Supplementary Material for: Definitive liver radiotherapy for intrahepatic cholangiocarcinoma with extrahepatic metastases

Introduction: Tumor-related liver failure (TRLF) is the most common cause of death in patients with intrahepatic cholangiocarcinoma (ICC). Though we previously showed that liver radiotherapy (L-RT) for locally advanced ICC is associated with less frequent TRLF and longer overall survival (OS), the role of L-RT for patients with extrahepatic metastatic disease (M1) remains undefined. We sought to compare outcomes for M1 ICC patients treated with and without L-RT.

Methods: We reviewed ICC patients found to have M1 disease at initial diagnosis at a single institution between 2010 and 2021 who received L-RT, matching them with an institutional cohort by propensity score and a National Cancer Database (NCDB) cohort by frequency technique. The median biologically effective dose (BED10) was 98 Gy (interquartile range [IQR] 80.5-97.9 Gy) for L-RT. Patients treated with other local therapies or supportive care alone were excluded. We analyzed survival with Cox proportional hazards modeling.

Results: We identified 61 patients who received L-RT and 220 who received chemotherapy alone. At median follow up of 11 months after diagnosis, median OS was 9 months (95% confidence interval [CI] 8-11) and 21 months (CI 17-26) for patients receiving chemotherapy alone and L-RT, respectively. TRLF was the cause of death more often in the patients who received chemotherapy alone compared to those who received L-RT (82% vs. 47%; P=0.001). On multivariable propensity-score matched analysis, associations with lower risk of death included duration of upfront chemotherapy (hazard ratio [HR] 0.82; P=0.005) and receipt of L-RT (HR 0.40; P=0.002). The median OS from diagnosis for NCDB chemotherapy alone cohort was shorter than that of the institutional L-RT cohort (9 vs. 22 months; P

引言：肿瘤相关性肝衰竭（TRLF）是肝内胆管癌（ICC）患者死亡的最常见原因。尽管我们先前的研究表明，局部晚期ICC患者接受肝脏放射治疗（L-RT）与TRLF发生频率降低及总生存期（OS）延长相关，但对于肝外转移性疾病（M1）患者接受L-RT的作用尚无明确定论。本研究旨在比较接受L-RT与未接受L-RT治疗的M1 ICC患者的预后。方法：我们回顾了2010年至2021年间在单一机构初次诊断为M1疾病并接受L-RT治疗的ICC患者，并通过倾向得分匹配与院内队列相匹配，通过频率技术匹配与国家癌症数据库（NCDB）队列相匹配。L-RT的中位生物有效剂量（BED10）为98 Gy（四分位数间距 [IQR] 80.5-97.9 Gy）。仅接受其他局部治疗或支持性护理的患者被排除在外。我们使用Cox比例风险模型分析了生存率。结果：我们确定了61名接受L-RT治疗的患者和220名仅接受化疗的患者。在诊断后中位随访11个月时，仅接受化疗的患者和接受L-RT的患者的中位OS分别为9个月（95%置信区间 [CI] 8-11）和21个月（CI 17-26）。与仅接受化疗的患者相比，接受L-RT的患者死亡原因更频繁的是TRLF（82% vs. 47%；P=0.001）。在多变量倾向得分匹配分析中，与较低死亡风险相关的因素包括首线化疗的持续时间（风险比 [HR] 0.82；P=0.005）和接受L-RT（HR 0.40；P=0.002）。来自NCDB的仅接受化疗队列的中位OS短于接受L-RT的院内队列（9个月 vs. 22个月；P