Investigation of nerve fibre imaging in radiosurgery

20%-40%的癌症患者会发生脑转移(BM)。随着癌症患者寿命的延长，这种发病率可能会增加。有效的治疗为患者提供了高质量的生活，但由于患者数量的增加和与治疗失败相关的风险，有效的治疗必须是有效和准确的。一种越来越常用的精确治疗方法是“立体定向脑放射外科手术”(SRS)，它避开了敏感的大脑区域，如果后来诊断出新的转移瘤，可以重复使用，超过50%的病例会发生这种情况。 与神经外科(NS)一样，SRS依靠磁共振成像(MRI)来计划治疗。在NS中，MRI为神经外科医生提供了通过大脑的最佳方法，避开了重要的大脑结构。在SRS中，MRI提供了辐射束的最佳路径。人们越来越有兴趣使用一种名为扩散张量成像(DTI)的MRI技术来获得脑神经纤维图，以进行NS规划。DTI也可用于SRS计划，以最大限度地减少对重要神经通路和神经的损伤，特别是当患者以前有SRS的时候。此外，DTI可以改善对神经纤维的辐射损伤的检测，并比目前的成像更好地描绘肿瘤的边界。然而，DTI对空间失真非常敏感，这限制了它的应用。 Synaptive Medical是一家总部位于多伦多的医疗设备/软件公司，该公司已开发出解决方案，用于纠正纤维束可视化并将其纳入NS计划(BrightMatterTM计划)，以及评估传入的DTI扫描以满足最低诊断要求(BrightMatterTM Bridge)。该提案的主要目标是调查Synaptive的解决方案如何提高SRS规划的准确性。项目里程碑包括：评估当前使用的DTI协议、SRS规划所需的功能、查看BM边界的能力以及可视化SRS造成的神经纤维损伤的能力。

20-40% of all cancer patients develop brain metastases (BM). The incidence is likely to increase as cancer patients are living longer. Effective treatment provides patients with a high quality of life, but must be efficient and accurate due to increasing patient numbers and the risks associated with treatment failure. An increasingly used precise treatment is "stereotactic brain radiosurgery" (SRS), which avoids sensitive brain regions and can be used repeatedly if new metastases are later diagnosed, which happens in more than 50% of cases. As in neurosurgery (NS), SRS relies on magnetic resonance imaging (MRI) for planning treatment. In NS, MRI provides the neurosurgeon with the optimal approach through the brain, avoiding important brain structures. In SRS, MRI provides the optimal path of the radiation beams. There is increasing interest in obtaining brain nerve fiber maps using an MRI technique called "diffusion tensor imaging" (DTI) for NS planning. DTI could also be used in SRS planning to minimize injury to important neural pathways and nerves, especially when patients have had previous SRS. Furthermore, DTI may improve detection of radiation damage to nerve fibers, and better delineate tumour boundary than with current imaging. However, DTI is very sensitive to spatial distortions, which currently limits its utility. Synaptive Medical is a medical device/software company based in Toronto that has developed solutions for correcting and incorporating fiber tract visualization into NS planning (BrightMatterTM Plan), as well assessing incoming DTI scans for meeting minimum diagnostic requirements (BrightMatterTM Bridge). The main proposal objective is to investigate how Synaptive's solutions may improve SRS planning accuracy. Project milestones include evaluation of: currently used DTI protocols, functionality needed for SRS planning, ability to see BM boundary, and ability to visualize nerve fiber damage from SRS.