Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada.
Intelligent Energy-based Tumor Ablation Laboratory, School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China.
Int J Hyperthermia. 2022;39(1):733-742. doi: 10.1080/02656736.2022.2075567.
To achieve a result of a large tumor ablation volume with minimal thermal damage to the surrounding blood vessels by designing a few clinically-adjustable operating parameters in radiofrequency ablation (RFA) for liver tumors abutting complex vascular structures.
Response surface method (RSM) was employed to correlate the ablated tumor volume () and thermal damage to blood vessels () based on RFA operating parameters: ablation time, electrode position, and insertion angle. A coupled electric-thermal-fluid RFA computer model was created as the testbed for RSM to simulate RFA process. Then, an optimal RFA protocol for the two conflicting goals, namely (1) large tumor ablation and (2) small thermal damage to the surrounding blood vessels, has been achieved under a specific ablation environment.
Linear regression analysis confirmed that the RFA protocol significantly affected and (the adjusted coefficient of determination = 93.61% and 95.03%, respectively). For a proposed liver tumor scenario (liver tumor with a dimension of 432.9 cm abutting a complex vascular structure), an optimized RFA protocol was found based on the regression results in RSM. Compared with a reference RFA protocol, in which the electrode was centered in the tumor with a 12-min ablation time, the optimized RFA protocol has increased from 98.1% to 99.6% and decreased from 4.1% to 0.4%, achieving nearly the complete ablation of proposed liver tumor and ignorable thermal damages to vessels.
This work showed that it is possible to design a few clinically-adjustable operating parameters of RFA for achieving a large tumor ablation volume while minimizing thermal damage to the surrounding blood vessels.
通过设计几个临床可调节的射频消融（RFA）操作参数，实现毗邻复杂血管结构的肝肿瘤的大肿瘤消融体积，同时将对周围血管的热损伤最小化。
响应面法（RSM）用于根据 RFA 操作参数（消融时间、电极位置和插入角度）关联消融肿瘤体积（）和对血管的热损伤（）。创建了一个耦合的电热流 RFA 计算机模型作为 RSM 的测试平台，以模拟 RFA 过程。然后，在特定的消融环境下，为两个相互冲突的目标（即 1）大肿瘤消融和 2）对周围血管的小热损伤，实现了最佳的 RFA 方案。
线性回归分析证实，RFA 方案显著影响（调整后的决定系数分别为 93.61%和 95.03%）。对于提出的肝肿瘤情况（毗邻复杂血管结构的 432.9cm 尺寸的肝肿瘤），根据 RSM 中的回归结果找到了优化的 RFA 方案。与参考 RFA 方案相比，在参考 RFA 方案中，电极位于肿瘤中心，消融时间为 12 分钟，优化的 RFA 方案使增加了 1.5%，从 98.1%增加到 99.6%，同时使减少了 1.1%，从 4.1%减少到 0.4%，几乎完全消融了所提出的肝肿瘤，并且对血管的热损伤可以忽略不计。
这项工作表明，设计几个临床可调节的 RFA 操作参数，有可能实现大肿瘤消融体积，同时将对周围血管的热损伤最小化。
