Abstract No. 160 Unresectable Intrahepatic Cholangiocarcinoma Treated with Radiation Segmentectomy/lobectomy Using Y90-labeled Glass Microspheres

To evaluate the safety and efficacy of radiation segmentectomy/lobectomy using Y90-labeled glass microspheres in patients with unresectable intrahepatic cholangiocarcinoma (IHC). This institutional review board-approved, single-center, retrospective study included 16 patients with IHC who received radiation segmentectomy or lobectomy treatment using Y90-labeled glass microspheres between May 2009 and October 2019. Radiation segmentectomy/lobectomy was defined as at least 190 Gy dose delivered into the treated liver volume . Patients were not excluded if they had prior liver-directed therapy or chemotherapy. Median follow-up time was 7.5 months (range, 2.4-54.2 months). At the time of this analysis, 14 (87.5%) patients had died. The median OS from IHC diagnosis was 22.7 months (95% CI: 13.9-66.1) and from radioembolization was 7 months (95% CI: 4.33-54.17). Patients who did not receive chemotherapy before the radioembolization had significantly longer median OS (26.8 vs 5.9 months, P = 0.037). Four patients had > 20 months survival after radioembolization including 2 patients with survival of 42 and 54 months. Patients with albumin toxicity grade of 0 had significantly longer median OS than patients with grades of 1 or 2 (20.4 vs 4.9 vs 3.2 months, P = 0.000). A bilirubin toxicity grade of 0 was associated with a significantly longer median OS than grade of 2 or 4 (11 vs 5.4 vs 3.2 months; P = 0.000). Patients with an AST or ALT toxicity grade of 0 had longer median OS than patients with toxicity grade of 1. There was no 30-day mortality. No severe complications were reported. Mild, grade 1 or 2 clinical toxicity was reported in 14 patients, the most common complaints were fatigue (n = 9, 56.2%) and abdominal pain (n = 10, 62.5%). Thirty-three events of mild (grade 1 and 2) biochemical toxicities were detected in 14 (87.5%) patients at 3-month follow-up after treatment. Grade 4 elevated bilirubin was detected in 1(6.3%) patient. The MELD score was not significantly different at the 3-month follow-up compared with the baseline (6.79 ± 1.61 vs 8.64 ± 3.77, P = 0.39). Radiation segmentectomy/lobectomy is safe with minimal side effects. The median OS of the study group was modest, however, 4 patients (25%) showed excellent survival. These results suggest a need for a larger scale study to better define the IHC patient group who could most benefit from this procedure.