Background and purpose

Because myxoid liposarcomas are more radiosensitive than other soft tissue sarcomas, there have been several reports of 50 Gy preoperative radiation therapy combined with surgery, but the wound complication rate is reportedly high. We have performed preoperative irradiation at a reduced dose of 40 Gy and definitive radiation therapy for unresectable cases. This study aimed to report the tumor reduction rate and oncological results with a reduced dose of preoperative irradiation and the outcome of definitive irradiation for unresectable cases.

Materials and methods

Forty-one patients with myxoid liposarcoma treated in our institution between 2002 and 2021 were included. We examined the tumor volume shrinkage rate with preoperative radiation, compared complications and oncological outcomes between preoperative radiation and surgery-only cases, and investigated the prognosis and tumor shrinkage of definitive radiation cases.

Results

The total dose irradiated was 40 Gy except in two cases. The mean tumor volume reduction rate was 52.0%. A decreased dose of preoperative radiation did not worsen clinical outcomes with fewer complications. The total dose of definitive radiation was approximately 60 Gy. The mean tumor volume reduction rate was 55.0%. The tumor shrinkage maintenance rate was 100% in a median follow-up period of 50.5 months.

Conclusion

Preoperative radiation therapy for myxoid liposarcoma near vital organs is a good approach because even with a reduced dose of 40 Gy, significant tumor reduction and excellent results were achieved. Definitive radiation therapy is the recommended treatment for older patients with serious comorbidities or inoperable patients.

中文翻译：

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放射治疗在粘液样圆细胞脂肪肉瘤治疗方案中的意义

背景和目的

由于粘液样脂肪肉瘤比其他软组织肉瘤对放射更敏感，已有数例术前50 Gy放射治疗联合手术的报道，但据报道伤口并发症发生率较高。我们对无法切除的病例进行了 40 Gy 剂量的术前放射治疗和根治性放射治疗。本研究旨在报告减少术前照射剂量的肿瘤缩小率和肿瘤学结果以及不可切除病例的最终照射结果。

材料和方法

2002 年至 2021 年间，我们机构治疗了 41 名粘液样脂肪肉瘤患者。我们检查了术前放疗的肿瘤体积缩小率，比较了术前放疗和仅手术病例的并发症和肿瘤学结果，并研究了最终放疗病例的预后和肿瘤缩小情况。

结果

除两例外，总照射剂量为 40 Gy。平均肿瘤体积缩小率为52.0%。术前放疗剂量的减少并没有使临床结果恶化，并发症也更少。最终辐射的总剂量约为 60 Gy。平均肿瘤体积缩小率为55.0%。中位随访时间为 50.5 个月，肿瘤缩小维持率为 100%。

结论

对重要器官附近的粘液样脂肪肉瘤进行术前放射治疗是一种很好的方法，因为即使减少 40 Gy 的剂量，也能显着减少肿瘤并取得优异的效果。对于患有严重合并症的老年患者或无法手术的患者，推荐采用根治性放射治疗。