作者报告了减少剂量烷化剂化疗联合放疗对欧洲小儿软组织肉瘤研究组 (EpSSG) 标准风险非肺泡横纹肌肉瘤 (NA-RMS) 的前瞻性评估。局部淋巴结阴性组间横纹肌肉瘤研究 (IRS) II/III NA-RMS在有利部位（C 亚组），<25 岁，接受 5 个周期的异环磷酰胺、长春新碱和放线菌素 (IVA) 化疗（30 g/m2 异环磷酰胺）和 4 个周期的长春新碱和放线菌素（如果接受放疗），或 9 个周期IVA (54 g/m2 异环磷酰胺) ± 放射治疗。对于 IRS III 肿瘤，考虑延迟原发肿瘤切除。主要终点是无事件生存期（EFS）和总生存期（OS）。从2005年10月至2016年12月，招募了359名可评估患者：眼眶，164名（45.7％）；头颈部非脑膜旁，77 例（21.4%）；和泌尿生殖非膀胱/前列腺，118 (32.9%)。 EFS 和 OS 分别为 77.4%（95% 置信区间 [CI]，72.5-81.6）和 93.5%（95% CI，90.1-95.8）。较低剂量烷基化剂化疗和放疗实现了 93.7% 的 5 年 OS，但与较高剂量烷基化剂化疗/放疗的差异并不显着 (p = 0.8003)。辅助放疗改善了 EFS，5 年估计为 84.7%，而未放疗的 5 年估计为 65.2% (p < .0001)，但 OS 没有改善 (p = .9298)。省略眼眶肿瘤的放射治疗会降低 OS（5 年生存率为 87.1%，而接受放射治疗的 OS 为 97.3%，p = .0257）。 R0 切除 (n = 60) 后，放疗并未显着改善 EFS 或 OS。用于局部肿瘤控制的放疗可以减少 EpSSG 标准风险亚组 C RMS 患者的烷化剂累积剂量。省略放疗并不影响所有患者的 OS，除了那些患有眼眶 RMS 的患者，并且与较差的 EFS 相关。© 2024 作者。 《癌症》由 Wiley periodicals LLC 代表美国癌症协会出版。

The authors report the prospective evaluation of reduced dose alkylator chemotherapy combined with radiotherapy for European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) standard risk nonalveolar rhabdomyosarcoma (NA-RMS).Localized node negative Intergroup Rhabdomyosarcoma Study (IRS) II/III NA-RMS at favorable sites (subgroup C), <25 years old, received five cycles of ifosfamide, vincristine, and dactinomycin (IVA) chemotherapy (30 g/m2 ifosfamide) and four cycles of vincristine and dactinomycin (if receiving radiotherapy), or nine cycles of IVA (54 g/m2 ifosfamide) ± radiotherapy. Delayed primary tumor excision was considered for IRS III tumors. The primary end points were event-free survival (EFS) and overall survival (OS).From October 2005 to December 2016, 359 evaluable patients were recruited: orbit, 164 (45.7%); head and neck nonparameningeal, 77 (21.4%); and genitourinary non-bladder/prostate, 118 (32.9%). EFS and OS were 77.4% (95% confidence interval [CI], 72.5-81.6) and 93.5% (95% CI, 90.1-95.8), respectively. Lower dose alkylator chemotherapy and radiotherapy achieved 5-year OS of 93.7% but the difference with higher dose alkylator chemotherapy +/- radiotherapy was not significant (p = 0.8003). Adjuvant radiotherapy improved EFS with 5-year estimates of 84.7% versus 65.2% for nonirradiated (p < .0001), but not OS (p = .9298). Omitting radiotherapy for orbital tumors reduced OS (5-year was 87.1% vs. 97.3% for irradiated, p = .0257). Following R0 resection (n = 60), radiotherapy did not significantly improve EFS or OS.Radiotherapy for local tumor control allows for reduction of cumulative dose of alkylators in EpSSG standard risk subgroup C RMS patients. The omission of radiotherapy did not affect OS in all patients except those with orbital RMS and was associated with inferior EFS.© 2024 The Author(s). Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.