Background/Objectives: Surgery remains the mainstay of treatment for retroperitoneal sarcoma (RPS); however, definitive therapeutic strategies for patients with insufficient surgical margins and unresectable disease owing to locally advanced RPS remain unclear. Carbon ion radiotherapy (CIRT) has been employed in patients with unresectable RPS. This study aimed to evaluate the effectiveness of CIRT in this patient population. Methods: A retrospective analysis was conducted in 76 patients with unresectable RPS treated with CIRT. Of these, 95% had a confirmed prognosis until 2022. In 74 patients, the prescribed relative biological effectiveness dose was 70.4 Gy, delivered in 16 fractions over 4 weeks. Respiratory gating was used, and spot scanning irradiation has been performed in all patients since 2016. Results: The 3- and 5-year overall survival rates for the entire cohort were 68.3% and 49.4%, respectively, with a median overall survival time of 58.1 months. The 3- and 5-year local control rates were 79.0% and 72.0%, respectively. Among 47 naïve patients with treatment-naïve tumors, the 3- and 5-year abdominal recurrence-free survival rates were 51.1% and 29.1%, respectively. Late adverse events of grade 3 or higher occurred in 4 (5.2%) patients. Conclusions: CIRT represents a definitive treatment option for patients with unresectable RPS. In the future, multicenter studies should be conducted to evaluate the effectiveness of CIRT for RPS in larger patient cohorts.
背景/目的：手术仍是腹膜后肉瘤的主要治疗手段，但对于手术切缘不足或因局部晚期腹膜后肉瘤导致无法切除的患者，其确切治疗策略尚不明确。碳离子放疗已应用于无法切除的腹膜后肉瘤患者。本研究旨在评估碳离子放疗在此类患者群体中的疗效。方法：对76例接受碳离子放疗的无法切除腹膜后肉瘤患者进行回顾性分析。其中95%的患者预后随访至2022年。74例患者接受处方相对生物有效性剂量70.4 Gy，分16次在4周内完成。所有治疗均采用呼吸门控技术，2016年后全部患者采用点扫描照射技术。结果：全组患者3年及5年总生存率分别为68.3%和49.4%，中位总生存时间为58.1个月。3年及5年局部控制率分别为79.0%和72.0%。在47例初治患者中，3年及5年腹腔无复发生存率分别为51.1%和29.1%。4例（5.2%）患者发生3级及以上晚期不良反应。结论：碳离子放疗可作为无法切除腹膜后肉瘤患者的根治性治疗选择。未来应开展多中心研究，在更大患者群体中评估碳离子放疗对腹膜后肉瘤的疗效。
Carbon Ion Radiotherapy for Retroperitoneal Sarcoma: A Single-Institution Study
肿瘤(癌症)患者之家