全瘤及肺CT灌注早期评估肺肿瘤射频消融反应的兔肺VX2肿瘤模型病理-影像对照及初步临床研究

CT-guided percutaneous radiofrequency ablation (RFA) is an novel technique for minimally invasive treatment for unoperated primary and secondary lung tumors. However, the response evalutaion by imaging methods is still complicated. The early accurate assessment of the ablative reaction after RFA using functional imaging is an urgent need to study.In our study, an first-pass CT perfusion (CTP)study using the dy-volume scan mode and low X-ray dose technique will be taken both in whole tumor with the dual-blood supply mode of pulmonary and systemic circulation and in the lung parenchyma with the single mode of pulmonary circulation. This CTP examiantion will be underwent using a rabbit lung VX2 tumor mode to investigate the realations between the variations and distributions of quantitative CTP parameters in the ablative tumors and "safty zone" in the surrouding lung parenchyma and the pathological changes before RFA and in early stage after RFA, such as coagulation necrosis, tumor tissue, the "ghost cell" phenomenon, alveolar effusion,congested lung with hemorrhage and inflammatory reactions. This examiantion will also be used to investigate the feasiblity and capability of judgment of the residual tumor and assessment of the ablative margin in the early stage after RFA and to evaluate the relations between the early CTP characteristics and the clinical outcome of patients. This study could be provide possibly the animal experimental,pathological,and clinical bases for use of CTP in monitoring the reaction of RFA in pulmonary neoplasms. A new avenue for post-RFA imaging surveillance in pulmonary malignancy be hoped to open though this issue.

射频消融术是原发及继发性肺癌的一种新型微创性局部治疗方法，但术后影像学评价复杂。更加准确地利用功能影像学新方法早期评估消融反应是目前需迫切研究的课题。本研究将基于射频消融术所致瘤体和瘤周肺实质安全区的凝固性坏死、残留肿瘤组织、"鬼影细胞"、肺泡积液、肺充血及炎性反应等早期病理学改变，拟联合采用基于低剂量dy-volume动态增强技术的肺动脉及支气管动脉-双血供全瘤及肺动脉-单血供肺实质的首过期CT灌注成像方法，探索兔肺VX2移植肿瘤模型的CT灌注参数在瘤体内及周围肺实质的定量值及空间分布与消融术前及术后早期病理学的对照关系，并探讨CT灌注早期判断肺肿瘤患者消融术后瘤内残留及瘤周安全区的可行性及准确性，评估术后早期CT灌注特征与肿瘤临床转归的相关性，为完善肺肿瘤射频消融术后疗效的影像学评价提供动物实验、病理学及初步临床实践基础。希望通过此研究为肺肿瘤射频消融术的综合影像学评估开辟新的途径。

背景：目前既有的影像学方法对肺肿瘤射频消融（Radiofrequency ablation, RFA）术后的评估存在一定限度，尤其是对安全区（CT上表现为肿瘤周围的磨玻璃区，ground-glass opacity, GGO）的评估。本研究试图利用CT灌注分别对瘤灶及瘤周GGO进行血流灌注参数定量分析，并与病理进行对照，以期达到早期疗效评估。.主要研究内容：（1）兔肺VX2肿瘤模型的建立及血供观察；（2）兔肺双血供-CT灌注检查造影剂注射方案的优化；（3）兔肺VX2肿瘤RFA术前、术后即刻、术后3天、7天及14天CT灌注检查；（4）兔肺VX2肿瘤RFA后CT灌注参数的变化与病理对照.重要结果：RFA术后即刻、3、7、14天瘤灶肺动脉血流量（PF）均明显降低（p值均为0.00，a=0.05），支气管动脉血流量（BF）在RFA术后即刻、3、7天明显下降（p值均为0.00，a=0.05）；残留组BF明显高于彻底RFA组（p=0.01，a=0.05），BF>11.8 ml/min/100ml对残瘤诊断的敏感度及特异度分别为75%，91.67%，ROC曲线下面积为0.81。残留组瘤周GGO PF值明显高于正常对照组及彻底消融组（p=0.01，0.00，a=0.05）PF>23.9 ml/min/100ml对残瘤诊断的敏感度及特异度分别为100%，85.71%，ROC曲线下面积为1。.科学意义：BF值及PF值可分别对RFA术后瘤区及瘤周进行早期评估。