Tumor Ablation using Radiofrequency

描述：(改编自调查人员的摘要)的长期目标 本研究课题是发展和优化图像引导射频技术。 (RF)患者的肿瘤消融。微创热疗技术的研究进展 肿瘤消融治疗是介入放射科医生和 是NCI诊断成像计划的指定特定兴趣， 尤其是对于肝脏局灶性病变，考虑到手术切除的发病率 以及大量无法手术的患者。虽然RF在 消融小肿瘤，所获得的肿瘤破坏程度 受组织生理学的限制。这项建议评估了 射频过程中改变生物环境的佐剂和药物调节 消融以克服这一障碍。他们在模型中的初步研究 证明直接注射或全身给药 在射频过程中显著减少血流量和/或改变组织传导性 与单独使用射频相比，增加了组织的加热和凝固。然而，进一步 在将这些策略应用于临床实践之前，需要进行研究，因为 药物操作可能对肿瘤消融产生不同的影响。 因此，这项提议将对未来产生直接和立即的影响。 射频肿瘤消融术的研究方向和临床应用。 要研究的三个假设包括：1)射频加热和由此产生的 凝血与肿瘤血流量呈负相关；2)射频加热 凝血与组织电导率达到最大值相关，然后 减少；以及3)结合技术减少血流量和改变 射频过程中的组织电导率对组织加热和 与任何一种单独的技术相比，凝固法。这将通过以下方式实现： A)表征血流对兔射频消融效果的影响 VX2癌和大鼠R3230乳腺癌细胞模型的建立 血管活性药物；b)表征改变组织的影响 射频消融前注射生理盐水对电导率的影响 R3230和正常猪肝脏模型；以及c)优化 血流和组织电导率改变对射频消融疗效的影响 在R3230模型中直接注射乙醇或在生理盐水中稀释的醋酸； 和/或d)在所有三种情况下进行系统和注射联合辅助治疗 模特们。将比较射频组织加热和凝固以确定 在每个肿瘤和组织模型中提高射频消融效率的最佳方法。

DESCRIPTION: (Adapted from the investigator's abstract) The long range goal of this research project is to develop and optimize image-guided radiofrequency (RF) tumor ablation in patients. The development of minimally-invasive thermal tumor ablation therapies is a major interest of interventional radiologists and is a designated specific interest of the Diagnostic Imaging Program of the NCI, particularly for focal liver lesions, given the morbidity of surgical resection and the large number of inoperable patients. While RF has been successful in ablating small tumors, the extent of tumor destruction obtained has been limited by tissue physiology. This proposal assesses the unique potential of adjuvant, pharmacologic modulation to alter the biologic environment during RF ablation to overcome this barrier. Their preliminary studies in models demonstrate that direct injection or systemic administration of agents that reduce blood flow and/or alter tissue conductivity during RF substantially increases tissue heating and coagulation compared to RF alone. However, further study is required prior to adapting these strategies for clinical practice, as pharmacologic manipulations may exert variable effects on ablation in tumors. Thus, this proposal will have a direct and immediate impact on the future research directions and the clinical implementation of RF tumor ablation. The three hypotheses to be studied include: 1) that RF heating and resultant coagulation correlate inversely with blood flow in tumors; 2) that RF heating and coagulation correlate with tissue conductivity to maximum values and then decrease; and 3) that combined techniques to decrease blood flow and alter tissue conductivity during RF have synergistic effects on tissue heating and coagulation compared to either technique alone. This will be accomplished by: a) characterizing the effects of blood flow on RF ablation efficacy in rabbit VX2 carcinoma and rat R3230 mammary adenocarcinoma tumor models using vasoactive pharmaceuticals; b) characterizing the effects of altering tissue conductivity with pre-treatment saline injection on RF ablation efficacy in R3230 and normal swine liver models; and c) optimizing the combined effects of altered blood flow and tissue conductivity on RF ablation efficacy with directly injected ethanol or acetic acid diluted in saline in the R3230 model; and/or d) combined systemic and injection adjuvant therapies in all three models. RF tissue heating and coagulation will be compared to determine the best method for increasing RF ablation efficacy in each tumor and tissue model.