Polyethylene Glycol Epirubicin-Loaded Transcatheter Arterial Chemoembolization Procedures Utilizing a Combined Approach with 100 and 200 µm Microspheres: A Promising Alternative to Current Standards

Clinical question
How effective and safe is transarterial chemoembolization using 100 µm and 200 µm epirubicin-loaded polyethylene glycol using combined microsphere sizing strategy for hepatocellular carcinoma?

Take-away point
Staged embolization with 100 µm embolic followed by 200 µm embolic with epirubicin was technically feasible and demonstrated excellent imaging response compared to commonly sited data within the literature suggesting an advantage to sequential administration during embolization.

Reference
Lucatelli, Pierleone, et al. Polyethylene Glycol Epirubicin-Loaded Transcatheter Arterial Chemoembolization Procedures Utilizing a Combined Approach with 100 and 200 µm Microspheres: A Promising Alternative to Current Standards. Journal of Vascular and Interventional Radiology. 2019

Click here for abstract

Study design: Prospective

Funding source: Self-funded or unfunded

Setting: Single-center 

Summary

Drug eluting embolic (DEE) transarterial chemoembolization (TACE) is a well-established procedure for the treatment of hepatocellular carcinoma. However, there is no consensus protocol for embolic sizing with a wide range employed throughout the literature. The authors hypothesized that a combination of particle calibers, 100 µm and 200 µm, could combine tumoral blood stasis and proximal embolization. In this single center, prospective trial, a combined embolization protocol using LifePearl (Terumo, Tokyo, Japan) 100 µm and 200 µm particles loaded with epirubicin was evaluated for clinical outcomes in patients with hepatocellular carcinoma. 

36 patients with 54 hepatocellular carcinoma tumors were enrolled. DEE TACE was performed with epirubicin, first with 100 µm particles followed by 200 µm particles with embolization endpoint of 10 heart beats stasis. Study primary endpoints were tumoral response at follow up intervals, tumoral diameter and administered dose correlated with mRECIST response, and toxicity. By mRECIST criteria, complete response at 1 month, 3-6 months, 9-12 months and 15-18 months was 61.1% 65.9%, 63.6%, and 62.5%. Disease control rate was 100%, 92.7%, 90.0%, and 93.7% (1, 3-6, 9-12, and 15-18 month follow up). Notably, 47.6% of tumors < 2 cm reached 10 beats stasis with 100 µm particles alone, while only 18.5% of all tumors required only 100 µm particles. Among all treatments, only 3 adverse events occurred, all mild (grade 2) which resolved within 24 hours.

Commentary

There is a significant amount of heterogeneity among the protocols used within the literature for TACE procedure. The complete response rate and disease control rates demonstrated in this study were superior to much of the current TACE literature. With multiple factors being involved, such as drug of choice (epirubicin versus doxorubicin), embolic of choice (LifePearl a polyethylene glycol particle versus numerous other beads and conventional TACE), and embolization protocol (sequential usage of two sizes), it is difficult to determine which or which combination are responsible for the results. The authors did include pathologic data demonstrating the smaller particles were predominantly found intratumorally which the larger particles were seen in the peritumoral arterioles, suggesting the two sizes could serve different purposes during treatment combing enhanced intra-tumoral dose delivery with effective proximal ischemic embolization. While mainly limited do to the small sample size of 36 patients, this does provide evidence that we can optimize our embolization protocols. While further research is necessary, large randomized control trials would be difficult and unlikely to parse out the optimal medication, particle size(s), and bead for TACE.

Post Author:
David M Mauro, MD
Assistant Professor
Department of Radiology, Vascular and Interventional Radiology
University of North Carolina
@DavidMauroMD