两个国家肉瘤中心在选择 2-3 级深部软组织肉瘤 (STS) 患者进行术后放疗 (RT) 方面采用了不同的方法。我们评估了两个中心治疗的患者局部复发的潜在差异。在肉瘤中心 1 (SC1)，除了某些边缘宽于 1 厘米的小肿瘤外，放疗是所有肿瘤的标准治疗方法。肉瘤中心 2 (SC2) 避免对肿瘤进行放疗，无论肿瘤大小如何，如果切除的边缘宽于 1 厘米和/或有实体屏障。我们纳入了 386 名年龄超过 18 岁的患者 (SC1/SC2 = 196/190)，这些患者被诊断患有非转移性 2-3 级、四肢或躯干壁深部 STS，并接受了初次手术治疗（仅切除肿瘤）负裕度）从2000年1月1日到2016年12月31日。应用了Kaplan-Meier生存分析、竞争风险分析和特定原因Cox回归。共有 284 名患者接受了初次 RT，其中 163 名患者 (83%) 在 SC1 接受治疗，121 名患者 (64%) 在 SC2 接受治疗 (p < 0.001)。 SC1 时五年局部复发的累积发生率为 15%（95% CI：10-19%），SC2 时为 14%（95% CI：9-19%）。多变量分析显示各中心之间的局部复发没有显着差异。我们的结论是，当使用意向治疗原则将所有可用患者纳入分析时，对 2-3 级深部 STS 患者采用更具选择性的术后放疗方法并不会导致更高的局部复发率。然而，根据本研究设计，我们不能排除如果对边缘宽于 1 厘米和/或实体屏障的所有切除肿瘤进行放疗，局部复发率是否会更低。

Two national sarcoma centers have had different approaches for selecting patients with grade 2-3 deep-seated soft tissue sarcomas (STS) for postoperative radiotherapy (RT). We evaluated potential differences in local recurrence in patients treated at the two centers. At Sarcoma Center 1 (SC1), RT was the standard treatment for all tumors except certain small tumors excised with a margin wider than 1 cm. Sarcoma Center 2 (SC2) avoided RT for tumors regardless of tumor size if removed with a margin wider than 1 cm and/or a solid barrier. We included 386 patients (SC1/SC2 = 196/190) over 18 years of age diagnosed with a non-metastatic grade 2-3, deep-seated STS of the extremities or trunk wall, who underwent primary surgical treatment (only tumors excised with a negative margin) from 1 January 2000, to 31 December 2016. Kaplan-Meier survival analysis, competing risk analysis, and cause-specific Cox regression were applied. A total of 284 patients received primary RT, 163 (83%) at SC1 and 121 (64%) at SC2 (p < 0.001). The cumulative incidence of local recurrence at five years was 15% (95% CI: 10-19%) at SC1 and 14% (95% CI: 9-19%) at SC2. Multivariate analysis showed no significant differences in local recurrence between the centers. We concluded that when entering all available patients into the analysis using an intention-to-treat principle, a more selective approach to postoperative RT in patients with grade 2-3 deep-seated STS did not lead to a higher local recurrence rate. However, with this study design, we cannot rule out if the local recurrence rate could have been lower if RT was administered to all tumors removed with a margin wider than 1 cm and/or a solid barrier.