Background/Objectives: Despite multimodal therapeutic concepts, treatment of recurrent malignant gliomas remains challenging. Stereotactic radiosurgery (SRS) may be a possible safe and effective non-invasive salvage treatment. In this study, we aim to investigate the SRS treatment outcomes using partly 18F-Fluorethylthyrosine (FET)-PET-imaging sequences for SRS treatment planning focusing on overall survival, event-free survival, and the incidence and factors influencing radiation necrosis (RN) occurrence. Additionally, we evaluated the potential application of AI-based tumor segmentation. Methods: We conducted a retrospective analysis of patients with recurrent malignant glioma treated with single-fraction or hypofractionated SRS at our institution. The outcomes assessed included local control, overall survival (OS), and local event-free survival (LEFS, defined as the interval until tumor recurrence or the onset of RN). We also performed a simulation analysis to assess the potential of AI-based tumor segmentation. Results: The study included 27 patients with a median age of 57 years and 41 lesions. The median OS post-SRS was 9.6 months and an LEFS of 5.2 months. Factors positively influencing OS and LEFS included the gross tumor volume (GTV) of the lesions before SRS therapy, presence of an IDH mutation, and lomustine treatment post-SRS. The incidence of RN post-SRS was 31.7%. RN was confirmed histopathologically in 15.4%, based on MRI in 46.2% and by FET-PET in 38.5% of lesions. In a simulation analysis, AI-based tumor segmentation reliably delineated all lesions, requiring only minimal manual adjustments to define target volumes. Conclusions: High-dose SRS is a feasible salvage treatment for small-volume recurrent high-grade gliomas, achieving local control and survival outcomes comparable to other re-irradiation strategies. IDH mutation, smaller tumor volume, and lomustine therapy were associated with improved survival. RN occurred frequently, particularly in periventricular lesions. AI-based tumor segmentation showed promise in well-defined satellite recurrences, but remains limited in cavity-adjacent lesions, underlining the need for expert review and18FET-PET imaging.
背景/目的：尽管存在多模式治疗理念，复发性恶性胶质瘤的治疗仍具挑战性。立体定向放射外科（SRS）可能是一种安全有效的非侵入性挽救治疗方案。本研究旨在探讨采用部分¹⁸F-氟乙基酪氨酸（FET）-PET成像序列进行SRS治疗计划后的疗效，重点关注总生存期、无事件生存期以及放射性坏死（RN）的发生率及其影响因素。此外，我们还评估了基于人工智能的肿瘤分割技术的潜在应用价值。方法：我们对本机构接受单次或大分割SRS治疗的复发性恶性胶质瘤患者进行了回顾性分析。评估指标包括局部控制率、总生存期（OS）和局部无事件生存期（LEFS，定义为直至肿瘤复发或RN发生的时间间隔）。同时，我们进行了模拟分析以评估基于AI的肿瘤分割技术的潜力。结果：研究共纳入27例患者（中位年龄57岁）的41个病灶。SRS治疗后中位OS为9.6个月，中位LEFS为5.2个月。对OS和LEFS产生积极影响的因素包括：SRS治疗前病灶的肿瘤大体体积（GTV）、IDH突变的存在以及SRS后洛莫司汀治疗。SRS后RN发生率为31.7%。其中15.4%的病灶经组织病理学确诊，46.2%基于MRI诊断，38.5%通过FET-PET确认。在模拟分析中，基于AI的肿瘤分割技术能可靠勾画所有病灶，仅需极少人工调整即可确定靶区范围。结论：大剂量SRS是治疗小体积复发性高级别胶质瘤的可行挽救方案，其局部控制率和生存结局与其他再照射策略相当。IDH突变、较小肿瘤体积和洛莫司汀治疗与生存改善相关。RN发生频繁，尤其在脑室周围病灶中。基于AI的肿瘤分割技术在边界清晰的卫星复发灶中表现良好，但在瘤腔邻近病灶中仍存在局限，这强调了专家审核和¹⁸FET-PET成像的必要性。
肿瘤(癌症)患者之家