Macroscopic vascular invasion (MVI) significantly impacts survival in patients with hepatocellular carcinoma (HCC), warranting systemic therapy over locoregional therapy. Despite novel approaches, HCC with MVI has a poor prognosis compared to early-to intermediate-stage HCC. This study aimed to evaluate the safety and efficacy of carbon-ion radiotherapy (C-ion RT) for HCC characterized by MVI. This retrospective cohort study evaluated HCC patients with MVI treated using C-ion RT with a dose of 45.0–48.0 Gy/2 fractions or 52.8–60.0 Gy/4 fractions between 1995 and 2020 at our institution in Japan. We analyzed the prognostic factors and rates of local recurrence, survival, and adverse events. The local recurrence rate was determined using the cumulative incidence function, with death as a competing event. Survival rates were determined using the Kaplan–Meier method. The log-rank test for univariate analysis and the Cox proportional hazards model for multivariate analysis were used to compare subgroups. In total, 76 patients with a median age of 71 years (range, 45–86 years) were evaluated. Among them, 68 had Child–Pugh grade A while eight had grade B disease. In 17 patients, the vascular tumor thrombus reached the inferior vena cava or main trunk of the portal vein. Over a median follow-up period of 27.9 months (range, 1.5–180.4 months), the 2-year overall survival, progression-free survival, and local recurrence rates were 70.0% (95% confidence interval [CI]: 57.7–79.4%), 32.7% (95% CI: 22.0–43.8%), and 8.9% (95% CI: 1.7–23.5%), respectively. A naïve tumor and a single lesion were significant prognostic factors for overall survival in the univariate analysis. Albumin-bilirubin grade 1 and a single lesion were independent prognostic factors in the multivariate analysis. Overall, four patients (5%) experienced grade 3 late adverse events, with no observed grade 4 or 5 acute or late adverse events. C-ion RT for HCC with MVI showed favorable local control and survival benefits with minimal toxicity.

中文翻译：

---

碳离子放射治疗伴大血管侵犯的肝细胞癌：一项回顾性队列研究

宏观血管侵犯（MVI）显着影响肝细胞癌（HCC）患者的生存，因此需要全身治疗而不是局部治疗。尽管有新的方法，但与早中期 HCC 相比，MVI 的 HCC 预后较差。本研究旨在评估碳离子放射治疗（C-ion RT）治疗以 MVI 为特征的 HCC 的安全性和有效性。这项回顾性队列研究评估了 1995 年至 2020 年间在我们日本机构使用 C 离子放疗（剂量为 45.0–48.0 Gy/2 分次或 52.8–60.0 Gy/4 分次）治疗的 MVI 的 HCC 患者。我们分析了预后因素以及局部复发率、生存率和不良事件。使用累积发生率函数确定局部复发率，其中死亡作为竞争事件。使用Kaplan-Meier 方法确定存活率。使用单变量分析的对数秩检验和多变量分析的 Cox 比例风险模型来比较亚组。总共对 76 名中位年龄为 71 岁（范围 45-86 岁）的患者进行了评估。其中，68 例患有 Child-Pugh A 级疾病，8 例患有 B 级疾病。 17例患者血管瘤栓到达下腔静脉或门静脉主干。中位随访期为 27.9 个月（范围为 1.5-180.4 个月），2 年总生存率、无进展生存率和局部复发率为 70.0%（95% 置信区间 [CI]：57.7-79.4） %)、32.7% (95% CI: 22.0–43.8%) 和 8.9% (95% CI: 1.7–23.5%)。在单变量分析中，幼稚肿瘤和单一病变是总体生存的重要预后因素。多变量分析中，1 级白蛋白-胆红素和单一病变是独立的预后因素。总体而言，4 名患者 (5%) 经历了 3 级晚期不良事件，没有观察到 4 级或 5 级急性或晚期不良事件。 C 离子放疗联合 MVI 治疗 HCC 显示出良好的局部控制和生存益处，且毒性最小。