Real-time Ultrasonic Monitoring of Tumor Ablation

描述（由申请人提供）：射频（RF）和微波消融技术是间质性局灶性消融治疗，可以经皮方式使用。它们允许原位破坏肝、肾和前列腺肿瘤。然而，射频消融治疗后的局部复发率高达34- 55%，部分原因是在常规超声引导下治疗后无法可视化坏死区（热损伤）。弹性成像是一种很有前途的工具，用于可视化射频消融导致的组织坏死区。本研究的目的是开发和评估技术，超声为基础的体内弹性成像可视化消融区域的热治疗期间和之后，并确定是否弹性成像图像提供的程度和治疗区域的可行性的临床信息。该研究计划开发和评价“RF电极位移”弹性成像。首先使用精密机械测试装置测量正常肝脏、肝脏肿瘤和转移瘤以及消融肝脏的基本弹性模量特性。使用在肝脏组织中测量的杨氏模量的弹性成像体模也将用于确定标测消融区域的可靠性。特殊的幻影，包括那些具有复杂的形状，将挑战电极位移弹性成像在现实条件下。将利用有限元分析（FEA）对射频电极位移引起的组织位移进行建模，并外推和理解体模结果。将进行体内研究，以测试在木盘HCC癌症和兔VX 2转移模型上用于体内弹性成像的电极位移弹性成像，以评价消融治疗前后癌症的弹性成像描述。将使用消融组织的光学显微镜对弹性图与组织病理学进行比较，以确定弹性图是否能够区分消融（坏死）与未消融（具有活癌细胞的区域）和正常组织区域。电极位移弹性成像沿着2-D互相关处理的实时实施将在Siemens AnglomerTM扫描仪上实施。最后，将使用在Siemens Anastomic扫描仪上开发的实时弹性成像模式在较大的猪动物模型和肿瘤模型上进行初步研究（原发性HCC和转移瘤模型），以评价在实际成像条件下使用弹性成像监测经皮射频消融的能力。在微创射频消融过程中，体内弹性成像监测消融性癌症治疗的进展和结果可以使一大群患者受益。

DESCRIPTION (provided by applicant): Radiofrequency (RF) and microwave ablation techniques are interstitial, focal ablative therapies that can be used in a percutaneous fashion. They permit in situ destruction of hepatic, renal and prostatic tumors. However, local recurrence rates after RF ablative therapy are as high as 34-55%, due in part to the inability to visualize the zone of necrosis (thermal lesion) after treatment under conventional ultrasound guidance. Elastography is a promising tool for visualizing the zone of necrosis in tissue resulting from RF ablation. The goal of this research is to develop and evaluate techniques for ultrasound-based in-vivo elastography for visualizing ablated regions during and after thermal therapy, and to determine whether elastographic images provide clinical information on the extent and viability of the treated region. The research plan develops and evaluates "RF electrode displacement" elastography. Basic elastic modulus properties of normal liver, liver neoplasms and metastases, and ablated liver wjll first be measured using a precision mechanical testing device. Elastography phantoms using the Young's Modulus measured in liver tissue will also be used to determine the reliability of mapping out ablated regions. Special phantoms, including those that have complex shapes, will challenge electrode displacement elastography under realistic conditions. Finite element analysis (FEA) will be utilized to model tissue displacements induced by RF electrode displacements and to extrapolate and understand phantom results. In-vivo studies will be conducted to test electrode displacement elastography for in-vivo elastographic imaging both on a wood- chuck HCC cancer and Rabbit VX2 metastases model to evaluate the elastographic depiction of cancers before and after ablation therapy. Comparisons of the elastograms with histopathology using light microscopy of ablated tissue will be performed to determine if elastograms are able to differentiate ablated (necrotic) from unablated (regions with viable cancer cells) and normal tissue regions. Real-time implementation of electrode displacement elastography along with 2-D cross-correlation processing will be implemented on the Siemens Antares scanner. Finally, a pilot study will be performed using the real-time elastographic modality developed on the Siemens Antares scanner on both a larger porcine animal model and tumor model (both the primary HCC and metastases model) to evaluate the ability to monitor percutaneous RF ablation using elastography under actual imaging conditions Clinical application of in-vivo elastography to monitor the progression and outcome of ablative cancer treatments during the minimally invasive RF ablation procedure could benefit a large group of patients.