Radioembolization for Unresectable Intrahepatic Cholangiocarcinoma: Review of Safety, Response Evaluation Criteria in Solid Tumors 1.1 Imaging Response and Survival

The optimal palliative treatment for unresectable intrahepatic cholangiocarcinoma (ICC) remains controversial. While selective internal radiation therapy (SIRT) using yttrium-90 microspheres is a well-accepted treatment for hepatocellular carcinoma, data related to its use for locally advanced ICC remain relatively scarce. Twenty-nine patients (mean age 66 +/- 11 years; 15 female) with unresectable biopsy-proven ICC treated with SIRT between June 2008 and April 2015 were retrospectively evaluated for post-treatment toxicity, overall survival, and imaging response using response evaluation criteria in solid tumors (RECIST) 1.1 criteria. RECIST 1.1 response was evaluable following 26 treatments [complete response (CR):0, partial response (PR):3; stable disease (SD):16, progression of disease (PD):7]. Objective response rate (CR+PR) was 12%. Disease control rate (CR+PR+SD) was 73%. Median time to progression was 5.6 [95% confidence interval (CI): 0-12.0] months. Median survival following SIRT was 9.1 (95% CI: 1.7-16.4) months. Post-treatment survival was prolonged in patients with absence of extrahepatic disease (p=0.03) and correlated with RECIST 1.1 response (p=0.02). Toxicities were limited to grade I severity and occurred following 27% of treatments. These findings support the safe, effective use of SIRT for unresectable ICC. Post-treatment survival is prolonged in patients with absence of extrahepatic disease at baseline. RECIST 1.1 response following SIRT for ICC is predictive of survival.