Streamlining Radioembolization for Cholangiocarcinoma or Metastatic Liver Cancer ≤ 7 cm : Multicenter Prospective Registry Study
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.
• Adult aged 19 and over
⁃ metastatic liver cancer or cholangiocarcinoma
‣ the diameter of the largest tumor ≤ 7cm, tumor number 5 or less
∙ FLR volume \> 30% of total non-tumorous liver volume
• Dysmorphic intratumoral vessel : absent, if present, 3mm or thinner ⑥ Child-Pugh class A
⁃ Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1 ⑧ No major organ dysfunction according to blood test performed within two months of study enrollment A. Leukocytes ≥ 1,000/µL and ≤ 20,000/µL B. Hemoglobin ≥ 6.0 g/dL (transfusion allowed to meet this criterion) C. Total bilirubin ≤ 2.0 mg/dL D. Platelet ≥ 40,000/µL E. International normalized ratio (INR) ≤ 2.0 for patients not taking anticoagulants F. Aspartate transaminase (AST) ≤ 800 IU/L (i.e., ≤ 20X upper normal limit) G. Alanine transaminase (ALT) ≤ 800 IU/L (i.e., ≤ 20X upper normal limit) H. Creatinine ≤ 2.5 mg/dL (If patients is undergoing hemodialysis, no limit of creatinine) ⑨ Patients with a life expectancy of more than 3 months ⑩ For women of childbearing age, a negative serum pregnancy test. ⑪ Patients who have adequately understood the clinical trial and consented in writing