Synchrotron Microbeam Radiation Therapy (MRT) has repeatedly proven its superiority compared with conventional radiotherapy for glioma control in preclinical research. The clinical transfer phase of MRT has recently gained momentum; seven dogs with suspected glioma were treated under clinical conditions to determine the feasibility and safety of MRT. We administered a single fraction of 3D-conformal, image-guided MRT. Ultra-high-dose rate synchrotron X-ray microbeams (50 µm-wide, 400 µm-spaced) were delivered through five conformal irradiation ports. The PTV received ~25 Gy peak dose (within microbeams) per port, corresponding to a minimal cumulated valley dose (diffusing between microbeams) of 2.8 Gy. The dogs underwent clinical and MRI follow-up, and owner evaluations. One dog was lost to follow-up. Clinical exams of the remaining six dogs during the first 3 months did not indicate radiotoxicity induced by MRT. Quality of life improved from 7.3/10 [±0.7] to 8.9/10 [±0.3]. Tumor-induced seizure activity decreased significantly. A significant tumor volume reduction of 69% [±6%] was reached 3 months after MRT. Our study is the first neuro-oncologic veterinary trial of 3D-conformal Synchrotron MRT and reveals that MRT does not induce acute to subacute radiotoxicity in normal brain tissues. MRT improves quality of life and leads to remarkable tumor volume reduction despite low valley dose delivery. This trial is an essential step towards the forthcoming clinical application of MRT against deep-seated human brain tumors.
同步辐射微束放疗在临床前研究中已多次被证实对胶质瘤的控制效果优于传统放疗。目前该技术的临床转化阶段进展迅速：本研究在临床条件下对七只疑似胶质瘤犬只进行治疗，以评估同步辐射微束放疗的可行性与安全性。我们采用单次三维适形图像引导的微束放疗方案，通过五个适形照射端口输送超高剂量率同步辐射X射线微束（束宽50微米，间距400微米）。每个端口的计划靶区接收约25 Gy的峰值剂量（微束内部），对应累积最低谷剂量（微束间扩散区域）为2.8 Gy。通过临床检查、磁共振成像随访及饲主评估进行疗效监测，其中一只犬只失访。其余六只犬只在治疗后三个月内的临床检查均未发现放疗毒性反应。生活质量评分从7.3/10[±0.7]提升至8.9/10[±0.3]，肿瘤诱发的癫痫发作显著减少，治疗后三个月肿瘤体积实现69%[±6%]的显著缩减。本研究是首个三维适形同步辐射微束放疗的神经肿瘤学兽医临床试验，结果表明该技术不会引起正常脑组织的急性至亚急性放射毒性，在低谷剂量条件下仍能改善生活质量并实现显著的肿瘤体积缩减。该试验为推动微束放疗在未来治疗深部人类脑肿瘤的临床应用迈出了关键一步。
肿瘤(癌症)患者之家