Supplementary file 1_Iodine-125 brachytherapy for orbital-invasive low-grade myxofibrosarcoma of the maxillary sinus: a case report challenging conventional therapeutic paradigms.docx

Low-grade myxofibrosarcoma (LGMFS) is a rare subtype of soft tissue sarcoma, with an estimated incidence of approximately 0.18 cases per million population, accounting for about 0.6% of all soft tissue sarcomas. It is characterized by a high local recurrence rate and malignant potential. Orbital involvement secondary to maxillary sinus LGMFS represents an exceptionally rare occurrence. The management of such cases is complicated by anatomical complexity (e.g., proximity to optic nerve, lacrimal apparatus, and orbital vasculature) and limitations of conventional therapies, including radical resection combined with chemoradiation. In this anatomically complex case of recurrent Low-Grade Myxofibrosarcoma, iodine-125 brachytherapy achieved durable local control (12-month progression-free survival), demonstrating superior precision targeting and reduced systemic toxicity compared to conventional therapies. No acute radiation toxicity was observed, while facial swelling and eye pain were relieved with concurrent improvement in visual function.

低度恶性黏液纤维肉瘤（Low-grade myxofibrosarcoma, LGMFS）是一种罕见的软组织肉瘤亚型，据估计其发病率约为0.18例/百万人口，约占所有软组织肉瘤的0.6%。该肿瘤以高局部复发率与恶性潜能为主要特征。继发于上颌窦低度恶性黏液纤维肉瘤的眼眶受累极为罕见。此类病例的诊疗因解剖结构复杂（如毗邻视神经、泪器及眼眶血管系统）且常规治疗手段存在局限（如需联合根治性切除术与放化疗）而颇具挑战。本案例为解剖结构复杂的复发性低度恶性黏液纤维肉瘤病例，采用碘-125近距离放射治疗实现了持久的局部控制（12个月无进展生存期），相较于常规治疗展现出更优异的精准靶向性与更低的全身毒性。本次治疗未观察到急性放射毒性，患者面部肿胀与眼痛症状得以缓解，视功能亦同步改善。