Combined Microsphere Sizing Strategy May Offer Alternative to Current Standards

A combined microsphere sizing strategy seemed technically feasible and had a promising toxicity profile and effectiveness measures, researchers reported.

The study was prospective, single-center, and had a single arm consisting of 36 consecutive patients with hepatocellular carcinoma (HCC) who had 54 naïve lesions. The protocol examined was a combination of 100 μm ± 25 and 200 μm ± 50 epirubicin-loaded polyethylene glycol (PEG) microsphere drug-eluting embolic transcatheter arterial chemoembolization.

Treatment consisted of embolization with 100 μm ± 25 microspheres, with 200 μm ± 50 microspheres administered if stasis (defined as 10 heart beats) was not reached. The researchers said that each syringe (2 mL) of PEG microsphere was loaded with 50 mg of epirubicin. The Modified Response Evaluation Criteria In Solid Tumors with multidetector computed tomography/magnetic resonance imaging at 1, 3-6, 9-12, and 15-18 months was used to evaluate results.

The investigators found that stasis was achieved with 100 μm ± 25 microspheres alone in 10 of 21 lesions that were less than 2 cm in diameter.  All other lesions needed adjunctive treatment with 200 μm ± 50 microspheres.

Adverse events included grade 1 acute liver bile duct injury in 3 of 39 cases and grade 2 PES in 3 of 39 cases. At 1 month, complete response was 61.1% and objective response (complete response + partial response) was 83.3%. At 3 to 6 months, complete response was 65.5% and objective response was 65.85%, and at 9 to 12 months complete response was 63.63% and objective response was 63.63%. Finally, at 15 to 18 months complete response was 62.5% and objective response was 62.5%. The researchers noted that there was no single factor that predicted outcomes except for albumin level at baseline for complete response.

“In conclusion, the proposed combined embolization protocol consisting of sequential administration of 100 μm ± 25 and 200 μm ± 50 PEG microspheres preloaded with epirubicin showed sustained CR and DC rates of 60% and 90%, respectively, up to 15–18 months from the initial treatment,” the authors stated. They added, “Randomized controlled studies are needed to compare the oncologic outcome of different materials, calibers, and drugs of DEE transcatheter arterial chemoembolization protocols.”


Lucatelli P, Argirò R, De Rubeis G, 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. J Vasc Interv Radiol. 2019 Mar;30(3):305-313. doi: 10.1016/j.jvir.2018.10.026. Epub 2019 Jan 31.