment of liver malignancies. Multicentric, prospective and randomized studies are necessary to confirm these findings.

Balloon-occluded transcatheter arterial chemoembolization for hepatocellular carcinoma

Transcatheter arterial chemoembolization (TACE) is widely accepted as a treatment for patients with hepatocellular carcinoma (HCC) in the intermediate stage according to the Barcelona Clinic Liver Cancer (BCLC) guidelines. Recently, balloon-occluded TACE (B-TACE) was developed in Japan. Despite the lack of a clear definition, B-TACE is generally defined as the infusion of emulsion of chemotherapeutic agents with lipiodol followed by gelatin particles under the occlusion of feeding arteries by a microballoon catheter, which leads to the dense lipiodol emulsion (LE) accumulation in HCC nodules. This phenomenon cannot be explained only by the prevention of proximal migration and leakage of embolization materials; it further involves causing local changes in the hemodynamics of the surrounding occlusion artery and targeted HCC nodules. Balloon-occluded arterial stump pressure plays an important role in the dense LE accumulation in targeted HCC nodules. Although randomized controlled trials comparing the therapeutic effect and the prognosis of B-TACE to those of the other TACE procedures, such as conventional-TACE and drug-eluting beads TACE, are still lacking, B-TACE is thought to be a promising treatment. The purpose of this review is to summarize the mechanism, therapeutic effect, indication, prognosis and complications of B-TACE.