基于能谱CT的脑胶质瘤放疗疗效影像学定量评估

Stereotatic radiosurgery(SRS) is one of the important treatments for refractory and recurrent brain glioma.The accuracy of three dimensional conformal radiation field drawing and the sensitivity of early predictions for brain tissue and tumor cells after irradiation are essential for radiation safety and effectiveness.In this project, single energy CT value, spectral curve slope, base material concentration of Spectral CT and quantitative indicators of CT perfusion parameters were compared with the pathological analysis to explore the spectral CT quantitative detection indicators that can accurately detect the tumor cell density, proliferation activity and local blood vessels permeability.Then construct a multi-parameter fusion stereoscopic model which can accurately display the invasion range of tumor cells;Through Quantitative analyzed the Imaging phenotype characteristics of spectral CT and CT perfusion images, pathologic features, general data and the information of the intervention measures before and after radiotherapy, establish an individual image prediction model that can early predict the tendency of the tumor cell density, the proliferative activity and local blood vessel wall permeability.In this project, Rat C6 Glioma was used to pre-clinically validate the proposed model to reveal the mechanism of tumor cell proliferation after X - ray irradiation,and actrally provide a theoretical basis for the construction of accurate navigation of target irradiation dose and sensitive radiotherapy efficacy evaluation.

立体定向放疗是难治性、复发性脑胶质瘤重要的治疗手段之一，三维适形照射野的精准绘制及照射后局部脑组织和肿瘤细胞对射线敏感性的早期预判对放疗安全性和有效性至关重要。本项目采用能谱CT单能量CT值、能谱曲线斜率、基物质浓度及CT灌注各参数量化指标与病理对照分析，探寻能够准确检测瘤细胞密度、增殖活性及局部血管壁透过性的能谱CT定量检测指标，进而构建能够准确显示肿瘤细胞侵袭范围的多参数融合立体模型；通过放疗前后能谱CT与CT灌注图像的影像表型特征、病理改变、一般资料、干预措施信息的定量分析，构建个体化影像学预测模型，实现放疗后肿瘤细胞密度、增殖活性及局部血管壁透过性变化规律的影像学早期评估。本项目以大鼠C6脑胶质瘤对所提出模型进行预临床验证，揭示X线照射大鼠C6脑胶质瘤后以上各指标动态变化规律，阐释X线照射后肿瘤细胞增殖趋势变化的机制，为构建精准的靶区照射剂量导航和敏感的放疗后疗效评估提供理论依据。

脑胶质瘤的诊治仍然是临床难点，放、化疗等治疗后脑组织和肿瘤细胞对治疗的早期预判对治疗的安全性和有效性至关重要。能谱 CT 作为近年来逐渐应用于临床的多参数功能成像方法，能够实现对组织微细结构和功能状态的量化检测。本项目通过能谱CT单能量CT值、基物质浓度及能谱曲线斜率各定量参数与大鼠脑胶质瘤放疗、化疗、抗血管治疗及激素治疗后病理改变进行对照，结果表明能谱CT参数能够实现对大鼠脑胶质瘤血管生成与抗血管生成、放疗、化疗后肿瘤细胞增殖指数以及激素地塞米松治疗后肿瘤免疫微环境的早期改变进行定量分析，揭示了各种治疗后大鼠C6脑胶质瘤能谱CT各指标动态变化规律，阐释了治疗后肿瘤血管及瘤细胞增殖趋势变化的机制，从而为脑胶质瘤疗效的影像学定量评估提供了一种新方法、新思路，推进实现脑胶质瘤的精准治疗。另外，本项目在涉及脑胶质瘤影像的诊断与鉴别诊断、预测分子分型、分级方面及能谱CT影像定量分析方面进行了大量临床研究，结果表明影像学定量分析方法能够利用深层次的肿瘤表型特征分析肿瘤微观异质性，从而对临床各种疾病的诊断与治疗提供更多的指导。