Selective internal radiation therapy using yttrium-90 microspheres for treatment of localized and locally advanced intrahepatic cholangiocarcinoma.

OBJECTIVES: To evaluate safety and effectiveness of selective internal radiation therapy (SIRT) using yttrium-90 for localized and locally advanced intrahepatic cholangiocarcinoma (iCCA). METHODS: A retrospective review was performed of patients with localized iCCA treated with SIRT at a single institution. Overall survival (OS), local tumor response, progression-free survival (PFS), and toxicity were collected. Stratified analysis was performed based on surgical resection. Predictor analysis of OS was performed using the Fine-Grey regression analysis model with patients bridged to surgery regarded as competing events. RESULTS: A total of 28 consecutive patients with localized iCCA were treated with a total of 38 sessions of SIRT (17 segmental, 13 lobar, and 8 combined deliveries) and a mean dominant target dose per session of 238.4 ± 130.0 Gy. The cumulative radiologic response rate was 16/28 (57.1%) with a median PFS of 265 days. Median survival time (MST) was 22.9 months for the entire cohort with 1-year and 3-year survival of 78.4% and 45.1%, respectively. Ten patients (34.5%) were downstaged to surgical intervention (7 resection, 3 transplant) and showed longer OS (p = 0.027). The 1-year and 3-year OS for patients who received surgery were 100% and 62.5% (95% CI: 14.2-89.3%), respectively. Age (p = 0.028), Eastern Cooperative Oncology Group performance status (p = 0.030), and objective radiologic response (p=0.014) are associated with OS. Two ≥grade 3 hyperbilirubinemia, anemia, and one pleuro-biliary fistula occurred post-SIRT. CONCLUSIONS: SIRT for localized iCCA is safe and effective in achieving radiological response, downstaging to surgery and transplant, and resulting in pathologic necrosis. CLINICAL RELEVANCE STATEMENT: Selective internal radiation therapy should be considered for patients with localized and locally advanced intrahepatic cholangiocarcinoma. KEY POINTS: • The effectiveness of radioembolization for intrahepatic cholangiocarcinoma (iCCA) can be underestimated given the inclusion of extrahepatic disease. • Radioembolization is safe and effective for local and locally advanced iCCA. Age, Eastern Cooperative Oncology Group performance status, and radiologic response are associated with survival. • Radioembolization should be considered for patients with localized and locally advanced iCCA.