Physiologically gated micro-beam radiation therapy using electronically controlled field emission x-ray source array.
Physiologically gated micro-beam radiation therapy using electronically controlled field emission x-ray source array.
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使用电子控制场发射 X 射线源阵列进行生理门控微束放射治疗。
DOI：
10.1117/12.2007998
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Zhou,Otto
中科院分区：
文献类型：
--
作者：
Chtcheprov,Pavel;Hadsell,Michael;Burk,Laurel;Ger,Rachel;Zhang,Lei;Yuan,Hong;Lee,YuehZ;Chang,Sha;Lu,Jianping;Zhou,Otto
微束放射治疗（MRT）使用相距不到一毫米的高剂量窄（10-100微米宽）辐射束的平行平面来治疗癌性肿瘤。这种基于同步辐射的实验性治疗方法已被证明在高达1000Gy的入口剂量下可以保留正常组织，同时仍然有效地根除肿瘤并延长肿瘤小动物模型的寿命。治疗过程中的运动可导致微束位置的显著移动，从而导致束宽变宽，峰谷剂量比（PVDR）降低，从而降低MRT的有效性。最近，我们开发了第一台用于小动物治疗的台式图像引导MRT系统，该系统使用高功率碳纳米管（CNT） x射线源阵列。碳纳米管场发射x射线源可以与外部触发信号电子同步，使x射线辐射的生理门控发射最小化运动模糊。在此，我们报告呼吸门控MRT的幻像研究结果。利用伺服电机对小鼠呼吸进行了模拟。初步结果表明，在不加门控的情况下，微束的十分之一全宽（FWTM）可提高70%，PVDR可降低50%。但是通过适当的门控，波束宽度和PVDR的变化可以忽略不计。未来的实验将包括小鼠模型的辐照和比较对照组和门控辐照的组织学染色。
Micro-beam radiation therapy (MRT) uses parallel planes of high dose narrow (10-100 um in width) radiation beams separated by a fraction of a millimeter to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000Gy of entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during the treatment can result in significant movement of micro beam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), and thus can reduce the effectiveness of the MRT. Recently we have developed the first bench-top image guided MRT system for small animal treatment using a high powered carbon nanotube (CNT) x-ray source array. The CNT field emission x-ray source can be electronically synchronized to an external triggering signal to enable physiologically gated firing of x-ray radiation to minimize motion blurring. Here we report the results of phantom study of respiratory gated MRT. A simulation of mouse breathing was performed using a servo motor. Preliminary results show that without gating the micro beam full width at tenth maximum (FWTM) can increase by 70% and PVDR can decrease up to 50%. But with proper gating, both the beam width and PVDR changes can be negligible. Future experiments will involve irradiation of mouse models and comparing histology stains between the controls and the gated irradiation.