What size Embospheres are recommended?

Embosphere Size Selection for Transarterial Chemoembolization (TACE)

For hepatocellular carcinoma (HCC) treatment, Embospheres sized 100-300 μm are recommended as the primary choice, with size selection tailored to tumor size: DEBs ≤150 μm for small HCCs and DEBs ≥300 μm for large HCCs with arteriovenous shunts. 1

Size Selection Based on Tumor Characteristics

Tumor Size Considerations

• For HCC ≥3 cm: Use 100-300 μm Embospheres as most tumor-feeding arteries are larger than 300 μm, allowing effective intratumoral accumulation 1
• For HCC ≤2 cm: Consider smaller microspheres (≤150 μm) as the mean diameter of tumor-feeding arteries is approximately 200 μm 1
• For large HCCs with arterioportal or arteriovenous shunts: Consider DEBs ≥300 μm to prevent potential liver and lung damage from smaller particles passing through shunts 1

Efficacy Considerations

• DEBs 100-300 μm have demonstrated better outcomes and lower complication rates compared to larger sizes (300-500 μm and 500-700 μm) in retrospective studies 1
• In Korea, interventional radiologists predominantly prefer DEBs 100-300 μm, with DEBs ≥300 μm rarely used 1
• Recent use of DEBs ≤150 μm aims to enhance intratumoral accumulation, though further investigation is needed regarding efficacy and safety 1

Safety Considerations

Potential Complications

• Small DEBs may require larger particle loads for large HCCs, potentially increasing complication risk 1
• Large DEBs may result in insufficient intratumoral accumulation and damage to arteries and biliary tract due to proximal stagnation 1
• Non-selective infusion of small and permanent embolic agents should be avoided to prevent biliary, hepatic arterial, and parenchymal injury 1

Tumor Vascularity and Arteriovenous Shunts

• For tumors with arteriovenous shunts, consider embolizing the shunts with larger particles prior to DEB-TACE 1
• Too small DEBs in the presence of shunts can potentially cause liver and lung damage through systemic circulation 1
• Superselective delivery is recommended for both efficacy and safety regardless of particle size 1

Clinical Application Algorithm

1. Assess tumor size:

   • For HCC ≤2 cm: Consider DEBs ≤150 μm to enhance penetration into fine tumor-feeding arteries 1
   • For HCC 2-5 cm: Use DEBs 100-300 μm for optimal response 1
   • For HCC >5 cm: Consider DEBs ≥300 μm, especially with arteriovenous shunts 1

2. Evaluate tumor vascularity and presence of shunts:

   • If arteriovenous shunts present: Use larger DEBs (≥300 μm) or embolize shunts first 1
   • For hypervascular tumors: Standard 100-300 μm is appropriate 1

3. Consider delivery method:

   • Always aim for superselective delivery to maximize efficacy and minimize complications 1
   • Dilute DEBs with 30-50 mL of liquid mixture (contrast media and normal saline) to prevent particle clumping 1

Special Considerations

• For small HCCs (≤3 cm), conventional TACE (cTACE) may provide better objective response rates than DEB-TACE with 100-300 μm microspheres 1
• The relationship between DEB size and complications remains controversial, with most complications reported in non-selective DEB-TACE procedures 1
• When using smaller DEBs (≤150 μm), limit doxorubicin dose to 100 mg per session to minimize procedure-related complications 1