Streamlining Radioembolization for CCC and Metastatic Liver Cancer

TARE uses radioactive microspheres (20-60 μm), which are trapped in tumors due to abnormal vasculature, while normal liver sinusoids (≤15 μm) prevent their passage. However, some microspheres may drain into hepatic veins and reach the lungs, risking radiation pneumonitis. Pre-procedural evaluation with angiography and nuclear imaging (MAA scan with SPECT/CT) is required to calculate lung shunt fraction (LSF). TARE is contraindicated if LSF \>20%, and may be used with caution if LSF is 10-20%. Findings associated with high LSF include large tumors, hepatic vein invasion, TIPS, and dysmorphic intratumoral vessels. In contrast, small or medium sized (\<7 cm) cholangiocarcinoma or metastatic liver cancers without hepatic vein invasion or dysmorphic vessels show consistently low LSF (\<5%). Over 10 years at SNUH, no cases of radiation pneumonitis have been observed in such patients. Therefore, "streamlining TARE" omits pre-procedural nuclear imaging for this group to reduce procedural delays, reserving nuclear imaging for patients who need it most. SIR-Spheres (SIRTEX) facilitate single-session TARE as they are provided in a bulk vial, unlike TheraSphere which requires advance preparation based on dosimetry. Protocol Overview : Procedure: Same-day angiography, cone-beam CT, and TARE using SIR-Spheres. Dosimetry: Lung shunt fraction is assumed as 5%, estimated lung dose is capped at 10 Gy. Tumor dose goal: 80\~400 Gy (around 250Gy)(single-compartment MIRD), or 300 \~ 1000 Gy (multi-compartment MIRD). minimal tumor dose by partition dosimetry : 100Gy Software: Simplicit90Y for planning, Y90 PET/CT the next day for post-treatment dosimetry. Follow-up: 1 year; additional treatments follow institutional guidelines. This streamlined approach maximizes efficiency while maintaining safety in selected patients.

NCT Number	NCT07043387
Lead Sponsor	Seoul National University Hospital
Conditions	Metastatic Colorectal Carcinoma (mCRC), Metastatic Liver Cancer, Cholangiocarcinoma
Enrollment	60 participants
Start Date	2025-06-22
Primary Completion	2028-12-30 (estimated)
Study Completion	2029-06-30 (estimated)
Updated on ClinicalTrials.gov	2025-07-24