(15) Survival Outcomes for Yttrium-90 Radioembolization to Treat Unresectable Intrahepatic Cholangiocarcinoma

Priyali Saxena, Medical Student – Medical Student, University of Illinois College of Medicine; Faisal Al-Qawasmi, Medical Student – Medical Student, University of Illinois College of Medicine

Purpose: Intrahepatic cholangiocarcinoma (ICC) is a progressive disease with a poor prognosis. Surgical resection is curative, but most patients with ICC are ineligible. While systemic therapy with gemcitabine-cisplatin has traditionally been used, transarterial radioembolization (TARE) using yttrium-90 (Y90) has shown promising results in the treatment of unresectable ICC. This abstract will provide a review of the application and potential advantages of TARE-Y90 in this context.

Material and Methods: A systematic literature review was performed using the PubMed database with the search terms "intrahepatic cholangiocarcinoma" and "Y-90 radioembolization" to assess the survival outcomes of TARE-Y90 as a first-line treatment, in combination with gemcitabine-cisplatin, and as salvage/consolidation therapy for ICC.

Results: The included studies exhibited variations in patient cohort compositions, treatment histories, and inclusion criteria. TARE-Y90 shows promising outcomes in unresectable ICC, with reported median OS ranging from 9 to 22 months. A meta-analysis of 789 patients had a pooled median OS of 13.5 months, while Gupta et al. reported a median OS of 14.2 months in a study with 136 participants. Improved OS was associated with solitary tumors, no vascular involvement, higher baseline albumin, and no prior chemotherapy, consistent with existing literature. A phase 2 clinical trial involving 41 patients showed a median OS of 22 months using combined TARE-Y90 and gemcitabine-cisplatin therapy. However, the existing literature presents conflicting evidence regarding the survival advantages of utilizing TARE-Y90 as a first-line therapy compared to its combination with systemic therapy.

Conclusions: TARE-Y90 shows promise for achieving favorable long-term survival outcomes in ICC treatment. It induces an atrophy-hypertrophy complex, enhancing the future liver remnant for potential surgical resection. It can be used as a bridge to transplant or to downstage tumors, the latter demonstrating comparable long-term outcomes to primary resection with a median OS of up to 3 years. TARE provides targeted intra-tumor radiation, offering comparable outcomes to transarterial chemoembolization (TACE) with minimal toxicity and fewer adverse events. Further research is needed to determine the optimal timing of Y90 administration with systemic therapy and to identify ideal candidates for downstaging prior to resection.